بسم
هللا
الرحمن
الرحيم
Face bow:
like instrument used to record the
-
: is a caliper
Definition
spatial relationship of the maxillary arch to some
anatomic reference point or points and then transfer this
relationship to an articulator.
• To record the relationship of the jaws to the
to orient the casts in
and
opening axis of the jaws
this same relationship to the opening axis of the
articulator.
• To support the maxillary cast while it is being
mounted on the articulator.
) During complete denture fabrication while balanced occlusion is desired
1
2) During fixed partial denture fabrication to obtain accurate crowns and
ridges.
3) When cusp form of teeth are used for complete denture fabrication.
4) When interocclusal check records are used.
5) During full mouth rehabilitation when accurate occlusal restorations are
to be made.
6) When vertical dimension at occlusion is to be changed during teeth
setting.
7) In gnathological studies and treatment.
8) For making occlusal corrections after denture processing.
Types of face bow:
1) Arbitrary face bows
A. Fascia type
Example:
- Hanau fascia type face bow.
- Denar fascia face bow.
1) Arbitrary face bows
B
.Ear piece type
Example:
Hanau ear piece type face bow Hanau spring bow.
Whip mix quick mount face bow.
Denar slidematic face bow.
2) Kinematic face bow or hinge bow
Example:
Hanau kinematic face bow.
Denar kinematic face bow.
Parts of face bow
1. U-shaped frame or assembly.
2. Condyle rods / Ear pieces.
3. Bite fork
4. Locking device
5. Orbital pointer
6. Nasion relator assembly
7. Intercondylar scale
8. Electronic device
9. Transfer zig
U-shaped frame or assembly
• It is the main part of face bow to which all other parts
are attached with the help of clamps.
• It should be large enough that extend from the region
of one TMJ around the front of the face to the other TMJ
and wide enough to avoid contact with sides of face.
Condyle rods and ear pieces
• They are attached on either side of the free end of U-shaped
frame.
• Fascia type of arbitrary face bows and kinematic face bows
have condylar rods. Ear piece type of arbitrary face bows have
ear pieces.
Bite fork
• They are attached on either side of the free end of U-
shaped frame.
• They are positioned on the patient at the approximate
or absolute location of the hinge axis or opening axis of
jaws.
Locking device
• Locking device helps in attaching bite fork to
the face bow.
• It also serves to support the face bow, the
maxillary occlusion rim and the maxillary cast
while the casts are being attached to the
articulator.
Orbital pointer
• It is present in Hanau arbitrary face bows.
• It marks the anterior reference point, which is
orbitale in case of Hanau arbitrary face bows.
Inter condylar scale
• It is a part of whip-mix quick mount arbitrary face
bow.
• It is present in front of face bow and indicates the
inter condylar distance as small, medium and large
(S, M, L).
1 . Avoids errors in occlusion of finished prosthesis.
2. Allows minor changes in the occlusal vertical dimension
in articulator without having to make new maxillo-
mandibular relations.
3. Most helpful in supporting the maxillary cast while it is
being mounted on the articulator.
4. Allows more accurate programming of the articulator.
When the dentist has completed recording the
maxillo-mandibular records and making the face bow
transfer, the dentist should do mounting of casts on
articulator.
Precautions must be observed when mounting casts on articulator, if not,
then, the casts mounted in an improper position and defects in
occlusion in the final prosthesis may occur.
