Relationship between maximum bite force and the gonial angle in crossbite

Introduction: Modification of overjet and posterior crossbite (PC) can affect the maximum bite force (MBF), in turn affecting the shape of the gonial angle (GA). Aims: To analyze MBF in PC and the correlation between MBF and GA in adults. Method: The evaluation was performed in 160 individuals, i.e., 88 men and 72 women (aged 18 to 39 years), divided into two groups: without PC, comprising 130 individuals (75 men and 55 women) and with PC, comprising 30 individuals (13 men and 17 women). The method consisted of the following steps: anamnesis, evaluation of the occlusion, MBF evaluation, and GA measurement. Evaluation of the occlusion was performed in order to classify the occlusion as with or without PC. The MBF was measured with a digital dynamometer [DDK/M model (Kratos, São Paulo, Brazil)]. Three measurements were performed in all individuals with the device positioned on the occlusal surface of the first molars, alternating with one-minute intervals, following which the means were calculated. GA measurement was performed with a goniometer on both, the right and left sides. The data collected were analyzed statistically by parametric tests, considering a significance level of 0.05 (5%). Results: MBF was higher for men, independent of the group and the side; in the group without PC, MBF was different between the sides just for women. Between the groups, MBF was higher for men in the group without PC. The correlation found between MBF and GA in both groups was negative or inversely proportional. Conclusions: The group with PC showed lower MBF in men and the correlation between MBF and GA was negative, suggesting that higher the MBF, the lower is the GA or vice versa. Correspondence to: Silvana Bommarito, Speech therapist; Associate professor, Department of Speech Pathology, Universidade Federal de São Paulo – UNIFESP/EPM, São Paulo, Brazil, E-mail: [email protected]