Date of Award
Spring 1995
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Ferguson, Donald J.
Second Advisor
Schuckit, William I.
Third Advisor
Kittleson, Russell T.
Abstract
The function of a dental articulator is to replicate the movement of the human mandible. In order to properly replicate the movement of the human mandible, an articulator should closely replicate the anatomy of the human temporomandibular joint. Most articulators in existence today use a ball and flat plane to simulate the mandibular condyle and articular eminence. In the human TMJ, the condyle is cylindrical and ovoid ("football shaped") and the articular eminence is a linear curved surface. The Polycentric Hinge Joint (POLY) articulator is designed with cylindrically shaped condyles, and a trough shaped articular fossa and curved articular eminence. The developers of the POLY claim that this articulator will more accurately simulate the motion of the human mandible because it more accurately replicates the anatomy of the human TMJ. The purpose of this study was to compare opening and protrusive movements on the SAM 2 and POLY articulators to these same movements in the human subjects in order to judge if one articulator simulates these motions better than the other. Twenty asymptomatic adult subjects volunteered to participate in the study at Marquette University, School of Dentistry. The sample consisted of eleven males and nine females with a mean age of 27 years, 5 months. Maxillary and mandibular study casts of each subject were mounted on both articulators utilizing arbitrary facebow transfers and centric occlusion bite registrations. The motion of the human mandible and both articulators was tracked using a Siemens Sirognathograph and Rotate version 2.3a software. The measurements were taken at 10mm of opening and 3mm of protrusion. The POLY more accurately replicated human mandibular motion in the horizontal plane of rotation during opening (p=.018) and the frontal plane of rotation during protrusion (p=.028). On all other measurements, both articulators were not different statistically. When the articulator values were subtracted from the subjects' values and statistically compared, the POLY was closer to the human values in four out of five parameters during opening with the exception being the vertical parameter. The POLY consistently performed closer to the subjects' jaw tracking measurements during opening mandibular movement.
Recommended Citation
Flanagan, Dennis J., "Accuracy of Replicating Mandibular Opening and Protrusive Movements with the Polycentric Hinge and SAM 2 Articulators" (1995). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5146.
https://epublications.marquette.edu/theses/5146