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 Table of Contents  
Year : 2016  |  Volume : 13  |  Issue : 1  |  Page : 40-43

Maxillomandibular syngnathia in an adult Nigerian patient

1 Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, College of Medicine University of Lagos, Lagos, Nigeria
2 Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Lagos, Nigeria

Date of Web Publication2-Feb-2016

Correspondence Address:
Olutayo James
Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, College of Medicine University of Lagos, Lagos
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1595-9587.175479

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Congenital maxillomandibular fusion is a very rare condition with few cases reported worldwide. This paper reports a rare case of bony maxillomandibular fusion of the jaws, with synechiae of buccal mucosa and the gingivae in an adult patient. Separation of the fusion was done under general anesthesia. Isolated cleft of the hard palate was discovered during surgery. This report adds more information to literature, by reporting an adult with syngnathia and isolated cleft of the hard palate.

Keywords: Cleft palate, mandible, maxilla, syngnathia, unilateral

How to cite this article:
James O, Ibikunle A A, Adeyemo W L, Ogunlewe M O, Ladeinde A L. Maxillomandibular syngnathia in an adult Nigerian patient. J Clin Sci 2016;13:40-3

How to cite this URL:
James O, Ibikunle A A, Adeyemo W L, Ogunlewe M O, Ladeinde A L. Maxillomandibular syngnathia in an adult Nigerian patient. J Clin Sci [serial online] 2016 [cited 2023 Jun 2];13:40-3. Available from: https://www.jcsjournal.org/text.asp?2016/13/1/40/175479

  Introduction Top

Congenital fusion of the jaws (syngnathia) is a rare group of anomalies.[1],[2] The presentation varies in severity from simple mucosal adhesion (synechiae) to extensive bony fusion (synostosis).[3],[4] Syngnathia may appear as an isolated bony fusion of the maxilla and mandible, but most reported cases in the literature appear in association with other anatomic oral and craniofacial anomalies.[3],[5],[6],[7],[8] Several cases with combination of cleft lip, cleft of hard and soft palate, oral soft tissue synechiae, hypoplasia of the proximal mandible, hemifacial microsomia, cleft of mandible, bifid tongue, small or absent tongue, zygomaticomandibular fusion, and some other regional and systemic anomalies have been reported.[5] Occurrences with popliteal pterygium syndrome, Aglossia-adactylia syndrome, and van der Woude syndrome have also been described.[1],[3] Unilateral bone syngnathia in association with an isolated cleft of the hard palate is more rarely reported. This report presents a case of unilateral bone syngnathia with the isolated cleft of the hard palate.

  Case Report Top

A 40-year-old female was referred to the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Lagos, Nigeria, with inability to open the mouth since childhood. She revealed that she had been unable to open her mouth since the age of 3 years due to a childhood infection, which she believed was measles. Both parents were unavailable to provide additional information on the course of the disease. The patient claimed that an unspecified surgical intervention was carried out when she was 5 years old, but there was no improvement in the clinical condition. She forced food through the residual edentulous space on the anterior maxilla left from loss of maxillary anterior teeth.

Detailed history revealed that the patient was the last of nine siblings of a nonconsanguineous couple. No history of such occurrence within the families of either parent was admitted. Her major concern was the inability to open the mouth.

On examination, there was some degree of facial asymmetry on account of a flattening of the right zygomatic prominence. The maxilla, mandible, and the zygoma were hypoplastic with reduced lower third facial height which was more marked on the right [Figure 1]. The temporomandibular joints (TMJs) were palpable bilaterally with an almost imperceptible movement on the right and slight movement on the left. Intraoral examination revealed inability to open the mouth [Figure 2]. The mandible was completely immobile, and neither lateral nor protrusive excursion was possible. The upper and lower jaws were fused on the right side from premolar region to the right retromolar pad. Adhesion of the right retro-commissural soft tissue to the fused arches was noted on the right side; this continued posteriorly as complete adhesion of the buccal mucosa to the slopes of the upper and lower arches, resulting in the absence of buccal vestibule on the right side of the oral cavity. The teeth present were as follows: 23, 24, 25, 26, 27, 28, 31, 32, 33, 34, 35, 36, 37, 38, 41, 42, and 44. There were deep overbite and reverse overjet anteriorly; the lower anterior teeth were also proclined. She could not give the account of how the missing teeth were lost.
Figure 1: Preoperative appearance of the patient revealing micrognathia

