Complications Associated with Cheek Tooth Extraction in the Horse Edward T. Earley, DVM; Jennifer E. Rawlinson, DVM, Robert M. Baratt, DVM Summary: Common indications for cheek tooth extraction in the horse include dental fracture, periodontal disease, severe decay/ caries, mandibular fracture with alveolar/tooth involvement, and periapical abscess. Complications secondary to extraction of cheek teeth are prevalent. Typical complications may include retained root tip(s), collateral damage of neighboring teeth and alveolar bone, mandibular fracture non-union or delayed union, cemental ankylosis, dilacerated root(s), oroantral/oronasal fistula, palatal deviation of cheek teeth, bone sequestration, sinus involvement, alveolar plug failure, and palatine artery laceration. This paper presents a series of cases that had complications following cheek tooth extraction. Anticipation of problematic extractions, recognition of complications, and appropriate treatment will aid the clinician in managing the inevitable cheek tooth extraction complication. J Vet Dent 30(4); 220-235, 2013
Introduction
Oral surgical complications from extraction of cheek teeth are variable but may have the potential for a high rate of incidence. The incidence of reported complications has been documented to be 0, 20, 32, and as high as 70 %.1-5 Recognition of procedures and conditions that are problematic reduces the incidence of complication and aids the veterinarian’s preparedness for an inevitable complication. When performing cheek tooth extraction in the equine patient, complications will occur. Complications may involve surrounding bone, sinus, soft tissue, periodontal tissues, neurovascular structures, and teeth. The manner in which these complications are recognized and managed determines a successful outcome. Patient assessment includes physical, oral, and radiographic examinations. Additional methods and procedures for evaluation such as computed tomography, endoscopy, histopathology, cytology, and microbiology may be indicated prior to initiating an extraction procedure or to manage a complication. Multiple techniques may be used for the extraction of cheek teeth, including oral extraction6, buccal approach with oral extraction7, repulsion8, modified repulsion9, and buccotomy with
transcortical osteotomy.9-12 Most extraction procedures can be performed with the horse standing using perineural anesthesia and appropriate sedative combinations.13-14 Extraoral examination should be done that assesses the head/ maxilla for swelling, fistulas, nasal discharge, malodorous breath, and abnormal sinus percussion. Both mandibles can be palpated along the medial and lateral ventral borders to determine if any irregular or abnormal thickness is present. The masseter muscle should be evaluated for asymmetry, atrophy, and heat or swelling. Intraoral examination is performed using an intraoral mirrora with a dental lightb (or an intraoral camera system) in conjunction with a dental explorerc and periodontal probed.15 A dental explorer is used to evaluate the teeth, focusing on defects, fractures, and pulp exposure. The tactile sensitivity of a dental explorer increases as the size of the explorer head decreases. A periodontal probe is used to evaluate the gingival attachment to the teeth. The tip of the periodontal probe should be thin and flexible so that it can easily slide into small periodontal defects/ pockets and the incremental depth indicators should be easily visualized. Radiographs can be taken with the horse standing and the head down and low to the ground. This stance is comfortable for the horse and the person taking the radiographs. For extraoral and intraoral images, the mouth is held open with a dental speculumee that has minimal metal along the side of the horse’s face.16-21 An open mouth allows for the offset of the arcades when obtaining extraoral views and placement of film within the oral cavity for intraoral views. The maxillary arcades are imaged by placing the film/screen within the oral cavity and using a bisecting angle technique. Intraoral views of the mandibular arcades are obtained by utilizing a parallel or ventral oblique technique.21 The intraoral dorsoventral and ventrodorsal views can be taken with an aluminum speculume,f.22 The following cases are presented as examples of complications that can be associated with the extraction of cheek teeth. Each case will have a brief description of the oral and radiographic examination. After each case, there will be a short discussion detailing the importance of the examination finding(s) and identifying the complication(s). The potential complication can be eliminated or minimized with appropriate clinical acumen and foresight that prepares the clinician.
Oroantral Fistula and Retained Root Apex A 16-year-old Paint mare presented with a complicated crown fracture of the right maxillary fourth premolar tooth (108).23 The mare had a history of intermittent right facial swelling. When the swelling was present, the horse was very sensitive to palpation of the right face and the bit when ridden. Periodic, intermittent dosing with antibioticsg would resolve the swelling. The swelling and sensitivity would return a few weeks after the antibiotic treatment was discontinued. 220
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The intraoral examination revealed pulp exposure of pulp horns 3 and 5, and a periodontal pocket (12-mm depth x 3-mm diameter) along the mesiopalatal aspect of 108.24,25 The initial intraoral radiograph (dorsoventral view) showed bone loss along the mesial palatal aspect of 108 (Fig. 1). The extraoral view showed a fluid density at the rostral aspect of the rostral maxillary sinus, and slight cemental reaction along the buccal apex of 108 and the distal apex of the right maxillary first molar (109).
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Figure 1
Intraoral photograph in a 16-year-old Paint mare with a complicated crown fracture (arrows) of the right maxillary fourth premolar tooth (108)[A]. The initial intraoral dorsoventral view radio-graph (B) showed bone loss (arrows) along the mesial palatal aspect of 108.
Figure 2
Initial extraoral radiograph (A) in a 16-year-old Paint mare with a complicated crown fracture of the right maxillary fourth premolar tooth (108). There are signs of inflammation/fluid (orange arrows) in the rostral aspect of the maxillary sinus (green arrows). Note the mild cemental reaction along the buccal root apex of 108 (red arrows) and distal root apex of the right maxillary first molar tooth (109) [pink arrows]. The intraoral radiographic view (B) shows a widened and irregular periodontal ligament space along the mesial aspect of 109 (red arrows), an interproximal cemental reaction (green arrows), and loss of periodontal ligament space along the distal aspect of 108 (orange arrows).
Figure 3
Photographs in a 16-yearold Paint mare with a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing osteotomy directed over the apical aspect of 108 (A). After repulsion, the alveoli were filled with polyvinyl siloxane (PVS)k followed by gauze placement through the sinusotomy/osteotomy site. The gauze was removed after the PVS had hardened (B).
A bisecting angle intraoral radiograph revealed an irregular and thickened periodontal ligament with cemental reaction along the mesial aspect of 109 and loss of periodontal ligament space at the distal aspect of 108 (Fig. 2). Oral extraction of 108 was attempted. Tooth mobility was achieved, but extraction was not possible due to the cemental reaction, apparent ankylosis as noted by a loss of normal periodontal ligament space, and erosion of the clinical crown. An osteotomy was created in the maxillary bone over the apical aspect of 108 with a bone trephine.h The osteotomy was enlarged
with a laminectomy bur on a surgical handpiece.i,j The root apices of 108 were isolated and sectioned leaving a flat plateau of the remaining reserve crown for placement of a dental punch.k Following repulsion of 108, it was noted that the interproximal bone and reactive cementum of 108/109 were decayed and 109 was mobile. The osteotomy site was extended caudally and 109 was partially repulsed and then extracted orally. The rostral maxillary sinus was lavaged and the alveoli of 108 and 109 were curetted and debrided. Postoperative radiographs were taken to verify complete extraction and the alveoli were filled with polyJ VET DENT Vol. 30 No. 4 Winter 2013
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vinyl siloxane (PVS)l while gauze was placed apically through the sinusotomy/osteotomy site. The gauze was removed after the PVS had hardened (Fig. 3). The clinician (first author) failed to recognize a retained mesiobuccal root apex of 108 on the postextraction, intraoperative radiograph. The postoperative 8-week examination revealed a sinusitis with right nasal discharge and an oroantral fistula (alveolus to maxillary sinus) caudal to the retained root apex (Fig. 4). An 18-gauge needle was placed at the mesial aspect of the fistula as a marker and an intraoral radiograph was taken to confirm the nidus of the fistula (Fig. 5). Angled root tip elevatorsm,n,o were used to extract the root apex (Fig. 6).
The oroantral fistula was debrided and packed with PVS and the sinus was flushed. Oral and radiographic examinations revealed that the fistula was no longer present at the 7-month postoperative visit. The intraoral radiograph showed a small sequestrum, however based on the oral examination, it was decided to leave the sequestrum and monitor. The extraoral radiograph revealed a residual amount of fluid/soft tissue density in the right rostral maxillary sinus (Fig. 7). There had been no nasal discharge present during the previous 2-months. The patent was scheduled for another evaluation after 6-months.
Figure 4
Intraoperative intraoral radiograph (A) in a 16-yearold Paint mare following repulsion of a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing a retained mesiobuccal root apex of 108 (red arrows). The 8-week postoperative radiograph (B) shows signs of sinusitis (red arrows) and the retained 108 root apex (green arrows).
Figure 5
Intraoral photograph in a 16-year-old Paint mare 8-weeks following repulsion of a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing an oroantral fistula (A). Placement of an 18-gauge needle confirms the location of the retained mesiobuccal root apex of 108 in relation to the oroantral fistula (B).
Figure 6
Photograph in a 16-yearold Paint mare following extraction of the maxillary fourth premolar tooth (108) mesiobuccal root apex that was retained after repulsion of a complicated crown fracture of 108 (A) 8-weeks previously. An intraoral radiograph confirms extraction of the 108 mesiobuccal root apex (B).
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Figure 7
Photograph in a 16-year-old Paint mare 7-months following extraction of the maxillary fourth premolar tooth (108) mesiobuccal root apex and treatment of an assoiated oroantral fistula. The oronasal fistula had healed (A). The intraoral radiograph (B) showed a small sequestrum (arrow). The extraoral radiograph (C) showed a residual amount of fluid/soft tissue density (orange arrows) in the right rostral maxillary sinus (green arrows).
Alveolar Plug Failure Leading to Sinusitis A 16-year-old Arabian gelding was presented for a dental evaluation. The physical examination was normal other than the horse was slightly underweight with a body condition score of 4-5/9. The owner had noted sensitivity to the bit and head shaking when the horse was ridden. The behavior had become progressively worse over a 2 to 3-month period. Normally the horse was very calm and well mannered under saddle. The oral examination revealed a complicated crown of the left maxillary first molar tooth (209) which involved the clinical crown along the mesial aspect. Pulp horns 1 and 3 were exposed. The horse was very sensitive and painful when examining the 209. Tooth movement (1 to 2-mm) was noted during examination with a dental explorer. The pressure from the dental explorer stimulated a slight amount of bleeding that was noted along the palatal aspect. Periodontal probing depths along the palatal aspect of 209 ranged between 3 and 5-mm. Probing depths along the buccal aspect were 1 to 3-mm. Intraoral radiographic examination showed an irregular periodontal space along the distal aspect of the mesiobuccal apex of 209. The extraoral radiograph revealed no evidence of sinus
disease associated with 209 (Fig. 8). The periodontal disease was graded as stage 2 with minimal bone and attachment loss. The mobility index was rated as moderate with a score of 2.26,27 Based on the clinical and radiographic findings, the diagnosis was endodontic disease involving 209 with a class I endodonticperiodontal relationship.28 Intraoral extraction was attempted. The tooth became mobile but appeared to become “wedged” between the left maxillary fourth premolar (208) and second molar (210) teeth when slight extrusion forces were applied with the extraction forceps. Intraoral extraction was attempted again the following day but remained unsuccessful. A sinusotomy was created with a trephine and moderate repulsion forces were used to extract 209. The sinus was lavaged and the alveolus was packed with PVS. The soft tissues were closed over the sinusotomy site. The owner called with a report of food material and a thick white discharge draining from the sinus at the repulsion site and the left nostril 12-days postoperatively. The oral examination revealed that the alveolar plug had failed and large amounts of food material were present in the sinus creating an orofa-
Figure 8 Photograph (A) in a 16-year-old Arabian gelding with a complicated crown fracture of the left maxillary first molar tooth (209). Note the hemorrhage after manipulation of the tooth and gingiva with a dental explorer. An intraoral radiograph (B) showed an irregular periodontal ligament space along the distal aspect of the mesiobuccal apex of 209. The lateral extraoral radiographic view (C) showed no signs of sinus disease.
