Veterinary Ophthalmology (2015) 18, 5, 433–436
DOI:10.1111/vop.12225
CASE REPORT
Dacryocystitis following a nasolacrimal duct obstruction caused by an ectopic intranasal tooth in a dog Katrin Voelter-Ratson,* Regine Hagen,† Stefan Grundmann‡ and Bernhard Martin Spiess* *Equine Department, Ophthalmology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; †Section of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; and ‡Clinic of Small Animal Surgery, Section of Dentistry, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
Address communications to: K. Voelter-Ratson Tel.: +41 44 635 82 68 Fax: +41 44 635 89 40 e-mail: kvoelter@vetclinics. uzh.ch
Abstract Purpose To describe a nasolacrimal duct (NLD) obstruction secondary to an ectopic tooth in a 5-year-old male Border collie. The dog was presented with a 1-month history of mucopurulent discharge from the left eye (OS) preceded by a lifelong history of epiphora OS. Treatment with neomycin/polymyxin B/dexamethasone ophthalmic solution had not improved the clinical signs, and the NLD was not patent when irrigated by the referring veterinarian. Methods A complete ophthalmologic examination was performed followed by dacryocystorhinography and computed tomography (CT). Results The ophthalmologic examination revealed marked mucopurulent discharge, mild conjunctivitis, slightly elevated STT measurements, and a negative Jones test OS. Both nasolacrimal puncta OS could be cannulated without resistance for approximately 1.5 cm. Upon irrigation, copious amounts of mucopurulent discharge were exited through the corresponding punctum, while no fluid could be detected at the nares. Dacryocystorhinography was performed. Radiographs revealed an ectopic left canine tooth within the left nasal cavity. A cystic dilation of the NLD was observed proximal to the ectopic tooth. Computed tomography was performed to determine the exact position of the tooth and possible involvement of adjacent structures; CT confirmed the previous imaging findings. Treatment with systemic antibiotics, NSAIDs, and ofloxacin ophthalmic solution led to resolution of the clinical signs within several days. Surgery was declined by the owner. Conclusion This is the first case report describing a blocked NLD due to an ectopic tooth in a dog. Ectopic teeth should be included as a differential diagnosis in cases of dacryocystitis and chronic epiphora in dogs. Key Words: canine, nasolacrimal duct, tooth retention
CASE REPORT
A 5-year-old castrated male Border collie was presented to a veterinarian on multiple occasions for chronic unilateral epiphora, recurrent ocular discharge, and mild conjunctivitis OS. The veterinarian prescribed neomycin/polymyxin/ dexamethasone eye drops three times daily (TID) and attempted unsuccessfully to irrigate the nasolacrimal duct on multiple occasions. Clinical signs usually resolved after 1–2 weeks of topical medication, but recurrence and even© 2014 American College of Veterinary Ophthalmologists
tual loss of response to therapy, prompted referral to the ophthalmology department for further diagnostic evaluation. A complete ophthalmological examination was performed with a slit-lamp biomicroscope (Kowa SL-15; Kowa Company Ltd, Tokyo, Japan) and indirect ophthalmoscope (Omega 500; Heine, Ettenheim, Germany). Examination of the left eye (OS) showed marked mucopurulent discharge, the conjunctiva was markedly hyperemic, the Schirmer Tear Test (STT) reading was 27 mm/min, and the Jones Test was negative OS. The nasolacrimal
434 voelter-ratson
ET AL.
