Influence of functional head postures on the dynamic functional occlusal parameters

Abstract

Background:The dentist utilizes supine position during therapeutic procedures, while the patients assumes extended head posture during mastication. It is critical for the restorative dentist to evaluate and understand the possible effect of change in head posture on occlusal contacts. An understanding of the possible effect will help in better restorative rehabilitation.Aim:The aim of the following study is to evaluate the influence of head postures on the dynamic occlusal parameters.Subjects and Methods:Study group consisted of 50 students from College of Dentistry, King Khalid University. The students were selected randomly from the college student body; they were in the age group of 18-25 years. The head posture evaluated were supine position, upright sitting position and alert feeding position. The head postures were standardized by goniometer and dynamic occlusal contacts were analyzed with Tscan. The data obtained was subjected to statistical analysis with repeated measures of ANOVA to identify the changes in occlusal contacts.Results:The occlusion time was 1.366 (0.484), 1.226 (0.562) and 0.997 (0.429) s for supine, upright and alert feeding position respectively. Disclusion time was for right lateral movement was 0.872 (0.372), 0.629 (0.290) and 0.831 (0.369) s for corresponding head postures. Left lateral disclusion time was 0.621 (0.274), 0.274 (0.345) s for upright and alert feeding posture. Repeated measures of ANOVA showed statistically significant difference between occlusal contacts in different head postures.Conclusion:Within the limitation of the study, it was concluded that there were significant changes in initial occlusal contact, occlusion and disclusion time at all the head postures evaluated in the study.

Are jaw range of motion, muscle function and proprioception impaired in adults with persistent temporomandibular disorders? A systematic review and meta‐analysis

“…Two studies reported increased joint position error in TMD groups compared with controls, while two studies found no significant difference between groups. One study 16 reported a significant difference between TMD and control groups when discriminating between mouth opening ranges in relation to a reference block; although overall did not find a significant difference between groups.…”

“…Monteiro et al 1987 59 Higher error in movement accuracy in laterotrusion in TMD group compared to controls (R P = .0005, L P = .0013) between groups. One study 16 reported a significant difference between TMD and control groups when discriminating between mouth opening ranges in relation to a reference block;…”

The reciprocal jaw-muscle reflexes elicited by anterior- and back-tooth-contacts—a perspective to explain the control of the masticatory muscles

“…The slightly forward inclined head-posture, as instructed to the subjects of the present study sitting on a stool and unsupported by a headrest may also have added to the percentage of AF-bites in comparison to the otherwise analogous T-Scan recording technique employed by Koos et al 22 For ventrally flexed head positions, the axis of rotation of mandible moves forward, according to the “sliding cranium” -phenomenon 26 possibly increasing the likelihood of AF-bites, as has been demonstrated in previous T-Scan studies. 27 , 28 Furthermore, tiny, jaw-closure associated ventral head movements of the unsupported head are coined with protrusion-oriented movements of mandible. 29 During the natural, cyclic chewing movements, the repeated open-close movements would probably not allow sufficient time for the synovial spaces to recuperate and re-inflate between cycles.…”

Effect of head posture on tooth contacts in dentate and complete denture wearers using computerized occlusal analysis system

“…30° ventroflexion was included in the study for it is considered as active feeding head position based on the earlier research findings. [ 1 ] The head extends forward by approximately 30° during food consumption; this head posture is known as active feeding posture. It is critical for the dentist to evaluate and understand the possible effect of a change in head posture on occlusal contacts[ 1 ] as generally only upright-erect position is used during restorative procedures, occlusion evaluation, and correction.…”

“…These head postures can be divided into an active feeding position posture, upward erect posture and extended head posture. [ 1 2 ] The head extends forward by approximately 30° during food consumption; this head posture is known as active feeding posture. [ 2 ] This posture shifts the mandible and its closure path anteriorly.…”