Reduced three-dimensional airway volume is a function of skeletal dysmorphology in Treacher Collins syndrome.

BACKGROUND: Children with Treacher Collins syndrome frequently present with obstructive sleep apnea and respiratory insufficiency. The purpose of this study was to three-dimensionally calculate upper airway volume in these patients. The authors also assessed the correlation between bony craniofacial morphology and spatial position with airway volume.

METHODS: Thirty Treacher Collins syndrome patients who have not been operated on were compared with a sample of 35 age- and sex-matched unaffected controls. Upper airway volume was stratified into retropalatal and retroglossal aspects. Three-dimensional craniometric findings were compared between patients and controls. Among Treacher Collins syndrome patients, the authors assessed the relationship of craniofacial morphology and spatial positioning to airway volume. Statistical analyses included independent sample t tests and Pearson correlation coefficient analyses.

RESULTS: Decreased total upper airway volume (p = 0.034) was found in the Treacher Collins syndrome group, attributable primarily to a decrease in retroglossal airway volume (p = 0.009). Regarding three-dimensional craniometric variables, maxillary and mandibular length (r = 0.76, p < 0.001; and r = 0.68, p < 0.001), and the anterior and posterior cranial base (r = 0.61, p < 0.001; and r = 0.77, p < 0.001) were positively correlated with airway volume in Treacher Collins syndrome patients. Transverse internal diameters of the upper airway were also positively correlated with airway volume (r = 0.635, p = 0.001; and r = 0.511, p = 0.006); however, no correlation was shown for the anteroposterior airway diameters.

CONCLUSIONS: Three-dimensional analysis revealed diminished upper airway volume in Treacher Collins syndrome, with the retroglossal region being the most severely constricted. Maxillomandibular dysmorphologies, and their relationship to the cranial base, correlated significantly with airway findings.