Calnan 1953 - BJPS - Submucous Cleft

Summary

Submucous cleft palate is a rare condition that is often overlooked in diagnosis. It is characterized by a cleft in the soft palate that is covered by oral mucosa, giving the appearance of a normal palate. However, muscle union is deficient. This results in velopharyngeal incompetence, causing nasal speech known as rhinolalia.

The condition may be associated with cleft lip, or be an isolated defect. The etiology is unknown but likely has a genetic component. Pathologically, there is a fibrous band representing the cleft, with absence of the levator palatini and palatopharyngeus muscles across the cleft. Clinically, in addition to nasal speech, patients have a short palate, bifid uvula, and transverse furrow on the palate. Lateral radiographs demonstrate failure of the soft palate to reach the posterior pharyngeal wall during speech, though it can during forced effort like blowing. This differentiates it from cerebral agenesis conditions with poor palatal function.

Differential diagnoses include congenital short palate, paralysis, trauma from tonsillectomy, and functional causes. But thorough examination, radiographs, and family history can distinguish submucous cleft palate.

The treatment is surgical - excision of the fibrous cleft and V-Y retroposition of the soft palate to lengthen it. This should be done before speech develops, around 12 months of age, to prevent abnormal speech patterns. Of 18 cases treated by the authors, 14 achieved normal speech post-operatively. Most required some speech therapy to correct residual issues like hypernasality. Success depends on re-establishing velopharyngeal competence. If speech remains poor months after surgery, reasons for failure should be sought. Two cases were found to have persistent deep pharynx and short palate radiographically. Both improved with pharyngoplasty.

Overall, normal speech can be expected after surgical repair and speech therapy in 80% of cases. But thorough postoperative assessment is key, with further procedures like pharyngoplasty considered for failures. The aim should be normal speech through establishment of a competent velopharyngeal sphincter. Submucous cleft palate may be rare, but its proper identification and treatment can have a major impact on a patient's speech and quality of life.