title: Kinematic Modeling of Normal Voluntary Mandibular Opening and Closing Velocity-Initial Study.
abstract: OBJECTIVE
  Determination and quantification of voluntary mandibular velocity movement has not been a thoroughly studied parameter of masticatory movement. This study attempted to objectively define kinematics of mandibular movement based on numerical (digital) analysis of the relations and interactions of velocity diagram records in healthy female individuals.
  
  
  METHODS
  Using a computerized mandibular scanner (K7 Evaluation Software), 72 diagrams of voluntary mandibular velocity movements (36 for opening, 36 for closing) for women with clinically normal motor and functional activities of the masticatory system were recorded. Multiple measurements were analyzed focusing on the curve for maximum velocity records. For each movement, the loop of temporary velocities was determined. The diagram was then entered into AutoCad calculation software where movement analysis was performed. The real maximum velocity values on opening (Vmax ), closing (V0 ), and average velocity values (Vav ) as well as movement accelerations (a) were recorded. Additionally, functional (A1-A2) and geometric (P1-P4) analysis of loop constituent phases were performed, and the relations between the obtained areas were defined. Velocity means and correlation coefficient values for various velocity phases were calculated.
  
  
  RESULTS
  The Wilcoxon test produced the following maximum and average velocity results: Vmax = 394 ± 102, Vav = 222 ± 61 for opening, and Vmax = 409 ± 94, Vav = 225 ± 55 mm/s for closing. Both mandibular movement range and velocity change showed significant variability achieving the highest velocity in P2 phase.
  
  
  CONCLUSIONS
  Voluntary mandibular velocity presents significant variations between healthy individuals. Maximum velocity is obtained when incisal separation is between 12.8 and 13.5 mm. An improved understanding of the patterns of normal mandibular movements may provide an invaluable diagnostic aid to pathological changes within the masticatory system.
authors.affiliation: Teaching Assistant, Prosthetic Department, Oral Rehabilitation Clinic, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gawriołek
authors.affiliation: Teaching Assistant, Department of Conservative Dentistry, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Gawriołek
authors.affiliation: Research Engineer, Oral Rehabilitation Clinic Research Unit, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Komosa
authors.affiliation: Associate Professor, Prosthetic Department, Oral Rehabilitation Clinic, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Paweł R
authors.initials: PR
authors.lastname: Piotrowski
authors.affiliation: Associate Professor, Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH.
authors.forename: Shereen S
authors.initials: SS
authors.lastname: Azer
mesh_terms: D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008334:Mandible; D008409:Mastication; D008954:Models, Biological; D009068:Movement; D012984:Software; D013704:Temporomandibular Joint
keywords: Mandibular open and closing movements; instant velocity loop; mandibular kinematics; maximum velocity