• (For more information or questions, contact Dr. Hewitt at 702.395.1800, or by e-mail at: dr.hewitt@cheyennewest.com)

    malocclusion

    A malocclusion is the condition in which the positioning of the teeth is abnormal, causing them to occlude, or come in contact with each other, in an abnormal fashion. Some malocclusions are such that they result in damage being caused to either the soft tissues of the mouth, or to certain teeth in the mouth.

    One common malocclusion is one in which the lower jaw is slightly too long (prognathism), resulting in the mandibular canine teeth (lower jaw fangs) impacting on the maxillary lateral incisors, which are the small teeth just inside of the maxillary canine teeth (upper jaw fangs). When this occurs, it causes several problems. It can result in movement of the upper teeth forward, cause the lower canine teeth to not fully erupt from the gums, and predisposes the affected teeth to periodontal disease. More importantly, it tends to cause long term damage, pain, and abnormal wear of both the mandibular canine teeth and the maxillary incisors. This can result in pulpitis, or in enamel defects.

    Pulpitis occurs when a tooth has an impact, thermal (heat) damage, or long-term improper pressure (usually from a malocclusion). The improper pressure can cause direct inflammation of the pulp (pulpitis) or disruption of the blood supply to the tooth. Either of these will result in blood leakage into the dentinal tubules, which causes discoloration of a tooth from pink to purple (sometimes gray), or even just an ivory color.

    malocclusion2

    The affected tooth or teeth are, in almost all cases, no longer living teeth. When a tooth is no longer living, the pulp of the tooth becomes necrotic (a term used to described dead tissue that is starting to decay), and becomes a place to harbor bacteria from the bloodstream, which can result in abscessation. In addition, it becomes a source of chronic pain, as well as allowing leakage of the necrotic contents of the pulp chamber into the blood stream. The only way to determine if this has happened is by taking dental x-rays to evaluate the affected tooth. Dental x-rays are taken under anesthesia in animals. Therefore, we will not know for certain if the affected tooth is living or not, until we are actually performing the treatment procedure.
    When a tooth has become devitalized, there are only 2 options. We must either do root canal therapy or extract the tooth. These topics are covered in much more detail in other handouts available from us.

    If the mandibular canines are impacting the incisors in an inappropriate way, and there is no evidence that the affected teeth are non-vital, there are 2 options:
    1) True orthodontics. This is a process where we use a device (called an appliance), such as an artificial ramp or buttons and elastic bands, to guide the teeth into a position where they are no longer causing pain or damage. The advantage of doing true orthodontics is that it preserves all of the natural teeth in the mouth. The disadvantages are several. It requires at least 2 anesthetic procedures (one to place the appliance or buttons, and one to remove it). If, during the course of treatment, the pet damages the appliance or buttons (usually by inappropriate chewing behavior), then an additional procedure will be required to replace the damaged item, at additional cost. The length of time the appliance or buttons is left in place is determined by several factors, but is usually anywhere from 3-8 months. In addition, this approach is more expensive than the alternative. In some cases, due to the position of the adjoining teeth and based on how severe the lengthening of the jaw is, orthodontics may not be an option.
    2) Since the mandibular canines are the far more important of the affected teeth in this situation, it is also reasonable to just extract the maxillary (upper) incisors that are being impacted. This requires extracting one or two of the upper incisors on each side. The goal is to make a natural space for the mandibular incisors to fit into, thus eliminating the abnormal tooth to tooth contact, and stopping the resulting pain and damage. This is done in a single procedure, with minimal follow-up. In addition, it is significantly less expensive.

    Additional information and handouts can be found online at the web sites of:
    The American Veterinary Dental Society – http://www.avds-online.org/resources.htm
    The American Veterinary Dental College – http://www.avdc.org/?q=node/2
    Veterinary Partner web site – http://www.veterinarypartner.com
    Veterinary Oral Health Council – http://www.vohc.org

    Updated July 2011

    CHEYENNE WEST ANIMAL HOSPITAL
    3650 N. Buffalo Dr.
    Las Vegas, NV 89129
    702-395-1800
    Brian Hewitt, DVM