RPD Manual 11 - Removable Prosthodontics - Dalhousie University

Major Connectors - 34
3. Position
- The inferior border should be as low as the lingual frenum and tissue reflections of
the floor of the mouth will permit, as determined by observing functional
movements of the tongue.
- The superior border should be l.5-2.0 mm or more below the free gingival
margin. For hygienic reasons the superior border should still be kept as far from
the gingival margin as possible.
- In distal extension cases there will be some tissue-ward movement of the lingual bar
as the denture base moves during function. If bone loss occurs over the edentulous
ridges, this movement can become more pronounced and this will cause the lingual
bar to impinge upon the lingual tissues. To eliminate the lingual bar from impinging
the soft tissues, a wax spacer (relief) of one thickness of 30 gauge wax is placed
under the major connector when it is being waxed for casting.
Note the anterior portion of the major
connector moves forward as the
posterior portion is loaded and rotates
around the rest. If relief is not
provided, impingement occurs.
B. Lingual Plate (Linguoplate)
The lingual plate consists of a lingual bar plus an
extension over the cingula of anterior teeth. This
mandibular major connector should only be considered in
those rare instances where a lingual bar cannot be used.
Most often, this occurs when there is a high floor of the
mouth, a prominent lingual frenum or lingual tori that
would be impinged upon by a lingual bar, if it was made
with adequate height and distance from the free gingival
margin.
The lingual plate has also been advocated for extensive distal extension cases with severe
vertical resorption of ridges (i.e. little resistance to horizontal rotational tendencies). In these
cases the major connector could provide some additional stability. The lingual plate has been
advocated for use to reduce heavy calculus formation or to stabilize mobile anterior teeth.
However, the plate usually does not reduce mobility, other than stabilizing the teeth during
function. Mobility per se is not a problem unless it is increasing (i.e. pathological process
continuing). Since mobility is often related to periodontal bone loss and since the plate
complicates hygiene by closing the lingual opening of the embrasure spaces, this connector
actually may be contraindicated when mobile teeth are present. When large diastemas are
present, the lingual plate may show through the embrasure spaces.