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Figure 9
Photograph (A) in a 16-year-old Arabian gelding 12-days following repulsion of the fractured left maxillary first molar tooth (209). The alveolar plug failed leading to clinical signs of maxillary sinusitis. The intraoral photograph (B) showed food and debris in the rostral maxillary sinus. The extraoral radiograph (C) showed signs of sinusitis limited to the rostral maxillary sinus.
Figure 10
Photograph (A) at the 2-month postoperative examination in a 16-year-old Arabian gelding following oroantral fistula treatment for failure of the alveolar plug following repulsion of the fractured left maxillary first molar tooth (209). There is complete healing and restored gingival attachment at the left maxillary fourth premolar (208) and first molar (210) teeth. The extraoral radiograph (B) shows a mild tissue/fluid density in the rostral maxillary sinus (green arrows).
cial fistula (communication between the oral cavity and skin). Radiographic evaluation indicated that the sinus infection was limited primarily to the rostral maxillary sinus (Fig. 9). The horse was hospitalized and aggressive oral and sinus lavage was instituted over the next 10-days. The alveolus was packed with PVS. The horse was presented at 1, 2, and 11-months for postoperative physical and radiographic examinations. The sinus healed and the alveolus filled-in with complete gingival attachment at 208 and 210 (Figs. 10). Many different materials have been advocated for the use
Palatine Artery Laceration
A 17-year-old Shire mare presented with a history of moderate weight loss and difficulty in chewing. Physical examination revealed that the mare had a body score of 4-5 on a scale of 9.30 Physical examination was normal. Oral examination revealed that the right mandibular first molar tooth (409) was severely elongated by approximately 3-cm. The right maxillary first molar tooth (109) had a complicated fracture of the clinical and reserve 224
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of plugging/packing an alveolus following extraction of a cheek tooth, including wax, polymethylmethacrylate (PMMA), gauze, casting material, and PVS.29 The ideal material for plugging should be able to seal the alveolus yet not restrict healing. The plug should not extend into the apical one-half of the alveolus since this positioning could restrict healing or allow for migration of the plug into the sinus. Possible causes of alveolar plug failure in this case would include an incomplete fill of the coronal alveolus or improper shaping of the PVS to the margins of the alveolus during plug curing to a rigid state.
crowns. Food was packed deeply into the alveolus around the tooth fragments. A medially displaced fragment of 109 created a large and deep palatal defect. A 5-cm periodontal probe was placed at maximum depth into the center of the tooth and alveolus. Hemorrhage was evident following lavage of feed material from the alveolus (Fig. 11). The fracture was suspected to involve the root apices.
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Intraoral radiographs confirmed that 109 was comminuted into multiple fragments that did involve the root apices. The fractured 109 was classified as a complicated crown-root fracture.31 The extraoral radiographic examination showed a fluid and/or soft tissue density associated with the right rostral maxillary sinus (Fig. 12). Partial crown reduction was performed on 409 followed by oral extraction of the 109 tooth fragments. Gingival elevatorsp were used to separate the gingival attachments from the fragments. Angled root tip elevators were used to dislodge the fragments. Fragment forcepsq were used to remove the large palatal fragment and two smaller buccal fragments. The palatine artery bled profusely when the large palatal fragment was removed. Using several surgical towels and gauze, direct pressure was applied to the palate over a 20-minute period to slow hemorrhage until a clot could form. When the dental fragment was extracted with the forceps, it was apparent that part of the hard palate and
associated palatine artery were damaged and removed during the extraction process. Examination of the large palatal fragment revealed that a segment of the hard palate and associated palatine artery were attached/adhered/ankylosed to the dental fragment (Fig. 12). The greater palatine artery courses along the medial aspect of the maxillary cheek teeth at the submucosal aspect of the hard palate along the palatine groove/process. It is a direct extension of the maxillary artery and passes through the palatine canal and extends rostrally to join its counterpart (right or left palatine artery) caudal to the incisor teeth, entering the interincisive canal to form the incisive artery. The palatine groove does not completely enclose or protect the palatine artery. The artery is in close proximity to the alveolar bone of the maxillary cheek teeth. There is a risk of lacerating or tearing the artery when attempting an extraction when extensive pathology is present along the medial/ palatal alveolar wall aspect.
Figure 11
Photographs in 17-yearold Shire mare with a complicated fracture of the clinical and reserve crowns of the right maxillary first molar tooth (109). Oral examination revealed that the right mandibular first molar tooth (409) had approximately 3-cm of elongation (A). Note the food impaction and palatal fragment of 109 (B).
Figure 12
Intraoral radiograph (A) in 17-year-old Shire mare with a complicated fracture of the clinical and reserve crowns of the right maxillary first molar tooth (109). The tooth fracture was classified as a complicated crown-root fracture (A). The extraoral radiograph (B) shows a fluid/soft tissue density involving the right rostral maxillary sinus (arrows). The extracted palatally displaced fragment (C) reveals the attached hard palate segment and palatine artery.
Oronasal Communication
A 7-year-old Quarter Horse gelding was examined for a right nasal discharge of 4 to 6-months duration. The oral examination revealed a complicated fracture of the right maxillary fourth premolar tooth (108) involving the clinical and reserve crowns. The remaining reserve crown was displaced into the hard palate creat-
ing a large defect (Fig. 13). A periodontal probe could be passed along the palatal aspect of 108 into the maxillary sinus. Extraoral radiographic examination confirmed a right maxillary sinusitis based on the presence of a fluid/soft tissue density noted in the right rostral and caudal maxillary sinuses. A fluid J VET DENT Vol. 30 No. 4 Winter 2013
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line was evident in the right caudal maxillary sinus. The intraoral radiographic examination showed severe decay of the 108 (Fig. 13). Both views indicated that the root structure and remaining reserve crown were larger in diameter than the occlusal space between the neighboring right maxillary third premolar (107) and first molar (109) teeth. The diagnosis was a malformed, decayed 108 with stage 4 periodontal disease.26,27 An oronasal communication was diagnosed with associated right maxillary sinusitis. The 108 was extracted (Fig. 13). An intraoral surgical radiograph confirmed the complete removal of 108. The sinus was lavaged BID with saline and high pressure water for 2 to 3-weeks. The alveolus was also lavaged and re-packed every 7 to 10-days. A small piece of alveolar bone and dental fragment were removed at the 10-day postoperative examination. The right nasal discharge had ceased by the 10-day postoperative examination. The alveolus was healing with granulation tissue but the oronasal communication remained (Fig. 14). The 8-week postoperative examination showed alveolar bone healing yet a 2 x 5-mm oronasal communication remained along the mesial palatal aspect. The extraoral radiographic examination indicated normal bone healing with continuing resolution of the right rostral maxillary sinusitis. The intraoral radiographic examination showed slight alveolar bone healing along the edges of the repulsed sinus/alveolar bone (Fig. 14). Eleven months of bi-monthly aggressive lavage, debridement, and re-packing failed to resolve the oronasal communication. Debridement of the oronasal communication was done using cannulas, curettes, bone files, and brushesr,s,t,u.
Packing material included iodine-soaked gauze, scarlet oilsoaked gauze, CaSO4, and reabsorbable collagenv,w.32 PMMA and VPS were trialed, but the materials would not stay in place based on the location of the fistula and the thin palatal bone. The chronic oronasal communication measured 4 mm x 10-mm in length. (Fig. 15). The extraoral radiographic examination showed that there was evidence of soft tissue consolidation and bone densities within the right rostral maxillary sinus. The fluid/soft tissue densities were resolving in the right caudal maxillary sinus when compared with the initial extraoral radiographic view. The intraoral radiographic examination showed healing of alveolar bone. The alveolar/ palatal bone appeared to be consolidating around the defect with a possible communication through the bone (Fig. 15). The techniques available for the repair of oronasal communication are limited in horses. Flap procedures have not been developed as in other species due to limited access and visual challenges. Equine bone allografts may be an option in the future. Currently, bone allograftsx are available in dogs. A procedure describing the transposition of the labii superioris muscle for oromaxillary sinus communication has been described.34,35 This procedure involves repairing the communication through the sinus by isolating and transecting the rostral tendon of the levator labii superioris muscle. The tendon and muscle are guided through the sinus and communication, into the oral cavity, and exiting through a buccotomy. Care should be taken to avoid damage to the dorsal buccal branch of the facial nerve and the parotid salivary duct.
Figure 13
Photograph (A) in a 7-year-old Quarter Horse gelding with a complicated fracture of the right maxillary fourth premolar tooth (108) involving the clinical and reserve crowns. The remaining reserve crown was displaced into the hard palate creating a large defect. The extraoral radiograph (B) shows a fluid/tissue density evident in the rostral maxillary sinus (red arrows) and caudal maxillary sinus (green arrows). There is also a fluid line evident in the caudal maxillary sinus (blue arrows). The intraoral radiographic examination showed severe decay of 108 (C). Note that the root and apical reserve crown is wider in diameter than the remnant of the clinical crown and coronal reserve crown. The extracted 108 confirmed the malformed, decayed tooth pathology (D).
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Figure 14
Photograph (A) in a 7-year-old Quarter Horse gelding 3-weeks following repulsion of a complicated fracture of the right maxillary fourth premolar tooth (108) showing the patent oronasal fistula healing with granulation tissue. The 8-week postoperative oral examination showed a 2 x 5-mm oronasal fistula (arrow) along the mesial palatal aspect (B). The 8-week intraoral radiographic (C) examination showed slight alveolar bone healing along the borders (arrows) of the repulsion site sinus/alveolar bone.
