Digital motion analysis of temporomandibular joint functions
Jász Bálint
Dental Research Division
Dr. Varga Gábor
SE Fogorvoskari Oktatási Centrum
2025-05-28 13:00:00
Dental Research
Dr. Varga Gábor
Dr. Jász Máté
Dr. Vaszilkó Mihály
Dr. Baráth Zoltán
Dr. Kellermayer Miklós
Dr. Dézsi Anna
Dr. Nagy Ákos
The TMJ is in many ways the most unique joint in our body. Examination methods that have become available in the 21st century have allowed much more accurate and much more complex analysis of these joint than ever before. These methods include digital motion analysis. In the present studies, a KaVo Arcus Digma II ultrasonic digital motion analyser was used. This device has a resolution of 50 m, so that both static positions and dynamic movements can be investigated with high accuracy. The first study compared the various CR determination methods commonly used in clinical practice.
As the study group consisted of individuals with natural or restored dentition (with minimal restorations), the MIP was used as the reference point. The CR positions determined by different methods were, thus, compared to this reference. The results showed that the CR positions determined by Dawson's manipulation and by raising the tongue to the border of the hard and soft palate (linguomandibular homotropy) did not differ significantly from the MIP.
These methods can, therefore, be safely used to determine CR position. Positions determined by gothic arch tracer (adduction field, apex of gothic arch) and positions recorded by placing the tongue to the palatal rugae are significantly different from MIP along at least one axis in the caudal or ventral direction.
However, this deviation is so small and, given the limitations, these methods are probably safe to use in everyday practice. However, methods involving passive and active retrusion of the jaw always result in a posterior deviation from MIP and are not recommended.
In the second study, joint movements occurring in the first 5 mm of mouth opening were investigated. The average of three consecutive mouth openings of the patients was analysed. The data obtained clearly show that from the first millimetre of mouth opening onwards, in addition to rotation, there is a continuous translational movement of the condyle. These data should be taken into account in any dental treatment involving a change of vertical or horizontal maxillo-mandibular position.
