The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
FIGURE 3. Restored joints and attachments, such as lateral pterygoid, can give an anterior-medial tension to the bilateral condyles, which not only helps to close the lingual gap of mandibular fracture but also benefits restoration of the mandibular width.
manipulation or open reduction; (2) reduction of the medial condylar fragment and fixation with screws, or removal of the fragment if it is less than 50% of the condylar width; however, in cases with a tiny condylar fragment, it was left in situ; and (3) management of the other associated mandibular fractures by ORIF. Our suggestion is that the dislocated intracapsular condylar fractures should not be removed, and it should be given surgical treatment. The attachment of lateral pterygoid should be reserved during the surgery. Based on the review and analysis on the 28 cases, our findings demonstrated that under the same osteosynthesis condition for mandibular symphyseal fracture, surgical treatment has significantly better effects than the close treatment to treat patients with dislocated intracapsular condylar fracture (P < 0.01). A possible mechanism may be that the restored joints and lateral pterygoid can give an anterior-medial tension to the bilateral condyles, which not only helps to close the lingual gap but also benefits restoration of the mandibular width. It is similar to a class II lever whose fulcrum is located at the symphyseal fracture, and force arm is located in the condyle (Fig. 3). If no surgery reduction for condylar fracture was performed, or removal of medial condylar fracture fragment, this mechanism would be invalid. Although these are the authors' viewpoints without any document to refer, there is no doubt that for this type of fracture, surgical treatment for the dislocated intracapsular condylar fracture is beneficial for the dislocated condyle repositioning back to its original physiological position, closure of the mandibular lingual gap, and restoration the transverse dimension of the mandible.
REFERENCES 1. Renato S, Sergio MLJ, Luciana A, et al. Incidence and patterns of mandibular condyle fractures. J Oral Maxillofac Surg 2010;68: 1252–1259 2. Ongodia D, Li Z, Zhou HH, et al. Comparative analysis of trends in the treatment of mandibular fractures. J Oral Maxillofac Surg 2014;26:276–279 3. Newman L. A clinical evaluation of the long-term outcome of patients treated for bilateral fracture of the mandibular condyles. Br J Oral Maxillofac Surg 1998;36:176–179 4. Michael E, Manson PN, Joachim P. Principles of internal fixation of the craniomaxillofacial skeleton trauma and orthognathic surgery. Stuttgart: Thieme, 2012:301 5. Ellis E 3rd, Throckmorton GS. Treatment of mandibular condyle process fractures: biological considerations. J Oral and Maxillofac Surg 2005;63:115–134 6. Huelke DF, Harger JH. Maxillofacial injuries: their nature and mechanisms of production. J Oral Surg 1969;27:451–460 7. He D, Ellis E 3rd, Zhang Y. Etiology of temporomandibular joint ankylosis secondary to condylar fractures: the role of concomitant mandibular fractures. J Oral Maxillofac Surg 2008;66:77–84
Brief Clinical Studies
8. Duan D, Zhang Y. A clinical investigation on disc displacement in sagittal fracture of the mandibular condyle and its association with TMJ ankylosis development. J Oral MaxillofacSurg 2011;40:134–138 9. Radhakrishna S, Ramesh B. Rare case of superolateral dislocation of the condyle. Oral Maxillofac Surg 2013;17:59–61 10. Shen L, Li P, Li J, et al. Management of superolateral dislocation of the mandibular condyle: a retrospective study of 10 cases. J Craniomaxillofac Surg 2014;42:53–58 11. Prabhakar V, Singla S. Bilateral anterosuperior dislocation of intact mandibular condyles in the temporal fossa. Int J Oral MaxillofacSurg 2011;40:640–643 12. Gregory Farwell D. Management of symphyseal and parasymphyseal mandibular fractures. Operative Techniques in Otolaryngology 2008;19:108–112 13. Ellis E 3rd, Tharanon W. Facial width problems associated with rigid fixation of mandibular fractures: case reports. J Oral Maxillofac Surg 1992;53:87 14. Edward E 3rd, He DM, et al. Fractures of the mandible: how much fixation enough. Chin J Stomatol 2007;42:257–262 15. Lee SH, Son SI, Park JH, et al. Reduction of prolonged bilateral temporomandibular joint dislocation by midline mandibulotomy. Int J Oral MaxillofacSurg 2006;35:1054–1056 16. Amaral MB, Bueno SC, Silva AA, et al. Superolateral dislocation of