Background and purpose : Patients with 22q11.2 deletion syndrome (DS) present a spectrum of functional and anatomic abnormalities that may contribute to alterations in velopharyngeal (VP) valving, including cleft palate or submucous cleft palate, palatopharyngeal hypotonia, adenoid hypoplasia, cervical spine abnormalities and platybasia. Platybasia corresponds to an anatomical abnormality of the skull base in which the anterior cranial base angle is more obtuse. This anatomical alteration may determine an altered position of the posterior wall of the pharynx, therefore it may influence the VPI. The objective of this study is to determine the relationship between the angle of the skull base and velopharyngeal insufficiency (VPI) in patients with 22q11.2 DS. This will contribute to determine the best treatment option in the management of VPI.
Methods : 23 patients with 22q11.2 DS between the ages of 6 and 27 years (mean age 13.1 years), were included in the study group. Each patient was diagnosed with a 22q11.2 deletion as confirmed by fluorescence in situ hybridization analysis. Every patient underwent cephalometric characterization by a single operator to determine alterations in the skull base. Patients with severe mental retardation and evident alveolar cleft were excluded. In these patients the presence of platybasia was determined, in addition to a speech evaluation to establish the presence of VPI with its respective severity.
Results : 21 of the 23 patients (91%) had platybasia as anatomical characteristic of the cranial base. Of these patients, 85% had VPI with scores up to 5.
Conclusions : There is a relationship between the presence of platybasia and VPI in patients with the 22q11.2 DS.
Key words : 22q11.2 deletion syndrome; platybasia; velopharyngeal insufficiency