Open Mouth Jaw Locking in a Cat and a Literature Review

Open mouth jaw locking in dogs and cats is characterized by an inability to close the mouth that usually results from fixed mandibular coronoid process displacement lateral to the ipsilateral zygomatic arch and abnormal contact pressure between these two structures. Other causes of an open mouth persentation include temporomandibular luxation or dysplasia and trigeminal neuropathy. While historic and physical findings can be suggestive of likely causes, imaging, most commonly radiography, is often required to confirm the diagnosis, and computed tomography may be used as an adjunctive or the sole imaging modality. Manual reduction is the first-line treatment method in open mouth jaw locking secondary to coronoid processzygomatic arch interlocking and temporomandibular dislocation. An understanding of the anatomy and function of the temporomandibular joint is essential in making a diagnosis and in the management of the different conditions. This report describes the clinical presentation, imaging diagnosis and management of a case of feline open mouth jaw locking and temporomandibular joint luxation and subluxation. An intra-oral approach to manual reduction is described in the report.