the intact mandibular condyle associated with panfacial fracture: a case report and literature review. Dent Traumatol 2011;27:235–240 17. Hochban W, Ellers M, Umstadt HE, et al. Zur operativen Reposition und Fixation von Unterkiefergelenkfortsatzfrakturen von enoral. Fortschr Kiefer Gesichtschir 1996;41:80 18. Baker AW, McMahon J, Moos KF. Current consensus on the management of fractures of the mandibular condyle. Int J Oral Maxillofac Sur 1998;27:258–266 19. Raveh J, Vuillemin T, Ladrach R. Open reduction of the dislocated fractured condylar process: indications and surgical procedures. J Oral Maxillofac Surg 1989;47:120–126 20. Li Z, Ongodia D, et al. Clinical characteristics and treatment of superolateral dislocation of the mandibular condyle. J Oral Maxillofac Surg 2013;42:1575–1578
Temporal Bone Resorption: An Uncommon Complication After Mandibular Distraction Shi Feng, MD, Zhiyong Zhang, MD, Lei Shi, MD, Xiaojun Tang, MD, Wei Liu, MD, Lin Yin, MD, Bin Yang, MD Abstract: Temporal bone absorption is a very infrequent complication following a intraoral mandibular distraction. We present a case of severe temporal bone absorption with skull base bone From the Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Received October 20, 2014. Accepted for publication December 1, 2014. Address correspondence and reprint requests to Lei Shi, MD, Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Rd, Shi-Jing-Shan, Beijing 100144, China; E-mail: [email protected] Supported by PUMC Youth Fund.(Project No. 33320140099). The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001452
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
e185
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Brief Clinical Studies
destruction in a child who experienced the mandibular distraction operation. In her follow-up of the 6th month, it was observed that the implanted distraction device drilled to the temporal bone and stretch into the middle cranial fossa. We recommend to optimize the positioning of the osteotomy and the design of the distraction to avoid the otential risk of adjacent skull destruction. Key Words: Hemifacial microsomia, Mandibular distraction osteogenesis, Complication
M
andibular distraction is an established method in the management of hemifacial microsomia or other micrognathia-related deformities.1–3 However, complications including infection, haemorrhage, incomplete osteogenesis, failure of distraction, and inferior alveolar nerve damage frequently occurs in the therapitic process.4 Temporal bone absorption is a very rare complication with few reports in the literature. Here, we present an rare complication of a severe temporal bone resorption caused by the elongated distractor device following mandibular distraction in a 7-year-old girl.
CLINICAL REPORT A 7-year-old girl, with hemifacial microsomia of Pruzansky-Kaban type IIB on the left side, was presented for mandibular distraction. Facial findings of physical examination included the facial asymmetry, an underdeveloped external ear (microtia), an absent ear canal, and no facial nerve involvement. No feeding, breathing,and speech problems were involved. She had an obvious asymmetric jaw and inclined chin as a result of the imbalance development of the mandible. Oral examination showed an inclined occlusal plane towards left side. She underwent a series of preoperative assessment, including cephalometric and panoramic radiographs, a computed tomography scan, three-dimensional reconstruction and computer aided design, the aim of which was to assist in correcting her craniofacial deformity. Radiographs and CT reconstruction images indicated that her severe facial asymmetry occurred largely because of the mandibular rumas hypoplasia on the left side. (Fig. 1) For avioding teeth damage, we designed a modified osteotomy line parallel to the occlusal plane. The rumas mandibular distractor was adopted (No.68.88.13 vertical titan lower jaw distractor for the left side, 20 mm, from Medicon company, Ganasacker 15 D-78532 Tuttlingen, German). Secondly, the distraction osteogenesis surgery was operated. After
FIGURE 1. X-ray radiographs collected before the distraction. (A) and (B) were collected before the operation of distractor implantation. They indicated that the facial asymmetry occurred largely because of the mandibular rumas hypoplasia on the left side. (C) and (D) were collected before the distraction showing the mandibular osteotomy site and the distractor fixing direction.
