Question 1

Major connectors-Definition:

Accepted Answer

The component that connects the parts of the RPD on one side of the arch to those on the other side All other parts of the RPD are directly or indirectly attached to the major Connector Provides cross arch stability to resist functional forces

Question 2

Q: What is cross arch stability?

Accepted Answer

A: resistance against dislodging or rotational forces obtained by using natural teeth on the opposite side of the dental arch from the edentulous space

Question 3

MAJOR CONNECTORS Requirements:

Accepted Answer

1. Must be Rigid 2. Must provide vertical support and protect the soft tissues 3. Must provide a means of obtaining indirect retention where indicated 4. Provide an opportunity of positioning denture base where needed 5. Maintain patient comfort 6. Should not create food entrapment areas /as far as possible self cleaning 7. Should not interfere with tongue /should not cause irritation to tongue 8. Should not impinge on oral tissues when the restoration is placed, removed, or rotates in function 9. Should not cover more tissues than absolutely necessary

Question 4

Maxillary Major Connectors Basic Design Requirements:

Accepted Answer

Rigidity Free gingival margin (FGM) 6mm Parallel and 90° Auxiliary role in indirect retention Round boarders Crossing midline at 90°

Question 5

Basic requirement: rigidity

Accepted Answer

As the major connector unifies all other components of the RPD, these could not be effective if the major connector is flexible A flexible major connector could result to: 1. Damage to the supporting tissues /structures 2. Patient discomfort 3. Ineffective RPD (e.g. lack of retention) A rigid major connector ensures that the occlusal loads are spread evenly throughout the available supporting structures A wide distribution of occlusal loads results in smaller loads applied per surface area unit This reduces the risk of damaging the supporting structures

Question 6

Why Rigid?

Accepted Answer

Rigidity determines the design and hence the various types of connectors

Question 7

Major connectors Basic design considerations:

Accepted Answer

Do not extend to moveable tissue (non-attached mucosa) Avoid impinging on gingival tissues Avoid bony/soft tissue undercuts during placement/removal Provide relief in areas of possible interference Consider possible rotation of free end saddle RPDs

Question 8

Major connectors- Basic design considerations:

Accepted Answer

Consider possible rotation of free end saddle RPDs Crossing must be at right angles to the margin to produce the least possible contact with the soft tissue Auxiliary role in indirect retention Round boarders

Question 9

TYPES OF MAXILLARYMAJOR CONNECTORS:

Accepted Answer

Single posterior palatal bar Palatal strap Anteroposterior, or double, palatal bar Horseshoe, or U-shaped connector Closed horseshoe, or anteroposterior palatal strap Complete palate

Question 10

Single palatal bar-Indications:

Accepted Answer

Bilateral edentulous spaces of short span which is entirely tooth-supported Limited usage

Question 11

Single palatal bar-Advantages/Disadvantages:

Accepted Answer

Advantages: 1. Minimum coverage 2. Although most widely used but as an interim partial denture until more definitive treatment can be considered. Disadvantages: 1. Lacks rigidity 2. It is frequently made either too thin and flexible or too bulky.

Question 12

Single Palatal Strap Indications for Use:

Accepted Answer

Bilateral edentulous spaces of short span in a tooth- supported restoration.

Question 13

Characteristics and Location:

Accepted Answer

Anterior border follows the valleys between rugae as nearly as possible at right angles to median suture line. Posterior border at right angle to median suture line. Strap should be 8 mm wide or approximately as wide as the combined width of a maxillary premolar and first molar. Confined within an area bounded by the four principal rests.

Question 14

Anterior-Posterior Strap Indications for Use:

Accepted Answer

Class I and II arches in which excellent abutment and residual ridge support exists, and direct retention can be made adequate without the need for indirect retention. Long edentulous spans in Class II, modification 1 arches. Class IV arches in which anterior teeth must be replaced with a removable partial denture. Inoperable palatal tori that do not extend posteriorly to the junction of the hard and soft palates.

Question 15

_Posterior palatal connector/Anterior palatal strap:_

Accepted Answer

_Anterior palatal strap_: anterior border not placed farther anteriorly than anterior rests and never closer than 6 mm to lingual gingival crevices; follows the valleys of the rugae at right angles to the median palatal suture. Posterior border, if in rugae area, follows valleys of rugae at right angles to the median palatal suture _Posterior palatal connector_: posterior border located at junction of hard and soft palates and at right angles to median palatal suture and extended to hamular notch area(s) on distal extension side(s).

Question 16

Q: What are the advantages of palatal straps major connectors?

Accepted Answer

Rigidity Midpalatal straps cause little interference with tongue, easily accepted by patients

Question 17

Q: What are the disadvantages of palatal straps major connectors?

Accepted Answer

Anterior straps may interfere with tongue / speech if extending on the rugae May be difficult to cast accurately to ensure a close fit in high vaulted palates Posterior straps may not be well tolerated if extending too far posteriorly

Question 18

Complete Palatal Plate Indications for Use:

Accepted Answer

In most situations in which only some or all anterior teeth remain. Class II arch with a large posterior modification space and some missing anterior teeth. Class I arch with one to four premolars and some or all anterior teeth remaining, when abutment support is poor and cannot otherwise be enhanced; residual ridges have undergone extreme vertical resorption; direct retention is difficult to obtain. In the absence of a pedunculated torus.

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Component parts of RPDs: major and minor connectors, rests and rest seats Flashcards

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