23- Facebow mounting (transfer) on a semi-adjustable articulator скачать в хорошем качестве

23- Facebow mounting (transfer) on a semi-adjustable articulator

Part 1: Components of Face bow & Semi-adjustable Articulator Components of Face bow: • Adjustable bow (arch) with screws to control inter-condylar distance. • In some semi-adjustable articulators the inter-condylar distance is fixed to an average and can't be changed. • Two ear pieces inserted in both external auditory meatus used as posterior points of reference. • Nasion relator used as an anterior 3rd point of reference. • There are 2 types of bite forks: (Dentulous or Edentulous) • The edentulous fork used here attached just 2 mm below the occlusal plane • The fork rod should be in the same line with the mid-line of the face and the mid-line oriented on the occlusal rims. Components of the semi-adjustable articulator • Upper member - Lower member - Hinge - 2 vertical posts - Mounting rings - Vertical guide post - Incisal pin - Incisal guide table (Plane or adjustable). • Adjustable horizontal condylar inclination and adjustable Bennett angle. • Accessories 1. Campers table: used for mounting of the upper cast instead of face bow. 2. Adjustable incisal guide table: Used to adjust both protrusive & lateral incisal guidance. 3. Fork support: Stabilize the bite fork during mounting of the upper cast. 4. Dentulous bite fork: Used in registering the cranio-maxillary orientation for dentate patients. 5. Elastic band: Used to maintain the vertical dimension of the articulator by holding both members firm during the setting of the mounting plaster. Part 2: Mounting of the upper cast using face bow record • Remove the Nasion relator from the face bow. • Remove the vertical guide post from the articulator. • Apply the face bow to the articulator by insert the ear pieces holes into the condylar pins (rods) then tight all face bow screws. • Close the upper member to rest on the horizontal metallic plate of the face bow. • The elastic band may be used to firmly hold the face bow in relationship to the articulator during the mounting procedure. • Fork support applied to stabilize the bite fork. • Apply the upper cast over the upper record block. Be sure that there is sufficient space for mounting plaster or trim the base of the cast. • Scoring of the cast base is important in order to relate it again, if it is detached from the mounting plaster. • Put a thin layer of Vaseline on the mounting rings. This will facilitate its removal from the mounting plaster after finishing the case. • Scoring of the casts. • Mix a small amount of plaster and apply it over the upper cast and some on the upper mounting ring. • Close the upper member again and remove the excess plaster then wait until setting of the mounting plaster. • Remove any excess plaster or add plaster to any deficient area. • After setting of the mounting plaster you can now remove the fork support and the face bow from the articulator. • Loosen the face bow screws then remove the ear pieces from the condylar rods. • Attach the vertical guide post to the articulator so that the upper member parallel to the lower one. • Remove the occlusal rim from the bite fork and seal it to the upper cast. • The incisal pin is pointed to the mid-line and parallel to the occlusal plane. • The magnetic mounting ring can be easily removed from articulator. This facilitate the setting procedure of artificial teeth away from the articulator. Part 3: Mounting of the lower cast using centric relation record • Seal the lower occlusal rim to the lower cast properly. • Then seal the upper occlusal rim with the lower occlusal rim. • Heals of the occlusal rims or the casts must not touch posteriorly. • Mix a small amount of plaster to mount the lower cast to the articulator. • Close the lower member over the mounting plaster, remove the excess plaster and add it to any deficient areas. • The vertical post must touch the incisal guide table during and after setting of the mounting plaster. • Elastic band used to hold both articulator members together to maintain the V.D.O. during and after the setting of the mounting plaster. • After setting of the mounting plaster removes the elastic band. Now the articulator is ready for setting of the artificial teeth. • The posterior lock of the articulator is used to limit the articulator movement to simple hinge opening like (Mean value articulator). • Don't forget to tight the screw fixing the vertical post to maintain the vertical dimension of occlusion during setting of artificial teeth.