Dental and Skeletal Discrepancies

The causes of malocclusions can be classified into two major categories: dental or skeletal. One way to distinguish between the two is to compare tooth size and arch dimensions in Class I occlusions that have no crowding with Class I malocclusions exhibiting severe crowding. The results will reveal the dental or skeletal causes of crowding. This information will be helpful in planning prior to orthodontic treatment.

Dental Discrepancies

Identifying the causes of malocclusion is one of the most important issues in orthodontics. Dental crowding can be the consequence of a tooth size-dental arch dimension discrepancy. Different theories have tried to explain the causes of dental crowding, which can include hereditary and environmental factors.

Tooth size discrepancy can occur within an arch or between the upper and the lower arches. Within an arch, an example of a tooth size discrepancy would be diminutive lateral incisors or pegged-shaped laterals. Because these teeth are small, there will be extra space in the upper arch. This space will need to be filled in artificially after the teeth are straightened.

Skeletal Discrepancies

Dr. Fulton's specialty is technically known as orthodontics and maxillofacial orthopedics. Most people think of orthodontics as relating only to teeth. However, the facial bones, specifically the upper and lower jaws are important facets in every case. The upper and lower jaws must be in harmony in order for the teeth to occlude properly.

Not only does Dr. Fulton want to create healthy and beautiful smiles, but also beautiful faces. Within the scope of orthodontics, growth modification on younger patients is often a part of treatment. In non-growing adults, a jaw discrepancy between the maxilla and the mandible may need to be camouflaged by manipulating the teeth or be surgically corrected by an oral surgeon.

Examples:

• Mandibular Retrognathia: The lower jaw appears weak.
• Mandibular Prognathia: The lower jaw appears too large.
• Maxillary Deficiency: The upper jaw appears small.
• VME, Vertical Maxillary Excess: The upper jaw appears to be too long, creating an excessive, gummy smile.
• Apertognathia: When teeth don't touch, resulting in an open bite. This condition can be due to a skeletal deformity.

The most common skeletal discrepancies are mandibular retrognathia and maxillary deficiency. Dr. Fulton recommends early treatment for growth modification in both cases. With mandibular retrognathia, or a weak lower jaw, she will often recommend a Herbst appliance to maximize the natural growth potential of the patient’s lower jaw. If a maxillary deficiency involves a narrow upper arch, early treatment using a palatal expander is often recommended by Dr. Fulton.

Herbst Appliance

Palatal Expander