- There are 3 main techniques used to record centric relation: chinpoint guidance, bilateral manipulation, and unguided method. - The most consistent and repeatable technique is Dawson's method, which deprograms the muscles from their habitual closing pattern to allow the condyles to rest in an unstrained position. - To mount the casts on an articulator, a facebow record is made and used to transfer the maxillary cast orientation. The maxillary cast is mounted, followed by the mandibular cast using an interocclusal record in centric relation. Condylar guidance is set using lateral records.

1. CENTRIC RELATION RECORD
There are 3 techniques that are frequently used.
a) Chinpoint guidance.
b) Bilateral manipulation.
c) Unguided method.
Chinpoint guidance puts the condyles in the most posterior and superior
position and is not muscle guided.
The unguided method produces a “physiologic muscle” position (condyles
placed anterosuperiorly on the articulator disc along the articulator eminence). It is
difficult to achieve consistent results with this method because of the patient’s
muscle activity.
The most consistent, repeatable results can be accomplished by utilizing the
technique of Dawson. It was his opinion that the neuromuscular system monitors
all sensory impulses from the teeth and jaws and programs occlusal contact to
occur where the protective stimuli are minimal. This position, through repeated
closures, become habitual and is maintained at the expense of normal muscle
function. To enable the condyles to be placed in an unstrained position, the
musculature must first be deprogrammed from its habitual closing pattern.
ARTICULATION OF CASTS
Hanau Facebow and Articulator:

2. - Hanau spring bow (Teledyne)
- Hanau series 184 wide-vue, arcon, semiadjustable
The Hanau spring-bow is an ear-piece facebow that utilizes a one-piece
spring steel bow. It is simple in design and can be used with the removable bite
fork assembly and mounting platform.

3. Face bow record
- Soften a sheet of baseplate wax in hot water and completely cover
the bitefork with it.
- Position the wax-covered bitefork against the maxillary teeth and
have the patient close until the mandibular teeth contact the wax on
the underside of the fork.
- Cool the wax in the mouth with an air syringe. Remove the fork
from the mouth and finish coding it in a bowl of cold tap water. Trim
off excess and any areas imprinted by soft tissue.
- Seat the maxillary cast in the wax record to be sure that it is stable. If
there is any rocking of the cast, cheek the occlusal surfaces of the
cast for any nodules of stone. If there are none, either the cast or
record is distorted and must be remade.
- Insert the transfer rod of the assembly into the bow socket on the
underside of the black centerpiece on the front of the face bow. It is
made sure that the flat surface on the front of the rod faces the
operator as it is placed in the socket.
- While the patient grips the bite fork between the maxillary and
mandibular teeth, position the loosened bite fork clamp over the bite

4. fork shaft. The face bow should be pointed upward during this
action.
- Open the bow by pulling outward on the arms and swing it down
into position, placing on earpiece gently into each external auditory
meatus. Have the patient adjust the earpieces to the most
comfortable seated position.
- Mark the orbitale on the patient’s face to provide on anterior
reference point. Gently swing the orbitale pointer towards the
reference mark.
- Elevate the front of the face bow along the transfer rod of the bite
fork assembly until the pointer is at the plane of the anterior
reference point.
- Grasp the bow to resist torquing and tighten the three thumb screws
in order from left to right.
Mounting the maxillary cast
- Prepare the articulator to accept the casts by setting the inclination of
the enclosed condylar track mechanisms at 30 degrees on each side.
“Bennet angle” ring for the progressive mandibular lateral
translation should be set at 30 degrees.

