An underbite, a condition where the lower jaw extends beyond the upper jaw, results in a distinct facial appearance. Correcting this misalignment often leads to noticeable changes in facial features, improving facial balance and harmony. This article explores what an underbite entails, how treatment alters facial aesthetics, correction methods, and functional benefits.
What an Underbite Is
An underbite occurs when the lower front teeth protrude past the upper front teeth, with the lower jaw sitting forward relative to the upper jaw. This misalignment can range from mild, where it is barely noticeable, to severe, with a significant gap between the upper and lower teeth. It often leads to a prominent chin and a somewhat “concave” facial profile.
The underlying causes of an underbite are often genetic, influencing the size and shape of the jawbones and teeth. In some instances, childhood habits like prolonged thumb sucking, extended pacifier use past age three, or tongue thrusting can contribute to its development. An underbite can also result from an injury that affects jaw alignment.
How Treatment Alters Facial Features
Correcting an underbite reshapes the face by aligning the jaws, which harmonizes the facial profile. A key change is improved chin projection, making a previously prominent chin less pronounced and more proportionate. This adjustment can soften facial features that might have appeared hard or “square-jawed” due to the forward lower jaw.
Treatment also enhances jawline symmetry and definition, leading to a more balanced facial structure. Jaw repositioning also affects facial soft tissues like lips and cheeks, improving lip alignment and creating a more natural resting position. Changes in the nose-to-lip angle can also occur, potentially leading to a more defined or slightly upturned nose. The goal of treatment is to achieve more harmonious facial proportions and symmetry.
Methods of Correction
Underbite correction involves various approaches, tailored to the patient’s age and misalignment severity. For younger patients whose bones are still developing, orthodontic treatments can guide jaw growth. Devices like upper jaw expanders, which widen the upper jaw, or reverse-pull facemasks, which gently pull the upper jaw forward, can be effective. These methods aim to improve the jaw relationship during a period of active growth.
For adults or more severe cases, orthodontic treatment like braces or clear aligners can reposition teeth and contribute to minor jaw adjustments. For significant skeletal discrepancies where jawbones are misaligned, orthognathic surgery (jaw surgery) is often necessary. This surgical procedure directly repositions the jawbones to achieve proper alignment, with titanium screws and plates often used to secure the new position. A combination of orthodontic treatment before and after surgery is often required to ensure optimal tooth and jaw alignment.
Beyond Aesthetics: Functional Improvements
While aesthetics motivate underbite correction, functional benefits are equally important for health and well-being. Correction improves chewing efficiency, as upper and lower teeth meet properly, facilitating better food breakdown and digestion. This reduces strain on jaw muscles and joints, alleviating discomfort or pain often associated with temporomandibular joint (TMJ) issues.
Speech articulation also improves, as correct jaw and teeth alignment allows for proper tongue placement and airflow during speaking. An underbite can also lead to abnormal wear and tear on teeth due to uneven biting forces. Correction helps protect teeth from excessive damage. Better oral hygiene becomes more achievable when teeth are properly aligned, reducing the risk of tooth decay and gum disease.