puncta were open and appeared normal in location, size, and shape. Anterograde cannulation and flushing of the NLD were possible from the lower to the corresponding upper punctum but not through the nares. Copious amounts of mucopurulent material exited the corresponding ipsilateral punctum. The remainder of the examination was unremarkable. Examination of the right eye showed no abnormalities with a STT reading of 20 mm/min and a patent NLD. Treatment with topical 0.3% ofloxacin ophthalmic solution three times daily, oral amoxicillin/clavulanic acid (20 mg/kg) twice daily, and carprofen (4 mg/kg) once daily was initiated. Bacterial culture of a conjunctival swab was positive for Corynebacterium. Bacterial sensitivity testing for Corynebacterium was not performed by the laboratory as no standardized MICs are published for the Kirby–Bauer agar diffusion test method. Recommendations for treatment with b-Lactam-antibiotics or cephalosporine antibiotics were given based on the spectrum of activity for these antibiotics. Marked improvement of the clinical signs was noted within 6 days. The owner agreed to perform dacryocystorhinography. Six days following initial presentation, the dog was sedated with 30 lg/kg acepromazine and 0.2 mg/kg methadon intramuscularly, and general anesthesia was induced with 3.5 mg/kg propofol intravenously. Anesthesia was maintained with isoflurane. Lateral and ventrodorsal radiographs of the skull were performed (Fig. 1). On both projections, a well-developed tooth was visible located in the left rostral nasal cavity and the left maxillary canine tooth was missing. The abnormally located tooth was significantly smaller than the right maxillary canine tooth. Bulbous swelling was observed at the level of the root, which was of opacity similar to the remainder of the tooth. Otherwise, the skull was radiographically unremarkable. The upper and lower puncta were cannulated with an intravenous catheter (Terumo Surflo i.v. catheter 20G 9 1 ¼ “) without the guide wire and approximately 1 ml of iodinated contrast medium (Visipaque, 270 mg I/mL; GE Healthcare, Opfikon, Switzerland) was slowly injected. A lateral radiograph showed contrast filling of the proximal nasolacrimal duct and bifocal dilation of the NLD caudal to the abnormally located tooth with traces of contrast medium surrounding the apparent dilated segments (Fig. 2). A CT scan (Brilliance CT 16-slice (Philips AG, Zurich, Switzerland)) of the skull was performed immediately after the dacryocystorhinography, to accurately localize the position of the tooth and the nasolacrimal blockage. The dog was positioned in sternal recumbency, the skull scanned and the images reconstructed in both bone and soft tissue windows. The left nasolacrimal duct showed good filling in its proximal part to the rostral contour of the second premolar (PM2). Caudal to PM2 contrast medium was seen in two small, well-defined areas in the left nasal cavity. (Fig. 3) Contrast medium was also seen outlining the nasal and rostral ethmoid turbinates. (Fig. 4,5) The left maxillary canine tooth was malpositioned and misshapen; the
Figures 1. In the lateral and ventrodorsal radiographs, a welldeveloped tooth was visible, located in the left rostral nasal cavity and the left maxillary canine tooth was missing. The abnormally located tooth was significantly smaller than the right maxillary canine tooth and showed bulbous swelling of dental opacity at the level of the root.
root was approximately in the correct location; however, it was directly abutting the maxillary bone, which appeared thin and mildly irregular at this level compared to the contralateral (right) side. The neck and crown of the tooth were located caudal and axial to its root. (Fig. 4,5) The small size and abnormal shape of the tooth compared to the right maxillary canine tooth was confirmed with CT. Deformation of the nasal passages, mainly left sided with mild right-sided displacement of the nasal septum and an abrupt termination of the contrast filled NLD at the level of the caudal root of PM2 were noted. (Fig. 6) An ectopic left maxillary canine tooth causing deformation of the left nasal cavity and complete occlusion of the left nasolacrimal duct was diagnosed. Leakage of contrast medium into the left nasal cavity was noted. The owner declined surgical intervention in the form of an oral or nasal approach to remove the tooth due to the invasiveness of the surgery, potential morbidity, and
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
ectopic tooth blocking nasolacrimal duct 435
Figure 2. A lateral radiograph showing contrast filling of the proximal NLD and bifocal dilation of the NLD caudal to the abnormally located tooth.
