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Opening-closing
Translatory movement of the mandibular codyle along the the posterior wall of the articular eminence
Border movements of the mandibleBorder movements of the mandible
The most extreme positions to which The most extreme positions to which the jaw is able to movethe jaw is able to move (Posselt,1952)
– Laterally: max. 10 mm– Opening: 50-60 mm
– Protrusion: 9 mm– Retrusion: 1mm
Described from sagittal, frontal and Described from sagittal, frontal and horizontal planeshorizontal planes
Usually not affected by head or body Usually not affected by head or body postureposture
Posselt’s diagramPosselt’s diagram
Sagittal plane border movements– Tracing of the
maximum vertical and antero-posterior movements of the symphysis point
Postural rest position
Habitual opening
ICP
1. Intercuspal position
2. Retruded contact position
3. Rotational opening
4. Maximum opening, condylar translation
5. Maximum protrusion reverse incisal overbite position
Determinants of the sagittal Determinants of the sagittal border movementsborder movements
Incisors Posterior occlusion Temporomandibular joint Articular disc Muscles Ligaments
Determinants of the frontal border Determinants of the frontal border movementsmovements
Anatomy of teeth Occlusion Wear Overbite Overjet Joint capsule Ligaments
Gothic arch tracing (Gothic arch tracing (Gysi, 1910Gysi, 1910))
Border movements in the horizontal plane– Intraoral
registration plate– Pantographic
registration device
a: RCP,
ICP-IKP = 1 mm
The Bennett movement (lateral The Bennett movement (lateral shift - „IMMEDIATE SIDE shift - „IMMEDIATE SIDE
SHIFT”)SHIFT”)
The bodily shift of the mandible toward the working side during lateral
excursion
Determinants of the horizontal Determinants of the horizontal border movementsborder movements Condyle Glenoid fossa Ligaments Inclination of teeth
Clinical significance of tooth and joint morphology
Movements are determined by the shape, position and anatomy of teeth and joint
mesiolingual cusp of the nonworking side upper first molar travels through the distbuccal groove of the mandibular nonworking side first molar
mesiolingual cusp of the working side upper first molar travels through the lingual grove of the lower working side first molar
Effect of cuspal inclination on the Effect of cuspal inclination on the Bennett movementBennett movement
0,75 mm
Determinants of occlusion (Determinants of the Determinants of occlusion (Determinants of the mandibular movements) mandibular movements)
Condylar guidanceCondylar guidance
Condylar path (Condylar
inclination)
– The angle between the
sagittal projection of
the condylar path and
the Frankfort plane
(Camper plane)
– 35O
Condylar angulation (Bennett angle):– The angle formed by the
sagittal plane and the path of the advancing condyle during lateral movement of the mandible, as viewed in the horizontal plane.
– 15O
Determinants of occlusion (Determinants of Determinants of occlusion (Determinants of the mandibular movements) the mandibular movements)
Tooth guidance
Incisal guidance
– the influence on
mandibular
movements by the
contacting surfaces of
the mandibular and
maxillary anterior
teeth
– 10O
Canine guidance (Lateral guidance)
– the influence on mandibular movements by the contacting surfaces of the mandibular and maxillary canines or posterior teeth
– 120O