Microstomia: A Rare but Serious Oral Manifestation of Inherited Disorders

Microstomia is a term used to describe a small oral aperture (Stedman, 1976). Trauma, ingestion of caustic substances, electrical and thermal burns of perioral tissues and reconstructive lip surgeries can result in undesired cicatricial scar formation and inhibit adequate mouth opening (Smith et al., 1982). Less commonly, microstomia can also occur as a result of systemic and/or inherited disorders. The orbicularis oris muscle, the primary muscle of the lips, forms the sphincter around the mouth and the philtral columns (Wust, 2006) The muscular layer is separated from the skin by a thin subcutaneous layer and from the mucosa below by a thin submucosal layer that contains the adnexa, sensory end organs, and lymph nodes (Wust, 2006). In acquired cases, perioral facial traumas may result in scarring and contraction caused by the involvement and infiltration of the complex perioral musculature during the healing process depending on the depth of injury (Wust, 2006). However, in genetic disorder related cases, the etiology of the condition is variable and mostly remains uncertain. Individuals with microstomia may experience several problems related to speech, nutritional needs, dental hygiene, facial expression and social interaction (Mordjikian, 2002). Additionally, airway and ventilation problems and aspiration can induce fatal consequences during general anaesthesia procedures (Jaminet et al., 2009). Management of microstomia is a complex treatment modality and demands complex functional and aesthetic requirements of soft tissues of circumoral region. Providing well functioning lips should be the main objective of the treatment and relapses should be prevented to obtain stable and long lasting results (Koymen et al., 2009). Treatment of the latter was based on mainly on surgical techniques, non-surgical approaches or combination of both methods. It is important to highlight the reconstruction of the orbicular sphincter for adequate lip function beside lip symmetry, which is the main objective of microstomia reconstruction. The aim of this chapter is to review the genetic diseases associated with microstomia and briefly discusses the surgical and non surgical management options of the condition.