Occlusal bite force measurements in different malocclusions

Abstract

Dento-facial anomalies have been diagnosed for centuries. The diagnosis or observation thereof is reported to date back to the Fifth Century AD where Hippocrates observed and noted numerous craniofacial deformities (Moyers, 1988) Through a complex process of reception, selection and categorizationthe human form particularly the cranium, jaws and related soft tissue structures, have been studied and categorized over the years (Moyers, 1988). Dockrell (1952) focused on the aetiology of malocclusion and through extensive work on the topic, established an equation for the improved identification of aetiology of malocclusion. This equation essentially communicates that a causative factor will act at a specified time, on an identified tissue, to produce particular results. Thus resulting in a deviation from the accepted “normal” relationship. This will result in the development of an archetypally defined, classifiable malocclusion. These so termed causative factors as elicited to in the equation play a pivotal role in the outcomes or resultant malocclusions (Dockrell, 1952). The plasticity in aetiology and resultant Skeletal or dental positional discrepancy should not be overlooked. Multiple factors may act together stabilising each other thus lessening the severity of the expected effect. This research project aims to identify the potential of occlusal bite forces as a causative factor in the “orthodontic equation” and shed light on timing as well as resulting Skeletal and growth effects of variance in occlusal force. Occlusal force is a combined and quantifiable measurement of contributory muscle strength. Through this study a comparative analysis of the occlusal force will be carried out amongst subjects exhibiting differences in age, gender, race, and growth pattern. This study aims to elucidate the influence of occlusal forces and masticatory muscle strength in relation to the resulting craniofacial development. Data was collected from patients exhibiting various dental classes namely Class I, Class II and Class III dental and Skeletal patterns. Bite force strength of patients in primary, mixed and permanent dentition was measured using an occlusal force meter. The occlusal force meter was sourced from a Japanese based company, Nagano Keiki Co. LTD. The readings were done in Kilo newton, which is the standard international (SI) measurement of force. The study population consisted of 180 male and 180 female subjects. This group was split into Skeletal Class I, II and III subjects and then further divided into the three directions of growth (Horizontal, normal and Vertical). The relationship of bite force to Skeletal Class and growth direction was analysed using mean readings from five points of reference on each subject. Analysis of covariance was carried out on the data set with a mean age of 15,33 years (covariant). There was a significant difference found in the bite forces between growth direction and Skeletal Class P<0,05. There was also and interaction found between Skeletal classes and direction of growth. These findings are supportive to the hypothesis that a relationship exists between bite force and malocclusion.