Transcript Mandibular major connectors

Mandibular major
connectors
Dr.Mohammad Al Sayed
7 / 3 / 1429
Design specification
1-The superior borders are placed at least 3 mm
from the gingival margins. where a 3 mm
cannot be obtained so, the metal should
extend onto the cingula of anterior teeth or
onto the lingual surfaces of posterior teeth.
2-The inferior border should not interfere with the
soft tissue movement of the floor of the mouth.
3-Relief of the tissue surface of the major
connector is required to prevent tissue
impingement at rest or during function.
4-The metal should be highly polished on the
tissue side to minimize plaque
accumulation.
Types of mandibular major
connectors
I-lingual bar.
II-sublingual bar.
III-double lingual bar.
IV-lingual plate.
V-labial bar.
I-Lingual
bar.
Indication:
It is the first choice major connector, should be used
whenever the functional depth of the lingual vestibule
equal or exceed 8mm.
Design:
1.the bar should be half pear-shaped in cross section.
superior inferior dimension is 5 mm ,and 2 mm in
thickness.
2.the superior border of the bar should be located at least 3
mm from the gingival margins of all adjacent teeth.
3.the inferior border placed at the functional depth of the
lingual vestibule.
4.relif of the tissue surface of the bar is necessary
Advantages:
1.the simplest mandibular major connector with
highest patient acceptance.
2.it does not cover the teeth or the gingival
tissues
disadvantages:
If it is not properly designed it may not be rigid.
2.Sublingual bar
Indications:
When the lingual bar cannot be used because the
of a lack of functional depth of the lingual
vestibule.
Design:
1.The sublingual bar is essentially a lingual bar
rotated horizontally.
2.The superior border of the bar should be located
at least 3 mm from the gingival margins of all
adjacent teeth.
Advantages:
1.It does not covers the teeth or tissues.
2.More rigid than a lingual bar in the horizontal
plane.
Disadvantages:
A functional impression of the vestibule is required
to accurately register the position and contour of
the vestibule.
3.The double lingual bar:
Indications:
1.When indirect retention is required.
2.When periodontally affected teeth that require
splinting are present.
Design:
1.It is made of two bars; cingulam bar (Kennedy bar) and
the conventional lingual bar. A rigid minor connector at
the embrasure between the canine and first premolars
joins the two bars. Rests are placed at each end of the
upper bar attached to the minor connector.
2.The lower bar has the same design as a single lingual
bar.
3.The upper bar is scalloped, and half-oval in cross section
(2-3 mm high, and 1 mm thick at its greatest diameter.
Advantages:
1.Provides indirect retention.
2.Contributes to horizontal stabilization.
3.No gingival margin coverage.
Disadvantages:
1.Tongue annoyance.
2.Food impaction if the upper bar is not in intimate
contact with the teeth.
4.Lingual plate
Indications:
1.When the functional depth of the lingual
vestibule (less than 5mm) is not enough for
bar placement.
2.When future loss of natural teeth is anticipated to
facilitate addition of artificial teeth to the partial
denture.
3.When splinting of anterior teeth is required.
4.When lingual tori is present.
Design:
1.It consists of a pear shaped lingual bar with a
thin metal extending upward from the superior
border of the bar onto the lingual surfaces of
the teeth above the cingula and survey lines.
2.In extension base partial denture the lingual
plates should have a rest on each side to
prevent labial movement of the teeth.
3.There should be adequate blockout and relief of
the soft tissue undercuts, undercuts in the
proximal areas of the teeth, the free gingival
margins and pear shaped bar.
Advantages:
1.The most rigid mandibular major connector.
2.It gives indirect retention to the partial denture.
3.Deflect food from impacting on lingual tissues.
4.Provide resistance against horizontal or lateral
forces.
5.Permits the replacement of lost teeth without
remaking the partial denture.
6.Help in splinting and prevent upper-eruption of
the anterior teeth.
Disadvantages:
Covers more teeth and gingival tissues than other
mandibular major connectors.
5.Labial bar
Indications:
1.When the mandibular teeth are so severely
inclined lingually as to prevent the use of
lingual major connector.
2.When large lingual tori exist and their removal is
contraindicated.
Design:
1.It is a half pear shaped bar, runs across the
mucosa labial to the anterior teeth.
2.Labial vestibule should be adequate to allow the
superior border to be placed at least 3 mm
below the free gingival margins.
3.Relief is required beneath the bar.
Advantages:
It solves the problem of severely inclined teeth and
avoids surgical intervention to remove large
torus.
Disadvantages:
1.It tends to lack rigidity since it is considerably
longer than a lingual bar.
2.The least comfortable mandibular major
connector.