Dental and temporomandibular joint pathology of the North American wolverine (Gulo gulo luscus)

Abstract

This study evaluated dental and temporomandibular joint (TMJ) pathology in North American wolverines (Gulo gulo luscus) from coastal southern Alaska, using 182 specimens (43.4 % females, 54.4 % male, 2.2 % unknown) collected across the 20th century. Among the individuals, 2.2 % were classified as young adults, 83.0 % as adults and 14.8 % had an undetermined age. High rates of dental diseases were identified, reflecting patterns seen in other wild carnivores, with acquired conditions occurring more frequently than congenital ones. Periodontitis was the most common pathology (98.9 %), with most cases showing mild severity (stage 2 = 98.9 %). Tooth fractures were identified in over two-thirds of the specimens, with deeper structural damage (complicated crown fractures = 26.2 %, complicated crown-root fractures = 23.1 %, root fractures = 31.3 %) observed more often than enamel fractures, likely due to typical biting behaviour. No significant differences in fracture prevalence were found between sexes (P = 0.3741). Enamel hypoplasia was rare (5.5 %), suggesting minimal systemic stress during dental development. Variations in root numbers were frequently noted (27.5 %), potentially reflecting an adaptive trait for dietary handling. Periapical lesions (9.9 %) were linked to pulp exposure (17.6 %, OR = 49.09, 95 % CI = 28.01–85.22, P <-0.0001), especially in the canine teeth, but were also seen in association with moderate to severe bone loss due to periodontitis (stages 3 and 4 = 65.9 %, OR = 7.75, 95 % CI = 2.20–24.80, P <0.0001). Attrition and abrasion were common (96.1 %), particularly affecting incisor and canine teeth, with a slightly higher incidence in females (U = 2,922, n = 79, n = 99, P = 0.0036), hinting at potential behavioural or dietary differences. TMJ pathology was uncommon (1.6 %) and mild, potentially suggesting that wolverine feeding habits may exert less stress on the joint compared to species with high bite-force diets. Overall, the observed dental and TMJ lesions align with patterns in other wild carnivores, suggesting similar environmental and behavioural influences. Future studies on dietary, genetic and longitudinal health factors could provide deeper insight into the dental adaptations and resilience of North American wolverines in their natural habitats.