Effects of centric relation prematurities of the frontal teeth

Centric relation prematurities of frontal teeth are frequently found with patients who have severe orthodontic anomalies or received extensive restorative treatment. They can cause a range of symptoms ranging from loosening of the teeth to temporomandibular disorders (TMD). The objective of this work has been to derive a mathematical description of the mandibular and periodontal forces generated by anterior prematurities for different incisor relations. In order to quantify the effect of contact area (location and inclination) and the tooth inclination, a two-dimensional mathematical approach was used. Vectorisation of the forces and bending moments makes it possible to predict under which conditions the load increase mainly affecting the anterior teeth can and may cause localized pain and eventually loosening and flaring/crowding of the upper/lower incisors and under which conditions the temporomandibular joint will suffer a large increase in retrusive force, which potentially leads to TMD. For 10 patients with anterior prematurities, analysis of the incisor relation was carried out. For all cases the conclusions drawn from the mathematical model were in full agreement with the reported symptoms, which could be successfully treated.