Facebow in orthodontics /certified fixed orthodontic courses by Indian dental academy


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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

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Facebow in orthodontics /certified fixed orthodontic courses by Indian dental academy

  1. 1. FACE BOW www.indiandentalacademy.com
  2. 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  3. 3. FACE BOW  “A Caliper like device which is used to record the relationship of the jaws to the tempromandibular joint and to orient the casts on the articulator to the relationship of the opening axis of the tempromandibular joint” - GPT www.indiandentalacademy.com
  4. 4. HISTORY AND DEVELOPMENT OF FACE BOW   In 1866, Francis H Balkwill introduced an instrument for measuring the angle formed between the plane of two lines drawn from the articulating surfaces of the condyle on to the incisal point and the occlusal plane. He estimated this angle now known as the BALKWILL’S ANGLE. -It has an average value of 26° www.indiandentalacademy.com
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  6. 6.  In 1889, CHARLES E.LUCE used what he called the photographic method to record the relative movements of 3 points on the mandible, the condyle, the angle and the symphisis.  Luces results corroborated Balkwill’s findings and there was considerable individual variations in the relative movement of the condyle, the angle and the symphisis. www.indiandentalacademy.com
  8. 8.  In 1896, WILLIAM E.WALKER introduced the facial clinometer -designed to determine the angle of the condylar paths on the face  Origin of extraoral method for recording mandibular movements  It didn’t allow for active transfer of the cast in the articulator www.indiandentalacademy.com
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  10. 10. In 1884, GEORGE K. BAGBY, obtained a patent for the Jaw gauge. This is described as the attachment to determine the location of the impression models in the articulators. In 1889, RICHMOND S. HAYES introduced the first example of a functional face bow like device.  It was used for locating the position of casts correctly in the articulator and he named it as the Articulating caliper. www.indiandentalacademy.com
  11. 11. In 1889,GEORGE B.SNOW developed the face bow which carries the relationship between the maxilla and the condyles, from the patient to the articulator.  The snow type of face bow uses estimated marks on the skin at the condyle points as the hinge axis position.  Snow used the ala-tragus line as the plane of reference. www.indiandentalacademy.com
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  13. 13. In 1908, GYSI developed a face bow primarily to record the paths of the condyle. Gysi used the prosthetic plane which is similar to the camper’s plane as the plane of reference In 1902,JOHN B.PARFITT introduced his anatomical articulator also called a model jaw. PARFITT introduced two mandibular face bows one to transfer the casts to the articulator and another one to produce the record of the contour of the condylar path. www.indiandentalacademy.com
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  16. 16. In 1924,WADSWORTH introduced a ‘T’attachment type of a face bow. It used a third point of reference indicator to determine the vertical position. This reference point is based on the naso-optic condylar triangle. www.indiandentalacademy.com
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  18. 18. Many modifications evolved out of the snow face bow. The new trend of using the infra orbital pointer as the third point of reference was invented in the late 1920’s. The Hanau, Bergstrom and the Dentatus company where among the first to adopt it. it’s true origin is unknown. www.indiandentalacademy.com
  19. 19. CLASSIFICATION ARBITRARY FACEBOW i) Facia facebow ii) Ear piece facebow - with orbital indicator - with nasal relator ACTUAL VALUE FACEBOW (kinematic or hingewww.indiandentalacademy.com axis facebow)
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  21. 21. PARTS OF A FACE BOW   “U” shaped frame - all other components of the face bow are attached to the frame with the clamps. - it records the plane of the cranium. Condylar rods - these are two small metallic rods on either side of the free end of the “U”shaped frame - it helps to locate the hinge axis or the opening axis of the TMJ. www.indiandentalacademy.com
  22. 22. Bite fork -it’s a U shaped plate which is attached to the occlusal rims while recording the orientation relationship. Locking device -part of the face bow that attaches the bite fork to the U shaped frame. -also supports the face bow,occlusal rims and the casts during articulation. www.indiandentalacademy.com
  23. 23. Orbital pointer -it marks the anterior reference point -it can be locked in positioned with a clamp -it only present in the arbitary face bow www.indiandentalacademy.com
  24. 24. KINEMATIC FACEBOW    Used to locate the true terminal hinge axis Difficult to perform accurately in edentulous situations due to REALEFF Indicated for the fabrication of FPD www.indiandentalacademy.com
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  26. 26. ARBITRARY FACEBOW    The condylar rods are positioned approximately 13mm anterior to the auditory meatus on the cantho-tragal line. This locates the rods within 5mm of the true hinge axis of the jaw. This is commonly used in complete denture constuction. www.indiandentalacademy.com