e186
FIGURE 2. Photograph showing the distractor implantation. A predesigned mandibular distractor was fixed on the left mandibular rumas after the procedure of osteotomy. The fixation of the distractor during the operation is showed in the left picture; The elongated distractor with the elongating part of 20 mm is showed in the right picture.
5 days, the left mandible rumas was distracted at the rate of one millimetre per day. The overall distraction distance were 20 mm in the vertical direction. (Fig. 2 and 3) Experiencing the stabilization of 6 months after distraction, her facial symmetry is significantly improved. The patient was also found to have an ideal mouth opening and occlusal function. However, before the second stage surgery performed, radiographs revealed a severe absorption of temporal bone caused by the elongated distractor, like a skull driller. Intraoperatively, we found the implanting device was severely adherent to the temporal bone. After the implanting device removed, there was a drilling hole left in the pneumatic madstoid bone (Fig. 4 and 5). Luckily, the girl had not suffered from any intracraniorelated complications after the operation.
DISCUSSION Few life-threatening complications related with mandibular distraction have been reported previously. Here, in this case we presented, the distraction device had drilled into the lateral parts of the middle fossa where the temporal lobes of the brain was supported. If not given full attention, this long-term complication of adjacent skull bone destruction
FIGURE 3. The schematic of this mandibular distractor from Medicon Company and the surgery of mandibular distraction osteogenesis. The initial state of the distractor before implantation is showed in the left picture; The elongated state of the distractor after distraction is showed in the right picture.
FIGURE 4. X-ray radiographs collected after the distraction. (E) and (F) were collected the day when the 20 mm-distraction was finished. It shows that her mandible was adjusted to the symmetrical position and her underlying anatomical structures defect was supplemented. (G) and (H) were collected 6 months after the distraction. The top of the distractor made a tiny displacement directing into the skull fossa. (As indicated by the arrows ).
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Brief Clinical Studies
5. El-saadi MM, Nasr MA. The effect of tissue expansion on skull bones in the paediatric age group from 2 to 7 years. J Plast Reconstr Aesthet Surg 2008;61:413–418 6. Burger EH, Klein-Nulend J. Mechanotransduction in bone-role of the lacuno-canalicular network. FASEB J 1999;13:S101–S112
FIGURE 5. CT radiographs collected 6 months after the operation showing a severe absorption of temporal bone caused by the elongated distractor,like a skull driller.
