Background: Congenital unilateral lower lip palsy or congenital hypoplasia of the depressor anguli oris muscle, also known as asymmetric crying facies, characterized by deformity of the lower lip, lacks aggressive surgical intervention methods. Although several dynamic and static reconstruction methods have been reported, textbooks introduce only passive surgical intervention, of weakening the unaffected side through techniques such as selective marginal mandibular neurectomy which, however, tends to produce lack of emotive movement. Therefore, a new surgical intervention for the reconstructive treatment of asymmetric crying facies is presented.
Methods: A bidirectional (horizontal and vertical) fascia was grafted to restore the aesthetic appearance of the asymmetric lower lip. The horizontal fascial strip achieves restoration of the center of the lower lip to its proper position, whereas the vertical fascial strip achieves aesthetic symmetry of the lower lip at mouth opening. Each end of the vertical strip is anchored to the lower lip and the mandibular bone, respectively, thereby allowing simultaneous movement of the mandible and lower lip.
Results: The reconstruction of unilateral lower lip palsy has been successfully performed on seven patients, with ages ranging from 2 years 9 months to 11 years 1 month, since June of 1996.
Conclusions: The aim of this procedure is not to achieve complete dynamic reanimation. However, with regard to its simplicity and minimal invasiveness and the satisfaction of the patients, it is considered to be a well-balanced surgical intervention.