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Figure 2: Intraoral examination revealed inability to open the mouth

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Three-dimensional (3D) reconstructed computed tomography (CT) scan of the head revealed a unilateral bony fusion of the right maxillary-mandibular arches [Figure 3]a. The maxilla, mandible, and the zygoma were hypoplastic, and the hypoplasia was more on the right side [Figure 3]b. In addition, there was hyperplasia of the right coronoid [Figure 3]b. There was an ankylotic mass around the right TMJ with complete joint space obliteration, as well as reduced joint space on the left and elongated coronoid process [Figure 3]c.
Figure 3: (a) Three-dimensional computed tomography showing bony fusion of the maxilla and the mandible. (b) Three-dimensional reconstructed computed tomography scan showing a right coronoid hyperplasia and hypoplasia of the mandible, maxilla, and the zygoma. (c) Three-dimensional computed tomography showing left coronoid hyperplasia

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She was then planned for bilateral coronoidectomy, right interpositional arthroplasty, release of fibrous bands, and separation of the maxillomandibular fusion under general anesthesia.

An elective tracheostomy was done to facilitate general anesthesia. A standard preauricular incision was placed on the right after infiltration of 1:200,000 adrenaline. A high condylectomy was then performed on the right TMJ. Bilateral coronoidectomy and release of the fibrous bands was also done. The maxillomadibular fusion was carefully separated via L-shaped osteotomy. The jaw was then opened with digital pressure; an intraoperative opening of about 31 mm (interincisal distance [IID]) was achieved. Opening of the mouth revealed a cleft of the hard palate [Figure 4]. Mucosa was advanced and sutured over the raw bone edges. The patient recovered satisfactorily from the surgery.
Figure 4: Exposure of the surgical site revealing bony fusion

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Active jaw exercise commenced about 24 h after the surgery and continued for 3 months postoperatively. The patient is still followed-up and mouth opening maintained at 30 mm IID; she is being planned for the repair of the cleft palate.

  Discussion Top

The present report describes the clinical features and management of a rare anomaly involving soft tissue (synechiae) and bony adhesions (synostosis) between maxilla and mandible. This congenital disorder can present with a wide range of severity. The presentation ranges from single mucosal band [4] to complete bony fusion which may be unilateral or bilateral, leaving a slit-like opening or complete.[3],[4],[5],[6],[7],[8],[9] Nwoku and Kekere-Ekun [10] reported cases of syngnathia, alveolar fusion extended to the zygoma. Our patient presented with right congenital syngnathia, right TMJ ankylosis, bilateral coronoid hyperplasia, and isolated cleft of the hard palate.

The etiology of the disorder is still uncertain. Several theories have been put forward to explain the occurrence of the malformation. The persistence of the buccopharyngeal membrane or amniotic constriction bands in the region of the developing branchial arches was advocated by Parkins and Boamah.[4] It has been suggested that oral adhesions represent remnants of the buccopharyngeal membrane, which normally disintegrates during the 4th week of intrauterine life. The condition, therefore, would be analogous to esophageal atresia or imperforate anus.[3] Credence was given to the fusion of the gums due to either an abnormality during ingrowth of ectoderm or more probably as a result of an abnormal process at a later stage of intrauterine development byother authors.[4],[8] Other suggested possible etiological factors include failure of tongue to protrude out around 7–8 weeks, hereditary,[6] abnormality of the stapedial artery, early loss of neural crest cells, teratogenic agent, environmental insults, trauma, drugs such as meclizine, and large doses of Vitamin A.[7] History taken from our patient provides no evidence of any familial occurrence or exposure to the suggested etiologic agents.