could finally lead to traumatic epiduralhematoma, cerebrospinal fluid leak, or even brain injury. The potential for such erosion probably relates to the constant compressive forces from the mandibular distractor. It has been observed that the abnormal external forces can cause skull bone destruction and distort cranial morphology.5 Furthermore, there is evidence that mechanical stimulation activates osteocytes to produce anabolic factors, which recruit new osteoblasts from the periosteum.6 Using this concept it is reasonable to explain local skull base erosion as a result of local impact. In this case, we notice that the mandibular distractor remained outside of the skull fossa when the 20 mm-distraction was finished. However, 6 months later, the top of the distractor made a tiny displacement drilling into the temporal bone(As indicated by the arrows in Fig. 4). Although it is well known that the skull outer table can be removed without untoward effects, the pressure of the mandibular distractor would finally exerted against the brain when the erosion penetrate the inner table. Then, the neurological consequences would follow. Additional factors responsible for the severe temporal bone resorption may include the overlong structure of distraction devices, the overhigh osteotomy site, and the improper distraction direction. Although internal mandibular distractor devices varies a lot, they almost share the same process of internal deformation during the elongating period. Such kind of gradual changes happened between the masseter muscle tissues and mandibular outer cortex have not received enough attention. In this case, it would appear that the elongating device, under the influence of the distraction force, can not only stretched mandible tissues, but extend towards the infratemporal area. Temporal bone resorption begins with invagination of the contact region.This significant rebuilding effect reminds us, the long-term effect on skull base bone should be take into consideration when designing the distraction length, osteotomy site and distraction direction. At the meantime, manufacturers of internal distractors could consider further improvement on the design to lessen unexpected effect on adjacent fractures. In summary, the authors report a uncommon complication of the skull base structures destruction following mandibular distraction. It highlights that the mandibular distraction has a potential risk of adjacent skull destruction. Therefore, it is necessary to optimize the positioning of the osteotomy and the design of the distraction.
REFERENCES 1. McCarthy JG, Katzen JT, Hopper R, et al. The first decade of mandibular distraction:Lessons we have learned. Plast. Reconstr. Surg 2002;110:1704 2. Ko EW, Hung KF, Huang CS, et al. Correction of facial asymmetry with multiplanar mandible distraction: A one-year follow-up study. Cleft Palate Craniofac.J 2004;41:5 3. Shetye PR, Grayson BH, Mackool RJ, et al. Long-Term Stability and Growth following Unilateral Mandibular Distraction in Growing Children with Craniofacial Microsomia. Plast Reconstr Surg 2006;118:985–95 4. Davies J, Turner S, Sandy JR. Distraction osteogenesis – a review. British Dental Journal 1998;185:462–467
Pleomorphic Adenoma Arising From the Palpebral Lobe of the Lacrimal Gland in a Patient With Thyroid-Associated Ophthalmopathy Jianhua Yan, MD, PhD, Jingchang Chen, MD, PhD, Tao Shen, MD, PhD Purpose/Background: To report a rare coexistence of pleomorphic adenoma arising from the palpebral lobe of the lacrimal gland and thyroid-associated ophthalmopathy in a Chinese patient. Methods: Case report of clinical features and imaging findings, orbital surgery, and histopathologic examination. Results: A Chinese woman (48 years old) with hyperthyroidism showed a gradually growing mass in the lateral region of the left upper eyelid that was present for 4 years and bilateral proptosis for 5 years. There was a slightly lower eyelid retraction in both eyes. Proptosis was 20 mm in the right eye and 22 mm in the left. A well-defined, nontender mass was palpable in the lateral upper eyelid of the left eye. Ultrasonography and computed tomography revealed a rounded homogenous mass measuring 14.1 13.2 mm in the lateral upper eyelid of the left eye and enlarged superior, medial, and inferior recti muscles in both eyes. At surgery, a grayishwhite round mass was observed after removal of the palpebral lobe of the lacrimal gland. The histopathological diagnosis was pleomorphic adenoma of the lacrimal gland. Conclusions: The coexistence of a pleomorphic adenoma of the lacrimal gland and thyroid-associated ophthalmopathy may indicate a pleomorphic adenoma likely due to an unknown autoimmune disorder. Key Words: Pleomorphic adenoma, Thyroid-associated ophthalmopathy, orbit, surgery, computed tomography
T
hyroid-associated ophthalmopathy (TAO) is the most common disease of the orbit, typically presenting with bilateral upper eyelid retraction, enlargement of extraocular muscles, and proptosis.
