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

A detailed cephalometric analysis was conducted on a sample of 31 adult mal es who underwent correction of mandibular prognathism by mandibular setback osteotomy (BSRO) with rigid fixation to evaluate the changes in uvulogloss opharyngeal morphology, hyoid bone position and head posture. Lateral cepha lograms were obtained 1-3 days prior to the operation and at standardized 6 months and 3 years post-operative follow-up. Statistical evaluation was pe rformed by paired Student's t-test and Pearson product moment correlation a nalysis. Inferior position of the hyoid bone (AH perpendicular to FH, AH perpendicul ar to ML, AH perpendicular to S) and valeculla (V perpendicular to FH) was recorded at the 6-month follow-up, a transient finding as at 3 years almost complete recovery to their pre-surgical position was noted. No posterior d isplacement of the above structures (AH-C3 Hor, V-C3) was recorded. Soft pa late length (pm-U) was increased and maintained at the long-term follow-up while its posture (NL/pm-U) became less upright. The tongue showed increase d length (V-T) and sagittal area (TA) and a more upright posture (VT/FH) at the late follow-up. Increased contact length between tongue and the soft p alate (CL) and less residual oropharyngeal area [area not occupied by soft tissues, (TA+SPA)/OPA] was found at the long-term follow-up. Craniocervical agulation (NSL/OPT, NSL/CVT) was increased indicating cervical hyperflexio n at the 3-year follow-up. Reduction of the sagittal dimension of the oroph aryngeal airway space (U-MPW) appeared at the first follow-up and was susta ined at the longest follow-up which, in conjunction with the decrease in re sidual oropharyngeal area, could raise questions regarding airway patency a fter mandibular setback osteotomy.