Facial asymmetry is characterized by differences in size, shape, or position between the left and right sides of the face. While a perfectly symmetrical face is rare, a noticeable imbalance can affect both appearance and oral function. Whether orthodontic treatment, such as braces, can correct this imbalance depends entirely on the underlying cause and severity. Braces are effective tools for realigning teeth and correcting bite issues, which may translate into positive visual changes in the lower face. This article explores the capabilities of orthodontic treatment and when a more comprehensive approach is required.
Understanding the Types of Asymmetry
The success of any treatment for facial imbalance hinges on accurately identifying the source of the asymmetry, which generally falls into three main categories.
Dental Asymmetry
Dental asymmetry originates solely from the teeth and their alignment, such as a shifted dental midline or uneven tooth wear due to an improper bite. This often involves malocclusions like crossbites, which can cause the lower jaw to shift to one side to find a comfortable closing position. Since the asymmetry is localized to the dentition, this type is the most amenable to correction with braces alone.
Skeletal Asymmetry
Skeletal asymmetry involves discrepancies in the underlying bone structure, specifically the size, shape, or position of the maxilla or mandible. This imbalance often results from unequal growth rates, developmental conditions, or trauma, and it is frequently more pronounced than dental asymmetry. Braces alone cannot physically alter the size or position of these jawbones once growth is complete.
Soft Tissue Asymmetry
The third category is soft tissue asymmetry, which relates to the muscles, fat, or skin, often due to muscle imbalance, congenital conditions, or previous injury. While soft tissue appearance may be indirectly influenced by repositioning the underlying teeth and jawbones, braces do not directly treat these issues. The classification of the asymmetry—dental versus skeletal—is the primary factor determining treatment sufficiency.
The Role of Braces in Correcting Dental Asymmetry
Orthodontic braces are highly effective in correcting asymmetry that is primarily dental in origin. Braces apply continuous pressure to move individual teeth into their correct positions within the dental arches. This controlled movement can resolve issues like a deviated dental midline, where the center line between the front teeth does not align with the center of the face. Correcting this discrepancy enhances the symmetry of the smile and the lower face.
Braces also treat malocclusions like unilateral crossbites, where upper teeth sit inside the lower teeth on one side. This bite problem can cause a functional shift, forcing the lower jaw to move laterally when closing, resulting in a visibly asymmetrical jaw position. Correcting the crossbite releases the jaw from this forced deviation, allowing it to settle into a natural, centered position. Aligning crowded teeth and leveling the occlusal plane further influences the perceived symmetry of the lips and cheeks.
When Braces Alone Are Insufficient
Braces move teeth through the alveolar bone but cannot change the size or spatial relationship of the jawbones themselves. When facial asymmetry is due to a significant skeletal discrepancy, such as one jaw being larger or smaller than the other, braces are limited to moving the teeth within their existing bony structure. This means braces cannot correct the underlying skeletal problem causing the facial imbalance.
In cases of mild to moderate skeletal asymmetry, orthodontists may employ dental camouflage. This technique involves tilting the teeth to compensate for the underlying jaw misalignment, creating a functional bite even though the jawbones remain asymmetrical. While this can improve the bite and reduce the visual impact, it does not offer a true correction of the skeletal issue and may lead to compromised dental results. For growing adolescents, functional appliances may be used alongside braces to guide jaw growth, but this approach is only effective during specific developmental stages.
Comprehensive Treatment Approaches
For patients with moderate to severe skeletal asymmetry, the most effective treatment involves a multi-disciplinary approach combining orthodontics with orthognathic surgery (corrective jaw surgery). This combined method is necessary because only surgery can physically reposition the misaligned upper or lower jawbones to achieve true skeletal symmetry. The coordinated process typically begins with pre-surgical orthodontics, which may last 12 to 18 months.
Pre-Surgical Orthodontics
During this initial phase, braces align the teeth within each jaw arch. The teeth are placed in positions necessary for the post-surgical alignment, even if they initially appear worse.
Orthognathic Surgery and Post-Surgical Care
The surgeon performs the orthognathic procedure to cut and reposition the jawbones, securing them with plates and screws to correct the skeletal imbalance. Following surgery, braces remain in place for several months of post-surgical orthodontics. This final phase fine-tunes the bite and ensures optimal dental alignment in the new jaw positions. For less severe skeletal issues, adjunct treatments such as Temporary Anchorage Devices (TADs) may be utilized to move teeth or minor parts of the jaw, potentially reducing the need for full surgery.