Bite force distribution on dental arch during clenching

Abstract

This study aimed to clarify the normal pattern of bite force distribution on the dental arch during maximum voluntary clenching at intercuspal position. Bite force was measured in forty two normal dentate subjects using pressure sensitive film, “Dental Prescale 50H, type R” (Fuji Photo Film, Co.) . Bite force distribution was expressed as a percentage of bite force on each tooth to the total force. The symmetry of bite force distribution was investigated using asymmetry index, which was defined as a percentage of the difference between the right and left side bite forces to the sum (|R-L|/ (R+L) x100 [%] ) . Measured bite force ranged from 205 to 1, 963 N (mean±S.D.: 879±388 N) . The distribution of bite force was characterized by posteriorly increasing forces, and the force reached to the peak at the second molar irrespective of the presence of the third molar occlusal contacts. However, the bite force distribution on anterior teeth was smaller in the subjects with contacts at the third molar than in the subjects without contacts. Mean asymmetry index of the bite force distribution was 9.3±6.7 % in all subjects, that showed symmetrical distribution of bite force. Asymmetry index was smaller in the subjects with contacts in the third molars than in the subjects without contact. The patterns of bite force on dental arches, presented in this study, are useful for the clinical application of bite force measurement in occlusal diagnosis.