Presentation:
On presentation, "Yellow" was in good body condition and was bright and alert. A mandibular
distoclusion was noted with a 13 mm overjet. The mandibular canine teeth were linguoverted,
causing traumatic defects to the hard palate adjacent to the maxillary canine teeth. The
remainder of his physical exam was within normal limits.
Diagnostics, Diagnosis, and Treatment:
Following induction of general anesthesia and tracheal intubation, dental radiographs were performed to confirm the presence of appropriate adult dentition and to assess the roots of deciduous teeth. Bilateral inferior alveolar nerve blocks were performed with 0.5% Marcaine. A gingival incision was created along the root of the deciduous canine teeth and the alveolar bone was exposed using a periosteal elevator. Gentle elevation on the mesial and distal surfaces of the teeth was performed with deciduous elevators, taking care to avoid the lingual aspect and damaging the underlying tooth bud. The teeth were removed in their entirety and the gingiva was closed in a tension-free, simple interrupted pattern with 5-0 Monocryl. The deciduous incisors were similarly extracted with deciduous elevators, without requiring gingival incisions. Post-extraction radiographs were performed to confirm complete extraction.
Outcome and Follow Up:
Recovery was uneventful. "Yellow" was discharged with instructions to the owner to provide a softened diet for 14 days while the extraction sites healed and to administer oral Metacam for the following 3 days. Extraction sites were checked after 2 weeks, and bite evaluation is planned when the adult dentition erupts around six months of age to determine if additional intervention is necessary.
Discussion:
Any class of malocclusion can be present in the deciduous phase. Jaw length discrepancies are more commonly seen at this stage, however. In some cases, the jaw may be genetically programmed for a normal bite and the malocclusion is temporary, due to varying growth rates in the maxilla and mandible. When the deciduous teeth are trapped by either a tooth or soft tissue, the normal growth rate and subsequent self-correction is adversely affected. As with "Yellow," thorough oral exams during routine wellness visits allow for an early treatment plan, and early intervention maximizes the probability of a normal adult bite.
The deciduous teeth are much sharper than the corresponding permanent teeth, so trauma and pain from misalignment are initially significantly more intense. If occlusal trauma is present, extraction of the abnormally placed deciduous teeth should be performed as soon as possible to alleviate the trauma and pain and to remove the adverse dental interlock and allow unimpeded jaw movement. Ideally this is performed at 6-8 weeks of age to provide maximal unimpeded growth of the jaw.
Extractions of deciduous teeth can be challenging, as the roots are proportionally much longer and thinner than in the corresponding permanent dentition. In addition, extreme care must be taken to avoid damaging the developing permanent tooth. Prior to eruption, the immature enamel is susceptible to damage, which can result in enamel hypocalcification. Current literature recommends closed extractions in cases with significant root resorption and a surgical approach when the tooth appears intact radiographically. Root fractures are a common complication of deciduous extraction attempts. A retained root tip can become infected or act as a foreign body, creating significant inflammation. In addition, retained root tips can deflect the permanent tooth from its normal eruptive path, contributing to malocclusion.
It is imperative that the client understands that, typically, treatment of a malocclusion by selective extraction of deciduous teeth is only the first step, unless the malocclusion is solely the result of adverse dental interlock. Depending on the severity and type of malocclusion present in the adult dentition, additional treatment options will include ball therapy, orthodontic appliances, and crown shortening with vital pulpotomy or selective extractions.
