Temporomandibular condylar articulation and finite helical axis determination using a motion tracking system. (August 2021)

• Record Type: Journal Article
• Authors: Shu, Jingheng; Feng, Yukai; Zheng, Tinghui; Shao, Bingmei; Liu, Zhan
• Is Part Of: Medical engineering & physics. Volume 94(2021)
• Page Start: 80
• Page End: 86
• Publication Date: 2021-08
• Subjects: Finite helical axis (FHA) -- Mandibular motions -- Temporomandibular joints (TMJs) -- Temporomandibular disorder; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2021.06.007
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: l Finite helical axis (FHA) was measured via a motion-tracking system and CT scan. l FHA of the mandible during mouth opening had an "L-shaped" distribution. l FHA indicated that the mandibular protrusion was a translational motion. l FHA during lateral protrusions crossed the ipsilateral temporomandibular joint. Abstract: Kinematics play an important role in assessing the recovery of the patients' temporomandibular joint (TMJ) and occlusal functions. The finite helical axis (FHA), which simplifies three parameters in Euler-angle descriptions, provides a comprehensive insight into TMJ kinematics. Additionally, the FHA is one of the potential indicators used in the diagnosis and treatment of TMDs and the design and use of the TMJ replacement. This study aimed to illustrate the changes in the FHA of the TMJs during basic mandibular motions. Visible markers were rigidly affixed to the mandibular dentition and a helmet. Four active motions were registered: mouth opening, mandibular protrusion, and left and right lateral protrusions. According to the models reconstructed from the computed tomography of the same subject and the relative distance of the markers, subject-specific condylar tracking was achieved, and the FHAs for the four motions were determined. In addition to the irregular distribution in the initial opening, the FHA of the opening formed an "L-shaped" curve. Mandibular protrusion is a translational motion with little rotation. Additionally, the FHA crossed the ipsilateral TMJ during lateral protrusions, from initially vertical directions generally to horizontal directions at the front view. The proposed method provides a feasible way for measuring the FHA.