From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, The People's Republic of China. Received October 21, 2014. Accepted for publication December 1, 2014. Address correspondence and reprint requests to Jianhua Yan, MD, PhD, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xieli Nan Rd, Guangzhou, 510060, The People's Republic of China; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001453
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
e187
FIGURE 3. Restored joints and attachments, such as lateral pterygoid, can give an anterior-medial tension to the bilateral condyles, which not only helps to close the lingual gap of mandibular fracture but also benefits restoration of the mandibular width.
manipulation or open reduction; (2) reduction of the medial condylar fragment and fixation with screws, or removal of the fragment if it is less than 50% of the condylar width; however, in cases with a tiny condylar fragment, it was left in situ; and (3) management of the other associated mandibular fractures by ORIF. Our suggestion is that the dislocated intracapsular condylar fractures should not be removed, and it should be given surgical treatment. The attachment of lateral pterygoid should be reserved during the surgery. Based on the review and analysis on the 28 cases, our findings demonstrated that under the same osteosynthesis condition for mandibular symphyseal fracture, surgical treatment has significantly better effects than the close treatment to treat patients with dislocated intracapsular condylar fracture (P < 0.01). A possible mechanism may be that the restored joints and lateral pterygoid can give an anterior-medial tension to the bilateral condyles, which not only helps to close the lingual gap but also benefits restoration of the mandibular width. It is similar to a class II lever whose fulcrum is located at the symphyseal fracture, and force arm is located in the condyle (Fig. 3). If no surgery reduction for condylar fracture was performed, or removal of medial condylar fracture fragment, this mechanism would be invalid. Although these are the authors' viewpoints without any document to refer, there is no doubt that for this type of fracture, surgical treatment for the dislocated intracapsular condylar fracture is beneficial for the dislocated condyle repositioning back to its original physiological position, closure of the mandibular lingual gap, and restoration the transverse dimension of the mandible.
REFERENCES 1. Renato S, Sergio MLJ, Luciana A, et al. Incidence and patterns of mandibular condyle fractures. J Oral Maxillofac Surg 2010;68: 1252–1259 2. Ongodia D, Li Z, Zhou HH, et al. Comparative analysis of trends in the treatment of mandibular fractures. J Oral Maxillofac Surg 2014;26:276–279 3. Newman L. A clinical evaluation of the long-term outcome of patients treated for bilateral fracture of the mandibular condyles. Br J Oral Maxillofac Surg 1998;36:176–179 4. Michael E, Manson PN, Joachim P. Principles of internal fixation of the craniomaxillofacial skeleton trauma and orthognathic surgery. Stuttgart: Thieme, 2012:301 5. Ellis E 3rd, Throckmorton GS. Treatment of mandibular condyle process fractures: biological considerations. J Oral and Maxillofac Surg 2005;63:115–134 6. Huelke DF, Harger JH. Maxillofacial injuries: their nature and mechanisms of production. J Oral Surg 1969;27:451–460 7. He D, Ellis E 3rd, Zhang Y. Etiology of temporomandibular joint ankylosis secondary to condylar fractures: the role of concomitant mandibular fractures. J Oral Maxillofac Surg 2008;66:77–84
Brief Clinical Studies
8. Duan D, Zhang Y. A clinical investigation on disc displacement in sagittal fracture of the mandibular condyle and its association with TMJ ankylosis development. J Oral MaxillofacSurg 2011;40:134–138 9. Radhakrishna S, Ramesh B. Rare case of superolateral dislocation of the condyle. Oral Maxillofac Surg 2013;17:59–61 10. Shen L, Li P, Li J, et al. Management of superolateral dislocation of the mandibular condyle: a retrospective study of 10 cases. J Craniomaxillofac Surg 2014;42:53–58 11. Prabhakar V, Singla S. Bilateral anterosuperior dislocation of intact mandibular condyles in the temporal fossa. Int J Oral MaxillofacSurg 2011;40:640–643 12. Gregory Farwell D. Management of symphyseal and parasymphyseal mandibular fractures. Operative Techniques in Otolaryngology 2008;19:108–112 13. Ellis E 3rd, Tharanon W. Facial width problems associated with rigid fixation of mandibular fractures: case reports. J Oral Maxillofac Surg 1992;53:87 14. Edward E 3rd, He DM, et al. Fractures of the mandible: how much fixation enough. Chin J Stomatol 2007;42:257–262 15. Lee SH, Son SI, Park JH, et al. Reduction