Mandibular position at chin‐point guided closure, intercuspation and final deglutition in asymptomatic and temporomandibular dysfunction subjects

Abstract

This study compared the mandibular position at chin-point guided jaw closure, intercuspation and final deglutition (position at the end of swallowing) in 159 asymptomatic subjects and 142 subjects with symptoms in the craniomandibular system. The symptomatic subjects were assigned to four groups showing an adapted centric posture, pain, luxation with reduction of the temporomandibular joint and pain with luxation and reduction. Computer equipment aided recording of hinge axis movements in three dimensions. While the three positions differed significantly in anterior-posterior direction on both sides and in inferior-superior direction on the right, a significant difference between asymptomatic and symptomatic subjects existed only in final deglutition on the left side and in the anterior-posterior location of the guided closure. Final deglutition did not coincide with the guided closure or the intercuspation in approximately 89%. A proportionally large standard deviation gave evidence against a strict relationship of the three positions in asymptomatic and symptomatic subjects. Because of this variability, final deglutition was not recommended for verification of centric relation or the intercuspal position.

Comparative study of intermaxillary relationships of manual and swallowing methods

“…Therefore, this position is closer to MI and is more appropriate than the position obtained with the other evaluated methods. These results are in agreement with those of other studies (6,13).…”

“…The swallowing technique was largely commented and criticized by some authors for its great variability (7,13). Considering the results obtained in this study and reported in the literature (8), the use of an anterior jig has contributes to reduce this variation.…”

“…These methods have limitations and are classified depending on whether the operator guides the mandible or the patients uses their own muscular action (5), swallowing (6,8), and transcutaneous nervous stimulation, denominated myocentric (11,12). All methods have been widely investigated and have received criticism for their use due to either anterior positioning (myocentric analysis) (7) or lack of reproducibility (swallowing) (7,13).…”

Comparación de la posición condilar entre dos técnicas de registro de relación céntrica mediante tomografía espiral

“…Otros estudios evalúan variaciones en la posición mandibular más que cambios a nivel condilar medidos con imágenes (3,7,9,10,(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) . Por otro lado, la RC se define cuando el cóndilo mandibular está ubicado en la posición más anterior y superior de la ATM enfrentando vertiente posterior de la eminencia articular (4) .…”

A controversy with respect to occlusion

“…Therefore, various methods were proposed, which could clinically determine a mandibular position for the ICP without depending on the condylar position, including the following methods; the speaking method [36] and the swallowing method [37], [38]. In addition, muscular position (MP) [39] defined as the horizontal contact position of the mandible by the reflex muscle pattern, acting as a terminal point of closing movement from the rest position [40], [41] can also be considered.…”