Figure 3. Transverse reconstruction in a bone window of the nasal chamber shows well circumscribed moderate distension of the left nasolacrimal duct which is filled with homogeneously hyperattenuating iodinated contrast medium. Lateral to the NLD dilation, there is contrast medium visible in the bony nasolacrimal canal and also outlining the nasal turbinates
Figure 5. Dorsal reconstruction in a bone window of the nasal chambers. The ectopic left maxillary canine tooth is in an abnormally caudal and dorsal position and the crown points caudally too. The hyperattenuating foci are contrast medium outlining the nasal turbinates. There is marked axial deviation of the left sided intranasal structures (nasal turbinates, nasal septum).
Figure 6. Sagittal reconstruction in a bone window showing a crosssection of the ectopic tooth (arrow) rostral to the distended nasolacrimal duct.
possible complications of persistent epiphora and chronic nasal discharge. Systemic and topical treatment were continued for another week. Clinical signs of dacryocystitis completely resolved 2 weeks after initiation of the systemic treatment, and the dog had no recurrences for the following 12 months. Mild epiphora remained. DISCUSSION
Figure 4. Transverse reconstruction in a bone window of the ectopic tooth demonstrating its intranasal location at this level and the deviation of the nasal septum and turbinates. Multiple small foci of hyperattenuating contrast medium outline the nasal turbinates dorsal to the abnormal tooth.
Nasolacrimal duct obstruction and dacryocystitis are well known, although rather rare diseases in the dog.1 Dacryocystitis is defined as inflammation of the lacrimal sac most commonly secondary to a NLD blockage. The most common cause for acquired nasolacrimal duct obstructions and dacryocystitis is a foreign body within the nasolacrimal sac.2 Other causes of NLD obstruction include congenital malformation, fractures to the maxillary and lacrimal bones, and neoplasia.1 While dental abnormalities have been reported to cause nasolacrimal duct obstructions in some species (i.e., rabbits), the same relationship
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
436 voelter-ratson
ET AL.
is not documented in dogs.1 Intranasal teeth are considered a rare finding in human medicine.3–5 There are several theories for the cause of intranasal teeth including trauma, genetic factors, and crowding of dentition, but the etiology remains unclear in the majority of cases.6,7 Depending on the location of the tooth, the NLD may be constricted leading to a cystic dilation of the NLD over time. Several case reports exist in human literature describing NLD blockage by unerupted teeth.4,8 In veterinary medicine, horses are a species known for ectopic teeth. One case report describes a supernumerary intranasal tooth in a horse, which was presented for abnormal upper respiratory noise.9 A complication commonly associated with unerupted teeth is the growth of epitheliumlined dentigerous cysts, which arise from the enamel organ where fluid is produced, accumulating between epithelium and unerupted crown. Expansion of the cyst may cause resorption of surrounding bone and adjacent tooth roots.10 One study showed that in many dogs these cysts were incidental findings, and brachycephalic dogs were the most common breeds affected.11 While in humans dentigerous cysts most commonly appear in the mandibula, reports of dogs show occurrence of cysts of the maxillary canine and first premolar teeth.11,12 Computed tomography scans are a very useful tool in diagnosing dentigerous cysts, because they circumvent superimposition and allow for 3D reconstruction. In this case report, a dentigerous cyst was not associated with the ectopic tooth on CT scan. The unerupted tooth in this case blocked the NLD completely, and there was already a marked cystic dilation of the NLD with contrast medium entering the nasal cavity. Contrast medium most likely entered the nasal cavity via a small preexisting or iatrogenic rupture. Traumatic rupture during dacryocystorhinography could not be ruled out even though contrast medium was injected carefully. Computed tomography was elected in this case to determine the exact position of