Jörg W Kleinfelder1, Klaus Ludwigt. 1. Department of Periodontology, University of Nijmegen, The Netherlands. g.kleinfelder@dent.kun.nl
Abstract
BACKGROUND: Chewing and biting forces are supposed to be limited by sensory input from periodontal mechanoreceptors. This is why the threshold level of those receptors should be lower in teeth with reduced periodontal tissue support. The purposes of the present study were to evaluate the influence of reduced periodontal tissue support on maximal bite force in natural dentitions and to study the effect of splinting on maximal bite force. METHODS: In 10 patients with reduced periodontal tissue support (test), as well as in 10 periodontally healthy subjects (control), maximal bite force was measured. The remaining periodontal ligament area in the test group was calculated from x-rays. Bite force was assessed at 4 mm mouth opening in the premolar region without and following splinting of the posterior teeth and transduced using a strain-gauge (full-bridge circuit). Maximal bite force measured with and without splinting was compared between test and control subjects, and within each group. RESULTS: In test subjects, the mean periodontal ligament area was 48.5% (SD = 10.1) across first premolars and 50.0% (SD = 12.2) across posterior teeth (control: 100%). In test subjects, the mean maximal bite force without splinting was 357 N (SD = 70), and in control subjects, 378 N (SD = 66; P > 0.05). After splinting, the bite force in test subjects was 509 N (SD = 75), and in control subjects, 534 N (SD = 49; P > 0.05). Bite force before and after splinting was P < 0.05 within each group. CONCLUSIONS: Reduced periodontal tissue support does not seem to limit bite force with maximal strength in natural dentitions as measured by a device that opens the bite by 4 mm. Furthermore, maximal biting forces at 4 mm mouth opening are increased when molar teeth are included in a posterior splint.
BACKGROUND: Chewing and biting forces are supposed to be limited by sensory input from periodontal mechanoreceptors. This is why the threshold level of those receptors should be lower in teeth with reduced periodontal tissue support. The purposes of the present study were to evaluate the influence of reduced periodontal tissue support on maximal bite force in natural dentitions and to study the effect of splinting on maximal bite force. METHODS: In 10 patients with reduced periodontal tissue support (test), as well as in 10 periodontally healthy subjects (control), maximal bite force was measured. The remaining periodontal ligament area in the test group was calculated from x-rays. Bite force was assessed at 4 mm mouth opening in the premolar region without and following splinting of the posterior teeth and transduced using a strain-gauge (full-bridge circuit). Maximal bite force measured with and without splinting was compared between test and control subjects, and within each group. RESULTS: In test subjects, the mean periodontal ligament area was 48.5% (SD = 10.1) across first premolars and 50.0% (SD = 12.2) across posterior teeth (control: 100%). In test subjects, the mean maximal bite force without splinting was 357 N (SD = 70), and in control subjects, 378 N (SD = 66; P > 0.05). After splinting, the bite force in test subjects was 509 N (SD = 75), and in control subjects, 534 N (SD = 49; P > 0.05). Bite force before and after splinting was P < 0.05 within each group. CONCLUSIONS: Reduced periodontal tissue support does not seem to limit bite force with maximal strength in natural dentitions as measured by a device that opens the bite by 4 mm. Furthermore, maximal biting forces at 4 mm mouth opening are increased when molar teeth are included in a posterior splint.