A System for the Study of Jaw Movements

ABSTRACT

This paper describes a system to record incisal and condylar movements. It consists of two Charge Coupled Device (CCD) cameras that detect the position of markers fixed to the face, real-time hardware to recognize the markers and software for three-dimensional reconstruction of condylar and mandibular movements. The subject sat upright in front of the cameras and was asked to perform jaw movements. The position of the markers was recorded and the coordinates were fed into the computer and converted to three-dimensional kinematic data by a mathematical algorithm implemented on an AT IBM personal computer. Dedicated software calculated the head movements and the mandibular movements separately and performed a three-dimensional mathematical reconstruction of the movements of the condylar points and the interincisive point, using the geometrical rules of a rigid body. This pilot study describes the pattern from opening, closing, protrusive, and lateral movements as obtained from healthy subjects with good dentition.

Additional information

Notes on contributors

Dong Wan Kang

Dr. Dong Wan Kang received his D.D.S. and Ph.D. degrees from Chosun University in Kwangju, Korea. He is now an assistant professor in the Department of Prosthodontics and TMJ Clinic at Chosun School of Dentistry. He is active in research in mandibular kinesiology in function and dysfunction. He conducted research at the Center of Craniofacial Pathophysiology, Turin School of Dentistry, in Turin, Italy, from January 1990 to November 1991. He is an active member of the International Association for Dental Research.

Franco Mongini

Dr. Franco Mongini received his M.D. degree from the University of Turin School of Medicine in Italy in 1963, and his D.D.S. degree in odontostomatology in 1967 from the University of Zurich, Switzerland. He received his Ph.D. degree from Rome University in 1971. He is a lecturer in gnathology and pathophysiology of the stomatognathic system at the University of Turin School of Dentistry, where he also serves as director of the University's Center of Craniofacial Pathophysiology. He has completed a four-year residency program for specialization in neurology.

Fabio Rossi

Fabio Rossi received his M.Sc. degree in electronic engineering from the Politecnic of Milan in Italy in 1990. Since 1988 he has been active at Bioengineering Technology and System (B.T.S). He has developed software for the analysis of movement and its graphical representation, particularly for the analysis of condylar movements based on the elaboration of television images.

Guido Tempia-Valenta

Dr. Guido Tempia-Valenta received his D.D.S. degree from the University of Turin School of Dentistry in Turin, Italy. Since 1983 he has been a resident at the Center of Gnathology and Pathophysiology of the Masticatory Function at that university. He is active in research at the institution, particularly in the area of mandibular movements and electromyography of the masticatory muscles. He is a member of the International Association for Dental Research.

Antonio Pedotti

Antonio Pedotti received his M.Sc. degree in electronic engineering from the Politecnic of Milan, Italy, in 1968. Since then he has been a researcher at the National Research Council. He is a professor in the Engineering Faculty, Milan Politecnic, Italy, and director of the Don Gnocchi Center of Bioengineering, in Milan. His current research activities include the analysis of biological systems, with special regard to posture and locomotion, medical infirmities, and technological developments.