Pure rotation in the temporomandibular joint during jaw opening? A digital motion analysis

Bálint Jász; Tamás Balogh; Szilvia Ambrus; Péter Schmidt; Gréta Lilla Bányai; Szandra Körmendi; Máté Jász

doi:10.1038/s41405-024-00213-8

Pure rotation in the temporomandibular joint during jaw opening? A digital motion analysis

BDJ Open. 2024 Apr 18;10(1):32. doi: 10.1038/s41405-024-00213-8.

Authors

Bálint Jász¹, Tamás Balogh², Szilvia Ambrus³, Péter Schmidt³, Gréta Lilla Bányai⁴, Szandra Körmendi³, Máté Jász³

Affiliations

¹ Semmelweis University, Faculty of Dentistry, Department of Prosthodontics, Budapest, Hungary. jasz.balint@semmelweis.hu.
² Parodont Clinic, Budapest, Hungary.
³ Semmelweis University, Faculty of Dentistry, Department of Prosthodontics, Budapest, Hungary.
⁴ Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Budapest, Hungary.

Abstract

Objective: In the temporomandibular joint two separate movements of rotation and translation occur in two articular spaces during mouth opening. Over the years, the approach has changed considerably, but it is still subject to controversy as to which of these movement is involved in the initial stage of mouth opening. In the present study, the extent of rotation and translation was investigated in the first 5 mm of mouth opening.

Materials and methods: The study was carried out on 46 volunteers. Anamnesis was taken and patients were examined. For the investigation, an ultrasonic digital motion analyser (KaVo Arcus Digma 2) was applied. The measurements were made after calibration to an arbitrary axis. Each participant performed three open-close movements in succession, starting from maximum intercuspal position.

Results: Data were statistically processed using cubic spline interpolation. Linear regression was then used. The resulting line is significantly (p < 0.0001) different from the horizontal that represents only rotational movement.

Conclusion: The results show that during mouth opening from maximum intercuspal position, translation is present continuously in addition to rotation. Therefore, it might be time to re-evaluate the principle of a pure rotational approach.