Neuromuscular Position of the Temporomandibular Joint Condyle in Fully Dentate Volunteers: Characteristics and Potential Indications.

Abstract

Purpose: To investigate the neuromuscular position of the mandible in the fifth and final part of a comprehensive investigation of the positions of the temporomandibular joint condyles.

Materials and methods: The neuromuscular condylar positions were recorded by four independent operators in 81 fully dentate subjects with healthy oral function using a central bearing point system and rapid closing movements. The most frequent adduction point was determined, and the recordings were repeated twice for each subject. The subjects' maxillary casts were mounted in an articulator using an individual facebow transfer, and subsequently the mandibular casts were mounted with a central bearing point registration on the tip of the Gothic arch, ie, in centric condylar position (CR). A custom-made electronic measuring articulator was used to determine the spatial distance between the condyles in centric relation, maximal occlusion, and the newly determined neuromuscular position.

Results: The reproducibility of the neuromuscular registrations was on average 0.52 ± 0.16 mm (range 0.04 to 2.53 mm) with the right and left side averaged. The average spatial distance of the condyles between maximal intercuspal position (MI) and neuromuscular position was 0.88 ± 0.30 mm (range 0.12 to 5.98 mm), again averaged for the right and left sides, whereas that between the CR and the neuromuscular position was 0.83 ± 0.27 mm (range 0.10 to 7.89 mm).

Conclusions: The neuromuscular mandibular position is neither identical to MI nor to CR. It can therefore be concluded that the registration of the neuromuscular adduction field should not be recommended for prosthodontic restorations in dentate or edentulous patients.