Abstract
Congenital oral synechiae are rare fibrous bands connecting the maxillary and mandibular structures. We report a male neonate referred to our oral and maxillofacial surgery service at 16 days of age with bilateral anterior and posterior oral synechiae, an atypical submucous cleft palate, and a concurrent left-sided congenital diaphragmatic hernia. The synechiae were undetected prenatally and obstructed neonatal intubation in the delivery suite, compounding the immediate airway demands of the diaphragmatic hernia. This triad has not been previously described, and comprehensive genetic testing identified no causative mutation. Following surgical repair of the hernia and release of the synechiae, oral feeding was established. Two years of follow-up demonstrate persistent challenges with feeding, speech, hearing, and recurrent infection, driven primarily by an unrepaired atypical palatal cleft. This case highlights the importance of recognizing oral synechiae when neonatal intubation fails unexpectedly, and the need for co-ordinated multidisciplinary care.
Introduction
Congenital oral synechiae are fibrous or mucomuscular bands that abnormally tether one part of the oral cavity to another. First described in 1887, <100 cases have been reported since Gartlan's 50-case series in 1993 [1]. Incidence is ~1 in 80 000 live births [2]. Olusanya and Akadiri classify them as fibrous (Type 1) or bony (Type 2) with anterior, posterior, and ramus-extending subtypes [3]. They occur in isolation or with recognized syndromes—Van der Woude and popliteal pterygium syndrome being the most notable, both IRF6-related [4] with cleft palate being the most frequent associated structural anomaly [5].
Congenital diaphragmatic hernia (CDH) affects 2–3 per 10 000 live births with mortality of 30%–50% [6]. A registry study of 13 600 CDH patients found 0.7% had a co-occurring orofacial cleft, with 8p23.1 deletion, Wolf-Hirschhorn syndrome, and trisomy 13 as recurring genetic associations [7]. The specific triad of oral synechiae, CDH, and cleft palate has not been previously described.
Case report
A male infant was referred at 16 days of age. He was born at 39-weeks following a prenatal diagnosis of left-sided CDH on third-trimester ultrasonography for large fundal height, 5 days before delivery, further demonstrated by X-ray after birth (Fig. 1). Trisomy screening was low risk; parents were non-consanguineous with no relevant family history.
Neonatal chest X-ray showing bowel herniated into the left chest with rightward mediastinal shift, consistent with left-sided congenital diaphragmatic hernia.
The neonatal intensive care unit team attended delivery in anticipation of the CDH. Neonatal intubation proved unexpectedly difficult, requiring multiple attempts. Only after formal maxillofacial review did the cause become clear: an anterior fibrous band connecting the lower lip to the maxilla had physically obstructed the oral aperture at the very moment airway control was most urgently needed (Fig. 2). As his father later reflected: ‘The thing that required urgent intubation and the thing that made intubation dangerous had arrived together, in the same child, at the same moment.’ The band detached spontaneously within 24 hours, leaving a lip pit remnant on the lower vermilion. Bilateral posterior bands remained unassessed while the infant was intubated.
Intraoral photograph showing bilateral fibrous bands connecting lower alveolar ridge to palate, restricting mouth opening, with lip pit on lower lip.
CDH was repaired on Day 5 via primary laparotomy, during which the paediatric surgeons noted additional intraoral bands. Examination at 16 days revealed bilateral posterior fibrous bands extending from the lower alveolar ridge to the palate (Fig. 3), classified as Olusanya Type 1, bilateral posterior, subtype 1b/1c. Palatal assessment demonstrated a submucous cleft with marked posterior hypoplasia in a morphology inconsistent with a standard cleft pattern. The infant had been nasogastrically fed from birth. Investigations including spinal, renal, and cranial ultrasonography and echocardiography were unremarkable beyond spontaneously resolving cardiac shunts and pulmonary hypertension. Videofluoroscopic swallow study confirmed safe mechanics. Chromosomal microarray and targeted genetic panels were negative.
Intra-operative intraoral photograph showing improved mouth opening with residual fibrous bands posteriorly following anterior surgical release.
