Bilateral dentigerous cysts in a dog

Correlation Between Radiographic and Histopathologic Findings Associated with Unerupted Teeth in Dogs

An association between unerupted teeth and dentigerous cysts is well known,^{1- 4} however little is known about the presence of disease and histopathologic changes in unerupted teeth without radiographic evidence of cyst formation. Forty-two dogs representing 25 breeds, ranging in age from 5 months to 12 years were selected based on radiographic evidence of an unerupted tooth or teeth, either as a primary complaint or incidental finding. Dogs meeting the study criteria were presented to a private dental referral practice within a period of eighteen months from December 2016 through May 2018. Patients were treated with conservative en bloc resection of the unerupted tooth and overlying bone as well as debridement of any cystic structure and biopsy of the samples collected. Radiographs were evaluated using criteria previously established to assess for evidence of a cyst.^{1, 5- 7} A total of 68 unerupted teeth were identified; 63 (92.7%) were mandibular first premolar teeth. Of the 63 unerupted mandibular first premolar teeth, 28 (44.4%) had radiographic evidence of a cystic structure. Histopathology revealed that 21 of 28 (75.0%) had evidence of non-keratinizing stratified squamous epithelium consistent with a cyst lining. Of the remaining 35 of 63 (55.6%) mandibular first premolar teeth with no radiographic evidence of a cyst, 27 (77.1%) had no histologic evidence of epithelium associated with the impacted tooth. Notably however, the remaining 8 of 35 (22.9%) unerupted teeth without radiographic evidence of a cyst did have histologic evidence of non-keratinizing stratified squamous epithelium associated with the impacted tooth.

A Clinical, Radiographic and Histological Study of Unerupted Teeth in Dogs and Cats: 73 Cases (2001-2018)

Lack of dental eruption may be accompanied by development of dentigerous cysts and has also been rarely associated with neoplasia. However, little information is available on prevalence of unerupted teeth and associated lesions in dogs and cats. The main objective of this study was to describe the epidemiologic data of canine and feline dental patients with unerupted teeth, and assess the prevalence of associated dentigerous cysts and tumors. Secondary aims included the evaluation of possible factors implicated in cystic development, and description of the histological features of dentigerous cysts. Medical and dental records, intraoral photographs, intraoral radiographs of client-owned dogs and cats with clinically missing teeth examined between 2001 and March 2018 were reviewed. Collected data included signalment, reason for presentation, number, type, depth of inclusion and angulation of unerupted teeth, presence of cystic lesions or tumors, abnormalities affecting involved teeth, histopathological findings, performed treatment and outcome. Seventy-three animals (69 dogs and 4 cats) with 113 unerupted teeth were included. The most frequent unerupted tooth in dogs was the first premolar teeth (78%), followed by the canine and third molar teeth. Dentigerous cysts were diagnosed associated with 48 (44.4%) teeth in dogs and one out of five unerupted teeth in cats. The affected teeth in dogs were predominantly in horizontal inclination (40%) and in soft tissue inclusion (77%). Brachycephalic canine breeds were overrepresented. The only unerupted tooth in boxer dogs was the first premolar tooth (32 teeth). Ninety percentage of boxers with unerupted teeth developed associated lesions (25 dentigerous cysts and one tumor). Two ameloblastomas (one in a dog and one in a cat) and one osteosarcoma (in a dog) were diagnosed in association with three unerupted teeth. Histology was essential in diagnosing two odontogenic cysts not evident on radiographs. In all cases that were followed-up, treatment (i.e., extraction, extraction and surgical curettage, or operculectomy) appeared successful. Untreated dentigerous cysts showed progression at re-examination. None of the unerupted teeth without evidence of cyst at the time of diagnosis showed incipient cystic development. None of the evaluated factors were associated with lack of eruption and/or development of associated lesions.

Repair of Bilateral Comminuted Mandibular Fractures in a 12-Week-Old Puppy Using Locking and Nonlocking Maxillofacial Reconstruction Plates

A 12-week-old male intact French bulldog presented to a university teaching hospital for bilateral comminuted caudal mandibular fractures following an altercation with another dog. The fractures were stabilized using locking and standard maxillofacial miniplates. The 8-week and 14-week postoperative reexaminations and radiographs revealed eventual bony healing and remodeling of both mandibular rami, but multiple complications associated with the miniplates were encountered. These included intraoral wound dehiscence, implant fracture, implant loosening, sequestrum formation, and an impacted right mandibular fourth premolar. Implant failure on the alveolar border in this case report was associated with the resorption and new bone deposition of the rostral/caudal ramus, respectively, associated with mandibular growth. An alternate surgical option would have been use of a longer, larger bridging plate placed on the ventral border without use of a dorsal plate to minimize these complications.

Incidence of Radiographic Cystic Lesions Associated With Unerupted Teeth in Dogs

Medical records and radiographs were retrospectively reviewed over a 3-year period (2012-2015) from dogs presented to a private dental referral practice. Medical records were evaluated for the diagnosis of impacted or embedded teeth. The identified dogs’ radiographs were reviewed for the presence of radiographically significant cystic lesions that were associated with the impacted or embedded teeth. Radiographic criteria were established by the authors for the purposes of identifying cystic lesions in dogs of different breeds and sizes, using established indices from human dental pathology as a basis. When histopathology results were available, they were reviewed and reported. In this study, 136 dogs ranging in age from 3 months to 17 years were diagnosed with 213 unerupted teeth during the study period. There were 62 (29.1%) of the 213 radiographically apparent cystic lesions identified based on the criteria proposed in this study. In this study, 146 (68.5%) of the 213 unerupted teeth were identified as mandibular first premolar teeth. Histopathology was obtained on 28 (45.1%) of the 62 diagnosed cystic lesions. Dentigerous cysts accounted for 20 (71.4%) of the 28 cystic lesions. Brachycephalic breeds were overrepresented in this study. Boxer, pug, Shih Tzu, and Boston terrier dogs were most likely to present with cystic lesions associated with unerupted teeth. Seventeen (85%) of the 20 cases with a histopathologic diagnosis of dentigerous cyst were found within these 4 brachycephalic breeds.