Figure 15
Photograph (A) in a 7-year-old Quarter Horse gelding 11-months following repulsion of a complicated fracture of the right maxillary fourth premolar tooth (108) showing the 4 x 10-mm oronasal fistula (arrows). The extraoral radiographic (B) examination shows consolidation of soft tissue/bone densities in the right rostral maxillary sinus (red arrows), and resolving fluid/soft tissue densities in the right caudal maxillary sinus (green arrows). The intraoral radiographic examination (C) showed probable consolidating bone around the fistula (orange arrows) and possible open communication through the alveolar/palatal bone (blue arrow).
Incompletely Healed Mandible Fracture An 8-year-old Haflinger mare presented with a left mandibular non-union. A large draining tract was present rostral to the left mandibular second premolar tooth (306) along the ventral aspect of the mandible. The fracture and drainage had been present for over 2-years. Swelling and edema could be palpated along the buccal and lingual aspects of the left mandible. Oral examination revealed a 2.5-cm fistula along the lingual aspect of 306 (Fig. 16). A fracture was evident on the extraoral radiograph extending to the mesial aspect of the 306 alveolus.
The intraoral ventrodorsal radiograph showed reactive periosteal bone along the medial aspect of the left mandible and alveolar bone loss along the lingual and mesial aspects of 306 (Fig.16). The diagnosis was a non-union of the left mandible with apical abscessation and severe periodontal disease of 306. Typically the affected tooth will need eventual extraction in order for a non-union fracture to heal. As a general rule, it is probably best to retain teeth that significantly contribute to fracture stability as long as severe periodontal disease is not present.36 Complete healing will not occur without addressing the local J VET DENT Vol. 30 No. 4 Winter 2013
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infection and associated osteomyelitis.37 The drainage from the mandible ceased by 2-weeks following extraction of 306 and the swelling decreased over a 2-month period. A 7-month post-extrac-
tion radiographic showed partial healing of the mandibular fracture. There was minimal swelling and no drainage during the previous 2-months (Fig. 17).
Figure 16
Photograph (A) in an 8-year-old Haflinger mare presented with a left mandibular non-union showing a 2.5-cm fistula along the lingual aspect of left mandibular second premolar tooth (306). The extraoral radiograph (B) shows a fracture (arrow) extending to the mesial aspect of 306. The intraoral ventrodorsal radiograph (C) shows reactive periosteal bone along the medial aspect of the left mandible (red arrows) and alveolar bone loss along the lingual and mesial aspects of 306 (green arrows).
Figure 17
Photograph (A) in an 8-year-old Haflinger mare presented with a left mandibular non-union showing the extracted left mandibular second premolar tooth (306). The 7-month post-extraction radiographic (B) shows partial union of the mandibular fracture.
Mandibular Fracture A 21-year-old Tennessee Walking Horse gelding presented for a chronic, 2-month duration of swelling and drainage from the right mandible. The intraoral examination revealed a fractured right mandibular fourth premolar tooth (408). The fracture involved the lingual aspect of the clinical crown resulting in pulp exposure of pulp horns 1, 2, 3 and 4. The intraoral radiograph of 408 revealed that the periodontal ligament was mostly absent and the distal root apex was undergoing tooth resorption. The extraoral radiograph showed a large draining tract beginning at the distal aspect of 408 and 228
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extending to the ventral cortex. The preoperative intraoral ventrodorsal radiograph showed a normal medial cortex of the right mandible (Fig. 18). An attempt to extract 408 orally failed when the clinical crown fractured secondary to probable ankylosis as indicated on the preoperative radiograph (Fig 19). An oral approach for tooth extraction in the horse may be contraindicated when there are radiographic signs that support tooth ankylosis and/ or resorption since these pathologies render the tooth susceptible to fracture during non-surgical extraction.
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A surgical extraction was indicated following fracture of the clinical crown. The anatomical structure of the mandible consists of light alveolar and cancellous bone enveloped within a cortical plate on the medial and lateral aspects. Much of the strength of the mandible is actually attributed to the large cheek teeth embedded within the bone. A repulsion surgery would likely be difficult and could potentially cause extensive damage to the surrounding mandibular bone. When excessive force is used to extract a mandibular cheek tooth, severe damage and/or fracture of the surrounding bone is a possible complication. An incision over the apical third of 408 and a transcortical osteotomy were performed to section and excise the reserve crown and root apices as an alternative to an osteotomy and repulsion.11,12 The lateral mandibular cortex and alveolar bone were sectioned using a surgical length crosscut bury and surgical length round burz on a high-speed handpieceaa; and then elevated with a bone chiselbb and elevatorcc. The mesial and distal root apices were isolated and sectioned. The remaining reserve crown was lightly tapped into the oral cavity. The alveolus was debrided and curetted following removal of the reserve crown and roots (Fig. 19). The coronal 1/3 of the alveolus was packed with PVS. Due to the swelling and inflammation present, a penrose drain was placed and the soft tissues were apposed. Immediate, 1- and 2-month postoperative intraoral radiographs were taken to monitor the bone healing at the osteotomy site (Fig. 20). At the 2-month postoperative examination, the intraoral oblique radiograph revealed a fracture
along the lingual aspect of 408 alveolus that was not evident at the 1-month evaluation. The 2-month intraoral ventrodorsal radiograph showed a prominent periosteal reaction along the medial aspect of the right mandible (Fig. 21). When comparing the initial preoperative and the 2-month postoperative intraoral ventrodorsal radiographs, it is apparent that the medial/lingual cortical bone was normal prior to the surgical extraction of 408. In addition, the initial radiographs provide evidence that the lateral/buccal and ventral cortical aspects of the right mandible were compromised from the chronic drainage/infection (Fig. 18). Typically, if the medial/lingual and ventral cortex is preserved during a transcortical osteotomy of the lateral/buccal cortex, fracture is not a complication.11 A retrospective study involving 10 horses reported that mandibular swelling and bone remodeling occur following this surgery.12 The median age of the horses was 5.5-years. In this study, 11 transcortical osteotomy procedures were performed in 10 horses. Of the 11 procedures, 10 were performed on the mandible. It was reported that 3 of the 10 horses exhibited mandibular swelling and bone remodeling > 6-months following the surgical procedure. Based on the results of this retrospective study, and the intraoral radiographic findings in this case; it would be prudent to image operated mandibles to evaluate long-term healing to determine the incidence of mandibular fracture following this procedure. The case reported here could be an exception since the horse was older and the mandible had signs of pathology preoperatively. However, this surgery should be considered with caution until further data has been compiled to evaluate the postoperative healing
Figure 18
Radiographs in a 21-year-old Tennessee Walking Horse gelding presented for a fractured right mandibular fourth premolar tooth (408) and a 2-month history of swelling and drainage from the right mandible. The intraoral radiograph (A) of 408 revealed that the periodontal ligament was mostly absent and the distal root apex was undergoing tooth resorption (arrows). The extraoral radiograph (B) showed a large draining tract (arrows) beginning at the distal aspect of 408 and extending to the ventral cortex. The preoperative intraoral ventrodorsal radiograph (C) showed a normal medial cortex (arrows) of the right mandible.
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Figure 19
Radiograph (A) in a 21-year-old Tennessee Walking Horse gelding presented for a fractured right mandibular fourth premolar tooth (408) and a 2-month history of swelling and drainage from the right mandible. Note the failed intraoral attempt to extract the tooth. Intraoperative photographs show sectioning of the 408 mesial apex (B) and the remaining reserve crown (green arrow) [C] after sectioning and removal of both apices (D).
Figure 20
Immediate (A) and 1-month postoperative (B) intraoral radiographs in a 21-year-old Tennessee Walking Horse gelding operated for buccotomy and transcortical osteotomy to extract the right mandibular fourth premolar tooth (408) show progressive remodeling of lingual cortical bone (green arrows).
Figure 21
Intraoral lateral (A) and ventrodorsal (B) radiographs in a 21-year-old Tennessee Walking Horse gelding 2-months following buccotomy and transcortical osteotomy for extraction of the right mandibular fourth premolar tooth (408) show a fracture line involving the lingual cortical bone (arrows) and reactive periosteal bone along the medial aspect of the right mandible (arrows).
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Dilacerated Roots and Reserve Crown process. A 4-year-old Quarter Horse gelding was examined for routine dental assessment. As a 2-year-old, the gelding had been kicked in the face by a pasture mate. The owners reported that there had been a slight amount of swelling that seemed to improve over a 2-week period. The physical examination revealed normal findings. Extraoral examination findings were normal. No swellings or facial asymmetry were evident. The intraoral examination revealed that the right maxillary third premolar tooth (107) had considerable (15-mm) elongation without evidence of occlusal contact. It was noted that the right mandibular third premolar tooth (407) had not erupted into occlusion (Fig. 22). Normal findings were observed when evaluating the occlusal surface of 407 and 107 with a dental explorer. The extraoral radiographic examination showed pathologic changes at the apical aspect 407. There was a pronounced cemental reaction with the reserve crown and root structure. This reactionary reparative process of the cementum inhibited the eruption of the tooth (Fig. 23). The diagnosis was dilacerated and ankylosed roots and reserve crown of 407 due to a cemental inflammatory response from chronic pulpitis. At 6-years-old, the gelding was examined for a draining tract along the right ventral mandible. The drainage had been present for 3 to 4-weeks. The oral examination showed that the drainage was along the rostral aspect of the ventral mandible. The intraoral examination revealed that 407 had partially erupted and the elongation of 107 was absent. The gingival attachment was normal for 407 and there was no evidence of a draining tract. The occlusal surface of 407 and 107 appeared normal when examined with a dental explorer. The intraoral radiographic examination of 407 was abnor-
mal. A widened, abnormally shaped pulp horn was noted. Based on the orientation, this would represent either pulp horn 2 or 5. The intraoral ventrodorsal view showed that 407 was rotated in a mesiolingual direction. A 20-gauge, blunt needledd placed into the draining tract was apparent at the distal root apex of 407 on the extraoral radiograph (Fig. 24). The diagnosis was dilacerated roots and apical disease/abscess of 407. A lateral approach to the right mandible was performed and the tooth was sectioned and lightly repulsed (Fig. 25). The alveolus was packed with PVS and the buccotomy site was closed. A postoperative radiograph revealed complete extraction of 407 (Fig 26). The horse developed a large bone sequestrum and severe periodontal disease involving the right mandibular second premolar tooth (406) 3-months following surgery. The bone sequestrum and 406 were extracted orally. It was evident that the mesial root and reserve crown were dilacerated in a linguomedial direction (Fig. 26). The 6-month postoperative examination revealed normal healing of the 406 and 407 alveoli (Fig. 27). There were radiographic signs of normal healing with slight thickening of the medial and ventral cortical bone (Fig. 28). It is hypothesized that both 406 and 407 were damaged from the injury sustained when the horse was 2-years-old. Maldevelopment of the reserve crowns and roots led to dilacerations involving both teeth. The inflammatory process associated with 407 caused partial cemental ankylosis and maleruption. It is interesting to note that by 6-years of age, 406 was able to erupt despite cemental restrictions imposed on the reserve crown and roots, and the crowding from neighboring teeth. However, the eruption process initiated a cascade of events, including mandibular swelling, drainage, and
Figure 22 Photographs in a 4-yearold Quarter Horse gelding with a previous history of facial swelling. Oral examination showed an elongated right maxillary third premolar tooth (107) [A] and an incompletely erupted right mandibular third premolar tooth (407) [B].
