Prenatal imaging of congenital maxillomandibular fusion: case report and review of the literature

Congenital Unilateral Syngnathia: A Report of a Rare Case

Congenital maxillomandibular syngnathia is an uncommon craniofacial disorder, with limited documented cases in the literature. It involves abnormal fusion of the maxilla and mandible, resulting in restricted mouth opening and airway difficulties, and is associated with various syndromes. We report a case of a nine-year-old girl who has been unable to open her mouth since birth. This case highlights the critical need for precise diagnosis and timely surgical intervention to ensure the best possible outcomes for individuals with this condition.

Congenital Maxillomandibular Syngnathia: Review of Literature and Proposed New Classification System

PURPOSE

Maxillomandibular fusion (syngnathia) is a rare craniofacial anomaly. It occurs as either fibrous (synechiae) or bony (synostosis) fusion of jaw or fusion of mandible to zygoma, tuberosity, hard palate and temporal bone. There are several documentations delineating this condition but owing to its varying presentation, association with both intraoral and extraoral anomalies and syndromes, reviewing it has been as uphill task. The non-unanimous description of cases in the literature and the use of different nomenclatures make it difficult to classify this condition.

METHODS

Extensive search of the literature was done from the year 1936 to 2018 which included a total of 118 cases with 62 cases of bony fusion, 48 cases of fibrous fusion and 8 cases of combined fusion, i.e., fibrous on one site and bony on another side.

RESULTS

This paper proposes a novel, simple and explicit classification system on the basis of nature of fusing tissues, location and extent, association with syndrome after reviewing the existing literature. Furthermore, this review reports 4 new cases of syngnathia along with their clinical, radiographic features and their management protocol.

CONCLUSIONS

This classification can be generalized to all the cases of syngnathia and can further facilitate in its appropriate diagnosis and treatment plan.

Syngnathia

Syngnathia is a congenital fusion of the upper and lower jaws. Its occurrence poses a significant challenge to feeding and its management is challenging to both the surgeon and the anaesthetist. Reports in the literature are mainly clinical reports or case series. To the knowledge of the authors and from the available literature, this is only the fourth report from Nigeria. The presentation and successful management of a Nigerian female neonate with congenital syngnathia is described and reviewed with literature.

Syngnathia-Congenital Maxillomandibular fusion: Case Report and Literature Review

Congenital maxillomandibular fusion is a rare disorder of the craniofacial region. Maintenance of the airway and difficulty in feeding are the main concerns for such patients. We performed a PubMed search to identify reported cases of syngnathia. With reference to the site of fusion and corresponding anomalies, the available studies were reviewed. The maxillomandibular fusion can be anterior fusion, unilateral or bilateral fusion, and complete fusion. The condition can be an isolated problem or associated with a syndrome. The condition requires immediate attention because it can be fatal. A case of isolated unilateral syngnathia, with the detailed review of the published data, is reported.

Separate development of the maxilla and mandible is controlled by regional signaling of the maxillomandibular junction during avian development

BACKGROUND

Syngnathia is a congenital craniofacial disorder characterized by bony or soft tissue fusion of upper and lower jaws. Previous studies suggested some causative signals, such as Foxc1 or Bmp4, cause the disruption of maxillomandibular identity, but their location and the interactive signals involved remain unexplored. We wanted to examine the embryonic origin of syngnathia based on the assumption that it may be located at the separation between the maxillary and mandibular processes. This region, known as the maxillomandibular junction (MMJ), is involved in segregation of cranial neural crest-derived mesenchyme into the presumptive upper and lower jaws.

RESULTS

Here we investigated the role of Fgf, Bmp, and retinoid signaling during development of MMJ in chicken embryos. By changing the levels of these signals with bead implants, we induced syngnathia with microstomia on the treated side, which showed increased Barx1 and neural cell adhesion molecule (NCAM) expression. Redistribution of proliferating cells was also observed at the proximal region to maxillary and mandibular arch around MMJ.

CONCLUSIONS

We propose that interactive molecular signaling by Fgfs, Bmps, and retinoids around MMJ is required for normal separation of the maxilla and mandible, as well as the proper positioning of beak commissure during early facial morphogenesis. Developmental Dynamics 246:28-40, 2017. © 2016 Wiley Periodicals, Inc.

Congenital Bilateral Zygomatico-Maxillo-Mandibular Fusion Associated With Gum Fusion

A congenial syngnathia is very rare condition. It can be simple mucosal fusion (synechiae), or complete bony fusion (synostosis) between the maxilla or zygoma and the mandible. Fusion of the ascending ramus of mandible to maxilla and zygoma is less common than fusions of the alveolar ridges of the mandible to the maxilla. Bony syngnathia is either isolated or complex in form. There are 59 cases of congenital bony syngnathia reported in the literature: the first report was by Burket in 1936. There are 16 reported cases of zygomatico-maxillo-mandibular fusion. In the reported cases, women expressed the isolated form more commonly whereas men demonstrated a more complex pattern of disease. The authors present another patient of bony syngnathia involving bilateral fusion of the ascending ramus and body of the mandible with the maxillary complex in a young man. Early surgery was performed to release the bony and soft tissue fusion on the eighth day from the baby's birth. A second operation was performed for recurrence when the baby was 2.5 months old. A customized splint, an intense postoperative program of mouth exercises, and close follow-up aims to prevent further refusion.

Congenital Syngnathia: Case Report and Review of Literature

Congenital bony fusion of the maxilla and mandible, especially as an isolated occurrence, is a very rare condition. The very few cases reported in the literature are mostly inadequate in description and confusing in nomenclature. An isolated case of syngnathia in a 60-year-old female patient with unilateral bony fusion (synostosis) of the maxilla and mandible associated with fibrous adhesions (synechiae) of the opposite site is reported. The existent literature is also reviewed.