What Causes Macrostomia?

1. Complete lateral facial cleft: The facial cleft runs from the corner of the mouth toward the bottom of the ear. The outside of the ear on the affected side of the face appears normal, and a region of soft tissue connects the cleft to the right lateral posterior hard palate. Internally there is no soft palate.
2. Simple macrostomia: It is less severe because it does not affect the facial muscles and is not associated with any soft tissue or bone deformities. A small cleft extends from the mouth and can be repaired surgically.
3. Macrostomia with diastasis of the facial musculature: Clefts in this variant are slightly more severe than the ones seen in simple macrostomia. It does not have bone deformities but includes minor soft tissue deformities. The defining feature is muscle diastasis, which is the separation of the masseter muscle. This can be partially corrected with surgery.
4. Isolated facial musculature diastasis: The facial cleft in this case results in a more severe muscle separation even though there is not a true open cleft. Bones in the region remain unaffected, and the phenotype appears as an indentation of the cheek rather than an open cleft. The external ear in this phenotype can be affected.

Surgical reconstruction of the defect is the main therapeutic option. The surgical repair of macrostomia bears structural, functional, and cosmetic concerns.

5 goals that are achieved with surgery for macrostomia

1. Formation of symmetric lips and oral commissure
2. Reconstruction of the orbicularis oris muscle to restore labial function
3. Reconstruction of the commissures of the mouth with a natural-looking contour
4. Closure of the defect with a minimally visible scar
5. Prevention of future scar contracture with lateral migration of commissures

There are several surgical options for the correction of macrostomia, including Z-plasty, W-plasty, triangular flaps, and straight-line closure.

Incisions are placed along the borders of the cleft, both inside and outside the mouth. The muscles are then brought into continuity, including the oral sphincter (orbicularis oris). The wound is then closed from the inside out.

Recovery from surgical correction of macrostomia is relatively simple. Sutures are absorbable and do not require removal. The surgery takes less than two hours and can be done on an outpatient basis. Patients must avoid contact sports or rough play for a period of at least three to four weeks. A soft diet is required for up to six weeks.

Fortunately, complications from macrostomia repair are limited. Typical surgical risks include bleeding, infection, anesthesia complications, and bad scarring. Additionally, there is a chance of asymmetry and a possibility for further surgical procedures. Anesthesia pre-evaluation could be required in syndromic patients with airway issues or other systemic problems, such as cardiac, pulmonary, or endocrinology defects.