Ankyloglossia Superior Syndrome With Complex Craniofacial Anomalies: Case Report and Literature Review

Maxillomandibular Fusion Along with Fusion of Dorsal Surface of the Tongue to the Hard Palate-A Case Report

RATIONALE

This case report presents a rare combination of congenital anomalies in an otherwise healthy male infant born at 36 weeks. The infant was diagnosed with congenital maxillomandibular synechia, ectrodactyly, and ankyloglossia superior syndrome (ASS).

PATIENT CONCERNS

Inability to open the mouth completely, feeding challenges, and a cleft palate. The infant was stabilized through successful positive pressure ventilation via a face mask at birth and enteral feeding was initiated via a feeding gastrostomy.

EXAMINATION

Diagnostic tests revealed a midline palatal cleft, hypoplastic jaws, persistent metopic suture, and a bony fusion at the midline.

TREATMENT

Sectioning of the bony spur along the midline and achieving a mouth opening of 2 cm post-manipulation. The patient is under follow-up, with future treatment plans including cleft palate correction at 12 months and potential frontomandibular and lower jaw advancement depending on growth trajectories.

TAKEAWAY LESSONS

This case underscores the complexity of managing multiple congenital anomalies and the need for individualized treatment plans.

Augmented BMP4 signal impairs tongue myogenesis

Tongue muscles are derived from mesodermal cells, while signals driven by cranial neural crest cells (CNCCs) regulate tongue myogenesis via tissue-tissue interaction. Based on such mechanisms of interaction, congenital tongue defects occur in CNC-related syndromes in humans. This study utilized a pathologic model for the syndrome of congenital bony syngnathia, Wnt1-Cre;pMes-Bmp4 mouse line, to explore impacts of enhanced CNCCs-originated BMP4 signal on tongue myogenesis via tissue-tissue interaction. Our results revealed that microglossia, a clinical phenotype of congenital bony syngnathia in humans exhibited in Wnt1-Cre;pMes-Bmp4 mice due to impaired myogenesis. The augmented BMP4 signal affected the distal distribution, proliferation, and differentiation of myogenic cells as well as tendon patterning, resulting in disarrangement and atrophy of tongue muscles and the loss of the anterior digastric muscle. This study demonstrated how a CNCCs-originated ligand impaired tongue myogenesis via a non-autonomous way, which provided potential formation mechanisms for understanding tongue abnormalities in CNC-related syndromes.