Maxillary Major Connector

Types of Maxillary Major Connector Type

Requirements

1- Palatal bar

- Narrow half oval with it's thickest point at the center. - Gently curved and shouldn't produce sharp angle at junction with the denture base.

2- Palatal strap

- Wide band of metal with a thin cross sectional dimension. - The most versatile and unobtrusive major connector. - Shouldn't ↓ than 8mm in width to avoid compromising rigidity. - ↑ the edentulous span length → ↑ Strap width: a) Ensure rigidity. b) Greater support from hard palate.

Advantages

Disadvantages

Indications

Contraindications

1- common used for many years. 2- now, used as interim application.

1- To provide rigidity it must be bulky. 2- Patient discomfort 3- Narrow anteroposteriorly (↓ vertical support from the bony plate).

- Only in short span Kennedy class III application.

- Shouldn't be placed anterior to 2nd premolar ↓ (It's bulk may produce noticeable discomfort& speech alteration).

1- located in two or more planes. ↓ (offers ↑ resistance to bending and twisting forces). ↓ [L-Beam principle] 2- Strong so, can be kept relatively thin. 3- ↓ interference with normal tongue action. 4- Pt. acceptance. 5- Distribute the applied stresses over a large area.

1- Pt. complaint from excessive palatal coverage: a) Anterior border: Posterior to palatal ruga or at the posterior slope of prominent ruga. b) Posterior border:. Anterior to junction of The Hard & The Soft palate. 2- ↑ Soft tissue coverage ↓ (Papillary hyperplasia) Due ↓ to a) Denture wearing 24 hour daily. b) Poor oral hygiene. c) Inadequate Pt. instructions.

- Unilateral distal extension R.P.D. (Class II Kennedy Classification ).

- Bilateral distal extension R.P.D. (Class I Kennedy Classification).

Type

Requirements

Advantages

Disadvantages

3- Anteroposterior palatal bar

- Both characteristics of palatal bar and palatal strap major connectors: a) Anterior bar (flat) as palatal strap. b) Posterior bar (half oval) as palatal bar. - [Circle effect] : Gives rigidity. - [L-Beam effect] : lying in different planes.

1- Rigidity is the main advantages. 2- Minimize soft tissue coverage. 3- Exceptional resistance to deformation.

4- Horseshoe connector

- Thin band of metal running along the lingual surfaces of the remaining teeth& extended onto the palatal tissues for 6-8 mm. - Rigidity can increased by extending the borders slightly onto the horizontal surfaces of the hard palate. - Should display symmetry - Should extend to the same height on both sides. - All borders should be gently curved& smooth.

1- Reasonably strong. 1- Tendency for the 2- Some vertical support connector to flex or from hard palate. deform. 3- Avoid bony ↓ prominence without (Stress concentration) affecting the vertical ↓ support. (Abutment damage) 2- To avoid flexing, It should be thicker than other major connectors. (↑ bulk) ↓ (Pt. discomfort& affecting Phonetics)

1- Frequently uncomfortable. 2- May annoy the tongue. 3- May interfere with phonetics. 4- ↓ support from the bony plate.

Indications

Contraindications

- When support isn't a major consideration. - When anterior and posterior abutments are widely separated. - Pt. with large palatal tori that can't be removed.

- Pt.'s with reduced Periodontal support. - Selected only if other choices have been considered& eliminated

- When several anterior teeth are being replaced. - Presence of a prominent Median suture line or torus. - Considered only if more rigid connectors can't be used.

- Poor indication for distal extension R.P.D. - When cross arch stabilization is required.

Type

Requirements

Advantages

Disadvantages

Indications

Contraindications

5- Antero posterior palatal strap

- Each strap 8mm in width at least and relatively thin in cross section. - Borders 6mm away from the gingival margin or extended to the palatal surface of remaining teeth. - Palatal borders should be smooth& curved. - When ant. teeth replaced: a) Anterior strap: Most posterior position. b) Posterior strap: Posterior position without contact the soft palate. - Open area: 20×15 at least

1- Rigid. 2- Good support from hard palate. 3- Metal over ruga is corrugated → ↑strength &↓ thickness ( < 1mm). 4- [Circle effect]. 5- [L-Beam effect].

1- Metal over ruga area may be thinner than other connectors. 2- Phonetics may be encountered. 3- Extensive length of the borders may cause irritation to the tongue.

- Numerous teeth are to be replaced. - Presence of tori. - When cross arch stabilization is required.

- If the open area ↓ than 15×20 mm other major connectors are preferred as: a) Wide palatal strap. b) Complete palate. c) Modified complete palate.

6- Complete palate

- ↑↑↑ rigidity& support. - ↑↑↑ Tissue coverage. - Anterior border 6mm away from the gingival margin or must cover the cingula of anterior teeth. - Slight mechanical seal by beading the post. border. - Post. Palatal seal should not be used in R.P.D. : a) Tissue rebounding will cause additional stresses. b) border molding can't be obtained.

1- Proper distribution of the applied stresses. 2- Provide additional stabilization for the prosthesis. 3-Intimate contact between connector& the hard palate: a) Dissipate the lateral& horizontal forces. b) ↑ the retention. 4- Pt. comfortable. 5- Little or no effect on phonetics. 6- [L-Beam effect]. 7- Thermal conductivity 8- Not porous.

1- Extensive tissue coverage may cause (Soft tissue hyperplasia) Due↓ to a) Poor oral hygiene. b) Prolonged denture wear. 2- Phonetics may be encountered.

- When all posterior teeth are to be replaced. - Remaining teeth are periodontally compromised.