A receding jaw, medically termed retrognathia, is a common condition where the lower jaw (mandible) is positioned noticeably further back than the upper jaw. This misalignment creates an imbalance in the facial profile, often making the chin appear underdeveloped or “weak.” Retrognathia is a form of malocclusion, meaning the upper and lower teeth do not align correctly, which can potentially lead to functional issues. Addressing this condition requires careful assessment to determine the underlying issue and guide the choice between non-surgical and surgical approaches.
Understanding the Root Cause
The treatment approach for a receding jaw is determined by the cause, categorized as either skeletal or dental. Skeletal retrognathia occurs when the jawbone is underdeveloped (mandibular hypoplasia) or positioned too far back. This structural problem requires correction of the bone position, typically through surgery. Dental retrognathia involves a well-proportioned jaw structure, but the lower teeth are positioned far back or the upper teeth are too far forward.
This misalignment of the teeth creates the visual appearance of a receding jaw and an improper bite. Dental issues are usually corrected through orthodontic treatment alone. Contributing factors are often inherited, with genetic predisposition influencing jawbone development.
Environmental factors also play a role, especially during early childhood development. Habits such as prolonged thumb-sucking, excessive pacifier use, and chronic mouth breathing can negatively influence the growth direction of the lower jaw. These habits can aggravate a pre-existing tendency toward a set-back position.
Non-Surgical and Appliance-Based Corrections
For growing patients, functional appliances offer an opportunity to non-surgically guide the development of the lower jaw. The Herbst appliance is a fixed device that physically postures the lower jaw forward using a telescoping rod mechanism attached to the molars. This continuous pressure encourages the lower jaw to grow into a more advanced position, correcting the skeletal discrepancy during active growth.
These appliances rely on the body’s natural growth potential to achieve a permanent change in bone position. Treatment with a Herbst appliance often lasts around 12 months and is frequently used with braces to align the teeth. For cases where the recession is primarily dental, traditional orthodontic treatment with braces or clear aligners can effectively reposition the teeth. Moving the lower teeth forward or the upper teeth backward corrects the malocclusion and improves the profile, creating the illusion of a more projected chin.
For adults with mild recession who seek improvement without affecting the bite, dermal fillers provide a non-surgical, temporary option. Injectable fillers, typically composed of hyaluronic acid, are strategically placed along the jawline and chin area. This procedure adds volume and projection to the soft tissue, enhancing the contour and definition of the chin without altering the underlying bone structure. The results are immediate but are not permanent, usually lasting between six months to two years.
Surgical Procedures for Jaw Realignment
For moderate to severe skeletal retrognathia in adults, or when growth modification is no longer an option, orthognathic surgery is the definitive treatment. The most common procedure for advancing a set-back lower jaw is the Bilateral Sagittal Split Osteotomy (BSSO). During this complex surgery, the lower jawbone is precisely cut on both sides behind the molars, allowing the surgeon to advance the entire segment forward into a new, corrected alignment.
Once repositioned, the jaw segment is secured with small titanium plates and screws while it heals. The BSSO procedure is performed entirely from inside the mouth, leaving no visible external scars. It requires pre- and post-surgical orthodontics to ensure the teeth align perfectly with the new jaw position. Patients can expect significant facial swelling, and a soft diet is typically maintained for four to six weeks to allow for proper bone healing.
In cases where the jaw alignment is acceptable but chin projection is lacking, a genioplasty, or chin surgery, may be performed. A sliding genioplasty involves cutting a piece of the chin bone and moving it forward, backward, or sideways to achieve the desired projection and shape. This technique uses the patient’s own bone, offering a permanent and customizable result that can address vertical or horizontal deficiencies.
Alternatively, a simpler approach is the placement of a chin implant, where a custom-shaped synthetic material is inserted over the existing bone to increase projection. While an implant is less invasive with a faster recovery, it is less versatile than a sliding genioplasty, as it only adds volume. Genioplasty primarily addresses the chin’s appearance, while BSSO corrects the position of the entire lower jaw and the functional bite.