tooth arrangement for preclinical prosthodontics

Dental tooth arrangement

1. Setting Anatomic TeethSetting Anatomic Teeth

2. When viewed facially, all maxillary anterior When viewed facially, all maxillary anterior
teeth are tilted mesially, with the lateral incisor teeth are tilted mesially, with the lateral incisor
inclined the most and raised about 1-2 mm above inclined the most and raised about 1-2 mm above
the plane. When viewed laterally, the incisors the plane. When viewed laterally, the incisors
are depressed at the cervical, with the lateral are depressed at the cervical, with the lateral
incisor being the most depressed, and the canine incisor being the most depressed, and the canine
being straight with the long axis perpendicular to being straight with the long axis perpendicular to
the occlusal plane.the occlusal plane.

3. When viewed facially, all the mandibular When viewed facially, all the mandibular
anterior teeth except the central incisors anterior teeth except the central incisors
are tilted mesially, with the canine inclined are tilted mesially, with the canine inclined
the most. When viewed laterally, the the most. When viewed laterally, the
central incisors are depressed at the central incisors are depressed at the
cervical, with the lateral incisor being cervical, with the lateral incisor being
straight, and the canine being inclined straight, and the canine being inclined
lingual to the long axis.lingual to the long axis.

4. The anterior teeth should not be positioned any The anterior teeth should not be positioned any
further forward than the depth of the labial vestibule, further forward than the depth of the labial vestibule,
determined by a line drawn from the depth of the determined by a line drawn from the depth of the
vestibule and perpendicular to a line drawn parallel to vestibule and perpendicular to a line drawn parallel to
the occlusal plane. The depth of the vestibule is the the occlusal plane. The depth of the vestibule is the
fulcrum point and the further forward a tooth extends fulcrum point and the further forward a tooth extends
beyond this point, the greater are the forces that tend beyond this point, the greater are the forces that tend
to dislodge the denture.to dislodge the denture.

5. The middle of the depth of the vestibule The middle of the depth of the vestibule
should be marked on the land areas of the should be marked on the land areas of the
maxillary & mandibular casts. Next, mark the maxillary & mandibular casts. Next, mark the
midline of the patient’s face by placing a dot midline of the patient’s face by placing a dot
on the incisive papilla and marking this midline on the incisive papilla and marking this midline
on the maxillary anterior land area, extending on the maxillary anterior land area, extending
down the front of the cast.down the front of the cast.

6. Make a cut with a heated, sharp knife, at the midline in
the anterior wax rim. Cut all the way to the baseplate.
Make a similar cut just distal to the canine point. Remove
this section of wax in its entirety. Reduce the anterior Reduce the anterior
ridge of the maxillary baseplate to provide a little extra ridge of the maxillary baseplate to provide a little extra
space for the tooth, but reduce the tooth if necessary to space for the tooth, but reduce the tooth if necessary to
fit properly.fit properly.

7. Use a flat plate resting flush with the occlusion Use a flat plate resting flush with the occlusion
rim to position the central incisor so that it rim to position the central incisor so that it
contacts the occlusal plane.contacts the occlusal plane.
Set the rest of the anterior teeth on the Set the rest of the anterior teeth on the
right side according to the curve defined by right side according to the curve defined by
the plastic ruler. The labioincisal line angle of the plastic ruler. The labioincisal line angle of
the incisors should touch the ruler, as well as the incisors should touch the ruler, as well as
the midbuccal surface of the canine.the midbuccal surface of the canine.

8. Use a flexible plastic ruler to verify that Use a flexible plastic ruler to verify that
the incisal portion of the tooth’s labial the incisal portion of the tooth’s labial
surface is properly located and in contact surface is properly located and in contact
with the anterior curvature of the occlusion with the anterior curvature of the occlusion
rim. rim.

9. An anterior view of the maxillary anterior An anterior view of the maxillary anterior
teeth shows that only the lateral incisors do teeth shows that only the lateral incisors do
not touch the occlusal plane as recorded by not touch the occlusal plane as recorded by
mandibular wax rim. With the maxillary mandibular wax rim. With the maxillary
anterior teeth set, record the patient’s anterior teeth set, record the patient’s
midline and set the mandibular anterior teeth.midline and set the mandibular anterior teeth.

10. The maxillary cast is placed back on the articulator. A The maxillary cast is placed back on the articulator. A
quick look will show that the maxillary teeth are set on the quick look will show that the maxillary teeth are set on the
same plane that the mandibular occlusion rim occupies, same plane that the mandibular occlusion rim occupies,
showing the value of having the maxillary and mandibular showing the value of having the maxillary and mandibular
rims made in intimate contact. If the maxillary teeth are rims made in intimate contact. If the maxillary teeth are
not on the same plane as the lower rim, they must be reset. not on the same plane as the lower rim, they must be reset.

11. Mark the midline of the mandibular ridge on the
mandibular wax rim and cut out a section representing the
right mandibular anterior teeth from the rim. Reduce the
thickness of the Triad baseplate from the middle of the
ridge to the labial to allow for easier setting of the
mandibular anterior teeth. A central incisor placed in this
space shows that considerable reduction must be made on
the cervico-lingual ridgelap surface before the tooth can be
set in position.

12. Mark the midline of the mandibular ridge on the
mandibular wax rim and cut out a section representing
the right mandibular anterior teeth from the rim.
Reduce the thickness of the Triad baseplate from the
middle of the ridge to the labial to allow for easier
setting of the mandibular anterior teeth. A central
incisor placed in this space shows that considerable
reduction must be made on the cervico-lingual ridgelap
surface before the tooth can be set in position.