Figure 23
Photograph (A) and extraoral radiograph (B) in a 4-year-old Quarter Horse gelding with a previous history of facial swelling. The right mandibular third premolar tooth (407) shows severe cemental reaction with dilacerated roots/reserve crown of 407.
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Figure 24
Radiographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 2-years after the facial swelling incident. The intraoral radiograph (A) of the right mandibular third premolar tooth (407) showed a widened, abnormally shaped pulp horn (arrows), either 2 or 5. The intraoral ventrodorsal radiograph (B) showed that 407 was rotated in a mesiolingual direction. A 20-gauge, blunt needledd placed into the draining tract (arrow) was apparent at the distal root apex of 407 on the extraoral radiograph (C).
Figure 25 Intraoperative photogrpahs showing extraction of the right mandibular third premolar tooth (407) in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible. Osteotomy was performed over the root apices of 407 (A) followed by sectioning of the apices (B). Following sectioning and elevation of the apices (C), the 407 reserve crown was repulsed (D).
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Figure 26
Radiographs following extraction of the right mandibular third premolar tooth (407) in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible. The postoperative radiograph shows the 407 extraction site (A). The extraoral (B) and intraoral ventrodorsal (C) radiographs 3-months following surgery show severe periodontal disease of the right second mandibular premolar tooth (406) with bone lysis along the mesial aspect (red arrows). A large sequestrum is present in the 407 alveolus (green arrows). The 406 postextraction image (D) shows the dilacerated root (green arrows), reserve crown of 406, and bony sequestra (red arrows).
Figure 27 Photographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 3-months following extraction of the right third mandibular premolar tooth (407) and sequestrectomy. The 406 (A) and the right mandibular third premolar tooth (407) [B] extraction sites show expected healing.
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Figure 28
Radiographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 3-months following extraction of the right third mandibular premolar tooth (406) and sequestrectomy. The extraoral lateral (A) and intraoral ventrodorsal (B) radiographs show thickened, healing medial (arrows) and ventral cortical bone.
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b c d e f g h i j k l m n o p q r s t u v w
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Dental Mirror, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Dental headlamp. Equine Specialties, Georgetown, TX Dental Explorer, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Periodontal Probe, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Alumispec, Harlton’s Equine Specialties, Columbus, OH Meister Aluminum Speculum, Jorgensen Laboratories, Loveland, CO Sulfamothoxazole and Trimethoprim tblts, USP. Vista Pharmaceutics, Inc. West Orange, NJ Trephines. Harlton’s Equine Specialties, Elmwood, WI Oval Carbide Bur – (Bur 4 mm diameter x 8 mm long, Shaft 3/32 “ diameter x 48 mm long), Brassler USA, Savannah, GA Hall Surgical Highspeed Handpiece. Hall Powered Instruments, Largo, FL Dental Punches. Harlton’s Equine Specialties, Elmwood, WI Aquasil Easy Mix Putty. Dentsply, Milford, DE Root Tip Elevators - Equine Dental Picks Potts Style, Medco Instruments, Hickory Hills, IL T-Handled 4 Positions Elevator. Equine Specialties, Georgetown, TX Extended molar fragment elevator set. Harlton’s Equine Specialties, Elmwood, WI Gingiva elevators, Medco Instrumnents, Hickory Hills, IL, Harlton’s Equine Specialties, Columbus, OH Fragment forceps, Medco Instruments, Hickory Hills, IL, Harlton’s Equine Specialties, Columbus, OH Intranasal cannula. Boehringer Ingelheim Vetmedica, Inc., St. Joeseph, MO BRUN Curette size #1-#5. Medco Instruments, Hickory Hills, IL Bone Files. Benco Dental. Pittston, PA Bore brushes. Outers. Onalaska, WI Bondex, Plaster of Paris, DAP Inc., Baltimore, MD Resorbable Collagen Plug, Collagen Matrix Inc. 508 Commerce St. Franklin Lakes, NJ
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Bone allografts. Veterinary Transplant Services, Kent, WA Carbide Bur – FG-558SL. White Carbide Burs. Lakewood, NJ Carbide Bur – FG-8SL. White Carbide Burs. Lakewood, NJ iM3 - LED Advantage L5200. Vancouver, WA Bone chisel (10mm, 16mm and 25 mm) Periosteal Elevators. Synthes, Paoli, PA Monoject 3 ml Syringe (Luer Lock) with 23 gauge x 1 ¼ inch blunt irrigating needle, Kendall Monoject, Tyco Healthcare Group LP, Mansfield, MASedivet, Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO Stubbs Full Mouth Speculum, Stubbs Equine Innovations, Inc., Johnson City, TX.
Author Information
From Large Animal Dentistry, Equine Farm Animal Hospital, Cornell University, Ithaca, NY and Laurel Highland Veterinary Clinic (Earley), 2586 Northway Road Ext., Williamsport, PA, 17701. Email: [email protected]
References
1. Dixon PM, Hawkes C and Townsend N. Complications of equine oral surgery. Vet Clin North Am Equine Pract 2008; 24: 499-514. 2. Tremaine WH. Complications associated with dental and paranasal sinus surgery. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Indianapolis, IN, 2006; 141-147. 3. Duncanson, GR. A case study of 125 horses presented to a general practitioner in the UK for cheek teeth removal. Equine Vet Education 2004, 6/3, 212-216. 4. Dixon PM, Dacre I, Tremaine WH, McCann J, Barakzai S.Standing oral extraction of cheek teeth in 100 horses (1998-2003). Equine Vet J 2005; 37: 105-112. 5. Lillich JD. Complications of dental surgery. Vet.Clin.North Am Equine Pract 1998; 14: 399-410. 6. Tremaine WH, Schumacher J. Exodontia In: Easley J, Dixon PM, Schumacher J, eds. Equine dentistry 3rd ed., Philadelphia: Saunders Elsevier 2011; 325-331. 7. Stoll M. Minimally Invasive Transbuccal Surgery and Screw Extraction. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 174-181. 8. Easley J. Dental repulsion. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 184-195. 9. Rawlinson JR, Review of Surgical Extraction of Maxillary Cheek Teeth. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Charlotte, NC, 2013; 80-84.
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10. Rawlinson JR. Review of surgical extraction of mandibular cheek teeth. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Charlotte, NC, 2013; 75-79. 11. Rawlinson JE. Surgical extraction of mandibular cheek teeth via alveolar bone removal. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 178-183. 12. Tremaine WH, McCluskie LK. Removal of 11 incompletely erupted, impacted cheek teeth in 10 horses using a dental alveolar transcortical osteotomy and buccotomy approach. Vet Surg 2010; 39: 884-90. 13. Rawlinson J. Addressing Pain: Regional Nerve Blocks. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 74-81. 14. Goodrich LR, Clark-Price S, Ludders J. How to attain effective and consistent sedation for standing procedures in the horse using constant rate infusion. Proceedings of the 50th Annual Convention of the American Association of Equine Practitioners, Denver, CO, 2004; 50: 229-232. 15. Easley JK. How to Properly Perform and Interpret an Endoscopic Examination of the Equine Oral Cavity. Proceedings of the 54th Annual Convention of the American Association of Equine Practitioners, San Diego, CA, 2008; 54: 383-385. 16. Galloway S. A Case Based Review of the Diagnostic Imaging of the Equine Incisors and Canine Teeth. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 149-156. 17. Baratt RM. A Case Based Review of the Diagnostic Imaging of the Maxillary Cheek Teeth and Sinuses. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 157-163. 18. Klugh DO. Intraoral Radiography of Equine Premolars and Molars. Proceedings of the 49th Annual Convention of the American Association of Equine Practitioners, New Orleans, LA, 2003; 280-286. 19. Baratt RM. Advances in Equine Dental Radiology. Vet Clin N Amer, Eq Practice, 2013: 29 (2): 367-396. 20. Earley ET. Dental Emergencies. In: Orsini JA and Divers TJ. Equine emergencies: treatment and procedures, 3rd ed., St. Louis: Saunders Elsevier, 2008; 176-186. 21. Earley ET, Intra oral radiography of equine incisors. Proceedings of the 22nd Annual Veterinary Dental Forum, Jacksonville, FL, 2008; 125-132. 22. Earley ET. A case based review – Diagnostic imaging of the mandibular cheek teeth. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 164-173. 23. Floyd MR. The modified Triadan system: nomenclature for veterinary dentistry. J Vet Dent 1991; 8: 18-19. 24. Dacre IT, Kempson S, Dixon PM. Pathologic studies of cheek teeth apical infections in the horse: 1. Normal endodontic anatomy and dentinal structure of equine cheek teeth. Vet Journal 2008; 178: 311-320. 25. Dacre IT. Equine Dental Pathology. In: Baker GJ, Easley J. Equine dentistry, 2nd ed. Philadelphia: Elsevier Saunders, 2005; 91-109. 26. Klugh, DO. Equine Periodontal Disease. Clin Tech Equine Pract 2005; 4:135-147. 27. Klugh, DO. A Review of Equine Periodontal Disease, Proceedings of the 52nd Annual Convention of the American Association of Equine Practitioners, San Antonio, TX, 2006; 52: 551-558. 28. Wiggs RB, Lobprise HB. Basic endodontic therapy. In: Wiggs RB, Lobprise HB. Veterinary dentistry, principles and practices, Philadelphia: Lippincott-Raven 1997; 280 -324. 29. Easley J. Equine Oral Extractions. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 147-152. 30. Gray LF. The veterinarian’s role in equine neglect: Recognizing and responding. Proceedings of the 50th Annual Convention of the American Association of Equine Practitioners, Denver, CO, 2004; 183-190. 31. Dental Fracture Classification, American Veterinary Dental College. American Veterinary Dental College Website (www.avdc.org), Nomenclature, Abnormalities of teeth, Dental fracture classification; 5-8. 32. Harris RJ. Clinical evaluation of a composite bone graft with a calcium sulfate barrier. J Periodontol 2004: 75: 685-692. 33. Wang HL, Tsao YP. Mineralized bone allograft-plug socket augmentation: rationale and technique. Implant Dent 2007;16: 33-41. 34. Brink P, How to perform levator labii superioris muscle transposition to treat oromaxillary sinus fistulae in horses. Proceedings of the 53rd Annual Convention of the American Association of Equine Practitioners, Orlando, FL, 2007; 53: 481-486. 35. Easley J, Schumacher J. Basic equine orthodontics and maxillofacial surgery. In: Easley J, Schumacher J. Equine dentistry, 3rd ed., Philadelphia: Elsevier 2011; 311-314. 36. Manfra-Marretta S. Maxillofacial surgery. Vet Clin North Amer Sm Anim Pract 1998; 28: 1285 1296. 37. Schloss AJ, Manfra Marretta S. Prognostic factors affecting teeth in the line of mandibular fractures. J Vet Dent 1990; 7: 7-9.