Surgical release of the bilateral posterior synechiae was performed under general anaesthesia once the infant was cardiorespiratorially stable following CDH repair. Sharp division of the bands took under 15 minutes without complication, with immediate improvement in oral aperture evident post-operatively. The surgical sites healed rapidly and completely (Fig. 4), and oral feeding was established over the following days. Atypical palatal anatomy precluded standard cleft repair; reassessment with the regional cleft service was planned for 18 months.
Extraoral photograph at 4 weeks post-operatively showing healthy mucosal healing and maintained oral opening without recurrence of synechiae.
At two years, the child's course has remained complex. Submucous cleft palate was confirmed at 12 months and repair is awaited, with speech limited to vowel sounds and nasal consonants accordingly. Tongue tie was divided in infancy. Hypodontia has emerged with the deciduous dentition. Weight has tracked from the 2nd to the 9th centile on high-energy formula and specialist teats. Hearing assessments suggest mild-to-moderate loss, confounded by recurrent otitis media. Prophylactic azithromycin commenced at 18 months has partially reduced a pattern of hospital admissions every 6 to 10 weeks. Severe respiratory syncytial virus bronchiolitis at 6 months required paediatric intensive care unit admission. An inguinal hernia has been identified, surgery pending. Genetic testing remains negative; whole-genome sequencing is planned. The father describes navigating multiple specialist teams without a co-ordinating pathway as ‘the hardest part of the journey.’
Discussion
Three features make this case unusual: simultaneous anterior and posterior oral synechiae, concurrent CDH, and an atypical cleft palate, in a neonate with no identifiable genetic cause. This combination has not been previously reported.
The anterior band obstructed the very intubation mandated by the CDH. Uchi et al. described a very-low-birth-weight infant in whom oral bands made intubation impossible, requiring surgical release under local anaesthesia on Days 10 and 17 [8], and Ho et al. reported a similar near-miss [9]. No consensus airway protocol exists for this situation; individualized planning with prenatal awareness is essential [10].
Oral synechiae form embryologically between weeks 7 and 8 of gestation [11], coinciding with diaphragm closure and secondary palate development — a shared developmental window that may underlie this case. Nord et al. found a 0.7% co-occurrence of orofacial clefts in 13 600 CDH patients, with 8p23.1 deletion (containing GATA4, expressed in the developing diaphragm), Wolf-Hirschhorn syndrome, and trisomy 13 as recurring associations [7]. Their CDH-plus-cleft cohort faced a 3.9-fold higher 7-day mortality than isolated CDH and was half as likely to be discharged, placing this infant's 2-year developmental trajectory in sobering context. Nord et al. specifically advocate trio whole-genome sequencing when panel testing is negative [7], as is now planned for this child.
Comparison with Uchi et al. [8] is instructive. Their patient had syndactyly, cryptorchidism, and cleft palate, ultimately meeting PPS diagnostic criteria. Our patient shares the cryptorchidism, cleft palate, and lip pitting but has no popliteal webbing, no syndactyly, and negative IRF6 testing, and the aetiology remains unknown.
Surgical release was effective and uncomplicated, consistent with the literature [5, 12, 13]. The greater challenge has been the downstream consequences of the unrepaired atypical palatal defect (Fig. 5) and the sustained respiratory infection burden. The family's account of navigating multiple poorly co-ordinated services reflects a well-recognized problem in complex craniofacial care [14] with real developmental consequences, a reminder that co-ordinated care is a clinical necessity. Oral synechiae must be considered when neonatal intubation is unexpectedly difficult alongside CDH, and negative panel genetics should prompt whole-genome sequencing rather than diagnostic closure [7, 15].
Photograph demonstrating atypical palatal appearance.
Acknowledgements
We are grateful to the patient's parents for their written consent to publish this case and for contributing the family perspective. We thank the neonatal, paediatric surgery, and cleft teams for their collaborative care of this child.
Conflicts of interest
None declared.
Funding
No funding was received for this work.
Data availability
All data are contained within the article.
Ethics
Not required for anonymized case report. Written informed consent obtained from patient's parents for publication of clinical details and images.
