What Are Jaw Abnormalities?
Jaw abnormalities affect the bite and appearance of patients. These may be due to a cleft lip and palate or other causes.
What Are the Signs and Symptoms of Jaw Abnormalities?
The most common jaw abnormalities are the following:
- A small upper jaw, with or without a large lower jaw, with upper teeth that are significantly behind the lower teeth (negative underjet)
- A small lower jaw, with lower teeth that are significantly behind the upper teeth (positive underjet)
- Front teeth that do not touch (anterior openbite)
- Upper teeth that show too much when smiling (excessive tooth show)
- An excessively small chin (microgenia)
- An asymmetric or tilted jaw causing an occlusal cant
How Are Jaw Abnormalities Diagnosed?
Jaw abnormalities are diagnosed on physical examination. When planning surgery, most patients will need orthodontics (braces).
How Are Jaw Abnormalities Treated?
Before surgery, a CT scan and dental models are obtained. This allows the surgeon to perform virtual surgical planning.
Surgery for jaw abnormalities can include one or a combination of the following procedures:
- LeFort 1: This operation moves the upper jaw in any direction. All incisions are inside the mouth.
- Bilateral sagittal splint osteotomy (BSSO): This operation moves the lower jaw in any direction. All incisions are inside the mouth, except for a very small 3mm incision on each cheek.
- Genioplasty: this operation moves the chin without repositioning the jaw itself. All incisions are inside the mouth.