An evaluation of terminal hinge position and neuromuscular position in edentulous patients. Part I. Maxillomandibular recordings.

The purpose of this investigation was to obtain information about the terminal hinge position (THP) and the neuromuscular position (NMP) in the edentulous population. The difference between the two positions was evaluated anteroposteriorly and mediolaterally to determine horizontal differences and reproducibility between days. In 25 edentulous subjects, five recordings were made at the neuromuscular position with no dentist guidance and five recordings at the terminal hinge position with dentist guidance; on a second day, the recordings were repeated. The differences between positions were evaluated by statistical methods. It was concluded that: (1) there is a discrepancy between the THP and the NMP for all edentulous subjects examined, (2) the NMP is anterior and medial or lateral to the THP, and (3) the NMP is not as reproducible as the THP.