major and minor connectors Flashcards
that component of a partial denture which joins the minor connectors and their attached assemblies together to form a solid unit
major connector
3 important parts of major connector
- counter leverage
- cross-arch stabilization
- unification of components
bracing elements on one side of the arch providing stability to the other
cross-arch stabilization (counterleverage)
-function as one unit
-broad stress distribution
-reduce torque
-avoid tissue damage
flexibility=force concentration
rigidity
-should not enter undercut areas
-avoid by changing path of insertion or by using blockout
this is example of:
non-interference with tissues
with non-interference with tissues, avoid terminating on:
- free gingival margin
-cross abruptly at 90 degrees
-relief is used to minimize impingement - lingual frenum and the movable soft palate
-soft tissue movements must also be allowed
-careful intraoral exam
minimize food impaction by
- locating margins away from the free gingival margin
-elminate traps or large concavities food gets stuck
have unobtrusive, smooth transition from connector to denture which is known as
butt joint
line angles of edges should be:
borders should not interfere with:
smooth and rounded
speech
maxillary major connectors
borders are placed parallel to a minimum of ___mm from gingival margin.
is relief required?
how should sit on rugae?
6mm
no relief required
anterior borders follow valleys between rugae
with max major connector, anterior and posterior borders should cross at the midline at:
the borders are beaded how thick:
midline at right angle
0.75mm wide and deep
to avoid tissue impingement should be
___mm from gingival crest(for max)
___mm from gingival crest (for mand)
and cross at what angle to the gingival margin
6mm max
3mm mand
right angle
what are the 4 max major connectors
palatal strap
palatal plate
anterior-posterior strap
horseshoe or U
what are the indications of using a palatal strap for max connector?
-tooth supported situations like class III
-small posterior edentulous areas
-minimal tissue supported required
8-10 mm anterior to posterior
contraindications of using a palatal strap for max connector
-distal extensions like class I or II
-severe palatal undercuts
-large tori
-if need to replace anterior teeth
-when need tissue support
advantages and disadvantages of palatal strap
advantages
-good support and rigidity
-distribute stress of mastication over wider area
disadvantages
-coverage of palate may cause discomfort and interfere with phonetics
location of palatal strap
anterior border follows valley between rugae at right angle to median suture
posterior border at right angle to median suture
4 principle rests
8-10 mm wide??
indications of palatal plate
- long-span distal extension w or w/o anterior tooth replacement
- flat residual ridges
- periodontally weakened abutments
contraindications of palatal plate
tori
advantages and disadvantages of palatal plate
adv
-optimum support and rigidity
-increases retention
disadv
-cant be used with tori
-covers palate and may diminish taste
-difficult to cast
location of palate plate
-anterior border between rugae valleys and at right angle to median suture
-posterior border extends to junction of soft and hard palate
what are the indications of anterior-posterior palatal strap
-have tori
-strong, widely separated abutments
-distal extension RPDs; distal extension RPDs also replacing anterior teeth
what are the contraindications of anterior-posterior palatal strap
-if pt has high narrow vaults
-phonetic interference
-bulky straps
adv for anterior-posterior palatal strap
adv
-minimal tissue coverage
-rigid
-straps in 2 planes
the anterior-posteriors palatal straps width are:
and palatal opening to be beneficial, the space should be how wide:
the posterior strap distal extension should be to:
6-8mm
15mm open
to vibrating line and extended through hamular notches
-tooth supported not more posterior than distal abutment
indications of horseshoe or U
**in a very high vault palate!
-large torus
-anterior tooth replacement
-pt is intolerant of palatal coverage
contraindications of horseshoe or U shaped
-least rigid max connector; therefore anytime another connector may be used
adv and disadv of horseshoe or u shaped
adv
can replace missing anteriors
conforms to pts previous experience
disadv
-requires additional bulk for rigid
-can interfere with speech
-even with rest may lack support causing tissue impingement
location of horseshoe/u shaped
anterior borders:
terminates in valley of rugae at right angle to suture or cingulum of teeth extending contact point to contact point
posterior borders:
located at turning point of palate
a prepared groove on the master cast along the designated borders of the max major connectors
this produces a positive ____ on the major connector of the RPD
beading of the max cast
bead
what are the functions of beading the max cast
-increased rigidity
-guide for finishing
-compensates for csating inaccuracies
-displaces soft tissue, preventing food/fluid collection
what are the 3 mand major connectors
lingual bar
lingual plate
labial bar
what are the indications of a lingual bar
whenever possible
-depth of at least 7mm measured from lowest point of gingival margins to floor of mouth is required!
contraindications of lingual bar
-shallow floor of mouth and prominent frenum
-inoperable tori
-teeth in linguversion
-teeth need stabilization
adv and disadv of lingual bar
adv: covers the minimum of the tissues
disadv: may be flexible
location of lingual bar
superior borders 3-4mm inferior to free gingival margin
bar height 4-5mm
inferior border at height of lingual sulcus with tongue slightly elevated
indications for lingual plate
[this is on teeth]
use this when cant use lingual bar
-if less than 7mm from gingival margins to floor of mouth
-future replacement of anterior teeth
-bilateral distal extension with flat residual ridges
contraindications for lingual plate
-severely crowded anterior teeth
-prominent diastemas
-teeth in linguoversion
lingual plate advantages
adv: more rigid than lingual bar
location for lingual plate
superior border contacts cingula of anterior teeth extending from contact point to contact point
inferior border at height of alveolar lingual sulcus with tongue elevated
must be supported by rests at terminal ends
indications of labial bar
lingually inclined anterior or posterior teeth
prominent superiorly located
inoperable tori
that component of a partial denture which joins the major connector with other parts of the framework
minor connector
minor connect joins:
to the major connector
-clasp assembly
-indirect retainers or auxiliary rests
-the denture base
this serves as an approach arm for a vertical projection or bar type clasp
minor connector
4 functions of minor connectors
-transfers functional stress to abutments
-transfers effect of retainers, rests and stabilizing components to the rest of the denture
-unites retainers, rests, and denture base to major connector
-helps to resist lateral movement
minor connector requirements
- rigid with minimal bulk
- located in embrasure
- triangular in shape
- thickest toward lingual
- joins major connector at right angle
- tapers to contact point
- smooth and rounded
- minimum of 5 mm between vertical connectors
portion of framework that contacts the proximal side of the tooth, is also considered a minor connector
proximal plate