of prolonged bilateral temporomandibular joint dislocation by midline mandibulotomy. Int J Oral MaxillofacSurg 2006;35:1054–1056 16. Amaral MB, Bueno SC, Silva AA, et al. Superolateral dislocation of the intact mandibular condyle associated with panfacial fracture: a case report and literature review. Dent Traumatol 2011;27:235–240 17. Hochban W, Ellers M, Umstadt HE, et al. Zur operativen Reposition und Fixation von Unterkiefergelenkfortsatzfrakturen von enoral. Fortschr Kiefer Gesichtschir 1996;41:80 18. Baker AW, McMahon J, Moos KF. Current consensus on the management of fractures of the mandibular condyle. Int J Oral Maxillofac Sur 1998;27:258–266 19. Raveh J, Vuillemin T, Ladrach R. Open reduction of the dislocated fractured condylar process: indications and surgical procedures. J Oral Maxillofac Surg 1989;47:120–126 20. Li Z, Ongodia D, et al. Clinical characteristics and treatment of superolateral dislocation of the mandibular condyle. J Oral Maxillofac Surg 2013;42:1575–1578
Temporal Bone Resorption: An Uncommon Complication After Mandibular Distraction Shi Feng, MD, Zhiyong Zhang, MD, Lei Shi, MD, Xiaojun Tang, MD, Wei Liu, MD, Lin Yin, MD, Bin Yang, MD Abstract: Temporal bone absorption is a very infrequent complication following a intraoral mandibular distraction. We present a case of severe temporal bone absorption with skull base bone From the Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Received October 20, 2014. Accepted for publication December 1, 2014. Address correspondence and reprint requests to Lei Shi, MD, Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Rd, Shi-Jing-Shan, Beijing 100144, China; E-mail: [email protected] Supported by PUMC Youth Fund.(Project No. 33320140099). The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001452
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
e185
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Brief Clinical Studies
destruction in a child who experienced the mandibular distraction operation. In her follow-up of the 6th month, it was observed that the implanted distraction device drilled to the temporal bone and stretch into the middle cranial fossa. We recommend to optimize the positioning of the osteotomy and the design of the distraction to avoid the otential risk of adjacent skull destruction. Key Words: Hemifacial microsomia, Mandibular distraction osteogenesis, Complication
M
andibular distraction is an established method in the management of hemifacial microsomia or other micrognathia-related deformities.1–3 However, complications including infection, haemorrhage, incomplete osteogenesis, failure of distraction, and inferior alveolar nerve damage frequently occurs in the therapitic process.4 Temporal bone absorption is a very rare complication with few reports in the literature. Here, we present an rare complication of a severe temporal bone resorption caused by the elongated distractor device following mandibular distraction in a 7-year-old girl.
CLINICAL REPORT A 7-year-old girl, with hemifacial microsomia of Pruzansky-Kaban type IIB on the left side, was presented for mandibular distraction. Facial findings of physical examination included the facial asymmetry, an underdeveloped external ear (microtia), an absent ear canal, and no facial nerve involvement. No feeding, breathing,and speech problems were involved. She had an obvious asymmetric jaw and inclined chin as a result of the imbalance development of the mandible. Oral examination showed an inclined occlusal plane towards left side. She underwent a series of preoperative assessment, including cephalometric and panoramic radiographs, a computed tomography scan, three-dimensional reconstruction and computer aided design, the aim of which was to assist in correcting her craniofacial deformity. Radiographs and CT reconstruction images indicated that her severe facial asymmetry occurred largely because of the mandibular rumas hypoplasia on the left side. (Fig. 1) For avioding teeth damage, we designed a modified osteotomy line parallel to the occlusal plane. The rumas mandibular distractor was adopted (No.68.88.13 vertical titan lower jaw distractor for the left side, 20 mm, from Medicon company, Ganasacker 15 D-78532 Tuttlingen, German). Secondly, the distraction osteogenesis surgery was operated. After
FIGURE 1. X-ray radiographs collected before the distraction. (A) and (B) were collected before the operation of distractor implantation. They indicated that the facial asymmetry occurred largely because of the mandibular rumas hypoplasia on the left side. (C) and (D) were collected before the distraction showing the mandibular osteotomy site and the distractor fixing direction.
