Quantitative analysis of occlusal force balance in intercuspal position using the Dental Prescale system in patients with temporomadibular disorders

Shinsuke Sadamori, DDS, PhD,(a) Hiroo Kotani, DDS, PhD,(b) Hitoshi Abekura, DDS, PhD,(a) and Taizo Hamada, DDS, PhD(a)

(a)Department of Prosthetic Dentistry, Programs for Applied Biomedicine Division of Cervico- Gnathostomatology, Hiroshima University Graduate School of Biomedical Sciences, and
(b)Kotani Dental Office, Hiroshima, Japan

Purpose: This study evaluated the quantitative analysis of occlusal data (occlusal contact areas, maximum pressure, mean pressure, occlusal force, and occlusal force balance) in intercuspal position in both healthy subjects and patients with temporomadibular disorders (TMD).
Materials and Methods: The occlusal data in intercuspal position were measured using the Dental Prescale system in 15 healthy persons and 16 patients with TMD, i.e., myofascial pain dysfunction syndrome (MPD group; eight patients) and disorders of the temporomandibular joints (TMJ group; eight patients). Force asymmetry index (force AI) was calculated to evaluate the occlusal force balance of the right and left sides.
Results: The value of the force AI of MPD patients was higher than that of healthy subjects. The mean of pressures and force AI of TMJ patients were higher than those of healthy subjects. The values of occlusal contact areas and occlusal force in TMJ patients were lower than those in healthy subjects, while the values of occlusal contact areas and occlusal force in MPD patients were higher than those in TMJ patients.
Conclusion: These data in this study suggest that the force asymmetry index is suitable as the parameter of TMD. (Int Chin J Dent 2007; 7: 43-47.)

Key Words: asymmetry index, Dental Prescale system, occlusal force balance, temporomadibular disorders.