ARTICULATORS ARTICULATORS They are a mechanical device that stimulates the movement of the mandible Principles of using articulators The mechanical replication of the path of movement of the posterior determinants , the TMJ . Then an instrument are used to fabricate a fixed or removable dental restoration . Classification of articulators According to the accuracy of reproducing the movement of the mandible According to the shape (1) Non-adjustable articulators Only a hinge opening Distance between the teeth and axis of rotation is shorter Affect the morphological feature Lead to : restoration with occlusal discrepancies which may lead to neuromuscular disorder According to the movement ( 2) semi-adjustable articulators Larger in size allow a close approximation of the anatomic distance between the axis of rotation and the teeth Intercondylar distance Similar to that in the average patient Adjustable condylar inclination , and incisal inclination ; Used in most single units and FPDA Accepted face bow transfer. (3) Fully adjustable articulators Advantage Most accurate. Has great accuracy in the reproduction, both horizontal & lateral inclination are adjusted according the the records taking from the patient’s mouth . Used for extensive treatment Disadvantage Expensive Required high skills & understanding. Required a lot of time to represent 3 records: Fully adjustable articulators According to the shape 1_arcon articulator Condylar element are placed on lower member ,the mechanical fosse are placed in the upper member simulating the position of glenoid fosse in the skull Arcon type According to the shape 2_nonarcon articulators The condylar element are placed in the upper member while the mechanical fosse are placed in the lower member Arcon type are widely used in fixed restoration because their accuracy and easy with which they disassemble to facilitate the occlusal waxing Non-arcon type To evaluate the patient occlusion , we have to place the diagnostic casts in the articulator in the same relationship to the TMJ as exist in the patient . This is done by using face bow to mount the maxillary cast and interocclusal wax record to mount the lower cast . Face bow It is an instrument used to record the position of maxillary arch relative to opening and closing Two types : 1_arbitary 2_kinematic Types of face bow (1) Arbitary Type: Whip mix face bow Denar face bow Hanau face bow Whip mix face bow Denar face bow and articulators Hanau face bow and articulator Mounting the maxillary cast Mounting the mandibular cast Examine the casts and the articulators The condyles is in the retruded position in its condylar track mechanism (against the posterior and superior walls of the condylar guide Both casts are completely seated in the interocclusal record Mounting stone is securely attached to both casts and mounting plates Custom anterior guidance Setting the mechanical incisal guide
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