the tooth and define surgical options and a possible approach.13,14 Similar cases of unerupted teeth have been described in human literature in which the teeth were endoscopically or surgically removed.3,4,8 Surgical removal of the tooth was performed by means of a Caldwell–Luc approach when large dentigerous cysts surrounded the ectopic tooth, or when the tooth could not be approached endoscopically.4,8 Removal of the tooth in this case would require an oral or nasal approach to the nasal cavity due to the size of the tooth and possible complications include chronic nasal discharge and persistent epiphora. Surgical exploration, extraction of the unerupted tooth and cannulation of the NLD at the time of diagnosis were declined by the owner as clinical signs of dacryocystitis resolved with systemic and topical treatment and episodes of conjunctivitis and dacryocystitis in the past were mild and controllable with topical treatment. Other, less invasive surgical options including conjunctival rhinostomy, conjunctival maxillary sinusoto-
my, and conjunctival buccostomy to relieve the signs of epiphora and potentially resolve the risk of recurrent dacryocystitis without removing the tooth, exist.1 Epiphora was the only chronic symptom in the dog for the following 12 months. Recurrences of dacryocystitis are likely due to the cystic dilation of the NLD. Growth of a dentigerous cyst with additional symptoms could make a surgical intervention unavoidable in the future. Because dentigerous cysts can grow over time radiographic monitoring was recommended in this case. To the authors’ knowledge, this is the first case report describing NLD obstruction and dacryocystitis caused by an intranasal ectopic tooth in a dog. Ectopic teeth should be added to the list of differential diagnoses’ for problems of the nasolacrimal system. REFERENCES 1. Gelatt KN. Chapter 15 Diseases and Surgery of the Canine Nasolacrimal System. In: Veterinary Ophthalmology, 5th edn. (eds Gelatt KN, Gilger BC, Kern TJ). Wiley Blackwell, Ames, Iowa, USA, 2013; 894–911. 2. Pope ER, Champagne ES, Fox D. Intraosseous approach to the nasolacrimal duct for removal of a foreign body in a dog. Journal of the American Veterinary Medical Association 2001; 218: 541–542, 526. 3. Kim DH, Kim JM, Chae SW et al. Endoscopic removal of an intranasal ectopic tooth. International Journal of Pediatric Otorhinolaryngology 2003; 67: 79–81. 4. Alexandrakis G, Hubbell RN, Aitken PA. Nasolacrimal duct obstruction secondary to ectopic teeth. Ophthalmology 2000; 107: 189–192. 5. Yeung KH, Lee KH. Intranasal tooth in a patient with a cleft lip and alveolus. Cleft Palate-Craniofacial Journal 1996; 33: 157–159. 6. Murty PS, Hazarika P, Hebbar GK. Supernumerary nasal teeth. Ear, Nose, and Throat Journal 1988; 67: 128–129. 7. Smith RA, Gordon NC, De Luchi SF. Intranasal teeth. Report of two cases and review of the literature. Oral Surgery, Oral Medicine, and Oral Pathology 1979; 47: 120–122. 8. Akyol UK, Salman IA. A case of an extensive dentigerous cyst in the maxillary sinus leading to epiphora and nasal obstruction. Journal of Emergency Medicine 2012; 43: 1004–1007. 9. de Mira MC, Ragle CA, Gablehouse KB et al. Endoscopic removal of a molariform supernumerary intranasal tooth (heterotopic polyodontia) in a horse. Journal of the American Veterinary Medical Association 2007; 231: 1374–1377. 10. Verstraete FJ, Lommer MJ. Oral and Maxillofacial Surgery in Dogs and Cats. Elsevier, Amsterdam, Netherlands, 2012. 11. Kim CG, Lee SY, Kim JW et al. Assessment of dental abnormalities by full-mouth radiography in small breed dogs. Journal of the American Animal Hospital Association 2013; 49: 23–30. 12. Verstraete FJ, Zin BP, Kass PH et al. Clinical signs and histologic findings in dogs with odontogenic cysts: 41 cases (1995?2010). Journal of the American Veterinary Medical Association 2011; 239: 1470–1476. 13. Okita W, Ichimura K, Iinuma T. Dentigerous cyst of the maxilla and its image diagnosis. Rhinology 1991; 29: 307–314. 14. Soukup JW, Lawrence JA, Pinkerton ME et al. Computed tomography-assisted management of a mandibular dentigerous cyst in a dog with a nasal carcinoma. Journal of the American Veterinary Medical Association 2009; 235: 710–714.