13. Remove enough wax to allow setting most of the posterior teeth
and thin the baseplate to allow for their positioning. Leave a small
segment of the wax rim intact and clearly mark the midline to
facilitate the setting of the teeth anterior to it. After these
teeth are set, remove this pillar to allow the last tooth to be set,
and those teeth anterior to it will indicate the center of the
ridge.

14. Check the position of the teeth to the center of Check the position of the teeth to the center of
the ridge with a tongue blade used as a straight the ridge with a tongue blade used as a straight
edge. Once it is verified by your lab bench edge. Once it is verified by your lab bench
instructor that this relationship is correct, you instructor that this relationship is correct, you
may begin setting the teeth on the other side, may begin setting the teeth on the other side,
using the same steps for setting, sequencing, and using the same steps for setting, sequencing, and
verification that were used on the other side.verification that were used on the other side.

15. With all the mandibular teeth set, check the With all the mandibular teeth set, check the
occlusal plane with a flat metal plate to verify occlusal plane with a flat metal plate to verify
that all the teeth contact the flat surface that all the teeth contact the flat surface
evenly. Expect some changes because of the evenly. Expect some changes because of the
shrinkage of the wax, which will shift the teeth shrinkage of the wax, which will shift the teeth
slightly. Correct any discrepancies before slightly. Correct any discrepancies before
moving on to setting the maxillary posterior moving on to setting the maxillary posterior
teeth.teeth.

16. With all the mandibular teeth set, check to see With all the mandibular teeth set, check to see
that all the teeth contact the flat surface of the that all the teeth contact the flat surface of the
maxillary wax rim evenly. If these teeth contact maxillary wax rim evenly. If these teeth contact
the wax rim evenly, begin setting the maxillary the wax rim evenly, begin setting the maxillary
posterior teeth.posterior teeth.

17. Remove the wax on one side of the maxillary
baseplate. A quick look will verify that the
maxillary posterior teeth should have plenty of
space to be set with little or no reduction. The
rim is left intact on the opposite side because
this will help you to maintain the location of the
occlusal plane.

18. Set the teeth on the maxillary right side so that the Set the teeth on the maxillary right side so that the
mesiolingual cusp of the maxillary first molar rests in the mesiolingual cusp of the maxillary first molar rests in the
central fossa of the mandibular first molar. Set the central fossa of the mandibular first molar. Set the
teeth so that the buccal surfaces of the premolar(s) and teeth so that the buccal surfaces of the premolar(s) and
mesial cusp of the first molar line up with the mid-buccal mesial cusp of the first molar line up with the mid-buccal
surface of the canine. The distobuccal cusp of the first surface of the canine. The distobuccal cusp of the first
molar should deviate approximately 20molar should deviate approximately 20
oo
from this plane from this plane
and the second molar will fall along this plane.and the second molar will fall along this plane.

19. If a maxillary second molar were set, the buccal If a maxillary second molar were set, the buccal
cusps should line up with a second plane that is cusps should line up with a second plane that is
determined by the buccal surfaces of the maxillary determined by the buccal surfaces of the maxillary
first molar. In this case, there was not room first molar. In this case, there was not room
enough to do so, because the opposing mandibular enough to do so, because the opposing mandibular
tooth would have to be set on the incline of the tooth would have to be set on the incline of the
retromolar pad.retromolar pad.

20. Set the teeth on the maxillary right side so that the Set the teeth on the maxillary right side so that the
mesiolingual cusp of the maxillary first molar rests in the mesiolingual cusp of the maxillary first molar rests in the
central fossa of the mandibular first molar. Then move it central fossa of the mandibular first molar. Then move it
up so that the distobuccal cusp is ½ mm off the flat up so that the distobuccal cusp is ½ mm off the flat
plane. If there were room to set a maxillary second plane. If there were room to set a maxillary second
molar, its mesiobuccal cusp would be 1 mm off the flat molar, its mesiobuccal cusp would be 1 mm off the flat
plane and its distobuccal cusp would be 1plane and its distobuccal cusp would be 1½ mm½ mm off the flat off the flat
plane.plane.

21. Adjust the occlusal surfaces of all posterior teeth
to contact their opposing counterparts properly.
Note: There is no vertical overlap of the anterior
teeth at this time. With the anatomical maxillary
posterior teeth properly positioned and having
established a compensating curve and in harmonious
centric occlusion with the anatomical mandibular
posterior teeth, the mandibular anterior teeth are
moved up to a point where the mandibular incisors
contact the maxillary central incisors in protrusive
and simultaneously with posterior teeth.

22. The compensating curve is obvious on these mandibular The compensating curve is obvious on these mandibular
molars which were adjusted so that they contact the molars which were adjusted so that they contact the
maxillary molars in their new positions. The teeth are maxillary molars in their new positions. The teeth are
designed to fit together in with the mandibular teeth to designed to fit together in with the mandibular teeth to
the outside of a curve. If they are set flat, there will the outside of a curve. If they are set flat, there will
be spaces between the maxillary molars. There should be be spaces between the maxillary molars. There should be
a definite Curve of Wilson visible when looking from the a definite Curve of Wilson visible when looking from the
back of the articulator back of the articulator . .
 

23. 



 
??
??
??
??
??
??
??
Questions?Questions?
Questions?Questions?
Questions?Questions?