猫の顎関節脱臼疑いで紹介された症例の後ろ向き分析

This study aimed to determine the proportion of cats referred for suspected temporomandibular joint (TMJ) luxation that were confirmed as true cases and to identify their final diagnoses. The objective was to highlight potential differential diagnoses to improve diagnostic accuracy and case management.

A total of 42 cats that were referred to our hospital for suspected TMJ luxation as a chief complaint from April 2020 to February 2025 were included in the study. According to owner reports, these patients commonly exhibited an inability to close the mouth, apparent mandibular deviation, and, in most cases, signs suggestive of oral pain.

Of the 42 cats studied, only 6 had isolated TMJ luxation. The rest had other diagnoses: 19 with end-stage periodontal disease, 5 with malocclusion, 4 with symphyseal separation, and 3 with open-mouth jaw locking resulting from other causes. Two had mandibular fractures, 2 had no significant findings, and 1 had TMJ ankylosis.

End-stage periodontal disease was the most common diagnosis among cats referred for suspected TMJ luxation. Other final diagnoses included TMJ luxation, malocclusion, fractures, mandibular symphyseal instability, open-mouth jaw locking resulting from other causes, and TMJ ankylosis. Diagnosis is challenging due to nonspecific signs that mimic other oral diseases and are often linked to complex maxillofacial injuries, requiring thorough exams and advanced imaging.

This study emphasizes the importance of considering differential diagnoses in cats presenting with signs resembling TMJ luxation and provides references to guide future clinical evaluation and decision-making.