29 Extraction of permanent teeth
The owner was concerned about the ‘long curved nose’ and the obsessive chewing on toys, furniture, etc. Their own veterinarian noted that the lower jaw was too short with respect to the upper jaw, and the dog was referred to us for evaluation and treatment of the malocclusion.
The pulp did not seem exposed to the environment on visual examination. Exploration was not attempted, since touching an exposed pulp would have caused extreme pain and potentially aggressive behaviour.
Figure 29.1 Traumatic lesions in the palatal mucosa. The upper jaw is long and narrow, while the lower jaw is of normal length and width for the breed. Consequently, the teeth are not occluding normally. Note the ulcerated indentations created by the maloccluding lower canines (they occlude with the palatal mucosa medial to the upper canines). Note also the indentations in the palatal mucosa where the lower incisors occlude. There is a generalized gingivitis as evidenced by the red and swollen gingival margins around the circumference of all teeth.
Malocclusion can result from jaw length and/or width discrepancy (skeletal malocclusion), from tooth malpositioning (dental malocclusion), or a combination of both. This case is a skeletal malocclusion and should therefore be considered as inheritable. Malocclusion causing discomfort and pathology always needs treating.
In human orthodontics, whether malocclusion is hereditary or acquired is not a consideration when planning treatment. This is in contrast to veterinary orthodontics, where aesthetics and ethical concerns are linked, and treatment for the sole purpose of showing dogs or cats cannot be encouraged. The aim of any treatment is primarily to make the animal comfortable; aesthetics are a secondary consideration.
It is essential to determine if the presenting malocclusion is hereditary or not. Orthodontic correction of a malocclusion is contraindicated where the malocclusion is hereditary, unless the animal is also neutered. The rationale for this is to avoid spread of inherited malocclusion within a breed.
Crown fractures are classified as complicated if the fracture line exposes the pulp to the oral environment and as uncomplicated if they do not involve pulpal exposure. Crown fractures are obvious visually. However, at times it can be difficult to determine if the pulp is exposed by the fracture line, and general anaesthesia for examination with a dental explorer and radiography are necessary.
An uncomplicated crown fracture usually requires minimal treatment, e.g. removal of sharp edges with a bur and sealing of the exposed dentine with a suitable liner or restorative material. However, such fractures do require monitoring (clinical examination and radiography) at regular intervals to ensure that the pulp remains vital. If pulp and periapical diseases develop, the tooth requires either extraction or endodontic therapy.