The dynamic distortion of the human mandible during parafunctional and physiological loading : an in vivo clinical study

• Main Author: Malden, Nicholas John
• Published: University of Edinburgh 2011
• Subjects: 617.6
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.726452

The linear distortion of the edentulous human mandible under functional loading was measured utilizing bilateral, anterior, osseointegrated oral implants as stable markers of bone position. These parasymphyseal implants were connected to a custom-made linear variable differential transducer (LVDT) to allow the recording of changes in mandibular arch width. Custom-made maxillary and mandibular prosthetic splints were manufactured to allow for the introduction of bite force transducers positioned bilaterally and posterior to the LVDT. These recorded biting forces in Newtons simultaneously with the LVDT recording in microns. This made possible further analysis of functional force in relation to the distortion of the human mandible. In total 16 human subjects were investigated from which 14 subjects provided useful data. The results were compared with previous studies which examined distortion of the human mandible during parafunctional activity and studies examining bite force levels in dentate as well as edentulous individuals. The results suggested that the level of distortion of the human mandible in function was similar with that seen in parafunctional activity and was at times was greater. The study also suggested that knowledge of the anatomical form of the atrophic lower jaw could be used to estimate the degree of distortion expected in a particular jaw during function. This, in turn, could inform on the optimal positioning of implants in the anterior of the mandible where the reduction of functional induced lateral stresses are considered important.