CHAPTER 5: MAXILLARY MAJOR CONNECTORS

Six basic types of maxillary major connectors

Single palatal strap

Combination anterior and posterior palatal strap–type connector

Palatal plate-type connector

U-shaped palatal connector

Single palatal bar

Anterior-posterior palatal bars

definite tooth support must be provided

Whenever it is necessary for the palatal connector to make contact with the teeth for reasons of support

accomplished by establishing definite rest seats on the predetermined abutment teeth

located far enough above the gingival attachment

to provide for bridging of the gin- gival crevice with blockout

located low enough on the tooth

to avoid unfavorable leverage

located low enough on the maxillary incisors and canine teeth

to avoid incisal interference of the opposing dentition

result when major connector components resting on unprepared inclined tooth surfaces

can lead to slippage of the denture or to orthodontic movement of the tooth, or to both

ways to prevent sequelae due to gingival third trauma

one should support the major connector with definite rests on the teeth

pro- vide adequate gingival relief

locate the connector far enough away from the gingival margin—to avoid any possible restriction of blood supply and entrapment of food debris

a sharp, angular form

should be avoided in any portion of a palatal connector

—all borders should be tapered toward the tissue

—all gingival crossings should be abrupt and at right angles to the major connector.

Single Palatal Strap

Bilateral tooth-supported prostheses even those with short edentulous spaces can be connected with this strap

can be rigid without objectionable bulk and tongue interference if the cast framework material is distributed in three planes

22-gauge matte plastic pattern can be used for suitable rigidity

should not be used to connect anterior replacements with distal extension bases due to torque and leverage issues

the bulk of the strap can interfere with speech when placed anteriorly

suitable for short-span tooth-supported bilateral edentulous areas

Can be used in tooth-supported unilateral edentulous situations

Width should be confined within supporting rest boundaries.

Combination Anterior and Posterior Palatal Strap–Type Connector / CAPPS

may be used with any Kennedy class of partially edentulous arch

A rigid palatal major connector, suitable for almost any maxillary partial denture design

Posterior palatal connectors should be flat and 8mm wide, located posteriorly to avoid tongue interference but anterior to the line of flexure

The connector's strength lies in the longitudinal connectors on either side, forming a square or rectangular frame

All maxillary major connectors should cross the midline at a right angle rather than on a diagonal

It has been suggested that the tongue will accept symmetrically placed compo- nents far more readily than those placed without regard for symmetry.

8mm wide

measurement for anterior & posterior part of Anterior and Posterior Palatal Strap–Type Connector

—9mm for uniformity

7-9mm

measurement for each side part of Anterior and Posterior Palatal Strap–Type Connector

—8mm for uniformity

Classes II and IV

what class does combination anterior-posterior connector design mostly used

Class III

what class does single wide palatal strap mostly used

Class I

what class does palatal plate–type or complete coverage connector mostly used

Anterior-posterior palatal strap–type major connector

Anterior component: Flat strap located posteriorly to avoid rugae coverage and tongue interference

anterior Border: Positioned posterior to a rugae crest or in the valley between two crests

Posterior strap is Thin, 8mm wide, located posteriorly on hard palate

Positioned at right angles to midline, not diagonally.

Palatal Plate–Type Connector

for 7-8 remaining teeth

Defined as thin, broad, contoured palatal coverage used as a maxillary major connector

Covers half or more of the hard palate; there’s still portion of palatal not covered

Anatomic replica palatal castings maintain uniform thickness and strength due to corrugated contours

Electrolytic polishing maintains thickness uniformity and faithfully reproduces anatomic palate contours in the finished denture.

Covers two-thirds of the palate

Anterior border follows valleys between rugae, not extending to indirect retainers

Posterior border located at hard and soft palates junction, not soft palate

In bilateral distal extension, indirect retainers are essential for resisting rotation

Provisions for a butt-type joint between denture bases and framework passes through the pterygomaxillary notch

palatal plate

the term used to designate any thin, broad, contoured palatal coverage used as a maxillary major connector and covering one half or more of the hard palate

advantages of anatomic contours of the palate

Allows for the creation of a thin metal plate replicating the patient's palate

Corrugation adds strength to the casting, enabling thinner casting with adequate rigidity

Surface irregularities are intentional, requiring only electrolytic polishing to maintain the original uniform thickness of the plastic pattern

Interfacial surface tension between metal and tissue provides greater prosthesis retention

Retention resistance is proportional to the total area of denture base contact with supporting tissue.

The required amount of both di- rect and indirect retention will depend on the amount of retention provided by the denture base.

the forces that retention must be adequate to resist

the pull of sticky foods

the action of moving border tissue against the denture

the forces of gravity

the more vi- olent forces of coughing and sneezing.

3 ways the palatal plate may be used

as a plate of varying width that covers the area between two or more edentulous areas

a a complete or partial cast plate extending posterior to hard and soft palates junction

as an anterior palatal connector with provision for extending acrylic resin denture base in posterior direction.

palatal plate

should be located anterior to the poste- rior palatal seal area

—The maxillary complete denture’s typi- cal posterior palatal seal is not necessary with a maxillary partial denture’s palatal plate because of the accuracy and stability of the cast metal.

