Examination of the Relationship Between Mandibular Position and Body Posture

Abstract

The purpose of this study was to evaluate the effect of changing mandibular position on body posture and reciprocally, body posture on mandibular position. Forty-five (45) asymptomatic subjects (24 males and 21 females, ages 21-53 years, mean age 30.7 years) were included in this study and randomly assigned to one of two groups, based on the table of random numbers. The only difference between group I and group II was the sequence of the testing. The MatScan (Tekscan, Inc., South Boston, MA) system was used to measure the result of changes in body posture (center of foot pressure: COP) while subjects maintained the following 5 mandibular positions: 1) rest position, 2) centric occlusion, 3) clinically midlined jaw position with the labial frena aligned, 4) a placebo wax appliance, worn around the labial surfaces of the teeth and 5) right eccentric mandibular position. The T-Scan II (Tekscan, Inc., South Boston, MA) system was used to analyze occlusal force distribution in two postural positions, with and without a heel lift under the right foot. Total trajectory length of COP in centric occlusion was shorter than in the rest position (p<0.05). COP area in right eccentric mandibular position was larger than in centric occlusion (p<0.05). When subjects used a heel lift under the right foot, occlusal forces shifted to the right side compared to no heel lift (p<0.01). Based on these findings, it was concluded that changing mandibular position affected body posture. Conversely, changing body posture affected mandibular position.

Additional information

Notes on contributors

Kiwamu Sakaguchi

Dr. Kiwamu Sakaguchi is an assistant professor at the Department of Oral Functional Prosthodontics at Hokkaido University Graduate School of Dental Medicine, Japan. He received his D.D.S. degree at Hokkaido University in 1995 and his Ph.D. degree from the same university in 1999. He joined the Craniofacial Pain Center at Tufts University where he engaged in research from 2003-2004.

Noshir R. Mehta

Dr. Noshir R. Mehta is a professor and chairman of general dentistry, director of the Craniofacial Pain Center and Assistant Dean of International Relarions at Tufts University School of Dental Medicine. He is a diplomate of the American Board of Orofacial Pain and is a fellow of the International College of Dentists and of the American College of Dentists. Since receiving his D.M.D. degree and his M.S. in periodontics at Tufts University, he has been involved in occlusion research. Dr. Mehta has lectured internationally on TMD/MPD and has published numerous scientific papers.

Emad F. Abdallah

Dr. Emad F. Abdallah is an Assistant Professor at the Craniofacial Pain Center, Tufts University School of Dental Medicine. He received his D.M.D. degree, certificate in Orthodontics, Masters of Science degree and certificate in temporomandibular disorders and orofacial pain from Tufts University. He is a diplomate of the American Board of Orofacial Pain. Dr. Abdallah has lectured internationally on orthodontics and orofacial pain.

Albert G. Forgione

Dr. Albert G. Forgione is Chief Clinical Consultant at the Craniofacial Pain Center at Tufts University School of Dental Medicine. He received a Ph.D. in psychology from Boston University and then joined Tufts University and lectured in behavioral medicine. Dr. Forgione established the first TMJ center at Tufts University School of Dental Medicine with Dr. Mehta in 1978.

Atsuro Yokoyama

Dr. Atsuro Yokoyama is a professor at the Department of Oral Functional Prosthodontics at Hokkaido University Graduate School of Dental Medicine, Japan.