OCCLUSAL EQUILIBRATION BETWEEN OPTION AND CLINICAL REALITY
made onto natural teeth before prosthetic treatments
with a view to not perpetuating occlusal cuspal
incongruous slopes.
D. The limitation of the envelope of masticatory
movements.
Elemental occlusal dental topography
The cusp slope of every tooth resembles a gothic
pyramid: it has a base, ridges (slopes) and a tip
(Fig. 1) Woelfel. An image of the teeth occlusal
contacts between the ridges of the teeth in occlusal
intercuspation is explanatory. Every maxillary and
mandibular lateral tooth has buccal and lingual cusps.
Every cusp has buccal and lingual ridges (slopes). Every
ridge (slope) of the lateral teeth has occlusal contacts
during masticatory movements (green color), except
for the buccal ridges (slopes) of buccal guidance cusps
of the maxillary teeth and lingual ridges (slopes) of
lingual guidance cusps of mandibular teeth (red color).
The buccal slopes of the guidance cusps of maxillary
teeth and the lingual slopes of guidance cusps of
mandibular teeth are rarely adjusted (Fig. 2).
Matherial and method
It is customary to use different diamond burs for occlusal
adjustments: round-end tapered diamond, chamfer
diamond, medium wheel diamond, round diamond
burs, dura-white different size, white polishing stones
of enamel, thin and extra thin articulating papers.
Occlusal equilibration using dental occlusal adjustment
has some subsequent stages:
I. The removal of all occlusal interferences on
intercuspation path of mandible movement around
hinge terminal axis (centric relation). These occlusal
interferences arise between CR and CO points on
Posselt’s diagram (Fig. 3).
The mandible closing into centric relation position
must be examined into two plans: frontal (close line)
and sagittal (close arch).
On the frontal close line, the direction of the mandible
close to the centric relation can be deviated towards
the left or right side because of occlusal interferences
(Fig. 4). On the sagittal close arch the direction of the
mandible close to the centric relation can be deviated
towards the mesial or distal side because of occlusal
interferences (Fig. 5). On the close line of the mandible
into centric relation, when tooth interferences are
present, one quadrant of the mandible slides towards
the cheek and the opposite quadrant slides towards
the tongue, irrespective of whether the mandible
slides right or left (Fig. 6).
Thus, on the level of the teeth of the quadrant sliding
towards the cheeks buccal ridges of maxillary support
cusps, or lingual ridges of mandibular support cusps
are ground: BULL.
On the level of the teeth of the quadrant sliding
towards the tongue lingual ridges of maxillary and /
or buccal ridges of the mandibular teeth are ground:
LUBL (Fig. 2; 7; 8).
On the sagittal close arch in centric relation the
STOMA.EDUJ (2015) 2 (1)
mandible slides toward the mesial direction when
occlusal interferences are present. These mesial
slides are not symmetrical (99%of the cases): usually
they are mesiolaterotrusives, and symmetrical only in
1% of the cases. On the sagittal close arch, when the
mandible slides towards the mesial, because of dental
interferences, the mesial slopes of maxillary cusps of
lateral teeth and distal slopes of mandibular cusps of
lateral teeth must be ground: MUDL (Fig. 9). One rule
of occlusal equilibration technique is that the slope of
the cusp must be ground is that whose tip is nearer the
central groove of antagonistic tooth.
II. The removal of occlusal interferences on the
laterotrusive (diagonotransversal) paths of the
masticatory cycle. The removal of occlusal interferences
on the laterotrusive functionally paths is coordinated
by the anterior (dental) and posterior (condylar)
guidances of the mandible. The laterotrusive guidance
is dependent on the individual masticatory cycle.
On the mandibular laterotrusive functionally paths
interferences can appear at the working or balancing
dental arches. As a rule the occlusal interferences of
balancing arches are removed first. The mandible
is guided alternatively, right and left from the centric
relation position on the functionally masticatory paths
with the purpose of occlusal interferences registration.
At the level of balancing arches buccal ridges of maxillary
(upper) lateral teeth or lingual ridges of mandibular
(lower) lateral teeth are removed: BULL. At the working
arches the lingual ridges of maxillary (upper) lateral teeth
or the buccal ridges of mandibular (lower) lateral teeth
are removed: LUBL (Fig. 10 and 11).
III. The removal of occlusal interferences on the protrusive
path of the masticatory cycle is done likewise. These
interferences can appear at the mesial slopes of cusps
of maxillary (upper) teeth and/or distal slopes of cusps
of mandibular (lower) teeth or at the level of the anterior
(dental) guidance path on lingual surfaces of upper
frontal teeth, or on labial surfaces of lower frontal teeth.
They frequently deviate the protrusive traiectorial
direction of the mandible toward the left or right sides.
So, having as functional mark of mandible protrusive
movement on posterior (condylar) and anterior
(dental) guidance primary interferences must remove
first. Usually, the primary interferences appears on the
occlusal surfaces