Relationships of changes in craniofacial morphology, head posture, and nasopharyngeal airway size following mandibular osteotomy.

The aim of the present study was to illustrate a possible relationship between changes in craniofacial morphology after mandibular osteotomy and changes in head posture and nasopharyngeal airway size. The material comprised standardized profile cephalograms of 52 patients with mandibular prognathism, all of whom underwent orthodontic adjustment before mandibular osteotomy. Mean age of the patients was 24.3 years; 12 men and 40 women participated in the study. The first profile radiograph of each patient was taken 1 day before surgical treatment in the natural head (mirror) position. All patients underwent mandibular surgery with a bilateral vertical ramus osteotomy. The cephalometric investigation was repeated approximately 1 year after the surgical procedure (means = 1.12 years). Craniofacial morphology was evaluated by 12 parameters describing sagittal and vertical jaw relationship. Head posture was evaluated by the craniocervical angulation and airway as nasopharyngeal airway size. Pearson's correlation analysis was used to evaluate the relationship between morphology, posture, and airway size before surgery and changes in these parameters after surgery. Before surgical treatment statistically significant correlations were found between posture and many morphologic variables, mostly mandibular. Small correlations were observed between posture and airway size, and airway size and morphology. After the surgical procedure, changes in posture were still related to changes in mandibular morphology, while other correlations between posture and morphology had been eliminated. Changes in nasopharyngeal airway size were not correlated to any changes in morphology, apart from maxillary prognathism, nor to changes in posture. The results indicated that mandibular morphology and function play a significant role in determining head posture.