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Introduction
Oral surgical complications from extraction of cheek teeth are variable but may have the potential for a high rate of incidence. The incidence of reported complications has been documented to be 0, 20, 32, and as high as 70 %.1-5 Recognition of procedures and conditions that are problematic reduces the incidence of complication and aids the veterinarian’s preparedness for an inevitable complication. When performing cheek tooth extraction in the equine patient, complications will occur. Complications may involve surrounding bone, sinus, soft tissue, periodontal tissues, neurovascular structures, and teeth. The manner in which these complications are recognized and managed determines a successful outcome. Patient assessment includes physical, oral, and radiographic examinations. Additional methods and procedures for evaluation such as computed tomography, endoscopy, histopathology, cytology, and microbiology may be indicated prior to initiating an extraction procedure or to manage a complication. Multiple techniques may be used for the extraction of cheek teeth, including oral extraction6, buccal approach with oral extraction7, repulsion8, modified repulsion9, and buccotomy with
transcortical osteotomy.9-12 Most extraction procedures can be performed with the horse standing using perineural anesthesia and appropriate sedative combinations.13-14 Extraoral examination should be done that assesses the head/ maxilla for swelling, fistulas, nasal discharge, malodorous breath, and abnormal sinus percussion. Both mandibles can be palpated along the medial and lateral ventral borders to determine if any irregular or abnormal thickness is present. The masseter muscle should be evaluated for asymmetry, atrophy, and heat or swelling. Intraoral examination is performed using an intraoral mirrora with a dental lightb (or an intraoral camera system) in conjunction with a dental explorerc and periodontal probed.15 A dental explorer is used to evaluate the teeth, focusing on defects, fractures, and pulp exposure. The tactile sensitivity of a dental explorer increases as the size of the explorer head decreases. A periodontal probe is used to evaluate the gingival attachment to the teeth. The tip of the periodontal probe should be thin and flexible so that it can easily slide into small periodontal defects/ pockets and the incremental depth indicators should be easily visualized. Radiographs can be taken with the horse standing and the head down and low to the ground. This stance is comfortable for the horse and the person taking the radiographs. For extraoral and intraoral images, the mouth is held open with a dental speculumee that has minimal metal along the side of the horse’s face.16-21 An open mouth allows for the offset of the arcades when obtaining extraoral views and placement of film within the oral cavity for intraoral views. The maxillary arcades are imaged by placing the film/screen within the oral cavity and using a bisecting angle technique. Intraoral views of the mandibular arcades are obtained by utilizing a parallel or ventral oblique technique.21 The intraoral dorsoventral and ventrodorsal views can be taken with an aluminum speculume,f.22 The following cases are presented as examples of complications that can be associated with the extraction of cheek teeth. Each case will have a brief description of the oral and radiographic examination. After each case, there will be a short discussion detailing the importance of the examination finding(s) and identifying the complication(s). The potential complication can be eliminated or minimized with appropriate clinical acumen and foresight that prepares the clinician.
Oroantral Fistula and Retained Root Apex A 16-year-old Paint mare presented with a complicated crown fracture of the right maxillary fourth premolar tooth (108).23 The mare had a history of intermittent right facial swelling. When the swelling was present, the horse was very sensitive to palpation of the right face and the bit when ridden. Periodic, intermittent dosing with antibioticsg would resolve the swelling. The swelling and sensitivity would return a few weeks after the antibiotic treatment was discontinued. 220
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The intraoral examination revealed pulp exposure of pulp horns 3 and 5, and a periodontal pocket (12-mm depth x 3-mm diameter) along the mesiopalatal aspect of 108.24,25 The initial intraoral radiograph (dorsoventral view) showed bone loss along the mesial palatal aspect of 108 (Fig. 1). The extraoral view showed a fluid density at the rostral aspect of the rostral maxillary sinus, and slight cemental reaction along the buccal apex of 108 and the distal apex of the right maxillary first molar (109).
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Figure 1
Intraoral photograph in a 16-year-old Paint mare with a complicated crown fracture (arrows) of the right maxillary fourth premolar tooth (108)[A]. The initial intraoral dorsoventral view radio-graph (B) showed bone loss (arrows) along the mesial palatal aspect of 108.
Figure 2
Initial extraoral radiograph (A) in a 16-year-old Paint mare with a complicated crown fracture of the right maxillary fourth premolar tooth (108). There are signs of inflammation/fluid (orange arrows) in the rostral aspect of the maxillary sinus (green arrows). Note the mild cemental reaction along the buccal root apex of 108 (red arrows) and distal root apex of the right maxillary first molar tooth (109) [pink arrows]. The intraoral radiographic view (B) shows a widened and irregular periodontal ligament space along the mesial aspect of 109 (red arrows), an interproximal cemental reaction (green arrows), and loss of periodontal ligament space along the distal aspect of 108 (orange arrows).
Figure 3
Photographs in a 16-yearold Paint mare with a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing osteotomy directed over the apical aspect of 108 (A). After repulsion, the alveoli were filled with polyvinyl siloxane (PVS)k followed by gauze placement through the sinusotomy/osteotomy site. The gauze was removed after the PVS had hardened (B).
A bisecting angle intraoral radiograph revealed an irregular and thickened periodontal ligament with cemental reaction along the mesial aspect of 109 and loss of periodontal ligament space at the distal aspect of 108 (Fig. 2). Oral extraction of 108 was attempted. Tooth mobility was achieved, but extraction was not possible due to the cemental reaction, apparent ankylosis as noted by a loss of normal periodontal ligament space, and erosion of the clinical crown. An osteotomy was created in the maxillary bone over the apical aspect of 108 with a bone trephine.h The osteotomy was enlarged
with a laminectomy bur on a surgical handpiece.i,j The root apices of 108 were isolated and sectioned leaving a flat plateau of the remaining reserve crown for placement of a dental punch.k Following repulsion of 108, it was noted that the interproximal bone and reactive cementum of 108/109 were decayed and 109 was mobile. The osteotomy site was extended caudally and 109 was partially repulsed and then extracted orally. The rostral maxillary sinus was lavaged and the alveoli of 108 and 109 were curetted and debrided. Postoperative radiographs were taken to verify complete extraction and the alveoli were filled with polyJ VET DENT Vol. 30 No. 4 Winter 2013
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vinyl siloxane (PVS)l while gauze was placed apically through the sinusotomy/osteotomy site. The gauze was removed after the PVS had hardened (Fig. 3). The clinician (first author) failed to recognize a retained mesiobuccal root apex of 108 on the postextraction, intraoperative radiograph. The postoperative 8-week examination revealed a sinusitis with right nasal discharge and an oroantral fistula (alveolus to maxillary sinus) caudal to the retained root apex (Fig. 4). An 18-gauge needle was placed at the mesial aspect of the fistula as a marker and an intraoral radiograph was taken to confirm the nidus of the fistula (Fig. 5). Angled root tip elevatorsm,n,o were used to extract the root apex (Fig. 6).
The oroantral fistula was debrided and packed with PVS and the sinus was flushed. Oral and radiographic examinations revealed that the fistula was no longer present at the 7-month postoperative visit. The intraoral radiograph showed a small sequestrum, however based on the oral examination, it was decided to leave the sequestrum and monitor. The extraoral radiograph revealed a residual amount of fluid/soft tissue density in the right rostral maxillary sinus (Fig. 7). There had been no nasal discharge present during the previous 2-months. The patent was scheduled for another evaluation after 6-months.
Figure 4
Intraoperative intraoral radiograph (A) in a 16-yearold Paint mare following repulsion of a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing a retained mesiobuccal root apex of 108 (red arrows). The 8-week postoperative radiograph (B) shows signs of sinusitis (red arrows) and the retained 108 root apex (green arrows).
Figure 5
Intraoral photograph in a 16-year-old Paint mare 8-weeks following repulsion of a complicated crown fracture of the right maxillary fourth premolar tooth (108) showing an oroantral fistula (A). Placement of an 18-gauge needle confirms the location of the retained mesiobuccal root apex of 108 in relation to the oroantral fistula (B).
Figure 6
Photograph in a 16-yearold Paint mare following extraction of the maxillary fourth premolar tooth (108) mesiobuccal root apex that was retained after repulsion of a complicated crown fracture of 108 (A) 8-weeks previously. An intraoral radiograph confirms extraction of the 108 mesiobuccal root apex (B).
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Figure 7
Photograph in a 16-year-old Paint mare 7-months following extraction of the maxillary fourth premolar tooth (108) mesiobuccal root apex and treatment of an assoiated oroantral fistula. The oronasal fistula had healed (A). The intraoral radiograph (B) showed a small sequestrum (arrow). The extraoral radiograph (C) showed a residual amount of fluid/soft tissue density (orange arrows) in the right rostral maxillary sinus (green arrows).
Alveolar Plug Failure Leading to Sinusitis A 16-year-old Arabian gelding was presented for a dental evaluation. The physical examination was normal other than the horse was slightly underweight with a body condition score of 4-5/9. The owner had noted sensitivity to the bit and head shaking when the horse was ridden. The behavior had become progressively worse over a 2 to 3-month period. Normally the horse was very calm and well mannered under saddle. The oral examination revealed a complicated crown of the left maxillary first molar tooth (209) which involved the clinical crown along the mesial aspect. Pulp horns 1 and 3 were exposed. The horse was very sensitive and painful when examining the 209. Tooth movement (1 to 2-mm) was noted during examination with a dental explorer. The pressure from the dental explorer stimulated a slight amount of bleeding that was noted along the palatal aspect. Periodontal probing depths along the palatal aspect of 209 ranged between 3 and 5-mm. Probing depths along the buccal aspect were 1 to 3-mm. Intraoral radiographic examination showed an irregular periodontal space along the distal aspect of the mesiobuccal apex of 209. The extraoral radiograph revealed no evidence of sinus
disease associated with 209 (Fig. 8). The periodontal disease was graded as stage 2 with minimal bone and attachment loss. The mobility index was rated as moderate with a score of 2.26,27 Based on the clinical and radiographic findings, the diagnosis was endodontic disease involving 209 with a class I endodonticperiodontal relationship.28 Intraoral extraction was attempted. The tooth became mobile but appeared to become “wedged” between the left maxillary fourth premolar (208) and second molar (210) teeth when slight extrusion forces were applied with the extraction forceps. Intraoral extraction was attempted again the following day but remained unsuccessful. A sinusotomy was created with a trephine and moderate repulsion forces were used to extract 209. The sinus was lavaged and the alveolus was packed with PVS. The soft tissues were closed over the sinusotomy site. The owner called with a report of food material and a thick white discharge draining from the sinus at the repulsion site and the left nostril 12-days postoperatively. The oral examination revealed that the alveolar plug had failed and large amounts of food material were present in the sinus creating an orofa-
Figure 8 Photograph (A) in a 16-year-old Arabian gelding with a complicated crown fracture of the left maxillary first molar tooth (209). Note the hemorrhage after manipulation of the tooth and gingiva with a dental explorer. An intraoral radiograph (B) showed an irregular periodontal ligament space along the distal aspect of the mesiobuccal apex of 209. The lateral extraoral radiographic view (C) showed no signs of sinus disease.
