Addressing a narrow smile often involves considering changes to the dental arch, lips, or underlying skeletal structure. A narrow smile can result from the positioning of the teeth or the physical dimension of the mouth opening, known as the oral commissures. Methods to address this range from non-invasive, temporary enhancements to permanent surgical procedures, each affecting the smile’s overall appearance differently.
Changing Smile Width Through Orthodontics
Orthodontic treatment focuses on repositioning the teeth and sometimes the jawbone to create the appearance of a wider smile. The goal is to reduce the “buccal corridors,” which are the dark, negative spaces visible between the cheeks and the back teeth when a person smiles widely. Narrow dental arches often make these dark spaces more noticeable.
In children and adolescents, a palatal expander physically widens the upper jaw (maxilla) by separating the mid-palatal suture. This skeletal expansion provides more space for teeth, broadening the dental arch and reducing the buccal corridor. For adults, whose mid-palatal suture has fused, conventional braces or clear aligners can widen the arch by tilting the teeth outward, a process called dental expansion. Although this approach does not change the physical jaw structure, the outward movement of the back teeth fills the buccal corridors, making the smile appear wider.
Surgical Procedures for Mouth and Lip Dimension
Surgical intervention is necessary for permanent, physical alterations to the mouth’s aperture or skeletal width. One common procedure is the Corner Lip Lift (cheiloplasty), which addresses downturned mouth corners. This involves removing a small, triangular piece of skin above the corners and suturing the area to subtly elevate the lip commissures. This modification creates a more neutral or slightly upturned resting expression but does not significantly increase the overall width of the lip opening.
A true mouth widening procedure, known as commissuroplasty, is performed to increase the horizontal distance between the mouth corners. This procedure is typically reserved for reconstructive purposes, such as correcting microstomia, but can be done for aesthetic reasons. The surgery advances the vermilion (the red part of the lip) outward and may require removing a small wedge of the orbicularis oris muscle to prevent post-surgical retraction. The change in width is limited, generally no more than 7mm, to minimize the risk of significant scarring and functional compromise.
When skeletal structure is the limiting factor, Surgically Assisted Maxillary Expansion (SAME) or Surgically Assisted Rapid Palatal Expansion (SARPE) may be performed on adults. This orthognathic surgery requires making bone cuts (osteotomies) in the upper jaw to surgically weaken the fused palatal suture. An expansion device gradually separates the bone segments over several months, permanently increasing the maxilla’s width. This procedure provides true skeletal widening, supporting a broader smile and improving dental arch alignment.
Non-Surgical Cosmetic Enhancements
Temporary and minimally invasive methods enhance soft tissue to create the illusion of a wider, more expressive mouth. Dermal fillers, primarily hyaluronic acid, are injected directly into the lips to add volume and definition. This added fullness stretches the lips laterally, highlighting the vermillion border and making the mouth look more prominent. Results typically last between six and eighteen months.
Another non-surgical approach uses neurotoxins, such as Botox, to selectively relax muscles around the mouth. A small amount is injected into the Depressor Anguli Oris (DAO) muscle, which pulls the mouth corners downward. Weakening the DAO allows opposing elevator muscles to gain a mechanical advantage, letting the mouth corners rest in a more neutral or subtly elevated position. This subtle lift contributes to the perception of a wider expression, with effects typically lasting three to four months.
Anatomical Limitations and Safety Considerations
Any procedure attempting to physically increase the mouth’s dimensions must contend with inherent anatomical constraints and significant safety risks. A major concern is the vulnerability of the marginal mandibular nerve, which controls the muscles of the lower lip. Damage to this nerve during surgery, particularly in the submandibular region, can result in permanent lower lip weakness or paralysis, leading to noticeable asymmetry when smiling.
Soft tissues impose limits on the extent of widening due to the risk of excessive tension and subsequent scarring. The orbicularis oris muscle acts as a sphincter and resists stretching; significant widening can lead to scar contracture. This may result in microstomia, a condition where the mouth opening is abnormally small, severely impacting function like speech and eating. Attempting to physically widen the mouth beyond natural tissue elasticity carries a high potential for functional and aesthetic complications.