Sagittal mandibular development effects on the dimensions of the awake pharyngeal airway passage.

OBJECTIVE: To test the hypothesis that sagittal mandibular development has no effects on the dimensions of the awake pharyngeal airway passage.

MATERIALS AND METHODS: Ninety-one subjects (age 15-25 years) with a normal vertical growth pattern of the mandible, normally positioned maxilla, and various sagittal mandibular developments were divided into three groups based on the sagittal mandibular development. Group I included 37 subjects who had a normally positioned mandible (76 degrees < or = angle between 'S,' 'N,' and 'B'; it represents the antero-posterior position of the maxilla in relation to the anterior cranial base [SNB] < or = 82 degrees ), Group II included 31 subjects in whom the mandible was retrognathic (SNB < 76 degrees ), and Group III included 23 subjects in whom the mandible was prognathic (SNB > 82 degrees ) in relation to the anterior cranial base. Lateral cephalograms were traced manually to evaluate the pharyngeal airway passage.

RESULTS: The length of the soft palate was significantly smaller in mandibular prognathism subjects than in subjects with mandibular retrognathism (P < .01). The thickness of the soft palate was significantly greater among subjects with mandibular prognathism than in subjects with normal (P < .01) and retrognathic (P < .001) mandibular development. The sagittal mandibular development had no effect on the dimensions of the nasopharyngeal and hypopharyngeal airway passage. The depth of the oropharynx was comparable among the subjects with normal and retrognathic mandibles but was greater (P < .001) among subjects with mandibular prognathism.

CONCLUSIONS: The hypothesis is rejected. Sagittal mandibular development had significant effects on the dimensions of the awake pharyngeal airway passage.