Mark II Instruction Manual - Whip Mix

IX. TREATMENT PROCEDURES
The rationale for utilizing the diagnostic
data obtained from protrusive and lateral
checkbite records is as follows.
When the protrusive inclination of the
superior fossa wall is adjusted to the
lateral checkbite record, a characteristic
of the orbiting condylar path is diagnosed.
This characteristic is associated
with the balancing inclines of posterior
teeth on the orbiting side – the mandibular
buccal cusps’ lingual inclines’ mesial
aspects and the maxillary lingual cusps’
buccal inclines distal aspects.
When the protrusive inclination of the
superior fossa wall is adjusted to the
protrusive checkbite record, the inclination
of the patient’s protrusive condylar
path is diagnosed. This inclination of
the superior fossa wall is associated
with the protrusive contacts of posterior
teeth – the mesial aspects of mandibular
cusps and the distal aspects of maxillary
cusps.
The orbiting path inclination of the superior
fossa wall adjusted to lateral
checkbite records is always equal to or
greater than the protrusive path inclination
of the superior fossa wall adjusted
to the protrusive checkbite record.
FIXED RESTORATION AND
REMOVABLE PARTIAL DENTURE
RESTORATIONS
Adjusting the protrusive inclination of
the superior fossa to an angle which
is slightly less than the patient’s protrusive
condylar path (5 to 10 degrees
less) when the restoration is fabricated
will prevent the fabrication of protrusive
contacts, or balancing contacts on the
orbiting side of posterior teeth in the
laboratory. This is due to the fact that
when the restoration is seated in the patient’s
mouth and the patient’s condyle
tracks a steeper protrusive and orbiting
condylar path, the posterior teeth will
separate in both the protrusive excursion
and in the lateral excursion on the
orbiting side.
COMPLETE DENTURES
Method 1. Adjusting the articulator to
the patient’s protrusive condylar
path inclinations for both the protrusive
and lateral excursive movements
allows the fabrication of protrusive
balance in the laboratory, When the
restoration is seated in the patient’s
mouth and the patient executes a
lateral mandibular movement with
the teeth in contact, the patient will
feel the primary occluding pressures
on the working side. If the patient’s
orbiting path is slightly steeper than
the articulator setting when the restoration
was fabricated, the patient
would perceive minimal occluding
pressures on the balancing side.
However orbiting side occlusal contact
would prevent loss of peripheral
seal.
Method 2. Adjusting the inclinations
of the superior fossa wall to the patient’s
orbiting path inclinations allow
the fabrication of bilateral balanced
occlusion in lateral excursive movements
in the laboratory. Subsequent
adjustment of the articulator to the
patient’s protrusive condylar path
inclinations permit adjustment of the
occlusion to protrusive balance. This
method permits development of full
arch balanced occlusion. (Note: Obtaining
accurate eccentric checkbite
records on extensive tissue borne
restorations, although theoretically
attainable, is a difficult accomplishment).
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