Dental and Temporomandibular Joint Pathology of the Grey Wolf ( Canis lupus )

Abstract

Skulls from 392 grey wolves (Canis lupus) were examined macroscopically according to predefined criteria. Two hundred and seven skulls were included in this study, comprised of 124 young adults (59.9%) and 83 adults (40.1%); of these, 65 (31.4%) specimens were from male wolves and 104 (50.3%) were from females, with 38 (18.4%) of unknown sex. Out of 8,694 possible teeth, 8,339 (95.9%) were present for evaluation. Fifty-five teeth (15.5%) were absent congenitally, 30 (8.5%) were lost during life and 270 (76.1%) were lost artefactually post mortem. Skeletal or dental malocclusion was present in 37 specimens (17.9%), with level bite being the most commonly encountered malocclusion. Enamel hypoplasia was present in five skulls (2.4%), affecting eight teeth (0.1%) in total. An abnormal number of roots was found on 23 teeth (0.3%) on 13 skulls (6.3%). Persistent deciduous teeth occurred in two (1.0%) specimens, affecting one (0.01%) tooth each. Fenestration or dehiscence was found associated with 203 teeth (2.4%) in 72 skulls (34.8%). Periodontitis was noted on 115 skulls (55.6%) and 1,000 teeth (11.5%), affecting significantly more adults (n = 63, 75.0%) than young adults (n = 52, 41.9%; P <0.0001). One hundred and sixty-one skulls (77.8%) showed signs of endodontal disease, including attrition or abrasion on 144 skulls (69.6%) and 2,522 teeth (30.2%) and 424 fractured teeth (5.1%) on 103 skulls (49.8%). Both lesions affected significantly more adults than young adults. Overt periapical disease was associated with six teeth (0.1%) distributed across five skulls (2.4%). A carious lesion was present on one tooth (0.01%) of one specimen (0.5%). Lesions consistent with temporomandibular joint (TMJ) osteoarthritis were found in 24 specimens (11.6%), affecting 38 joints (9.2%). Trauma to the skull, such as bite marks, bullet holes or blunt trauma, was noted in 44 skulls (21.2%). The grey wolf and the domestic dog (Canis lupus familiaris) share common dental diseases; however, the proportion and severity may vary. Although the clinical significance of dental and TMJ pathology in the grey wolf remains unknown, based on the impact of these disorders on the domestic dog, the occurrence and severity of these lesions are likely to play an important role in the morbidity and mortality of this wild canid species.

Dental and skull bone pathologies of the red fox (Vulpes vulpes) in Lithuania

“…Szuma (1999) similarly found that just 2.5% of 1453 red fox skulls had enamel hypoplasia, while Evenhuis et al (2018) identified only a single case among 637 grey fox skulls. Results were similar in a study of wolves, with 2.4% of skulls showing signs of enamel hypoplasia (Döring et al 2018). In a separate study, only 17 dogs and wolves were affected out of 544 individuals examined by Losey et al (2014).…”

“…Second stage periodontal disease is typically reported in previous research and, therefore, shows higher prevalence than in the current study. Döring et al (2018) An additional goal of the current research was to evaluate skull and mandible pathologies. Temporomandibular joint changes and osteoarthritis were excluded from the study, though a fuller analysis of these issues is warranted.…”

Dental pathology of the wild Iberian wolf (Canis lupus signatus): The study of a 20th century Portuguese museum collection

“… Valkenburgh (1988) refers that the most fractured teeth in African carnivores that consume bones, such as hyenas, are the canine teeth, followed by the premolars, first molars and incisive teeth. In Alaskan wolves, canines and premolars were found with fractures teeth in around half of the collection ( Döring et al., 2018 ), in opposition to the data published by Losey, Jessup, Nomokonova, and Sablin (2014) who noted fractures in 27.8% of wolves teeth, mainly in maxillary incisors and canines. The same team refer that male wolves suffered more tooth fracture than females, being the Subarctic Russian wolves those having more females than males affected.…”

“…However, natural history collections through their specimens and associated documentation, are important source of information allowing, for example, for collecting medical data from both domestic and wild animals. In fact, several species were already assessed for dental abnormalities using museum collection, as the case of gray wolf ( Canis lupus ) ( Barber-Meyer, 2012 ; Döring, Arzi, Winer, Kass, and Verstraete, 2018 ; Janssens, Verhaert, Berkowic, and Adriaens, 2016 ; Pavlović, Gomerčić, Gužvica, Kusak, and Huber, 2007 ; Valkenburgh, 1988 ; Vilà, Urios, and Castroviejo, 2008 ), red fox ( Vulpes vulpes ) ( Szuma, 2014 ), African lion ( Panthera leo ), leopard ( P. pardus ), jaguar ( P. onca ), cheetah ( Acinonyx jubatus ), puma ( Puma concolor ), spotted hyena ( Crocuta crocuta ), striped hyena ( Hyaena hyaena ), and the African wild dog ( Lycaon pictus ) ( Valkenburgh, 1988 ), Southern sea otter ( Enhydra lutris nereis ) ( Winer, Liong, and Verstraete, 2013 ), Iberian lynx ( Lynx pardinus ) ( Collados, Garcia, and Rice, 2018 ), domestic dog ( Canis lupus familiaris ) ( MacKinnon, 2010 ), domestic cat ( Felis silvestris catus ) and free-living Soay sheep ( Ovis aries ) ( Arthur et al., 2015 ).…”

Dental and Temporomandibular Joint Pathology of the Kit Fox (Vulpes macrotis)

“…Specimens were evaluated systematically for abnormalities using previously determined criteria (Table 1). This method has proven to be efficient and effective at consistently detecting signs of dental pathology and other osteological abnormalities such as temporomandibular osteoarthritis in other mammalian carnivores (Aalderink et al, 2015;Aghashani et al, 2016;Clark et al, 2017;Doring et al, 2018;Evenhuis et al, 2018). Presence of teeth was recorded and any missing teeth were categorized as artefactual loss, congenital absence or acquired loss.…”