Effect of surgical reduction of the tongue on dentofacial structure following mandibular setback.

PURPOSE: The objective of this study was to examine the effect of partial glossectomy on skeletal stability and postoperative changes after mandibular setback. PATIENTS AND METHODS: Sagittal split ramus osteotomy with semirigid fixation was performed in 21 patients with tongue reduction surgery (tongue reduction group) and was performed in 19 patients without tongue reduction (control group). Lateral cephalograms were evaluated preoperatively, immediately postoperatively, and 1 year postoperatively, to analyze the maxillomandibular relation and soft tissue morphology.
RESULTS: The results in both groups suggested that posterior and downward movement of the hyoid bone and narrowing of the upper pharyngeal airway at the tongue base were evident immediately postoperatively and rebounded to their original position 1 year after surgery. The tongue reduction had an effect to prevent narrowing of the posterior airway space and a tendency to reduce clockwise rotation of the mandible after the setback, but there was no significant difference between the 2 groups in the horizontal and vertical changes of incisal position at 1 year.
CONCLUSION: Adaptation of the hyoid bone position and tongue mass to the altered environment after setback surgery may preclude the necessity for downsizing the tongue against the relapse in patients with normal tongue morphology.