A Review of Temporomandibular Disorder and an Analysis of Mandibular Motion
type: CreativeWork
description: This study quantified mandibular motion of asymptomatic subjects upon jaw opening and closing. Five males, mean age of 28 years, agreed to participate; they showed no sign or symptom of temporomandibular disorder (TMD) on clinical examination or by anamnestic history. Mandibular motion for each subject was measured with a tracking system and software utilizing the Screw Displacement Axis (SDA), which is a mathematical approach to analyzing and quantifying the movement of an object in three dimensions. Rotation and translation were calculated, as well as two- and three-dimensional charting of condylar path and sagittal condylar intercepts. Furthermore, analyses examined error propagation, change in error amplitude with varying test conditions, and a comparison between theoretical and experimental data. The mean maximum roation around the screw displacement axes was 25.0o (sd=4.0o). Mean translation along the screw displacement axes was 2.3 mm (sd = 0.68 mm). The SDA intersection plots showed that the paths of motion for all subjects were posterior and inferior to the candyle. During opening, paths start nearer to the condyle and travel inferiorly and anteriorly. Jaw closing followed the reverse path (superior and posterior) with the final position approximating the area of the initial axis. Mean SDA intercepts with the sagittal plane of the condyle were positioned posterior and inferior of the selected center of the condyle. SDA position and orientation parameters were inversely related to the rotational increment. As rotational increments approached 5o, there was little change in the uncertainty values, indicating that data should be processed at increments of at least 4o to 5o. Coordinate data obtained with the tracking systemn displayed an error that was not present when the targets were stationary, nor did its amplitude change with a change in velocity. These observations led to the idea that the error associated with the tracking system relied purely on target p…
abstract: This study quantified mandibular motion of asymptomatic subjects upon jaw opening and closing. Five males, mean age of 28 years, agreed to participate; they showed no sign or symptom of temporomandibular disorder (TMD) on clinical examination or by anamnestic history. Mandibular motion for each subject was measured with a tracking system and software utilizing the Screw Displacement Axis (SDA), which is a mathematical approach to analyzing and quantifying the movement of an object in three dimensions. Rotation and translation were calculated, as well as two- and three-dimensional charting of condylar path and sagittal condylar intercepts. Furthermore, analyses examined error propagation, change in error amplitude with varying test conditions, and a comparison between theoretical and experimental data. The mean maximum roation around the screw displacement axes was 25.0o (sd=4.0o). Mean translation along the screw displacement axes was 2.3 mm (sd = 0.68 mm). The SDA intersection plots showed that the paths of motion for all subjects were posterior and inferior to the candyle. During opening, paths start nearer to the condyle and travel inferiorly and anteriorly. Jaw closing followed the reverse path (superior and posterior) with the final position approximating the area of the initial axis. Mean SDA intercepts with the sagittal plane of the condyle were positioned posterior and inferior of the selected center of the condyle. SDA position and orientation parameters were inversely related to the rotational increment. As rotational increments approached 5o, there was little change in the uncertainty values, indicating that data should be processed at increments of at least 4o to 5o. Coordinate data obtained with the tracking systemn displayed an error that was not present when the targets were stationary, nor did its amplitude change with a change in velocity. These observations led to the idea that the error associated with the tracking system relied purely on target p…
author: Lehman-Grimes, Shawn Patrick
keywords: TMJ, TMD (temporomandibular disorder), Joint Motion, Screw Displacement Axis (SDA), Medicine and Health Sciences
date published: 2005-05-01T07:00:00Z
date modified: 2026-07-24T05:00:11Z
provider: University of Tennessee Health Science Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Tennessee Health Science Center