www.sbdmj.com - Stomatologija - Baltic Dental and Maxillofacial Journal

Summary

The human masticatory system is special because apart from a larger amount of muscles than degrees of freedom its joints do not restrict its movements a priori. Therefore, each muscle is able to influence all six degrees of freedom which makes the system kinematically and mechanically indeterminate. Furthermore, its working space is principally determined by the dynamical properties of its muscles and not by passive constraints. It is concluded, that active and passive muscle tensions through occlusion and condylar surfaces are in a state of dynamical 3D equilibrium. During evolution the masticatory system assumed a number of structural elements designed to stabilize the dental arches to withstand powerful mastication forces which consist of different vectors. Moreover, the perfect correlations exist between occlusal stability and elevator muscle function, which are based on feedback mechanisms from periodontal pressoreceptors.The perfect geometry of the occlusal surfaces and dental arches jointly with well-balanced occlusion, solid proximal dental contacts and structure of the periodontal ligament guarantee physiologically acceptable distribution and compensation of the mastication forces, thus ensure long-lasting functioning of the teeth. This ideal from a functional viewpoint system may be damaged due to periodontal disease or partial dental loss. Restoration of the functional integrity of the dental arch is one of the most relevant problems in clinical dentistry. Functional equilibrium in and between the dental arches guarantee balanced functional stimulation of the masticatory apparatus and contributes to its harmonious development and maintenance.

Key words: bite force distribution, occlusion, human jaw biomechanics.

Received: 12 08 2004

Accepted for publishing: 20 09 2004

Gaivile Pileicikiene - D.D.S., ass.prof., Clinic of Prosthodontics, Kaunas Medical University, Lithuania.

Algimantas Surna – D.D.S., PhD, assoc.prof., Clinic of Prosthodontics, Kaunas Medical University, Lithuania.

Address correspondence to Gaivile Pileicikiene: Clinic of Prosthodontics, Sukileliu 51, Kaunas, Lithuania. E-mail: gaivile@takas.lt



	Baltic Dental and Maxillofacial Journal

September, 2004, Vol. 6, No. 3 CONTENTS SCIENTIFIC ARTICLES Dental Implant Stability at Stage I and II Surgery as Measured Using Resonance Frequency Analysis 67 - 72 The Ameloblastous Potentiality of Odontogenous Epithelium Demonstrated in Tissue Culture 73 - 76 Vertical Root Fractures in Endodontically Treated Teeth: A Clinical Survey 77 - 80 CLINICAL ARTICLES The Human Masticatory System From A Biomechanical Perspective: A Review 81 - 84 SCIENTIFIC ARTICLES Retentive and Stabilizing Properties of Stud and Magnetic Attachments Retaining Mandibular Overdenture. An in vitro Study 85 - 90 Accuracy of Traditional Clinical Examination in Combination with 3-D Computerized Axiography for Diagnosing Anterior Disk Displacement with Reduction 91 - 93 © 2004 Stomatologija		Stomatologija 2004; 6 (3): 81-4 161 KB The Human Masticatory System From A Biomechanical Perspective: A Review Gaivile Pileicikiene, Algimantas Surna Summary The human masticatory system is special because apart from a larger amount of muscles than degrees of freedom its joints do not restrict its movements a priori. Therefore, each muscle is able to influence all six degrees of freedom which makes the system kinematically and mechanically indeterminate. Furthermore, its working space is principally determined by the dynamical properties of its muscles and not by passive constraints. It is concluded, that active and passive muscle tensions through occlusion and condylar surfaces are in a state of dynamical 3D equilibrium. During evolution the masticatory system assumed a number of structural elements designed to stabilize the dental arches to withstand powerful mastication forces which consist of different vectors. Moreover, the perfect correlations exist between occlusal stability and elevator muscle function, which are based on feedback mechanisms from periodontal pressoreceptors.The perfect geometry of the occlusal surfaces and dental arches jointly with well-balanced occlusion, solid proximal dental contacts and structure of the periodontal ligament guarantee physiologically acceptable distribution and compensation of the mastication forces, thus ensure long-lasting functioning of the teeth. This ideal from a functional viewpoint system may be damaged due to periodontal disease or partial dental loss. Restoration of the functional integrity of the dental arch is one of the most relevant problems in clinical dentistry. Functional equilibrium in and between the dental arches guarantee balanced functional stimulation of the masticatory apparatus and contributes to its harmonious development and maintenance. Key words: bite force distribution, occlusion, human jaw biomechanics. Received: 12 08 2004 Accepted for publishing: 20 09 2004 Gaivile Pileicikiene - D.D.S., ass.prof., Clinic of Prosthodontics, Kaunas Medical University, Lithuania. Algimantas Surna – D.D.S., PhD, assoc.prof., Clinic of Prosthodontics, Kaunas Medical University, Lithuania. Address correspondence to Gaivile Pileicikiene: Clinic of Prosthodontics, Sukileliu 51, Kaunas, Lithuania. E-mail: gaivile@takas.lt