Parkins and Boamah.[4] suggested possible sequence of events as follows: Initial fusion of the gums, followed by posterior cleft palate due to failure of the tongue to drop fully because of the micrognathia and the fused gums, and eventually fibrous TMJ ankylosis which ensues as a result of immobility of the mandible. This sequence may possibly explain the unusual isolated cleft of the palate noticed in our patient.

Laster et al.[6] proposed a modified classification for bony syngnathia: Type 1a: Simple anterior syngnathia, characterized by bony fusion of the alveolar ridge only and without other congenital deformity in the head and neck; Type 1b: Complex anterior syngnathia, characterized by bony fusion of the alveolar ridges only and associated with other congenital deformity in the head and neck; Type 2a: Simple zygomaticomandibular syngnathia characterized by bony fusion of the mandible to the zygomatic complex causing only mandibular micrognathia; Type 2b: Complex zygomaticomandibular syngnathia, characterized by bony fusion of the mandible to the zygomatic complex and associated with clefts or TMJ ankylosis. The patient presented here had maxillomandibular syngnathia with an isolated cleft of hard palate, therefore, belonging to the Type 1b category of the classification by Laster et al.

Most reported cases of maxillomandibular fusion are usually discovered shortly after birth since the baby is unable to open the mouth or feed normally.[9],[10],[11],[12],[13] Martín et al.[11] recommended early treatment to mobilize the jaw; this is essential to relieve the restriction of mouth opening that affects infant growth and development due to problems in feeding, swallowing, and respiration. Our patient, unfortunately, presented late when the normal facial development has been adversely affected. She presented with retrusion of the mandible and maxilla with reduction in lower third facial height. The facial asymmetry is further worsened by the hypoplasia of the right zygoma. The late presentation was probably because the patient had fusion of the jaw only on the right side and coupled with the missing upper anterior teeth, she was able to feed through the small opening available. Naikmasur et al.[12] reported a case of congenital syngnathia in a woman presenting at the age of 60 years. Similarly, in our case, the patient presented at 40 years of age and had adjusted well to her disability.

Imaging is a requisite tool in the diagnosis of syngnathia. CT with 3D reconstruction was performed which revealed the precise anatomic and structural nature of the jaw fusion, thus allowing for accurate diagnosis and formulation of an appropriate treatment plan. The maxilla is grossly hypoplastic with affected side laden with impacted teeth.

Surgery is the only choice in the definitive management of syngnathia,[6],[7] the appropriate timing of the surgical correction is beyond infancy, it should be delayed to avoid damage to the facial growth centers and facial nerves.[6],[12] One of the main challenges in the management of such cases is maintenance of the airway during anesthesia. Tracheotomy and fiberoptic intubation are the most appropriate methods for the proper management of the airway in this case.[14],[15],[16] In this patient, the airway was secured with an elective tracheostomy to facilitate general anesthesia. The right TMJ was accessed via preauricular approach and a high condylectomy was then performed. The syngnathia was approached intra-orally with right buccal incision along the slope of the fused jaw bone; the maxillomandibular fusion exposed and carefully separated via L-shaped osteotomy. Bilateral coronoidectomy was finally performed and the jaw opened with digital pressure; an intraoperative opening of about 31 mm IID was achieved. Mucosa was advanced and sutured over the osteotomy edges, while a suframycetin impregnated gauze (sufratulle) pack was placed on the area not covered by the mucosa. A significant point about our case is the discovery of an isolated cleft of the hard palate on opening the jaw; this cleft did not follow the normal embryology cleft pattern. The cleft repair was delayed because the maxilla was very hypoplastic with a very friable mucosa covering. Aggressive physical therapy was immediately commenced postoperatively as recommended by Dawson et al.,[14] this is essential to maintain the mouth opening and to prevent relapse. The patient is currently being followed-up while awaiting surgery to close the cleft palate.

