The Prevalence of Concurrent Congenital and Developmental Dental Anomalies in Dogs with Class II Malocclusions Compared to Dogs with Normal Occlusion

Class II malocclusion in dogs is a skeletal abnormality characterized by mandibular distoclusion that can result in traumatic occlusion and compromised oral health. While associated soft tissue trauma is well recognized, the prevalence of concurrent congenital and developmental dental anomalies in affected dogs has not been systematically evaluated. The aim of this study was to determine the prevalence of dental anomalies in dogs with class II malocclusion and compare findings to dogs with normal occlusion. Medical records from three veterinary dentistry referral centers were retrospectively reviewed. Dogs with class II malocclusion were included if they had complete oral examinations, dental charting, and full-mouth diagnostic imaging. Control dogs met the same criteria. Dental anomalies were recorded, and multivariable generalized linear models were used to compare prevalence between groups while adjusting for age, sex, and body weight ( p  < .05). Eighty-seven dogs with class II malocclusion and 98 controls were included. Affected dogs had a significantly higher prevalence of dental crowding, persistent deciduous teeth, and rotated teeth. Other anomalies—including supernumerary teeth, hypodontia, infraeruption, enamel defects, dilaceration, fused roots, gemination, and impacted teeth—were observed but did not differ significantly between groups. Dogs with class II malocclusion are more likely to exhibit multiple dental anomalies compared to dogs with normal occlusion. These findings suggest overlapping developmental mechanisms affecting craniofacial growth and odontogenesis. Early recognition is important for timely intervention and improved patient welfare.