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
DOI:10.1111/vop.12225
CASE REPORT
Dacryocystitis following a nasolacrimal duct obstruction caused by an ectopic intranasal tooth in a dog Katrin Voelter-Ratson,* Regine Hagen,† Stefan Grundmann‡ and Bernhard Martin Spiess* *Equine Department, Ophthalmology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; †Section of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; and ‡Clinic of Small Animal Surgery, Section of Dentistry, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
Address communications to: K. Voelter-Ratson Tel.: +41 44 635 82 68 Fax: +41 44 635 89 40 e-mail: kvoelter@vetclinics. uzh.ch
Abstract Purpose To describe a nasolacrimal duct (NLD) obstruction secondary to an ectopic tooth in a 5-year-old male Border collie. The dog was presented with a 1-month history of mucopurulent discharge from the left eye (OS) preceded by a lifelong history of epiphora OS. Treatment with neomycin/polymyxin B/dexamethasone ophthalmic solution had not improved the clinical signs, and the NLD was not patent when irrigated by the referring veterinarian. Methods A complete ophthalmologic examination was performed followed by dacryocystorhinography and computed tomography (CT). Results The ophthalmologic examination revealed marked mucopurulent discharge, mild conjunctivitis, slightly elevated STT measurements, and a negative Jones test OS. Both nasolacrimal puncta OS could be cannulated without resistance for approximately 1.5 cm. Upon irrigation, copious amounts of mucopurulent discharge were exited through the corresponding punctum, while no fluid could be detected at the nares. Dacryocystorhinography was performed. Radiographs revealed an ectopic left canine tooth within the left nasal cavity. A cystic dilation of the NLD was observed proximal to the ectopic tooth. Computed tomography was performed to determine the exact position of the tooth and possible involvement of adjacent structures; CT confirmed the previous imaging findings. Treatment with systemic antibiotics, NSAIDs, and ofloxacin ophthalmic solution led to resolution of the clinical signs within several days. Surgery was declined by the owner. Conclusion This is the first case report describing a blocked NLD due to an ectopic tooth in a dog. Ectopic teeth should be included as a differential diagnosis in cases of dacryocystitis and chronic epiphora in dogs. Key Words: canine, nasolacrimal duct, tooth retention
CASE REPORT
A 5-year-old castrated male Border collie was presented to a veterinarian on multiple occasions for chronic unilateral epiphora, recurrent ocular discharge, and mild conjunctivitis OS. The veterinarian prescribed neomycin/polymyxin/ dexamethasone eye drops three times daily (TID) and attempted unsuccessfully to irrigate the nasolacrimal duct on multiple occasions. Clinical signs usually resolved after 1–2 weeks of topical medication, but recurrence and even© 2014 American College of Veterinary Ophthalmologists
tual loss of response to therapy, prompted referral to the ophthalmology department for further diagnostic evaluation. A complete ophthalmological examination was performed with a slit-lamp biomicroscope (Kowa SL-15; Kowa Company Ltd, Tokyo, Japan) and indirect ophthalmoscope (Omega 500; Heine, Ettenheim, Germany). Examination of the left eye (OS) showed marked mucopurulent discharge, the conjunctiva was markedly hyperemic, the Schirmer Tear Test (STT) reading was 27 mm/min, and the Jones Test was negative OS. The nasolacrimal
434 voelter-ratson
ET AL.
