Congenital Bony Syngnathia: A Proposed Classification

Abstract

Objective Congenital bony syngnathia is an extremely rare condition characterized by bony fusion of the jaws. Five new cases are described and the existent literature is reviewed. A classification system is proposed and treatment recommendations based on this classification are presented.

Isolated congenital maxillomandibular synechiae

“…It may be unilateral, bilateral with an anterior opening, or complete [1,2,[4][5][6]. In 1997, Dawson classified bony syngnathia into two types separated by whether or not an associated head and neck anomaly was present [3,7]. Later in 2001, Laster modified the classification to further define the location of the fusion, maxillomandibular versus zygomatico-mandibular [3].…”

Congenital Fibrous Maxillomandibular Fusion

“…Bilateral fusion in the posterior region is more common presentation. No sex predilection has been reported [7]. Less than 40 cases have been reported in literature; most commonly in association with popliteal pterygium syndrome [2].…”

“…The exact etiology of syngnathia is not known but some of the reported causes including Goodacre and Wallace's [6] experimental studies include persistence of buccopharyngeal membrane, amniotic constriction bands in the region of the developing first branchial arch, environmental insults, drugs such as meclozine and large doses of vitamin A. Dawson et al [7] in a review classified syngnathia as: Type 1 Simple syngnathia--with no other anomalies in the head and neck Their study did not provide any evidence of familial tendency, history of drug exposure or consanguinity. However, there was a clear history of consanguinity in our case.…”

Congenital fusion of the jaws: a management protocol

“…Osteotomy of the fusion can be performed easily with the help of 3D CT scanning. Recurrence can be prevented by interposing silicone sheets 10,22,26 or blocks and by interposing gauze packs for intraoral raw areas 4,25 .…”