An uneven jaw alignment, also known as a malocclusion, is a common reason people seek orthodontic care. The effectiveness of braces depends entirely on the underlying cause and the severity of the misalignment. Understanding the source of the problem—whether it is an issue with the teeth or the actual jaw structure—is the first step in determining the appropriate treatment path. Treatment can range from straightforward tooth movement with braces to complex procedures involving surgical intervention.
Defining Uneven Jaw Alignment
Malocclusion describes a condition where the upper and lower teeth do not properly align when the mouth is closed. Orthodontists differentiate between two primary causes: dental misalignment and skeletal misalignment.
Dental misalignment occurs when the teeth are crooked, crowded, or improperly spaced, but the underlying bone structure of the maxilla (upper jaw) and mandible (lower jaw) is correctly positioned. This is often seen in a Class I malocclusion, where the bite relationship is normal even if the teeth are irregular.
Skeletal misalignment, or jaw discrepancy, is a more involved problem where the size or position of the upper or lower jaw bones is mismatched. This structural issue creates significant unevenness that affects the entire bite and often leads to facial asymmetry. Examples include a severe Class II malocclusion (underdeveloped lower jaw/overbite) or a Class III malocclusion (protruding lower jaw/underbite). These issues require addressing the bone structure.
Braces and Minor Corrections
Braces are effective at correcting dental misalignment and minor bite issues by applying constant, gentle pressure to the teeth. The system of brackets bonded to the teeth and connected by a flexible archwire works by stimulating a natural biological process called bone remodeling. As pressure is applied to a tooth, the periodontal ligament surrounding its root stretches on one side and compresses on the other, causing the supporting bone to be resorbed and rebuilt in the new position.
This mechanism is ideal for moving teeth within the existing jaw structure, such as closing gaps, resolving crowding, and correcting minor rotations. Braces alone can sometimes camouflage a minor skeletal problem by tipping the teeth to improve the bite relationship, a technique known as dental compensation. Braces are often combined with appliances like elastics, which connect the upper and lower arches to apply force that influences the jaw relationship. Palatal expanders can widen the upper jaw to resolve crossbites, helping the teeth fit together better.
Treatments for Severe Skeletal Discrepancies
When unevenness is due to a pronounced skeletal mismatch, braces alone are not sufficient to achieve a stable and functional result. Moving teeth too far to compensate for a severe jaw discrepancy can destabilize the bite and compromise the health of the teeth and supporting bone. In these severe cases, the established treatment protocol is a combined surgical-orthodontic approach.
This treatment centers on orthognathic surgery, which involves physically repositioning the maxilla, mandible, or both, to create a harmonious skeletal relationship. The process is divided into three phases:
Pre-Surgical Orthodontics
During this phase, braces are worn to align the teeth relative to their respective jaw bones, often making the bite look temporarily worse before surgery.
Surgery
The oral and maxillofacial surgeon moves the jaw bones into their planned, corrected position.
Post-Surgical Orthodontics
This involves a period of fine-tuning with braces to ensure the teeth interlock perfectly in the newly aligned jaw position.
The Role of Patient Age in Treatment
Patient age plays a significant role in determining the treatment strategy because bone growth potential changes over time. For children and adolescents who are still growing, orthodontists utilize interceptive orthodontics, which focuses on guiding jaw development. Functional appliances, such as the Herbst or Twin Block devices, are used during this growth period to encourage or restrict the growth of the lower jaw.
These appliances harness natural forces to redirect growth, which is the only time a true skeletal correction can be achieved without surgery. For instance, a Herbst appliance can push the lower jaw forward to correct a Class II overbite while the bones are still malleable. Once an individual reaches skeletal maturity, the jaw bones are fixed, and growth modification is no longer possible. Significant skeletal unevenness then requires the combined surgical-orthodontic approach.