TEMPOROMANDIBULAR JOINT IN HEALTH AND DISEASE: A 3D MORPHOFUNCTIONAL ANALYSIS

Quantitative, objective and accurate evaluation of masticatory muscle activity and jaw movement is mandatory for a better understanding of the normal function and dysfunction of the stomatognathic apparatus. A non-invasive recording protocol, integrating an electromyographic system and an optoelectronic 3D-motion analyzer, has been developed and used to perform multifactorial estimations of TMJ functioning. The masticatory system has been objectively quantified, assessing bite stability, mandibular border movements and chewing performance, in both healthy and pathologic individuals. Three separate investigations have been made. In the first study, functional symmetries of the craniofacial complex involving the patterns of jaw movements and the activities of masticatory muscles were assessed in a control group of clinically healthy subjects. Data were evaluated separately for men and women, and a gender-related effect was tested, together with the potential influence of mandibular dimensions. In the second study, the same complete protocol was employed to analyze the masticatory function in patients with mild-moderate temporomandibular disorders, in order to provide new insight concerning a still controversial pathology. The aim of the third study was to assess the recovery of mandibular range of motion in border movements, focusing on the potential changes in mandibular condylar motion, analyzed in untreated patients with skeletal Class III malocclusions, and patients who had received orthognathic surgery for the correction of this dentoskeletal deformity. The outcomes suggest that the proposed method could be a useful tool to evaluate the neuromuscular coordination during the performance of static and dynamic masticatory activities, and to detect functionally altered stomatognathic conditions. Diagnosis of alterations of the stomatognathic apparatus, and assessment of the effects of therapy, would both profit from this quantitative approach, thus reducing the discordance among several clinical examinations.