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  28. 28. TYPES   Facia type -Posterior reference point is 13mm anterior to external auditory meatus -Anterior reference point is the orbitale Ear piece type -Posterior reference point is the EAM -Anterior reference point is the orbitale www.indiandentalacademy.com
  29. 29.  Denar facebow -Ant. reference is 43mm above the incisal edge of right central or lateral incisor -It is marked using a denar reference plane locator  Twirl bow -It relates the maxillary arch with the frankfort horizontal plane -It doesn’t require any physical attachment to the article www.indiandentalacademy.com
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  31. 31.  Whipmix facebow (quick mount FB) -Nasion related assembly with a plastic nose piece which determines the anterior reference point -It has a built in hinge axis locator ; automatically locates the hinge axis www.indiandentalacademy.com
  32. 32. HINGE AXIS    Hinge axis is an imaginary line around which the condyles can rotate without translation In 1921,McCollum,Stuart reported the discovery of first method locating hinge axis Controversies as to the presence of a single axis,the method and validity of recording the position on the skin have arisen because mechanical equipment is used to record movements involving living tissues www.indiandentalacademy.com
  33. 33. TERMINAL HINGE AXIS (TRANSVERSE HINGE AXIS)  It is an imaginary line which passes horizontally through the rotational centers of the right and left condyles when they are in the most distal retruded position in their respective glenoid fossa  The technique for locating the terminal hinge axis position is the same for dentulous and edentulous patients www.indiandentalacademy.com
  34. 34.       The hinge axis locating bow is attached rigidly to the mandible by means of a clutch Clutch is cemented over the teeth or clamp to the edentulous ridge Mandible is manipulated to the centric relation The patient makes guided opening and closing movements within the range of hinge opening Adjustments are made untill the stylii on the hinge axis bow only spin This indicates that the stylii are co-linear with the mandibular www.indiandentalacademy.com hinge axis
  35. 35. ARBITRARY HINGE AXIS    Most indirect techniques in dentistry does not require the accuracy of locating the true hinge axis WEINBERG in a study evaluated the degree of error of axis location and its relationship to the occlusion of teeth He concluded that ‘the transverse hinge axis location and the subsequent face bow transfer within a 5mm error is a practical and dependable method for orienting the maxillary cast’ www.indiandentalacademy.com
  36. 36. FACEBOW TRANSFER  ARBITRARY AXIS FOR HANAU FACEBOW - Richey condylar marker is used to scribe an arc 13mm anterior to the external auditory meatus. - using a ruler, a line is drawn from outer canthus of the eye to the tragus of the ear. - the point where the line intersects the arc locates the arbitrary axis www.indiandentalacademy.com
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  38. 38.  The bite fork is heated and inserted in to the maxillary rim parallel to the occlusal plane.  The recording base is inserted into the mouth, the extension rod is pass through the locking device.  The condylar rods are oriented over the arbitrary centres of rotation.  They are moved from side to side untill the readings on the condyle rod scales are same on both sides www.indiandentalacademy.com
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  41. 41.  The cross bars should be parallel to a line between the pupils of the eye  The lock nuts at the condyle rods are tightened to suspend the facebow and the bite fork is securely attached  Condylar lock nuts are released and the facebow and occlusal rim are transferred to the articulator  The instrument is locked in centric with the incisal pin flush with the upper member www.indiandentalacademy.com
  42. 42.  The facebow is adjusted by the elevating screw to align the occlusal plane with the groove mark on the half-way point of the incisal pin  A hanau mounting support or prop may be necessary to support the weight of maxillary cast and plaster during mounting www.indiandentalacademy.com
  43. 43. INDICATIONS     Cusp form of teeth are used Balanced occlusion in the eccentric position are desired Inter occlusal check records are used for verification of jaw position Occlusal vertical dimension is subject to change and alteration of tooth occlusal surfaces are necessary to accommodate the changes www.indiandentalacademy.com
  44. 44. CONCLUSION   Blind orientation of the maxillary casts on a articulator will result in errors The elimination of errors that can be produced by failure to use a facebow where indicated, justifies the time required and the procedures involved in the facebow transfer www.indiandentalacademy.com
  45. 45. REFERENCES: 1. Essentials of complete denture prosthodonticsSheldon winkler 2. Syllabus of complete dentures- Charles M.Heartwell 3. Prosthodontic treatment for edentulous patientsGeorge A.Zarb 4. History of articulators from face bow to gnathographJPD vol:10 dec2001 5. Appearance and early history of face bows- Journal of prosthodontics vol:9 sep2000 www.indiandentalacademy.com
  46. 46. www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com