The Function of Teeth

Chapter l: Research design
Gnathic Replicator development
Attachment of Recorders
Linear transducer measuring devices
Recording and storing data
Multiple displays

Chapter 2: Mandibular movement patterns
Typical masticatory cycle
Incisor point findings
Classic "RC-CO" slide
Role of canines in centering jaw closures
Child and adult chewing patterns compared
Speech
Unworn and worn teeth during chewing

Chapter 3: Condylar movement
The articular eminence
Shape of eminence reproduced in articulators
Stuart instrument history
Balanced occlusion for natural tooth restoration
Stuart and Lee instrument comparisons
Lee research System contribution

Chapter 4: Lateral joint stability
Condyle's capacity for movement
Boundaries of guided lateral condylar translation
Bennett effects, horizontal plane views
Bennett movement during chewing
Molar occlusal form study
Replicator plots of molar movement boundaries
Canine, Eminence and Bennett effect on molars
Bennett movement and molar restorations
Molar restorations and anterior guidance
Simplified condylar movement recorders

Chapter 5: Forces and muscle response to malocclusion
Force generated during chewing and swallowing
Force and EMG results
Vertical movement in normal & malocclusion subjects
Muscle response to malocclusion

Chapter 6: Natural tooth form
Natural tooth form
Teaching dental anatomy
Development of Instrumentation Systems
Patient treatment examples

Appendix: (Final Report for Research Project)
Instrumentation
Investigators
Summary of major findings
Publications
Additional Publications
Permissions to use previously published material

Chapter 1: Development of the measuring systern.
(15 min.)
Dr. Gibbs teils his personal history of the development of the Replicator System which was designed to record and reproduce total jaw chewing movements.

Chapter 2: Multiple jaw movement displays.
(24 min.)
Incisor, condyle and molar points are related to each other in both time and space in a number of displays. Movement of the condylar spheres of articulators during chewing are revealed for the first time.

Chapter 3: Use of teeth in normal and compromised occlusal relationships.
(23 min.)
Chewing and empty-mouth handguided mandibular movements are compared for the same subject. Bennett movement is clearly identified. Other demonstrations include: Chewing with worn and unworn teeth, jaw movement during speech, and muscle response to various types of maloccIusions.The concept of steep canines and vertical chewing is related to the complete chewing cycle.The shape of the eminence is recorded, reproduced and related to teeth. A Student demonstration teaches a simple way to record the steepness of the eminence and reproduce it in articulator controls.

Chapter 4: Force and EMG measurements.
(40 min.)
Dr. Gibbs describes how forces generated during chewing were measured and how fine-wire electrodes were inserted into muscles for EMG recording. Dr. Mahan continues with demonstrations of the reciprocal EMG activity of the superior and inferior bellies of the lateral pterygoid muscles, and interactions with other muscles of mastication.

Chapter 5: Vertical condyle movements and examples of patient treatments.
(16 min.)
Vertical condyle displacements produced by biting on a wood stick are compared with the displacements created by manual elevation of the mandible. A disk displacement and condyle dislocation are also reproduced.
Dr.Wold describes examples of patient treatments utilizing bioesthetic goals and principles.