puncta were open and appeared normal in location, size, and shape. Anterograde cannulation and flushing of the NLD were possible from the lower to the corresponding upper punctum but not through the nares. Copious amounts of mucopurulent material exited the corresponding ipsilateral punctum. The remainder of the examination was unremarkable. Examination of the right eye showed no abnormalities with a STT reading of 20 mm/min and a patent NLD. Treatment with topical 0.3% ofloxacin ophthalmic solution three times daily, oral amoxicillin/clavulanic acid (20 mg/kg) twice daily, and carprofen (4 mg/kg) once daily was initiated. Bacterial culture of a conjunctival swab was positive for Corynebacterium. Bacterial sensitivity testing for Corynebacterium was not performed by the laboratory as no standardized MICs are published for the Kirby–Bauer agar diffusion test method. Recommendations for treatment with b-Lactam-antibiotics or cephalosporine antibiotics were given based on the spectrum of activity for these antibiotics. Marked improvement of the clinical signs was noted within 6 days. The owner agreed to perform dacryocystorhinography. Six days following initial presentation, the dog was sedated with 30 lg/kg acepromazine and 0.2 mg/kg methadon intramuscularly, and general anesthesia was induced with 3.5 mg/kg propofol intravenously. Anesthesia was maintained with isoflurane. Lateral and ventrodorsal radiographs of the skull were performed (Fig. 1). On both projections, a well-developed tooth was visible located in the left rostral nasal cavity and the left maxillary canine tooth was missing. The abnormally located tooth was significantly smaller than the right maxillary canine tooth. Bulbous swelling was observed at the level of the root, which was of opacity similar to the remainder of the tooth. Otherwise, the skull was radiographically unremarkable. The upper and lower puncta were cannulated with an intravenous catheter (Terumo Surflo i.v. catheter 20G 9 1 ¼ “) without the guide wire and approximately 1 ml of iodinated contrast medium (Visipaque, 270 mg I/mL; GE Healthcare, Opfikon, Switzerland) was slowly injected. A lateral radiograph showed contrast filling of the proximal nasolacrimal duct and bifocal dilation of the NLD caudal to the abnormally located tooth with traces of contrast medium surrounding the apparent dilated segments (Fig. 2). A CT scan (Brilliance CT 16-slice (Philips AG, Zurich, Switzerland)) of the skull was performed immediately after the dacryocystorhinography, to accurately localize the position of the tooth and the nasolacrimal blockage. The dog was positioned in sternal recumbency, the skull scanned and the images reconstructed in both bone and soft tissue windows. The left nasolacrimal duct showed good filling in its proximal part to the rostral contour of the second premolar (PM2). Caudal to PM2 contrast medium was seen in two small, well-defined areas in the left nasal cavity. (Fig. 3) Contrast medium was also seen outlining the nasal and rostral ethmoid turbinates. (Fig. 4,5) The left maxillary canine tooth was malpositioned and misshapen; the
Figures 1. In the lateral and ventrodorsal radiographs, a welldeveloped tooth was visible, located in the left rostral nasal cavity and the left maxillary canine tooth was missing. The abnormally located tooth was significantly smaller than the right maxillary canine tooth and showed bulbous swelling of dental opacity at the level of the root.
root was approximately in the correct location; however, it was directly abutting the maxillary bone, which appeared thin and mildly irregular at this level compared to the contralateral (right) side. The neck and crown of the tooth were located caudal and axial to its root. (Fig. 4,5) The small size and abnormal shape of the tooth compared to the right maxillary canine tooth was confirmed with CT. Deformation of the nasal passages, mainly left sided with mild right-sided displacement of the nasal septum and an abrupt termination of the contrast filled NLD at the level of the caudal root of PM2 were noted. (Fig. 6) An ectopic left maxillary canine tooth causing deformation of the left nasal cavity and complete occlusion of the left nasolacrimal duct was diagnosed. Leakage of contrast medium into the left nasal cavity was noted. The owner declined surgical intervention in the form of an oral or nasal approach to remove the tooth due to the invasiveness of the surgery, potential morbidity, and
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
ectopic tooth blocking nasolacrimal duct 435
Figure 2. A lateral radiograph showing contrast filling of the proximal NLD and bifocal dilation of the NLD caudal to the abnormally located tooth.
Figure 3. Transverse reconstruction in a bone window of the nasal chamber shows well circumscribed moderate distension of the left nasolacrimal duct which is filled with homogeneously hyperattenuating iodinated contrast medium. Lateral to the NLD dilation, there is contrast medium visible in the bony nasolacrimal canal and also outlining the nasal turbinates
Figure 5. Dorsal reconstruction in a bone window of the nasal chambers. The ectopic left maxillary canine tooth is in an abnormally caudal and dorsal position and the crown points caudally too. The hyperattenuating foci are contrast medium outlining the nasal turbinates. There is marked axial deviation of the left sided intranasal structures (nasal turbinates, nasal septum).