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Figure 9
Photograph (A) in a 16-year-old Arabian gelding 12-days following repulsion of the fractured left maxillary first molar tooth (209). The alveolar plug failed leading to clinical signs of maxillary sinusitis. The intraoral photograph (B) showed food and debris in the rostral maxillary sinus. The extraoral radiograph (C) showed signs of sinusitis limited to the rostral maxillary sinus.
Figure 10
Photograph (A) at the 2-month postoperative examination in a 16-year-old Arabian gelding following oroantral fistula treatment for failure of the alveolar plug following repulsion of the fractured left maxillary first molar tooth (209). There is complete healing and restored gingival attachment at the left maxillary fourth premolar (208) and first molar (210) teeth. The extraoral radiograph (B) shows a mild tissue/fluid density in the rostral maxillary sinus (green arrows).
cial fistula (communication between the oral cavity and skin). Radiographic evaluation indicated that the sinus infection was limited primarily to the rostral maxillary sinus (Fig. 9). The horse was hospitalized and aggressive oral and sinus lavage was instituted over the next 10-days. The alveolus was packed with PVS. The horse was presented at 1, 2, and 11-months for postoperative physical and radiographic examinations. The sinus healed and the alveolus filled-in with complete gingival attachment at 208 and 210 (Figs. 10). Many different materials have been advocated for the use
Palatine Artery Laceration
A 17-year-old Shire mare presented with a history of moderate weight loss and difficulty in chewing. Physical examination revealed that the mare had a body score of 4-5 on a scale of 9.30 Physical examination was normal. Oral examination revealed that the right mandibular first molar tooth (409) was severely elongated by approximately 3-cm. The right maxillary first molar tooth (109) had a complicated fracture of the clinical and reserve 224
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of plugging/packing an alveolus following extraction of a cheek tooth, including wax, polymethylmethacrylate (PMMA), gauze, casting material, and PVS.29 The ideal material for plugging should be able to seal the alveolus yet not restrict healing. The plug should not extend into the apical one-half of the alveolus since this positioning could restrict healing or allow for migration of the plug into the sinus. Possible causes of alveolar plug failure in this case would include an incomplete fill of the coronal alveolus or improper shaping of the PVS to the margins of the alveolus during plug curing to a rigid state.
crowns. Food was packed deeply into the alveolus around the tooth fragments. A medially displaced fragment of 109 created a large and deep palatal defect. A 5-cm periodontal probe was placed at maximum depth into the center of the tooth and alveolus. Hemorrhage was evident following lavage of feed material from the alveolus (Fig. 11). The fracture was suspected to involve the root apices.
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Intraoral radiographs confirmed that 109 was comminuted into multiple fragments that did involve the root apices. The fractured 109 was classified as a complicated crown-root fracture.31 The extraoral radiographic examination showed a fluid and/or soft tissue density associated with the right rostral maxillary sinus (Fig. 12). Partial crown reduction was performed on 409 followed by oral extraction of the 109 tooth fragments. Gingival elevatorsp were used to separate the gingival attachments from the fragments. Angled root tip elevators were used to dislodge the fragments. Fragment forcepsq were used to remove the large palatal fragment and two smaller buccal fragments. The palatine artery bled profusely when the large palatal fragment was removed. Using several surgical towels and gauze, direct pressure was applied to the palate over a 20-minute period to slow hemorrhage until a clot could form. When the dental fragment was extracted with the forceps, it was apparent that part of the hard palate and
associated palatine artery were damaged and removed during the extraction process. Examination of the large palatal fragment revealed that a segment of the hard palate and associated palatine artery were attached/adhered/ankylosed to the dental fragment (Fig. 12). The greater palatine artery courses along the medial aspect of the maxillary cheek teeth at the submucosal aspect of the hard palate along the palatine groove/process. It is a direct extension of the maxillary artery and passes through the palatine canal and extends rostrally to join its counterpart (right or left palatine artery) caudal to the incisor teeth, entering the interincisive canal to form the incisive artery. The palatine groove does not completely enclose or protect the palatine artery. The artery is in close proximity to the alveolar bone of the maxillary cheek teeth. There is a risk of lacerating or tearing the artery when attempting an extraction when extensive pathology is present along the medial/ palatal alveolar wall aspect.
Figure 11
Photographs in 17-yearold Shire mare with a complicated fracture of the clinical and reserve crowns of the right maxillary first molar tooth (109). Oral examination revealed that the right mandibular first molar tooth (409) had approximately 3-cm of elongation (A). Note the food impaction and palatal fragment of 109 (B).
Figure 12
Intraoral radiograph (A) in 17-year-old Shire mare with a complicated fracture of the clinical and reserve crowns of the right maxillary first molar tooth (109). The tooth fracture was classified as a complicated crown-root fracture (A). The extraoral radiograph (B) shows a fluid/soft tissue density involving the right rostral maxillary sinus (arrows). The extracted palatally displaced fragment (C) reveals the attached hard palate segment and palatine artery.
Oronasal Communication
A 7-year-old Quarter Horse gelding was examined for a right nasal discharge of 4 to 6-months duration. The oral examination revealed a complicated fracture of the right maxillary fourth premolar tooth (108) involving the clinical and reserve crowns. The remaining reserve crown was displaced into the hard palate creat-
ing a large defect (Fig. 13). A periodontal probe could be passed along the palatal aspect of 108 into the maxillary sinus. Extraoral radiographic examination confirmed a right maxillary sinusitis based on the presence of a fluid/soft tissue density noted in the right rostral and caudal maxillary sinuses. A fluid J VET DENT Vol. 30 No. 4 Winter 2013
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line was evident in the right caudal maxillary sinus. The intraoral radiographic examination showed severe decay of the 108 (Fig. 13). Both views indicated that the root structure and remaining reserve crown were larger in diameter than the occlusal space between the neighboring right maxillary third premolar (107) and first molar (109) teeth. The diagnosis was a malformed, decayed 108 with stage 4 periodontal disease.26,27 An oronasal communication was diagnosed with associated right maxillary sinusitis. The 108 was extracted (Fig. 13). An intraoral surgical radiograph confirmed the complete removal of 108. The sinus was lavaged BID with saline and high pressure water for 2 to 3-weeks. The alveolus was also lavaged and re-packed every 7 to 10-days. A small piece of alveolar bone and dental fragment were removed at the 10-day postoperative examination. The right nasal discharge had ceased by the 10-day postoperative examination. The alveolus was healing with granulation tissue but the oronasal communication remained (Fig. 14). The 8-week postoperative examination showed alveolar bone healing yet a 2 x 5-mm oronasal communication remained along the mesial palatal aspect. The extraoral radiographic examination indicated normal bone healing with continuing resolution of the right rostral maxillary sinusitis. The intraoral radiographic examination showed slight alveolar bone healing along the edges of the repulsed sinus/alveolar bone (Fig. 14). Eleven months of bi-monthly aggressive lavage, debridement, and re-packing failed to resolve the oronasal communication. Debridement of the oronasal communication was done using cannulas, curettes, bone files, and brushesr,s,t,u.
Packing material included iodine-soaked gauze, scarlet oilsoaked gauze, CaSO4, and reabsorbable collagenv,w.32 PMMA and VPS were trialed, but the materials would not stay in place based on the location of the fistula and the thin palatal bone. The chronic oronasal communication measured 4 mm x 10-mm in length. (Fig. 15). The extraoral radiographic examination showed that there was evidence of soft tissue consolidation and bone densities within the right rostral maxillary sinus. The fluid/soft tissue densities were resolving in the right caudal maxillary sinus when compared with the initial extraoral radiographic view. The intraoral radiographic examination showed healing of alveolar bone. The alveolar/ palatal bone appeared to be consolidating around the defect with a possible communication through the bone (Fig. 15). The techniques available for the repair of oronasal communication are limited in horses. Flap procedures have not been developed as in other species due to limited access and visual challenges. Equine bone allografts may be an option in the future. Currently, bone allograftsx are available in dogs. A procedure describing the transposition of the labii superioris muscle for oromaxillary sinus communication has been described.34,35 This procedure involves repairing the communication through the sinus by isolating and transecting the rostral tendon of the levator labii superioris muscle. The tendon and muscle are guided through the sinus and communication, into the oral cavity, and exiting through a buccotomy. Care should be taken to avoid damage to the dorsal buccal branch of the facial nerve and the parotid salivary duct.
Figure 13
Photograph (A) in a 7-year-old Quarter Horse gelding with a complicated fracture of the right maxillary fourth premolar tooth (108) involving the clinical and reserve crowns. The remaining reserve crown was displaced into the hard palate creating a large defect. The extraoral radiograph (B) shows a fluid/tissue density evident in the rostral maxillary sinus (red arrows) and caudal maxillary sinus (green arrows). There is also a fluid line evident in the caudal maxillary sinus (blue arrows). The intraoral radiographic examination showed severe decay of 108 (C). Note that the root and apical reserve crown is wider in diameter than the remnant of the clinical crown and coronal reserve crown. The extracted 108 confirmed the malformed, decayed tooth pathology (D).
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Figure 14
Photograph (A) in a 7-year-old Quarter Horse gelding 3-weeks following repulsion of a complicated fracture of the right maxillary fourth premolar tooth (108) showing the patent oronasal fistula healing with granulation tissue. The 8-week postoperative oral examination showed a 2 x 5-mm oronasal fistula (arrow) along the mesial palatal aspect (B). The 8-week intraoral radiographic (C) examination showed slight alveolar bone healing along the borders (arrows) of the repulsion site sinus/alveolar bone.
Figure 15
Photograph (A) in a 7-year-old Quarter Horse gelding 11-months following repulsion of a complicated fracture of the right maxillary fourth premolar tooth (108) showing the 4 x 10-mm oronasal fistula (arrows). The extraoral radiographic (B) examination shows consolidation of soft tissue/bone densities in the right rostral maxillary sinus (red arrows), and resolving fluid/soft tissue densities in the right caudal maxillary sinus (green arrows). The intraoral radiographic examination (C) showed probable consolidating bone around the fistula (orange arrows) and possible open communication through the alveolar/palatal bone (blue arrow).
Incompletely Healed Mandible Fracture An 8-year-old Haflinger mare presented with a left mandibular non-union. A large draining tract was present rostral to the left mandibular second premolar tooth (306) along the ventral aspect of the mandible. The fracture and drainage had been present for over 2-years. Swelling and edema could be palpated along the buccal and lingual aspects of the left mandible. Oral examination revealed a 2.5-cm fistula along the lingual aspect of 306 (Fig. 16). A fracture was evident on the extraoral radiograph extending to the mesial aspect of the 306 alveolus.
