 Today I am going to discuss in detail about major connectors. Going to the contents. It includes introduction, definition, functions, idly requirements, types of maxillary major connectors, types of mandibular major connectors, maxillary major connectors in detail, design of maxillary major connectors, factors affecting the selection of the maxillary major connector, mandibular major connectors, design of mandibular major connector, materials used for maxillary, mandibular and maxillary major connectors, conclusion and references. Introduction. According to McCracken, no component of a removable partial denger should be added arbitrarily or conveniently. Each component should be added for a good reason and to serve a definite purpose. The components of a removable partial denger include major connector, minor connector, rest, direct retainer, indirect retainer and one or more denger bases. Definition. A major connector is the part of the removable partial denger that joins the components on one side of the arch to those on the opposite side. It is that unit of the partial denger to which all other parts are directly or indirectly attached. Functions of the major connector include unification of the major parts of the processes, distribution of the applied force throughout the arch to select a teeth and tissue, minimization of torque to the teeth, especially the abutment teeth, the principle of leverage is connected with this component part. A rigid major connector will limit movement possibilities by acting as the counteracting lever and this phenomenon is referred to as cross arch stability. And the cross arch stability is used to resist or limit the displacement by functional stresses. Ideal requirements. It should be rigid. It should not impinge on free zenzival margins and other soft issues. The border should be parallel to the mean margin of the zenzival line and the zenzival margins should be crossed at right angle and it should not allow put end-rapment. The borders of the macthery major connectors should always cross the parallel midline at 90 degree. Coverage of torries should be avoided. All major connectors should exhibit smooth rounded contours and when partial denger components must be external onto the tooth, embrasures may be used to disuse the thickness of the metal framework. In addition, it should provide vertical support for the removable partial denger. It should provide indirect retention. It should enable to place the denger bases when required. It should be used comfortable for the patient. It should be made with a material which is biocompactable. Types of macthery major connectors. It includes six types. Single palatal bar, single palatal strap, USA palatal major connector or horseshoe major connector, anterior posterior palatal bar, combination anterior and posterior palatal strap type major connector, palatal plate type major connector or complete palatal major connector. Types of mandibular major connectors. It also includes six types. Lingual bar, lingual plate, sublingual bar, lingual bar with singulum bar, singulum bar, lingual bar. Factors affecting the selection of the macthery connector. It mainly includes seven factors that is rigidity, presence of palatal torries, requirement of indirect retention, the need for anterior tooth replacement, the need to stabilize weakened teeth, quantity considerations and the mental attitude of the patient or patient comfort. Single palatal bar, palatal connector component of less than 8 mm in width is referred to as a bar. It is the narrow half oval with the thickest point at its center. The bar is gently curved and should not form sharp angles at the junction with denger base. And it is effectively located between the two halves of the denger and must be rigid enough to provide support and process stabilization. And it is often either too thin and flexible or either too bulky. Patient comfort and alteration of palatal contours is highly objectionable and it might cause discomfort to the patient. The decision to use single palatal bar instead of strap should be based on the size of the denger bearing areas that are connected. It is mainly limited to short span class 3 situations and place no tooth anterior to the second trimula position. And its only indication is that it is an in-rip partial denger until a more definitive treatment can be considered. Disadvantages, it is most difficult for the patient to adjust as to maintain the degree of rigidity it has to be made bulky. Narrow anterior posterior width with little vertical support from the bony palate and must derive its support by rest on the remaining natural teeth. Single palatal strap, it is the most versatile therefore most widely used. It consists of a wide band of metal with a thin cross-sectional dimension. It should not be less than 8 mm wide and the bilateral tooth support restorations even those with short dengela spaces are more effectively connected. The width increases as the dengela space increases in length. Bilateral tooth support restorations even those with short dengela spaces are more effectively connected with a single broad palatal strap connector. A wide palatal strap type may be used for unilateral distill extensions division. If the dengela area is extensive bilateral and is not supported posteriorly to the junction of the hard and soft palate, the connector is modified to complete palatal type. Moving to the advantages, as the palatal strap is located in three planes mainly the horizontal or the vault of the palate, vertical or the lateral slops of the palate and societal or the anterior slops of the palate. As it is located in two or more planes it offers great resistance to bending and twisting forces and thus it covers large area of palatal tissue so stress distribution is good. Force transmitted on different planes are counteracted more easily and greater rigidity with less bulk so it provides better patient comfort. Retention is improved by the intimate contact between the metal and soft tissue. Disadvantages, the patient may complain of excessive palatal coverage and this is mainly due to the improper positioning of the sharp border. The strap borders should terminate on the posterior slops of the prominent rugae and another disadvantage is the adverse soft tissue reaction which may lead to papillary hyperplasia. This mainly occurs due to the wearing of continuous wearing of the cast partial danger for almost 24 hours a day with accompanied with poor oral hygiene. Indications, bilateral and dangerous spaces of short span tooth support restoration. This is a preferred connector because it may be used for most descents. It distributes applicatory stress over a wide area. It may be made wide or narrow depending on the desired stress distribution. Next is the U shape palatal connector. It consists of a thin band of metal running along the lingual surfaces of the remaining teeth and extending on to the palatal tear tissues for 6 to 8 mm. The border should extend 6 mm from the ginsival margin and in some cases it covers the singular of