e186
FIGURE 2. Photograph showing the distractor implantation. A predesigned mandibular distractor was fixed on the left mandibular rumas after the procedure of osteotomy. The fixation of the distractor during the operation is showed in the left picture; The elongated distractor with the elongating part of 20 mm is showed in the right picture.
5 days, the left mandible rumas was distracted at the rate of one millimetre per day. The overall distraction distance were 20 mm in the vertical direction. (Fig. 2 and 3) Experiencing the stabilization of 6 months after distraction, her facial symmetry is significantly improved. The patient was also found to have an ideal mouth opening and occlusal function. However, before the second stage surgery performed, radiographs revealed a severe absorption of temporal bone caused by the elongated distractor, like a skull driller. Intraoperatively, we found the implanting device was severely adherent to the temporal bone. After the implanting device removed, there was a drilling hole left in the pneumatic madstoid bone (Fig. 4 and 5). Luckily, the girl had not suffered from any intracraniorelated complications after the operation.
DISCUSSION Few life-threatening complications related with mandibular distraction have been reported previously. Here, in this case we presented, the distraction device had drilled into the lateral parts of the middle fossa where the temporal lobes of the brain was supported. If not given full attention, this long-term complication of adjacent skull bone destruction
FIGURE 3. The schematic of this mandibular distractor from Medicon Company and the surgery of mandibular distraction osteogenesis. The initial state of the distractor before implantation is showed in the left picture; The elongated state of the distractor after distraction is showed in the right picture.
FIGURE 4. X-ray radiographs collected after the distraction. (E) and (F) were collected the day when the 20 mm-distraction was finished. It shows that her mandible was adjusted to the symmetrical position and her underlying anatomical structures defect was supplemented. (G) and (H) were collected 6 months after the distraction. The top of the distractor made a tiny displacement directing into the skull fossa. (As indicated by the arrows ).
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Brief Clinical Studies
5. El-saadi MM, Nasr MA. The effect of tissue expansion on skull bones in the paediatric age group from 2 to 7 years. J Plast Reconstr Aesthet Surg 2008;61:413–418 6. Burger EH, Klein-Nulend J. Mechanotransduction in bone-role of the lacuno-canalicular network. FASEB J 1999;13:S101–S112
FIGURE 5. CT radiographs collected 6 months after the operation showing a severe absorption of temporal bone caused by the elongated distractor,like a skull driller.
