Dental and temporomandibular joint pathology of the island fox (Urocyon littoralis)

Museum skull specimens from 318 island foxes (Urocyon littoralis) were examined macroscopically according to predefined criteria. The study population included males (n = 129, 40.6%), females (n = 93, 29.3%) and animals of unknown sex (n = 96, 30.2%), and comprised 182 (57.2%) adults, 118 (37.1%) young adults and 18 (5.7%) individuals of unknown age, with juveniles and neonates excluded. The number of teeth present for examination was 11,438 (85.6%) with 1918 (14.4%) absent artefactually, 4 (0.03%) absent congenitally and 243 (1.82%) lost ante mortem through acquired tooth loss. There were seven persistent deciduous teeth (0.05%) in three specimens and 11 supernumerary teeth (0.08%) in 10 specimens. Teeth with extra roots were found in 38 skulls (11.9%) with 0.48% of all teeth affected. Two (0.63%) specimens had one tooth with an abnormal form. Fifty-eight (18.2%) specimens had bone fenestrations. Of the alveoli examined, 5361 (46.9%) displayed bony changes suggestive of periodontitis, with 315 (99.1%) of skulls affected. Of the teeth available for examination in 310 specimens (97.5%), most (n = 6,040, 52.8%) had some degree of attrition or abrasion. Fractures affected 1217 (11.0%) of the teeth present in 266 specimens (83.6%). Twenty-three periapical lesions (0.20%) were present in 16 skulls (5.03%). Evidence of temporomandibular joint osteoarthritis was found in seven specimens (0.02%) on either the mandibular head of the condylar process or on the mandibular fossa of the temporal bone.