Surgical mandibular advancement and changes in uvuloglossopharyngeal morphology and head posture: a short- and long-term cephalometric study in males

The aim of the present study was to investigate, by means of an extensive c ephalometric examination, the alterations which took place in hyoid bone po sition, head posture, position and morphology of the soft palate, and tongu e acid sagittal dimensions of the pharyngeal airway after mandibular advanc ement osteotomy for the correction of mandibular retrognathism. The sample consisted only of adult males who underwent mandibular advancement by bilat eral sagittal ramus split osteotomy (BSRO) with rigid fixation. Profile cep halograms were obtained 1-3 days before surgery (20 subjects), and 6 months (20 subjects) and 3 years (19 subjects) after the surgery. Statistical eva luation was performed by paired Student's t-test and Pearson product moment correlation analysis. At the short-term follow-up, hyoid bone and vallecula assumed a more superi or (AH perpendicular to FH, AH perpendicular to ML, AM perpendicular to S, V perpendicular to FH) and anterior position (AH-C3 Hor, V-C3), which was m aintained at the long-term follow-up. The soft palate (NL/PM-U) became more upright at the short-term follow-up. The tongue demonstrated a transient i ncrease in height (H perpendicular to VT) and a less upright position (VT/F H) at the long-term observation. In addition, a more upright cervical spine (OPT/HOR, CVT/HOR) was recorded at the long-term follow-up. The pharyngeal airway space at the level of the oropharynx (U-MPW) and the retroglossal s pace at the base of the tongue (PASmin) showed an increase in the sagittal dimension at the short-term follow-up. Significant widening at the PASmin l evel was sustained at the long-term follow-up, indicating that mandibular a dvancement osteotomy could increase airway patency and be a treatment appro ach for sleep apnoea in selected patients.