Complete coverage palatal major connector.

terminates at the junction of the hard and soft palates

The anterior portion, the palatal linguo-plate, is supported by positive lingual rest seats on canines

The location of finishing lines is crucial in this connector, should be parallel to a line along the center of the ridge crest and located just lingual to an imaginary line contacting the lingual surfaces of missing natural teeth

Alteration of the natural palatal contour should be anticipated with its attendant detrimental effects on speech if these contours are not followed

is strongly advised when the last remaining abutment tooth on either side of a Class I arch is the canine or first premolar tooth, especially when the residual ridges have undergone excessive vertical resorption.

Portion contacting teeth must have positive support from rest seats

Acrylic-resin palate

may be used when relining is expected or cost is a factor

however, cast palate is still preferable due to its advantages over acrylic-resin palate despite higher costs

The complete palatal plate is not a connector that has received universal use. It has, how- ever, become accepted as a satisfactory palatal connector for many maxillary partial dentures.

2 methods used when complete coverage connector is used for excessive vertical resorption of residual ridges

use a complete cast plate that extends to the junction of the hard and soft palates

use a cast major connector anteriorly, with retention pos- teriorly, for the attachment of an acrylic-resin denture base that extends posterior to the anatomic landmarks previously described

U-shaped palatal connector

least rigid type of maxillary major connector

Used when large inoperable palatal torus prevents palatal coverage or anterior-posterior palatal strap-type framework

Less desirable from patient and mechanical standpoints

often fail due to their flexibility, leading to increased flexibility and movement open ends

In distal extension partial dentures, non-existent tooth support can cause movement and trauma to the residual ridge

Wider coverage of a U-shaped connector resembles a palatal plate-type connector, but narrow U designs often lack necessary rigidity

Multiple tooth support through definite rests can make a U-shaped connector more rigid

result when there is no support borders — gingival irritation and periodontal damage

A common error in the design of a U-shaped connector

its proximity to, or actual contact with, gingival tissue

principal objections to use of the U-shaped connector

Lack of rigidity may allow lateral flexure, causing torque or direct force to abutment teeth under occlusal forces

Design fails to provide good support characteristics, allowing tissue impingement during occlusal loading.

Bulk to enhance rigidity may increase tongue-hindrance areas.

Single Palatal Bar

a widely used but least logical palatal connector component

It must have concentrated bulk for cross-arch stress distribution and rigid enough to provide support and cross-arch stabilization

It must be centrally located between the halves of the denture

This practice is objectionable from patient comfort and alteration of palatal contours

A partial denture with a this bar is often too thin and flexible or too bulky and objectionable to the patient’s tongue

The decision to use a single palatal bar instead of a strap should be based on the size of the denture-bearing areas that are connected and on whether a single connector located between them would be rigid without objectionable bulk

bar

a palatal connector component less than 8 mm in width

Combination Anterior and Posterior Palatal Bar-Type Connectors

Exhibits similar disadvantages as single palatal bar

To be sufficiently rigid and to provide needed support and stability, these connectors could be too bulky and could interfere with tongue function

Because of its bulk and location, the anterior bar often interferes with the tongue

Beading

a term used to denote the scribing of a shallow groove on the maxillary master cast outlining the palatal major connector exclusive of rugae areasExclusively for rugae areas

Accomplished using cleoid carver

Care must be exercised to create a groove no larger than 0.5 mm in width or depth

A slightly rounded groove is preferred to a V-shaped groove

purposes of beading

To transfer the major connector design to the investment cast

To provide a visible finishing line for the casting

To ensure intimate tissue contact of the major connec- tor with selected palatal tissue

5 basic steps of Designing Maxillary Major Connectors by Blatterfein

Step 1: Outline of Primary Bearing Areas — Primary bearing areas are those covered by denture base(s)

Step 2: Outline of Nonbearing Areas — Nonbearing areas include lingual gingival tissue, hard areas of the medial palatal raphe, and palatal tissue posterior to the vibrating line

Step 3: Outline of Connector Areas — Provides outline or designate areas for major connector components

Step 4: Selection of Connector Type — Connectors should be of minimal bulk and positioned to avoid tongue interference during speech and mastication; must have a maximum of rigidity to distribute stress bilaterally

Step 5: Unification — After selection, denture base areas and connectors are joined.

4 factors on Selecting the type of connector(s)

mouth comfort

rigidity

location of denture bases

indirect retention

double- strap type of major connector

provides the maximum rigidity without bulk and total tissue coverage

principles in designing maxillary major connectors

Location of edentulous ridge areas influences choice of major connector strap

When edentulous areas are located anteriorly, the use of only a posterior strap is not recommended

when only posterior edentulous areas are present, the use of only an anterior strap is not recommended.

The need for indirect retention influences the outline of the major connector

Provision must be made in the major connector so that indirect retainers may be attached.

Single palatal strap

Anterior-posterior palatal strap

Palatal plate

U-shaped

Single palatal bar

Anterior-posterior palatal bars

single palatal strap–type major connector

Anterior-posterior palatal strap–type major connector

Palatal major connector covering two thirds of the palate

palatal plate major connector for a class I mod 1

Complete coverage palatal major connector

Maxillary major connector in the form of a palatal linguoplate with provisions for attaching the full-coverage resin den- ture base.

Completed removable partial denture with resin base

U-shaped palatal connector

Combination anterior-posterior palatal bar