the present teeth and the lateral palatal border should be at the junction of the horizontal and vertical slops of the palate. Indications, it can be used in cases of a large inoperable tore and when several anterior teeth are to be replaced the U shape or the whole shoe major connectors are used. In cases of palatal patients with exaggerated gag reflex and when pedodontally weakened anterior teeth needs some stabilizing support against whole shoe major connector is used. Disadvantages, the major disadvantage is the lack of rigidity that the lateral flexure under a closed force. Induced torque or direct lateral force to the abutment teeth and it has to be bulk to enhance the rigidity results in increased thickness. It may permit impeachment of the underlying tissues when subjected to occlusion loading. The next is the anterior and posterior palatal bar type connectors. The anterior bar is relatively flat. The posterior bar is half oval similar to the single posterior palatal bar connector but less bulky. The two bars are joined by flat longitudinal elements on each side of the lateral slops of the palate. The posterior bar should be located well back in the palate just anterior to the vibrating line. The two bars lying in different planes produce a structurally strong LBM effect. Both borders should be gently curved and be weld. Indications when support is not a major consideration and when the anterior and posterior abutments are widely separated, the anterior and posterior bar connectors may be used. And presence of torus palatinus that is either undercut or low blade or too massive and it may be used to say compromised for the patient. Contraindication in reduced pedodontal support of the remaining teeth as the main support of this major connector is from the strong abutment teeth. Reduced pedodontal support of the remaining teeth is adversely affected. Advantage is the main advantage is the rigidity. It follows the LBM principle so it is more rigid. And in comparison to the amount of soft tissue coverage, it is by far the most rigid maxillary major connector. This advantage is because of the limited palatal tissue contact, little support is derived from the bony palate. It may interfere with the speech especially the anterior bar. Anterior and posterior palatal strap type major connector. Stuxel is a rigid palatal major connector. Each palatal strap should be flat and has a minimum of 8 mm wide. The strap should be located as far posteriorly as possible to avoid indifference with the tongue. The thickness of the metal in the strap should be uniform. The border should be 6 mm away from the region's oval margin and should extend onto the lingual surfaces of the teeth. All the borders should be finished in smooth, gentle curves. The open area of the palate till region should be at least 20 into 15 mm. Indications include Canada's class 1 and class 2 arches. It also includes long edendular spans in class 2, modification 1 arches, class 4 arches and in case of inoperable tore also anterior posterior palatal strap can be used. Disadvantages even though metal over rugi area may be thinner, it can also cause indifference with the fontex. The extensive length of borders may cause annoyance or patient discomfort. The last type of major connector is the palatal plate or complete palatal type major connector. The full palatal connector is thin, broad, conduit, palatal coverage with the natural anatomy of the palatal reproduced. The anterior border is 6 mm away from the marginal gingiva and must cover the singular of the anterior teeth. The posterior border extends to the junction of the soft and hard palate. The material which covers the residual region should be one that can be refitted easily. That is basically it is made up of acrylic resin. The posterior border can be fabricated of either metal or acrylic resin. If this is of metal, the border must be precisely established to induce the soreness and the metal is difficult to alter satisfactorily. If it is of metal, it has to be extended more precisely than acrylic resin. Our orals may cause soreness and inflammation. A slide bead should be provided in the metal by lightly scraping the refractory cast prior to forming the wax pattern for the framework. The acrylic resin border is preferred when maximum adhesion and atmospheric seal is needed. Advantages, it is thin and reproduces faithfully the anatomic contours. Its uniform thickness and the thermal conductivity of the metal are readily acceptable to the tongue and underlying tissue. That is, when compared to all the major connectors, the complete palette provides the maximum thermal conductivity of the metal and it is greatly acceptable by the tongue and underlying tissue as it reproduces the natural contour of the palette. The corrugation in the anatomic replica adds strength to the casting. Thus the thinner casting with adequate rigidity can be made. Indeficient surface tension between metal and tissues produces the processes with greater retention. Disenverges include inflammation or hyperplasty and problems with phontics. Indications, they are mainly indicated in class 2 arch with a large posterior modification space. In most situations in which only some or all anterior teeth remain. When the last remaining abutment tooth on either side of the class 1 arch is the canine or first premular tooth a complete palette is advised. In the absence of pedunculated torus, again complete palette can be used. Contraindication, when there is a presence of tori which cannot be surgically removed, a full palette coverage cannot be given. Moving to the design of maxillary major connectors. In 1953, Blatterfein described a systematic approach to designing maxillary major connectors. It includes five steps. First one is the outline of primary bearing areas. The primary bearing areas are those that can be covered by denser base. The second step includes the outline of non-bearing areas. The non-bearing areas are the lingual gingival tissues within the 5 to 6 mm of the remaining teeth. The heart areas of the median palatal raffae including the tori and the palatal tissues posted to the vibrating line. And the third step is the outline of connector areas and the fourth step is the selection of the connector type. That is the which major connector should be selected. The connectors must have a maximum of rigidity to distribute the stress bilaterally. Connector should be of minimum bulk. When adagio- idengulus areas are located anteriorly, the use of only a posterior strap is not recommended. When only posterior idengulus areas are present, the use of only an anterior strap is not recommended. The need for indirect attention influences the outline of the major connector. And the last step is unification. After selection of the type of major connector, the denser base areas and the connectors are joined. So this concludes the maxillary major connectors. In detail, the basic types and the design of maxillary major connectors. The mandibular major connectors will be discussed in the next section. Thank you.