Evaluation of masticatory function after orthognathic surgery in mandibular prognathism

Objective: This study was to compare masticatory function before orthognathic surgery and 3 months after orthognathic surgery in mandibular prognathism patients and to study the relationship between the subjective assessment and the objective assessment of masticatory function. Material and method: The study group was 10 mandibular prognathism patients who had undergone pre-surgical orthodontic treatment. The masticatory function test was done before orthognathic surgery and 3 months after surgery. The control group was 10 skeletal class I patients with healthy dentate. Before the test, the dentition and the numbers of occlusal contact point were recorded in all subjects. The masticatory function test could be done by subjective and objective assessment. The subjective assessment was evaluated by using 7-item questionnaire. The objective assessment was evaluated by mixing ability test and maximum bite force test. To compare masticatory function between study and control group, the independent t-test was used. In comparison between pre- and post- operation in the study group, the paired t-test was used. Pearson correlation was used to analyze the relationship between the subjective and objective assessment. Result: The clinical test showed the increasing of questionnaire score, the color of chewed gum, the maximum bite force and the numbers of occlusal contact point. There was no statistical significance (p‹0.05) neither the relationship between subjective and objective assessment in the study nor the control group. Conclusion: The masticatory function efficiency in the study group was close to the control group without statistical significant at 3 months after surgery. The statistical significance was not found in both the relationship between subjective and objective assessment.