could finally lead to traumatic epiduralhematoma, cerebrospinal fluid leak, or even brain injury. The potential for such erosion probably relates to the constant compressive forces from the mandibular distractor. It has been observed that the abnormal external forces can cause skull bone destruction and distort cranial morphology.5 Furthermore, there is evidence that mechanical stimulation activates osteocytes to produce anabolic factors, which recruit new osteoblasts from the periosteum.6 Using this concept it is reasonable to explain local skull base erosion as a result of local impact. In this case, we notice that the mandibular distractor remained outside of the skull fossa when the 20 mm-distraction was finished. However, 6 months later, the top of the distractor made a tiny displacement drilling into the temporal bone(As indicated by the arrows in Fig. 4). Although it is well known that the skull outer table can be removed without untoward effects, the pressure of the mandibular distractor would finally exerted against the brain when the erosion penetrate the inner table. Then, the neurological consequences would follow. Additional factors responsible for the severe temporal bone resorption may include the overlong structure of distraction devices, the overhigh osteotomy site, and the improper distraction direction. Although internal mandibular distractor devices varies a lot, they almost share the same process of internal deformation during the elongating period. Such kind of gradual changes happened between the masseter muscle tissues and mandibular outer cortex have not received enough attention. In this case, it would appear that the elongating device, under the influence of the distraction force, can not only stretched mandible tissues, but extend towards the infratemporal area. Temporal bone resorption begins with invagination of the contact region.This significant rebuilding effect reminds us, the long-term effect on skull base bone should be take into consideration when designing the distraction length, osteotomy site and distraction direction. At the meantime, manufacturers of internal distractors could consider further improvement on the design to lessen unexpected effect on adjacent fractures. In summary, the authors report a uncommon complication of the skull base structures destruction following mandibular distraction. It highlights that the mandibular distraction has a potential risk of adjacent skull destruction. Therefore, it is necessary to optimize the positioning of the osteotomy and the design of the distraction.
REFERENCES 1. McCarthy JG, Katzen JT, Hopper R, et al. The first decade of mandibular distraction:Lessons we have learned. Plast. Reconstr. Surg 2002;110:1704 2. Ko EW, Hung KF, Huang CS, et al. Correction of facial asymmetry with multiplanar mandible distraction: A one-year follow-up study. Cleft Palate Craniofac.J 2004;41:5 3. Shetye PR, Grayson BH, Mackool RJ, et al. Long-Term Stability and Growth following Unilateral Mandibular Distraction in Growing Children with Craniofacial Microsomia. Plast Reconstr Surg 2006;118:985–95 4. Davies J, Turner S, Sandy JR. Distraction osteogenesis – a review. British Dental Journal 1998;185:462–467
Pleomorphic Adenoma Arising From the Palpebral Lobe of the Lacrimal Gland in a Patient With Thyroid-Associated Ophthalmopathy Jianhua Yan, MD, PhD, Jingchang Chen, MD, PhD, Tao Shen, MD, PhD Purpose/Background: To report a rare coexistence of pleomorphic adenoma arising from the palpebral lobe of the lacrimal gland and thyroid-associated ophthalmopathy in a Chinese patient. Methods: Case report of clinical features and imaging findings, orbital surgery, and histopathologic examination. Results: A Chinese woman (48 years old) with hyperthyroidism showed a gradually growing mass in the lateral region of the left upper eyelid that was present for 4 years and bilateral proptosis for 5 years. There was a slightly lower eyelid retraction in both eyes. Proptosis was 20 mm in the right eye and 22 mm in the left. A well-defined, nontender mass was palpable in the lateral upper eyelid of the left eye. Ultrasonography and computed tomography revealed a rounded homogenous mass measuring 14.1 13.2 mm in the lateral upper eyelid of the left eye and enlarged superior, medial, and inferior recti muscles in both eyes. At surgery, a grayishwhite round mass was observed after removal of the palpebral lobe of the lacrimal gland. The histopathological diagnosis was pleomorphic adenoma of the lacrimal gland. Conclusions: The coexistence of a pleomorphic adenoma of the lacrimal gland and thyroid-associated ophthalmopathy may indicate a pleomorphic adenoma likely due to an unknown autoimmune disorder. Key Words: Pleomorphic adenoma, Thyroid-associated ophthalmopathy, orbit, surgery, computed tomography
T
hyroid-associated ophthalmopathy (TAO) is the most common disease of the orbit, typically presenting with bilateral upper eyelid retraction, enlargement of extraocular muscles, and proptosis.
From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, The People's Republic of China. Received October 21, 2014. Accepted for publication December 1, 2014. Address correspondence and reprint requests to Jianhua Yan, MD, PhD, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xieli Nan Rd, Guangzhou, 510060, The People's Republic of China; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001453
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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