Masticatory function in patients with dentofacial deformities before and after orthognathic treatment-a prospective, longitudinal, and controlled study

Objectives: The aim of this study was to investigate the self-estimated masticatory ability and masticatory performance in patients with dentofacial deformities before and after orthognathic treatment; in comparison to an age-and gender-matched control group. Subjects and methods: The masticatory ability and masticatory performance were evaluated in 121 consecutive patients (treatment group), referred for orthognathic treatment. Eighteen months after treatment, 98 patients (81%) completed a follow-up examination. Masticatory ability was assessed on a visual analog scale, while the masticatory performance was evaluated by a masticatory test using round silicon tablets. Signs and symptoms of temporomandibular disorders (TMD) were registered by a clinical examination and a questionnaire. The control group comprised 56 age-and gender-matched subjects who were examined at baseline. Results: At the baseline examination, the treatment group had a significantly lower masticatory ability and performance compared with the control group. After treatment, the masticatory ability significantly improved in the treatment group and reached the same level as in the control group. The masticatory performance index increased significantly but was still lower than in the control group. Both the masticatory ability and masticatory performance were affected by the number of occlusal contacts during maximal biting pressure and by the self-estimated overall symptoms of TMD. Conclusions: Patients with dentofacial deformities, corrected by orthognathic treatment, have a significant positive treatment outcome in respect of masticatory ability and masticatory performance. Furthermore, the occlusion and symptoms of TMD have an impact on both masticatory ability and masticatory performance.