Age and gender influence on maximal bite force and masticatory muscles thickness

Abstract

The present study aimed investigate the age and gender influence on maximal molar bite force and at outlining the criteria for normal masticatory muscle development in a sample of 177 Brazilian Caucasian dentate individuals aged 7-80 years divided into five age groups: I (7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years), and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided in respect to gender (20 M/20 F). Bite force was recorded with a mouth-adapted 1000N dynamometer and the highest out of three records was regarded as the maximal bite force. The data were submitted to multivariate statistical analysis (SPSS 17.0 p<0.05). Effects of group and gender were found, but no interactions between them. The ANOVA showed significant differences between groups bilaterally. Bonferroni's test showed that group I had significantly lower bite force means at both sides as compared to all groups, except group V. No differences were found between the left and right sides. In all the groups, gender was found to be a significant factor associated with maximal bite force. A global comparison including all the subjects and measures showed that the means of men were approximately 30% higher than those of women. Within-group comparisons yielded similar results in all groups. Muscle thickness was measured with a SonoSite Titan ultrasound tool using a high-resolution real-time 56mm/10MHz linear-array transducer. Three ultrasound images were obtained from the bilateral masseter and temporal muscles at rest and at maximal voluntary contraction. The means of the three measures in each clinical condition were analyzed with multivariate statistical analysis (SPSS 17.0 p<0.05). A gradual increase in thickness of the masseter and temporal muscles was found both at rest and maximal voluntary contraction for groups I to IV, whereas a decrease in muscle thickness was observed in group V. Multivariate analysis showed that in both conditions there was an effect of group and gender. The study of the development of the stomatognathic system in relation to age and gender can provide useful data for the identification of normal and impaired functioning patterns. The results of this study indicate that age and gender are associated with structural and functional alterations in the muscles of the stomatognathic system.

Relationship between maximum bite force and the gonial angle in crossbite

“…When analyzing the MBF results, we found that men showed higher MBF compared to women, regardless of the side, and these findings are in agreement with studies by Bonakdarchian, Askari and Askari [7], Palinkas et al [8], Koç, Dogan and Bek [9], de Abreu et al [10], Takaki, Vieira and Bommarito [11], and Roldán et al [12].…”

“…These findings are not in agreement with Bonakdarchian et al [7], Palinkas et al [8], de Abreu et al [10], which did not find any significant difference between the right and left sides in both sexes, in individuals with absence of sagittal alterations.…”

“…In the study by Choi et al [19], the authors did not describe different MBF values between the sides, nor specified if the cross bites were unilateral, bilateral, or both. In their results, despite the evidence showing difference in MBF between men and women [7][8][9][10][11][12] similar to our study, the total means involving both sexes in each group were considered. The crossbite group had MBF of 475 N, similar to the value observed in our study, i.e., 447.6 N, when considering both the sexes.…”

“…In the study by Palinkas et al [8], where the same device was used, the authors considered MBF as the highest force obtained in three measurements, in a group with similar ages to our sample. The study reported lower values, with means of 339 N on the right side and 348 N on the left side for men, and 221 N on the right side and 247 N on the left side for women.…”

Effect of Radiation on the Performance of the Stomatognathic System – a Pilot Study

“…The measures were taken from the mandibular right and left first molar regions, where the maximal bite force occurs [9,10]. During the procedure, the patients sat on a chair, with the arms extended along the body and the hands lying on the thighs, and were instructed and trained on how to bite the dynamometer, to ensure the reliability of the procedure.…”