  Conclusion Top

Maxillomandibular fusion in an adult with an associated isolated cleft of hard palate is rare. This congenital disorder can present with a wide range of severity. We have presented a case with complete unilateral bony fusion. The etiology is still obscure and speculative. Surgery is still the mainstay in treating this rare condition. The specific procedure would depend on the extent of involvement and deformity at the time of presentation. Bilateral coronoidectomy, unilateral high condylectomy, arthroplasty, and fibrous adhesiolysis were found appropriate and were accomplished in the present case. Early intervention is essential to prevent growth and development disturbances commonly associated with the disorder.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Yazdi I, Amir Fakhraee AH. Congenital Fusion of Maxilla and Mandible (Bony Syngnathia): A Case Report. Arch Iranian Med 2005;203:1-4.  Back to cited text no. 1
Daniels JS. Congenital maxillomandibular fusion: A case report and review of the literature. J Craniomaxillofac Surg 2004;32:135-9.  Back to cited text no. 2
Puvabanditsin S, Garrow E, Sitburana O, Avila FM, Nabong MY, Biswas A. Syngnathia and van der woude syndrome: A case report and literature review. Cleft Palate Craniofac J 2003;40:104-6.  Back to cited text no. 3
Parkins GE, Boamah MO. Congenital maxillomandibular syngnathia: Case report. J Craniomaxillofac Surg 2009;37:276-8.  Back to cited text no. 4
Rogers GF, Greene AK, Oh AK, Robson C, Mulliken JB. Zygomaticotemporal synostosis: A rare cause of progressive facial asymmetry. Cleft Palate Craniofac J 2007;44:106-11.  Back to cited text no. 5
Laster Z, Temkin D, Zarfin Y, Kushnir A. Complete bony fusion of the mandible to the zygomatic complex and maxillary tuberosity: Case report and review. Int J Oral Maxillofac Surg 2001;30:75-9.  Back to cited text no. 6
Tauro DP, Kallappanavar NK, Kiran HY, Girhe VJ. Congenital zygomatico-mandibular fusion (pseudo-syngnathia?) in conjunction with unilateral anophthalmia: Review of terminology and classification. Cleft Palate Craniofac J 2012;49:626-9.  Back to cited text no. 7
Ajike SO, Adeosun OO, Adebayo ET, Anyiam JO, Jalo I, Chom ND. Congenital bilateral fusion of the maxillomandibular alveolar processes with craniosynostosis: Report of a rare case. Niger J Clin Pract 2008;11:77-80.  Back to cited text no. 8
El-Hakim IE, Al-Sebaei MO, Abuzennada S, AlYamani AO. Congenital fusion of the maxilla and mandible (congenital bony syngnathia). Int J Oral Maxillofac Surg 2010;39:933-6.  Back to cited text no. 9
Nwoku AL, Kekere-Ekun TA. Congenital ankylosis of the mandible. Report of a case noted at birth. J Maxillofac Surg 1986;14:150-2.  Back to cited text no. 10
Martín LP, Pérez MM, García EG, Martín-Moro JG, González JI, García MB. Atypical case of congenital maxillomandibular fusion with duplication of the craniofacial midline. Craniomaxillofac Trauma Reconstr 2011;4:113-20.  Back to cited text no. 11
Naikmasur VG, Sattur AP, Joshi SK, Rai A. Congenital syngnathia: Case report and review of literature. Cleft Palate Craniofac J 2010;47:654-60.  Back to cited text no. 12
Reddy MP, Raghu SR. Congenital fusion of jaw and ankyloblepharon filiforme adnatum: Malformation and multiple systems anomaly. Indian J Plast Surg 2012;45:557-9.  Back to cited text no. 13
[PUBMED]  Medknow Journal  
Dawson KH, Gruss JS, Myall RW. Congenital bony syngnathia: A proposed classification. Cleft Palate Craniofac J 1997;34:141-6.  Back to cited text no. 14
Bali R, Sharma P, Jain S, Thapar D. Congenital fibrous maxillomandibular fusion. J Maxillofac Oral Surg 2010;9:277-9.  Back to cited text no. 15
Alfery DD, Ward CF, Harwood IR, Mannino FL. Airway management for a neonate with congenital fusion of the jaws. Anesthesiology 1979;51:340-2.  Back to cited text no. 16


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

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