A.T.M. are the starting points for mandibular movements. They have to have a stable and static position and must have harmonious movements during the different functions of the masticatory system. Their main movements are rotation and translation.
Condylography allows for the analysis of their movements on three spatial planes. Electronic condylography (GAMMA V5) even allows for the differentiation between the rotation and translation movements.
The average angulation of the translation of the condyles is around 48◦. The average occlusal plane presents an average inclination of 12◦ compared to the Frankfurt plane.
When the condyle’s translation inclination decreases (in certain cases of arthrosis, up to 15◦), we have to posteriorly decrease the occlusal plane (lower angulation compared to the Frankfurt plane) in order to avoid posterior interference.
Inversely, when we see a condyle’s translation inclination that is too accentuated (up to 70◦ compared to the Frankfurt plane), we must posteriorly increase the occlusal plane to offer our patients better efficiency in mastication.