The intraoral ventrodorsal radiograph showed reactive periosteal bone along the medial aspect of the left mandible and alveolar bone loss along the lingual and mesial aspects of 306 (Fig.16). The diagnosis was a non-union of the left mandible with apical abscessation and severe periodontal disease of 306. Typically the affected tooth will need eventual extraction in order for a non-union fracture to heal. As a general rule, it is probably best to retain teeth that significantly contribute to fracture stability as long as severe periodontal disease is not present.36 Complete healing will not occur without addressing the local J VET DENT Vol. 30 No. 4 Winter 2013
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infection and associated osteomyelitis.37 The drainage from the mandible ceased by 2-weeks following extraction of 306 and the swelling decreased over a 2-month period. A 7-month post-extrac-
tion radiographic showed partial healing of the mandibular fracture. There was minimal swelling and no drainage during the previous 2-months (Fig. 17).
Figure 16
Photograph (A) in an 8-year-old Haflinger mare presented with a left mandibular non-union showing a 2.5-cm fistula along the lingual aspect of left mandibular second premolar tooth (306). The extraoral radiograph (B) shows a fracture (arrow) extending to the mesial aspect of 306. The intraoral ventrodorsal radiograph (C) shows reactive periosteal bone along the medial aspect of the left mandible (red arrows) and alveolar bone loss along the lingual and mesial aspects of 306 (green arrows).
Figure 17
Photograph (A) in an 8-year-old Haflinger mare presented with a left mandibular non-union showing the extracted left mandibular second premolar tooth (306). The 7-month post-extraction radiographic (B) shows partial union of the mandibular fracture.
Mandibular Fracture A 21-year-old Tennessee Walking Horse gelding presented for a chronic, 2-month duration of swelling and drainage from the right mandible. The intraoral examination revealed a fractured right mandibular fourth premolar tooth (408). The fracture involved the lingual aspect of the clinical crown resulting in pulp exposure of pulp horns 1, 2, 3 and 4. The intraoral radiograph of 408 revealed that the periodontal ligament was mostly absent and the distal root apex was undergoing tooth resorption. The extraoral radiograph showed a large draining tract beginning at the distal aspect of 408 and 228
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extending to the ventral cortex. The preoperative intraoral ventrodorsal radiograph showed a normal medial cortex of the right mandible (Fig. 18). An attempt to extract 408 orally failed when the clinical crown fractured secondary to probable ankylosis as indicated on the preoperative radiograph (Fig 19). An oral approach for tooth extraction in the horse may be contraindicated when there are radiographic signs that support tooth ankylosis and/ or resorption since these pathologies render the tooth susceptible to fracture during non-surgical extraction.
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A surgical extraction was indicated following fracture of the clinical crown. The anatomical structure of the mandible consists of light alveolar and cancellous bone enveloped within a cortical plate on the medial and lateral aspects. Much of the strength of the mandible is actually attributed to the large cheek teeth embedded within the bone. A repulsion surgery would likely be difficult and could potentially cause extensive damage to the surrounding mandibular bone. When excessive force is used to extract a mandibular cheek tooth, severe damage and/or fracture of the surrounding bone is a possible complication. An incision over the apical third of 408 and a transcortical osteotomy were performed to section and excise the reserve crown and root apices as an alternative to an osteotomy and repulsion.11,12 The lateral mandibular cortex and alveolar bone were sectioned using a surgical length crosscut bury and surgical length round burz on a high-speed handpieceaa; and then elevated with a bone chiselbb and elevatorcc. The mesial and distal root apices were isolated and sectioned. The remaining reserve crown was lightly tapped into the oral cavity. The alveolus was debrided and curetted following removal of the reserve crown and roots (Fig. 19). The coronal 1/3 of the alveolus was packed with PVS. Due to the swelling and inflammation present, a penrose drain was placed and the soft tissues were apposed. Immediate, 1- and 2-month postoperative intraoral radiographs were taken to monitor the bone healing at the osteotomy site (Fig. 20). At the 2-month postoperative examination, the intraoral oblique radiograph revealed a fracture
along the lingual aspect of 408 alveolus that was not evident at the 1-month evaluation. The 2-month intraoral ventrodorsal radiograph showed a prominent periosteal reaction along the medial aspect of the right mandible (Fig. 21). When comparing the initial preoperative and the 2-month postoperative intraoral ventrodorsal radiographs, it is apparent that the medial/lingual cortical bone was normal prior to the surgical extraction of 408. In addition, the initial radiographs provide evidence that the lateral/buccal and ventral cortical aspects of the right mandible were compromised from the chronic drainage/infection (Fig. 18). Typically, if the medial/lingual and ventral cortex is preserved during a transcortical osteotomy of the lateral/buccal cortex, fracture is not a complication.11 A retrospective study involving 10 horses reported that mandibular swelling and bone remodeling occur following this surgery.12 The median age of the horses was 5.5-years. In this study, 11 transcortical osteotomy procedures were performed in 10 horses. Of the 11 procedures, 10 were performed on the mandible. It was reported that 3 of the 10 horses exhibited mandibular swelling and bone remodeling > 6-months following the surgical procedure. Based on the results of this retrospective study, and the intraoral radiographic findings in this case; it would be prudent to image operated mandibles to evaluate long-term healing to determine the incidence of mandibular fracture following this procedure. The case reported here could be an exception since the horse was older and the mandible had signs of pathology preoperatively. However, this surgery should be considered with caution until further data has been compiled to evaluate the postoperative healing
Figure 18
Radiographs in a 21-year-old Tennessee Walking Horse gelding presented for a fractured right mandibular fourth premolar tooth (408) and a 2-month history of swelling and drainage from the right mandible. The intraoral radiograph (A) of 408 revealed that the periodontal ligament was mostly absent and the distal root apex was undergoing tooth resorption (arrows). The extraoral radiograph (B) showed a large draining tract (arrows) beginning at the distal aspect of 408 and extending to the ventral cortex. The preoperative intraoral ventrodorsal radiograph (C) showed a normal medial cortex (arrows) of the right mandible.
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Figure 19
Radiograph (A) in a 21-year-old Tennessee Walking Horse gelding presented for a fractured right mandibular fourth premolar tooth (408) and a 2-month history of swelling and drainage from the right mandible. Note the failed intraoral attempt to extract the tooth. Intraoperative photographs show sectioning of the 408 mesial apex (B) and the remaining reserve crown (green arrow) [C] after sectioning and removal of both apices (D).
Figure 20
Immediate (A) and 1-month postoperative (B) intraoral radiographs in a 21-year-old Tennessee Walking Horse gelding operated for buccotomy and transcortical osteotomy to extract the right mandibular fourth premolar tooth (408) show progressive remodeling of lingual cortical bone (green arrows).
Figure 21
Intraoral lateral (A) and ventrodorsal (B) radiographs in a 21-year-old Tennessee Walking Horse gelding 2-months following buccotomy and transcortical osteotomy for extraction of the right mandibular fourth premolar tooth (408) show a fracture line involving the lingual cortical bone (arrows) and reactive periosteal bone along the medial aspect of the right mandible (arrows).
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Dilacerated Roots and Reserve Crown process. A 4-year-old Quarter Horse gelding was examined for routine dental assessment. As a 2-year-old, the gelding had been kicked in the face by a pasture mate. The owners reported that there had been a slight amount of swelling that seemed to improve over a 2-week period. The physical examination revealed normal findings. Extraoral examination findings were normal. No swellings or facial asymmetry were evident. The intraoral examination revealed that the right maxillary third premolar tooth (107) had considerable (15-mm) elongation without evidence of occlusal contact. It was noted that the right mandibular third premolar tooth (407) had not erupted into occlusion (Fig. 22). Normal findings were observed when evaluating the occlusal surface of 407 and 107 with a dental explorer. The extraoral radiographic examination showed pathologic changes at the apical aspect 407. There was a pronounced cemental reaction with the reserve crown and root structure. This reactionary reparative process of the cementum inhibited the eruption of the tooth (Fig. 23). The diagnosis was dilacerated and ankylosed roots and reserve crown of 407 due to a cemental inflammatory response from chronic pulpitis. At 6-years-old, the gelding was examined for a draining tract along the right ventral mandible. The drainage had been present for 3 to 4-weeks. The oral examination showed that the drainage was along the rostral aspect of the ventral mandible. The intraoral examination revealed that 407 had partially erupted and the elongation of 107 was absent. The gingival attachment was normal for 407 and there was no evidence of a draining tract. The occlusal surface of 407 and 107 appeared normal when examined with a dental explorer. The intraoral radiographic examination of 407 was abnor-
mal. A widened, abnormally shaped pulp horn was noted. Based on the orientation, this would represent either pulp horn 2 or 5. The intraoral ventrodorsal view showed that 407 was rotated in a mesiolingual direction. A 20-gauge, blunt needledd placed into the draining tract was apparent at the distal root apex of 407 on the extraoral radiograph (Fig. 24). The diagnosis was dilacerated roots and apical disease/abscess of 407. A lateral approach to the right mandible was performed and the tooth was sectioned and lightly repulsed (Fig. 25). The alveolus was packed with PVS and the buccotomy site was closed. A postoperative radiograph revealed complete extraction of 407 (Fig 26). The horse developed a large bone sequestrum and severe periodontal disease involving the right mandibular second premolar tooth (406) 3-months following surgery. The bone sequestrum and 406 were extracted orally. It was evident that the mesial root and reserve crown were dilacerated in a linguomedial direction (Fig. 26). The 6-month postoperative examination revealed normal healing of the 406 and 407 alveoli (Fig. 27). There were radiographic signs of normal healing with slight thickening of the medial and ventral cortical bone (Fig. 28). It is hypothesized that both 406 and 407 were damaged from the injury sustained when the horse was 2-years-old. Maldevelopment of the reserve crowns and roots led to dilacerations involving both teeth. The inflammatory process associated with 407 caused partial cemental ankylosis and maleruption. It is interesting to note that by 6-years of age, 406 was able to erupt despite cemental restrictions imposed on the reserve crown and roots, and the crowding from neighboring teeth. However, the eruption process initiated a cascade of events, including mandibular swelling, drainage, and
Figure 22 Photographs in a 4-yearold Quarter Horse gelding with a previous history of facial swelling. Oral examination showed an elongated right maxillary third premolar tooth (107) [A] and an incompletely erupted right mandibular third premolar tooth (407) [B].
Figure 23
Photograph (A) and extraoral radiograph (B) in a 4-year-old Quarter Horse gelding with a previous history of facial swelling. The right mandibular third premolar tooth (407) shows severe cemental reaction with dilacerated roots/reserve crown of 407.