Figure 6. Sagittal reconstruction in a bone window showing a crosssection of the ectopic tooth (arrow) rostral to the distended nasolacrimal duct.
possible complications of persistent epiphora and chronic nasal discharge. Systemic and topical treatment were continued for another week. Clinical signs of dacryocystitis completely resolved 2 weeks after initiation of the systemic treatment, and the dog had no recurrences for the following 12 months. Mild epiphora remained. DISCUSSION
Figure 4. Transverse reconstruction in a bone window of the ectopic tooth demonstrating its intranasal location at this level and the deviation of the nasal septum and turbinates. Multiple small foci of hyperattenuating contrast medium outline the nasal turbinates dorsal to the abnormal tooth.
Nasolacrimal duct obstruction and dacryocystitis are well known, although rather rare diseases in the dog.1 Dacryocystitis is defined as inflammation of the lacrimal sac most commonly secondary to a NLD blockage. The most common cause for acquired nasolacrimal duct obstructions and dacryocystitis is a foreign body within the nasolacrimal sac.2 Other causes of NLD obstruction include congenital malformation, fractures to the maxillary and lacrimal bones, and neoplasia.1 While dental abnormalities have been reported to cause nasolacrimal duct obstructions in some species (i.e., rabbits), the same relationship
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
436 voelter-ratson
ET AL.
is not documented in dogs.1 Intranasal teeth are considered a rare finding in human medicine.3–5 There are several theories for the cause of intranasal teeth including trauma, genetic factors, and crowding of dentition, but the etiology remains unclear in the majority of cases.6,7 Depending on the location of the tooth, the NLD may be constricted leading to a cystic dilation of the NLD over time. Several case reports exist in human literature describing NLD blockage by unerupted teeth.4,8 In veterinary medicine, horses are a species known for ectopic teeth. One case report describes a supernumerary intranasal tooth in a horse, which was presented for abnormal upper respiratory noise.9 A complication commonly associated with unerupted teeth is the growth of epitheliumlined dentigerous cysts, which arise from the enamel organ where fluid is produced, accumulating between epithelium and unerupted crown. Expansion of the cyst may cause resorption of surrounding bone and adjacent tooth roots.10 One study showed that in many dogs these cysts were incidental findings, and brachycephalic dogs were the most common breeds affected.11 While in humans dentigerous cysts most commonly appear in the mandibula, reports of dogs show occurrence of cysts of the maxillary canine and first premolar teeth.11,12 Computed tomography scans are a very useful tool in diagnosing dentigerous cysts, because they circumvent superimposition and allow for 3D reconstruction. In this case report, a dentigerous cyst was not associated with the ectopic tooth on CT scan. The unerupted tooth in this case blocked the NLD completely, and there was already a marked cystic dilation of the NLD with contrast medium entering the nasal cavity. Contrast medium most likely entered the nasal cavity via a small preexisting or iatrogenic rupture. Traumatic rupture during dacryocystorhinography could not be ruled out even though contrast medium was injected carefully. Computed tomography was elected in this case to determine the exact position of the tooth and define surgical options and a possible approach.13,14 Similar cases of unerupted teeth have been described in human literature in which the teeth were endoscopically or surgically removed.3,4,8 Surgical removal of the tooth was performed by means of a Caldwell–Luc approach when large dentigerous cysts surrounded the ectopic tooth, or when the tooth could not be approached endoscopically.4,8 Removal