Diagnosis and management of Class II malocclusion.

To diagnose malocclusions in our patients, we must first understand what is a normal occlusion. Evaluation of a patient’s dental occlusion should be performed at the first puppy or kitten visit and documented in the medical record. This should start with identification of the skull type (brachycephalic, mesocephalic, dolichocephalic), as this will give indications of common abnormalities seen with various skull types (1). Next, the veterinarian should evaluate facial symmetry and the maxillomandibular relationship. Cats and dogs have anisognathic jaws, which means that the maxillae are wider and longer in relation to the mandibles. Dental interlock is assessed and normal occlusion includes the mandibular incisors occluding upon the cingulum of the maxillary incisors. Additionally, there should be a triad interlock involving the maxillary 3rd incisors, the mandibular canines, and the maxillary canines. The mandibular canine teeth should rest in the diastema between the maxillary 3rd incisors and the maxillary canine teeth, with the incisive tip of the mandibular canine completely visible when the patient is placed in a closed bite (1) (Figure 1). A normal relationship between the maxillary and mandibular premolars should appear as interdigitation with the maxillary premolars occluding distal to the mandibular counterpart and without contact, as the maxillary premolars should be buccal to the mandibular teeth due to the anisognathic nature of the jaw relationship. Finally, the molars form a contact of occlusal tables for crushing of food. The mesial and main cusp of the mandibular 1st molar is the exception, which occludes on the palatal aspect of the maxillary 4th premolar to form a shear for cutting of food (Figure 2). Open in a separate window Figure 1 Normal occlusion in a dog — Rostral view. Copyright AVDC used with permission.