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Figure 24
Radiographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 2-years after the facial swelling incident. The intraoral radiograph (A) of the right mandibular third premolar tooth (407) showed a widened, abnormally shaped pulp horn (arrows), either 2 or 5. The intraoral ventrodorsal radiograph (B) showed that 407 was rotated in a mesiolingual direction. A 20-gauge, blunt needledd placed into the draining tract (arrow) was apparent at the distal root apex of 407 on the extraoral radiograph (C).
Figure 25 Intraoperative photogrpahs showing extraction of the right mandibular third premolar tooth (407) in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible. Osteotomy was performed over the root apices of 407 (A) followed by sectioning of the apices (B). Following sectioning and elevation of the apices (C), the 407 reserve crown was repulsed (D).
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Figure 26
Radiographs following extraction of the right mandibular third premolar tooth (407) in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible. The postoperative radiograph shows the 407 extraction site (A). The extraoral (B) and intraoral ventrodorsal (C) radiographs 3-months following surgery show severe periodontal disease of the right second mandibular premolar tooth (406) with bone lysis along the mesial aspect (red arrows). A large sequestrum is present in the 407 alveolus (green arrows). The 406 postextraction image (D) shows the dilacerated root (green arrows), reserve crown of 406, and bony sequestra (red arrows).
Figure 27 Photographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 3-months following extraction of the right third mandibular premolar tooth (407) and sequestrectomy. The 406 (A) and the right mandibular third premolar tooth (407) [B] extraction sites show expected healing.
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Figure 28
Radiographs in a 6-year-old Quarter Horse gelding with a draining tract of the right ventral mandible 3-months following extraction of the right third mandibular premolar tooth (406) and sequestrectomy. The extraoral lateral (A) and intraoral ventrodorsal (B) radiographs show thickened, healing medial (arrows) and ventral cortical bone.
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b c d e f g h i j k l m n o p q r s t u v w
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Dental Mirror, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Dental headlamp. Equine Specialties, Georgetown, TX Dental Explorer, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Periodontal Probe, Harlton’s Equine Specialties, Columbus Ohio, Medco Instruments, Hickory Hills, IL Alumispec, Harlton’s Equine Specialties, Columbus, OH Meister Aluminum Speculum, Jorgensen Laboratories, Loveland, CO Sulfamothoxazole and Trimethoprim tblts, USP. Vista Pharmaceutics, Inc. West Orange, NJ Trephines. Harlton’s Equine Specialties, Elmwood, WI Oval Carbide Bur – (Bur 4 mm diameter x 8 mm long, Shaft 3/32 “ diameter x 48 mm long), Brassler USA, Savannah, GA Hall Surgical Highspeed Handpiece. Hall Powered Instruments, Largo, FL Dental Punches. Harlton’s Equine Specialties, Elmwood, WI Aquasil Easy Mix Putty. Dentsply, Milford, DE Root Tip Elevators - Equine Dental Picks Potts Style, Medco Instruments, Hickory Hills, IL T-Handled 4 Positions Elevator. Equine Specialties, Georgetown, TX Extended molar fragment elevator set. Harlton’s Equine Specialties, Elmwood, WI Gingiva elevators, Medco Instrumnents, Hickory Hills, IL, Harlton’s Equine Specialties, Columbus, OH Fragment forceps, Medco Instruments, Hickory Hills, IL, Harlton’s Equine Specialties, Columbus, OH Intranasal cannula. Boehringer Ingelheim Vetmedica, Inc., St. Joeseph, MO BRUN Curette size #1-#5. Medco Instruments, Hickory Hills, IL Bone Files. Benco Dental. Pittston, PA Bore brushes. Outers. Onalaska, WI Bondex, Plaster of Paris, DAP Inc., Baltimore, MD Resorbable Collagen Plug, Collagen Matrix Inc. 508 Commerce St. Franklin Lakes, NJ
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z aa bb cc dd ee
Bone allografts. Veterinary Transplant Services, Kent, WA Carbide Bur – FG-558SL. White Carbide Burs. Lakewood, NJ Carbide Bur – FG-8SL. White Carbide Burs. Lakewood, NJ iM3 - LED Advantage L5200. Vancouver, WA Bone chisel (10mm, 16mm and 25 mm) Periosteal Elevators. Synthes, Paoli, PA Monoject 3 ml Syringe (Luer Lock) with 23 gauge x 1 ¼ inch blunt irrigating needle, Kendall Monoject, Tyco Healthcare Group LP, Mansfield, MASedivet, Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO Stubbs Full Mouth Speculum, Stubbs Equine Innovations, Inc., Johnson City, TX.
Author Information
From Large Animal Dentistry, Equine Farm Animal Hospital, Cornell University, Ithaca, NY and Laurel Highland Veterinary Clinic (Earley), 2586 Northway Road Ext., Williamsport, PA, 17701. Email: [email protected]
References
1. Dixon PM, Hawkes C and Townsend N. Complications of equine oral surgery. Vet Clin North Am Equine Pract 2008; 24: 499-514. 2. Tremaine WH. Complications associated with dental and paranasal sinus surgery. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Indianapolis, IN, 2006; 141-147. 3. Duncanson, GR. A case study of 125 horses presented to a general practitioner in the UK for cheek teeth removal. Equine Vet Education 2004, 6/3, 212-216. 4. Dixon PM, Dacre I, Tremaine WH, McCann J, Barakzai S.Standing oral extraction of cheek teeth in 100 horses (1998-2003). Equine Vet J 2005; 37: 105-112. 5. Lillich JD. Complications of dental surgery. Vet.Clin.North Am Equine Pract 1998; 14: 399-410. 6. Tremaine WH, Schumacher J. Exodontia In: Easley J, Dixon PM, Schumacher J, eds. Equine dentistry 3rd ed., Philadelphia: Saunders Elsevier 2011; 325-331. 7. Stoll M. Minimally Invasive Transbuccal Surgery and Screw Extraction. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 174-181. 8. Easley J. Dental repulsion. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 184-195. 9. Rawlinson JR, Review of Surgical Extraction of Maxillary Cheek Teeth. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Charlotte, NC, 2013; 80-84.
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10. Rawlinson JR. Review of surgical extraction of mandibular cheek teeth. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Charlotte, NC, 2013; 75-79. 11. Rawlinson JE. Surgical extraction of mandibular cheek teeth via alveolar bone removal. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 178-183. 12. Tremaine WH, McCluskie LK. Removal of 11 incompletely erupted, impacted cheek teeth in 10 horses using a dental alveolar transcortical osteotomy and buccotomy approach. Vet Surg 2010; 39: 884-90. 13. Rawlinson J. Addressing Pain: Regional Nerve Blocks. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 74-81. 14. Goodrich LR, Clark-Price S, Ludders J. How to attain effective and consistent sedation for standing procedures in the horse using constant rate infusion. Proceedings of the 50th Annual Convention of the American Association of Equine Practitioners, Denver, CO, 2004; 50: 229-232. 15. Easley JK. How to Properly Perform and Interpret an Endoscopic Examination of the Equine Oral Cavity. Proceedings of the 54th Annual Convention of the American Association of Equine Practitioners, San Diego, CA, 2008; 54: 383-385. 16. Galloway S. A Case Based Review of the Diagnostic Imaging of the Equine Incisors and Canine Teeth. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 149-156. 17. Baratt RM. A Case Based Review of the Diagnostic Imaging of the Maxillary Cheek Teeth and Sinuses. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 157-163. 18. Klugh DO. Intraoral Radiography of Equine Premolars and Molars. Proceedings of the 49th Annual Convention of the American Association of Equine Practitioners, New Orleans, LA, 2003; 280-286. 19. Baratt RM. Advances in Equine Dental Radiology. Vet Clin N Amer, Eq Practice, 2013: 29 (2): 367-396. 20. Earley ET. Dental Emergencies. In: Orsini JA and Divers TJ. Equine emergencies: treatment and procedures, 3rd ed., St. Louis: Saunders Elsevier, 2008; 176-186. 21. Earley ET, Intra oral radiography of equine incisors. Proceedings of the 22nd Annual Veterinary Dental Forum, Jacksonville, FL, 2008; 125-132. 22. Earley ET. A case based review – Diagnostic imaging of the mandibular cheek teeth. Proceedings of the 23rd Annual Veterinary Dental Forum, Phoenix/Scottsdale, AZ, 2009; 164-173. 23. Floyd MR. The modified Triadan system: nomenclature for veterinary dentistry. J Vet Dent 1991; 8: 18-19. 24. Dacre IT, Kempson S, Dixon PM. Pathologic studies of cheek teeth apical infections in the horse: 1. Normal endodontic anatomy and dentinal structure of equine cheek teeth. Vet Journal 2008; 178: 311-320. 25. Dacre IT. Equine Dental Pathology. In: Baker GJ, Easley J. Equine dentistry, 2nd ed. Philadelphia: Elsevier Saunders, 2005; 91-109. 26. Klugh, DO. Equine Periodontal Disease. Clin Tech Equine Pract 2005; 4:135-147. 27. Klugh, DO. A Review of Equine Periodontal Disease, Proceedings of the 52nd Annual Convention of the American Association of Equine Practitioners, San Antonio, TX, 2006; 52: 551-558. 28. Wiggs RB, Lobprise HB. Basic endodontic therapy. In: Wiggs RB, Lobprise HB. Veterinary dentistry, principles and practices, Philadelphia: Lippincott-Raven 1997; 280 -324. 29. Easley J. Equine Oral Extractions. Proceedings of the American Association of Equine Practitioners Focus Meeting on Dentistry, Albuquerque, NM, 2011; 147-152. 30. Gray LF. The veterinarian’s role in equine neglect: Recognizing and responding. Proceedings of the 50th Annual Convention of the American Association of Equine Practitioners, Denver, CO, 2004; 183-190. 31. Dental Fracture Classification, American Veterinary Dental College. American Veterinary Dental College Website (www.avdc.org), Nomenclature, Abnormalities of teeth, Dental fracture classification; 5-8. 32. Harris RJ. Clinical evaluation of a composite bone graft with a calcium sulfate barrier. J Periodontol 2004: 75: 685-692. 33. Wang HL, Tsao YP. Mineralized bone allograft-plug socket augmentation: rationale and technique. Implant Dent 2007;16: 33-41. 34. Brink P, How to perform levator labii superioris muscle transposition to treat oromaxillary sinus fistulae in horses. Proceedings of the 53rd Annual Convention of the American Association of Equine Practitioners, Orlando, FL, 2007; 53: 481-486. 35. Easley J, Schumacher J. Basic equine orthodontics and maxillofacial surgery. In: Easley J, Schumacher J. Equine dentistry, 3rd ed., Philadelphia: Elsevier 2011; 311-314. 36. Manfra-Marretta S. Maxillofacial surgery. Vet Clin North Amer Sm Anim Pract 1998; 28: 1285 1296. 37. Schloss AJ, Manfra Marretta S. Prognostic factors affecting teeth in the line of mandibular fractures. J Vet Dent 1990; 7: 7-9.
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