Abstract

Background. Among many causes of asymmetrical smile in newborns, congenital hypoplasia of the depressor anguli oris muscle (DAO) is among rare ones. This asymmetry may continue to adulthood, as many patients may present with varying degree of smile animation discrepancies.
Methods. This case series comprises of 05 patients with congenital hypoplasia of depressor anguli oris muscle. These patients were not associated with other syndromes, congenital anomalies or paralysis of other branches of facial nerve. All were operated with the anterior belly of digastric mucle transfer (ABDMT).
Results. After mean follow up of 12 months, satisfactory outcomes were accomplished in all patients with all exhibiting improved symmetry during full mouth opening.
Conclusions.ABDMT proved to be most reliable method for restoration of depressor function which lead to excellent aesthetic and functional animation of lower face.

Key words: Key words: Congenital depressor anguli oris, Marginal mandibular nerve , Asymmetrical smile