of the tooth in this case would require an oral or nasal approach to the nasal cavity due to the size of the tooth and possible complications include chronic nasal discharge and persistent epiphora. Surgical exploration, extraction of the unerupted tooth and cannulation of the NLD at the time of diagnosis were declined by the owner as clinical signs of dacryocystitis resolved with systemic and topical treatment and episodes of conjunctivitis and dacryocystitis in the past were mild and controllable with topical treatment. Other, less invasive surgical options including conjunctival rhinostomy, conjunctival maxillary sinusoto-
my, and conjunctival buccostomy to relieve the signs of epiphora and potentially resolve the risk of recurrent dacryocystitis without removing the tooth, exist.1 Epiphora was the only chronic symptom in the dog for the following 12 months. Recurrences of dacryocystitis are likely due to the cystic dilation of the NLD. Growth of a dentigerous cyst with additional symptoms could make a surgical intervention unavoidable in the future. Because dentigerous cysts can grow over time radiographic monitoring was recommended in this case. To the authors’ knowledge, this is the first case report describing NLD obstruction and dacryocystitis caused by an intranasal ectopic tooth in a dog. Ectopic teeth should be added to the list of differential diagnoses’ for problems of the nasolacrimal system. REFERENCES 1. Gelatt KN. Chapter 15 Diseases and Surgery of the Canine Nasolacrimal System. In: Veterinary Ophthalmology, 5th edn. (eds Gelatt KN, Gilger BC, Kern TJ). Wiley Blackwell, Ames, Iowa, USA, 2013; 894–911. 2. Pope ER, Champagne ES, Fox D. Intraosseous approach to the nasolacrimal duct for removal of a foreign body in a dog. Journal of the American Veterinary Medical Association 2001; 218: 541–542, 526. 3. Kim DH, Kim JM, Chae SW et al. Endoscopic removal of an intranasal ectopic tooth. International Journal of Pediatric Otorhinolaryngology 2003; 67: 79–81. 4. Alexandrakis G, Hubbell RN, Aitken PA. Nasolacrimal duct obstruction secondary to ectopic teeth. Ophthalmology 2000; 107: 189–192. 5. Yeung KH, Lee KH. Intranasal tooth in a patient with a cleft lip and alveolus. Cleft Palate-Craniofacial Journal 1996; 33: 157–159. 6. Murty PS, Hazarika P, Hebbar GK. Supernumerary nasal teeth. Ear, Nose, and Throat Journal 1988; 67: 128–129. 7. Smith RA, Gordon NC, De Luchi SF. Intranasal teeth. Report of two cases and review of the literature. Oral Surgery, Oral Medicine, and Oral Pathology 1979; 47: 120–122. 8. Akyol UK, Salman IA. A case of an extensive dentigerous cyst in the maxillary sinus leading to epiphora and nasal obstruction. Journal of Emergency Medicine 2012; 43: 1004–1007. 9. de Mira MC, Ragle CA, Gablehouse KB et al. Endoscopic removal of a molariform supernumerary intranasal tooth (heterotopic polyodontia) in a horse. Journal of the American Veterinary Medical Association 2007; 231: 1374–1377. 10. Verstraete FJ, Lommer MJ. Oral and Maxillofacial Surgery in Dogs and Cats. Elsevier, Amsterdam, Netherlands, 2012. 11. Kim CG, Lee SY, Kim JW et al. Assessment of dental abnormalities by full-mouth radiography in small breed dogs. Journal of the American Animal Hospital Association 2013; 49: 23–30. 12. Verstraete FJ, Zin BP, Kass PH et al. Clinical signs and histologic findings in dogs with odontogenic cysts: 41 cases (1995?2010). Journal of the American Veterinary Medical Association 2011; 239: 1470–1476. 13. Okita W, Ichimura K, Iinuma T. Dentigerous cyst of the maxilla and its image diagnosis. Rhinology 1991; 29: 307–314. 14. Soukup JW, Lawrence JA, Pinkerton ME et al. Computed tomography-assisted management of a mandibular dentigerous cyst in a dog with a nasal carcinoma. Journal of the American Veterinary Medical Association 2009; 235: 710–714.
© 2014 American College of Veterinary Ophthalmologists, Veterinary Ophthalmology, 18, 433–436
