Orthodontic Treatment

Introduction

Mandibular canine tooth causing damage to the palatal mucosa (lance canines).

Orthodontics - inclined plane 1

Orthodontics - inclined plane 2

Orthodontics - lance canines

Orthodontic treatment is indicated in cases of dental malocclusion.

Orthodontic movement of teeth can be described as prolonged application of pressure to the tooth, resulting in movement of the tooth as the bone around it remodels. Bone on the compression side undergoes lysis allowing the tooth to move and bone formation on the tension side ensures that the tooth stays in the new position. In the ideal situation bone lysis and bone formation should be in equilibrium. In most practical situations, there is an imbalance and lysis occurs more rapidly. A retention phase maintaining the tooth in the new position while allowing time for bone formation is, therefore, necessary in many cases.

The optimal orthodontic force is one that moves teeth rapidly without resulting in structural damage, while causing the least amount of discomfort or pain. Factors that need to be considered for any orthodontic appliance are the magnitude of the force, the distribution of the force and the duration of the force. The ideal force is a light continuous force. Heavy continuous forces are damaging and should be avoided. Apart from the orthodontic forces applied, normal growth processes and forces from the lips, cheeks and tongue resting on the teeth will determine the outcome of the treatment.

The most common orthodontic procedures in veterinary medicine include moving the mandibular canines when they are causing trauma to the palatal mucosa using an inclined plane, or in the case of lance canines.

Indications

In humans, medical (predisposition to periodontal diseases), functional (alteration of mastication or speech) and psychological (alteration of aesthetics) problems relating to malocclusion are the primary reason for orthodontic treatment. 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.

Contraindications

• Ethical considerations
• Show animals
• Lack of owner compliance
• Lack of patient tolerance and compliance

Complications

Possible complications of orthodontic movement of teeth include pulpal disease, external root resorption, tooth mobility and pain. In short, the outcome of an orthodontic procedure is rarely predictable and needs frequent monitoring based on clinical signs and radiography.