Mandibular Major Connectors

Design configuration for mandibular major connectors

1. MANDIBULAR MAJOR
CONNECTORS
DR. AAMIR GODIL
DEPT. OF PROSTHODONTICS
M.A.R.D.C.

2. CAST PARTIAL DENTURE
Components of a typical removable partial denture are:
1. Major connectors
2. Minor connectors
3. Rests
4. Direct retainers
5. Indirect retainers
6. Denture base
7. Denture teeth

3. MAJOR CONNECTOR
“the part of a removable partial denture that joins the components on one
side of the arch to those on the opposite side.”
-Glossary of Prosthodontic Terms-9

4. FUNCTIONS OS MAJOR CONNECTOR
unification of the
major parts of the
prosthesis
distribution of the
applied force
throughout the arch to
selected teeth and
tissue
minimization of
torque to individual
teeth
cross-arch
stabilization

5. REQUIREMENTS OF A MAJOR CONNECTOR
1. Are made from an alloy compatible with oral tissue.
2. Are rigid and provide cross-arch stability through the principle of broad
distribution of stress.
3. Do not interfere with and are not irritating to the tongue.
4. Do not substantially alter the natural contour of the lingual surface of the
mandibular alveolar ridge or of the palatal vault.
5. Do not impinge on oral tissue when the restoration is placed, is removed, or
rotates in function.
6. Cover no more tissue than is absolutely necessary.
7. Do not contribute to retention or trapping of food particles.
8. Have support from other elements of the framework to minimize rotation
tendencies in function.
9. Contribute to the support of the prosthesis

6. MANDIBULAR MAJOR CONNECTORS
Lingual bar
Linguo-plate
Double lingual bar
Labial bar

7. LINGUAL BAR

8. 1. LINGUAL BAR
Most commonly used
Shape:
flat on tissue side
convex or tear-drop on tongue side (1/2 pear shape,
with thin edge toward teeth)
Size:
occluso-gingival width = 4 to 6 mm.
thickness = l.5 to 2 mm.

9. 1. LINGUAL BAR
•Lingual bar major connector should be located at least 4
mm inferior to gingival margins and farther if possible.
•The vertical height of a finished lingual bar should be at
least 4 mm for strength and rigidity.
•If less than 8 mm exists between gingival margins and the
movable floor of the mouth, linguoplatemay be used.

10. 1. LINGUAL BAR
▪Simple to fabricate.
▪Indicated for all tooth-supported removable partial
dentures unless there is insufficient space between the
marginal gingivae and the floor of the mouth.
▪Minimaltoothcontact=lessplaqueaccumulation.
▪If not designed properly, the framework may become too
weak and flexible.

11. SUB-LINGUAL BAR
▪A modification of the lingual bar where in the
placement is inferior and posterior to the usual
placement of a lingual bar, lying over and parallel
to the anterior floor of the mouth.
▪It can be substituted for lingual plate if the lingual
frenum does not interfere, or in the presence of an
anterior lingual undercut that would require
considerable blockoutfor a conventional lingual bar.
▪Contraindications:
▪interfering lingual tori
▪high attachment of a lingual frenum
▪interference with elevation of the floor of the
mouth during functional movements.

12. LINGUO-PLATE

13. 2. LINGUO-PLATE
The lingual plate consists of a lingual bar plus an extension
over the cingula of anterior teeth.
A linguoplateshould be made as thin as is technically
feasible and should be contoured to follow the contours of
the teeth and the embrasures.
Shape:
convex or tear-drop on tongue side (1/2 pear shape,
with thin edge toward teeth).

14. 2. LINGUO-PLATE
Indications:
•When the lingual frenum is high or the space available for a lingual
bar is limited. (Available sulcus depth <8 mm)
•In Class I situations in which the residual ridges have undergone
excessive vertical resorption. (Reduces horizontal rotations)
•For stabilizing periodontally weakened teeth. (Splinting)
•When the future replacement of one or more incisor teeth will be
facilitated by the addition of retention loops to an existing
linguoplate.

15. INTERRUPTED
LINGUO-PLATE
Interrupted linguoplate in the
presence of interproximal
spaces.

16. DOUBLE LINGUAL
BAR

17. 3. DOUBLE LINGUAL BAR (KENNEDY BAR)
▪A double lingual bar = lingual bar + lingual
plate major connectors.
INDICATIONS:
▪A double lingual bar is indicated primarily when
contact with the remaining mandibular anterior teeth
is indicated, but open embrasures exist.

18. 3. DOUBLE LINGUAL BAR (KENNEDY BAR)
SHAPE:
▪The lower component of this major connector should be half-pear
shaped in cross section, with its greatest diameter at the inferior
margin.
▪The upper bar should be half oval in cross section. This bar should be
2 to 3 mm in height and 1 mm thick. It should present a scalloped
appearance.
▪The two bars should be joined by rigid minor connectors at each end.

19. 3. DOUBLE LINGUAL BAR (KENNEDY BAR)
ADVANTAGES:
▪Indirect retention and horizontal stabilization.
▪Because the gingival tissues and the interproximal embrasures are not
covered, a free flow of saliva is permittedand the marginal gingiva
receives natural stimulation.
DISADVANTAGES:
▪Accumulation of debris.
▪Discomfort to tongue.

20. CINGULUM BAR
▪A cingulum bar located on or slightly above the cingula of
the anterior teeth may be added to the lingual bar or can
be used independently.
▪In addition, when wide diastemata exist between the lower
anterior teeth, a continuous bar retainer may be more
esthetically acceptable than a linguo-plate.

21. LABIAL BAR

22. 4. LABIAL BAR
INDICATIONS:
▪Extreme lingual inclination of the remaining
lower premolar and incisor teeth prevent the
use of a lingual bar major connector.
▪When a mandibular torus interferes with
placement of a lingual bar.
Use of a labial bar connector should be
avoided.

23. SWING LOCK DESIGN

24. SWING LOCK DESIGN
▪Linguoplate+ labial bar + hinge.
▪Support is provided by multiple rests on the remaining natural teeth.
▪Stabilization and reciprocation are provided by a linguoplatethat
contacts the remaining teeth and are supplemented by the labial bar
with its retentive struts.
▪Retention is provided by a bar type of retentive clasp with arms
projecting from the labial or buccal bar and contacting the infrabulge
areas on the labial surfaces of the teeth.

25. SWING LOCK DESIGN
INDICATIONS:
▪Missing key abutments
▪Unfavorable tooth contours
▪Unfavorablesoft tissue contours
▪Teeth with questionable prognoses
CONTRAINDICATIONS:
▪Poor oral hygiene or lack of motivation
for plaque control by the patient.
▪Presence of a shallow buccal or labial
vestibule or a high frenal attachment.

26. SUMMARY

27. EXAM ORIENTED QUESTIONS

28. EXAM ORIENTED QUESTIONS
LAQ:
1. Define major connectors. Classify maxillary/ mandibular major connectors and
describe them in detail with diagrams.
SAQ:
1. Requirements and functions of major connectors.
2. Lingual bar major connector
3. Lingual plate major connector
4. Swing lock major connector
5. Factors determining choice of mandibular major connectors

29. REFERENCES

30. THANK YOU