5. - Use petrolatum to lubricate the surfaces of the upper and lower
members of the articulator around the threaded mounting studs.
- Firmly secure a clean mounting plate to the mounting stud on the
upper member of the articulator. Attach a mounting guide or
platform to the lower member of the articulator.
- Loosen the thumbscrew on the front of the facebow and remove the
bitefork assembly. Place the vertical transfer rod of the assembly
into the hole at the front of the mounting guide and secure it by
tightening the screw. Adjust the cast support to touch the underside
of the wax on the bitefork.
- Soak the maxillary cast in a bowl of water, but do not cover the teeth
with water. Carefully seat the maxillary cast into the imprints in the
baseplate wax on the bite fork.
- Raise the upper-member of the articulator and place a golf-ball sized
mould of thick, creamy stone on the base of the cast. Swing the
upper member of the cast down until the incisal pin is resting on the
mounting guide or anterior table. Add more stone if necessary and
smooth off the top with a spatula.
- When the stone has set, remove the bitefork assembly and mounting
guide from the articulator. Attach a clean mounting plate to the
lower member of the articulator.

6. Mounting the mandibular cast
- Extend the incisal guide pin 1 to 2mm to compensate for the
thickness of the interocclusal wax record.
- Tighten the centric lock on each enclosed condylar track mechanism
to insure that the articulator is capable of nothing but hinge
movement.
- Invert the articulator on the bench top, resting it on the three thumb
nuts protruding from the upper member of the articulator.
- Place the centric relation wax interocclusal record on the teeth of the
maxillary cast.
- Place the mandibular cast into the interocclusal record and again
confirm complete seating. There should be no contact between the
maxillary and mandibular casts.
- Remove the mandibular cast and soak it in water for about 2 minutes
making sure that the teeth are not covered with water.
- Reseat the soaked mandibular cast into the record, swing the lower
member of the articulator up and back. Place a mound of thick,
creamy mounting stone on the bottom of the cast. Hinge the lower
member of the articulator back over into the soft mounting stone.

7. - The incisal guide pin should be resting firmly against the incisal
guide table. The hand should be used to steady the mandibular cast
in the retruded position wax registration until the mounting stone has
achieved an initial set.
Setting condylar guidance
- Lateral or protrusive interocclusal wax records are used for setting
the condylar inclination of this instrument.
- Loosen the thumbnut at the rear of each condylar track mechanism
so that it can be easily rotated. The condylar inclination is left at 30°.
The incisal guide pin should be raised out of contact with the incisal
table.
- Seat the right interocclusal record on the teeth of the mandibular
cast. Gently lower the upper member of the articulator until the
maxillary teeth-engage the wax record.
- Adjust the left condylar guide by changing the condylar inclination
with thumbnut located at the rear of the guide. If the condylar path is
too shallow, the anterior teeth will be drawn out of the wax record.
When the path becomes too steep, the posterior teeth become
unseated. The correct condylar inclination will be determined when
the cast is seated completely in the wax record. Tighten the nut at the
rear of the condylar guide.

8. - If a protrusive interocclusal wax record is used to establish the
condylar inclination, both condylar mechanisms are rotated
simultaneously in the same manner described above for setting each
condylar inclination separately.
- The lateral condylar guidance is estimated by using the formula,
L = H
/8 + 12
Custom Anterior guidance
- A customized anterior guidance jig can be made for this articulator
by using a round-end incisal pin and a flat anterior table.
- Raise the incisal guide pin atleast 1.0mm off the plastic incisal guide
block in all excursions.
- Moisten the surface of the guide block with monomer. Mix one-half
scoop of tray resin, and while it is still free-flowing, place a little on
the incisal guide table.
- Lubricate the tip of the incisal guide pin and the occluding surfaces
of anterior teeth with petrolatum.
- Close the articulator. The guide pin should sink into the soft acrylic
resin.
Move the articulator through all excursions repeatedly, keeping the anterior teeth
touching at all times. The pathways of all the movements will be imprinted by the tip of

9. the guide pin in the acrylic resin as a permanent record. Continue moving the casts until
polymerization is complete. Remove the excess.

10. the guide pin in the acrylic resin as a permanent record. Continue moving the casts until
polymerization is complete. Remove the excess.