A misaligned jaw, known clinically as malocclusion, refers to an incorrect relationship between the upper and lower teeth when the jaw is closed. This common condition is not merely a cosmetic concern; it can affect chewing, speech, and overall oral health. Malocclusion is often categorized into Class I (minor bite issues with normal jaw position), Class II (overbite, where the upper jaw or teeth protrude), and Class III (underbite, where the lower jaw or teeth protrude). These misalignments typically stem from a combination of genetic factors that influence jaw size and shape, as well as environmental influences like prolonged childhood habits such as thumb-sucking or pacifier use.
Understanding Dental Alignment Versus Skeletal Alignment
The question of whether braces can fix a misaligned jaw depends fundamentally on distinguishing between a dental problem and a skeletal one. Dental alignment issues, or dentoalveolar discrepancies, involve the position of the teeth within the jawbone, such as crowding, spacing, or rotated teeth. Traditional braces and clear aligners are designed to correct these issues, using light, consistent force to move teeth through the surrounding alveolar bone.
Skeletal alignment, in contrast, refers to a mismatch in the size, shape, or position of the maxilla (upper jaw) and the mandible (lower jaw). Braces can effectively move teeth within the existing jaw structure, but they cannot significantly change the actual size or position of the jawbones themselves, especially in adults. Adult jawbones are fully developed and dense, making them resistant to orthopedic change.
For adults with severe skeletal issues, orthodontic treatment alone is limited to dental compensation, where the teeth are tipped to mask the underlying jaw discrepancy. This camouflaging approach straightens the teeth but does not correct the foundational bone structure problem. The success of treatment therefore hinges on whether the malocclusion is primarily dental or a more complex skeletal one.
Non-Surgical Tools Used With Braces
When a patient is still growing, orthodontists can utilize specialized appliances in conjunction with braces to influence the development of the jawbones. This approach, known as dentofacial orthopedics, uses the body’s natural growth process to guide the jaws into a better relationship.
One common tool is the palatal expander, used when the upper jaw is too narrow, often resulting in a crossbite. The appliance is anchored to the upper molars and contains a central screw mechanism that the patient or parent turns daily. This action applies lateral pressure, gradually separating the two halves of the maxilla at the mid-palatal suture, providing a wider upper arch and creating space for crowded teeth.
Other appliances, such as functional appliances like the Twin Block or Herbst appliance, are used to correct a Class II malocclusion (overbite). These devices work by posturing the lower jaw forward, harnessing muscle activity to encourage mandibular growth or to move the upper teeth backward. These appliances are effective during the peak growth spurt to accelerate the forward positioning of the lower jaw.
For Class III malocclusions (underbites), a reverse-pull headgear, or facemask, is often employed to encourage the forward growth of a deficient upper jaw. This external appliance anchors onto the forehead and chin and uses elastics to pull the maxilla forward. The success of these orthopedic appliances is heavily dependent on patient compliance, often requiring 12 to 14 hours of wear per day.
When Corrective Jaw Surgery Is Required
For adult patients or those with severe jaw misalignment where growth modification is no longer possible, corrective jaw surgery becomes the definitive treatment option. This procedure is necessary when the skeletal discrepancy is too large to be corrected by moving the teeth alone, or when the jaw mismatch compromises function, breathing, or facial aesthetics.
Orthognathic surgery is a complex process spanning approximately two to three years, involving a multidisciplinary team of an orthodontist and an oral and maxillofacial surgeon. The process begins with pre-surgical orthodontics, during which braces are used to align the teeth precisely within their respective jawbones. This preparation, known as decompensation, often temporarily worsens the bite alignment because the teeth are moved upright, revealing the full extent of the underlying skeletal problem.
The surgery itself is performed under general anesthesia. Depending on the case, the surgeon performs an osteotomy, which involves making precise cuts in the bone to reposition the maxilla, the mandible, or both. The newly positioned jaw segment is then secured in place using small titanium plates and screws, which permanently stabilize the bone.
Following the surgery, the final phase is post-surgical orthodontics. During this time, the orthodontist uses light wires and elastics to fine-tune the bite, ensuring that the teeth interlock perfectly in the new skeletal relationship.