{"id":191,"date":"2024-03-07T07:29:49","date_gmt":"2024-03-07T07:29:49","guid":{"rendered":"https:\/\/ekitap.ankara.edu.tr\/dentures\/chapter\/major-baglayicilar\/"},"modified":"2025-11-14T11:58:16","modified_gmt":"2025-11-14T11:58:16","slug":"major-baglayicilar","status":"publish","type":"chapter","link":"https:\/\/ekitap.ankara.edu.tr\/dentures\/chapter\/major-baglayicilar\/","title":{"raw":"Major connectors","rendered":"Major connectors"},"content":{"raw":"Due to anatomical differences between the maxilla and mandible, the design and types of major connectors used in the upper and lower arches differ from one another.\r\n

Maxillary major connectors<\/h2>\r\nOn the tissue-surface of the maxillary major connector, a stop line is created along the peripheral border. This feature prevents the major connector from being embedded into the tissue and ensures proper adaptation between the connector and the underlying mucosa, thereby preventing food entrapment. The stop line is formed by preparing a groove 0.5 to 1.0 mm in depth and width on the master cast for the removable partial denture, and it should terminate 6 mm away from the gingival margins of the teeth. The depth of the stop line is determined according to the resiliency of the underlying tissues. It is prepared deeper along the lateral slopes of the hard palatal mucosa and shallower in the horizontal region overlying the median palatal suture.\r\n\r\nFour basic types of maxillary major connectors are considered:\r\n
    \r\n \t
  1. Palatal strap<\/li>\r\n \t
  2. Double palatal strap<\/li>\r\n \t
  3. U-shaped palatal connector<\/li>\r\n \t
  4. Full palatal plate<\/li>\r\n<\/ol>\r\n

    Palatal Strap<\/h3>\r\nAlthough it is associated with the edentulous area, palatal strap<\/strong> typically presents as a uniform-width strap that does not cover the free gingival margins, with its anterior border often located at the level of the rugae and its posterior border at the junction of the hard palate. Since the anterior palatal region is left uncovered, it does not interfere with phonation and is considered the most comfortable type of major connector for the patient. It can be made narrower in cases with shorter edentulous ridges and wider in cases with longer ridges, but it must be at least 8 mm wide. To increase resistance to deformation, it should either have a narrow surface with increased thickness or a broad surface with decreased thickness. When broad contact is achieved with the hard palate, it can provide excellent palatal support. This is one of the most frequently used maxillary major connectors.\r\n\r\nIndications:<\/strong>\r\n
      \r\n \t
    1. Class III modifications in which tooth-supported edentulous spaces are symmetrically located on both sides of the dental arch (Figure 5-1)<\/li>\r\n<\/ol>\r\n \r\n\r\n[caption id=\"attachment_168\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-1.<\/strong> A palatal strap major connector may be narrower in tooth-supported cases such as Class III with modifications.[\/caption]\r\n\r\n2. Certain Class I and Class II Mod. 1 cases that require the anterior palatal region to be left uncovered (Figure 5-2).\r\n\r\n \r\n\r\n[caption id=\"attachment_169\" align=\"alignnone\" width=\"639\"]\"Figure<\/a> Figure 5-2.<\/strong> In cases such as Class I Mod 1 (a)<\/strong> and Class II Mod 1 (b)<\/strong>, the palatal strap may be made wider when increased hard palate support is necessary.[\/caption]\r\n\r\n3. Class II and Class III cases in which, according to the concept of cross-arch stabilization, the support is provided from the tooth-supported side of the arch (Figure 5-3).\r\n\r\n \r\n\r\n[caption id=\"attachment_170\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-3. <\/strong>. In Class III cases, a palatal strap may be used to provide support from the opposing arch; however, its width should not be less than 8 mm.[\/caption]\r\n\r\nContraindications:<\/strong>\r\n
        \r\n \t
      1. Presence of torus palatinus,<\/li>\r\n \t
      2. Anatomical form of the hard palate being very rigid and flat,<\/li>\r\n \t
      3. Inadequate distribution of edentulous areas.<\/li>\r\n<\/ol>\r\n

        Double palatal strap<\/h3>\r\nDouble palatal strap<\/strong> consists of two palate strap, one in the anterior and one in the posterior region. The anterior strap, shaped wide and flat according to the indentations and prominences of the rugae, does not interfere with phonation or cause discomfort to the tongue. The posterior strap is placed according to the condition of the edentulous space and is narrower and thicker compared to the anterior strap. Compared to the palatal strap, it has better resistance to deformation; however, it is less effective in terms of tissue support. The open areas outside the straps provide comfort for the patient. It is the most rigid among the maxillary major connectors; however, it may cause discomfort in patients with a gag reflex.\r\n\r\nIndications:<\/strong>\r\n
          \r\n \t
        1. Modification Class II cases with a long span between the anterior and posterior abutment teeth (Figure 5-4) and Class III cases (Figure 5-5)<\/li>\r\n<\/ol>\r\n \r\n\r\n[caption id=\"attachment_171\" align=\"alignleft\" width=\"300\"]\"Figure<\/a> Figure 5-4.<\/strong> A double palatal strap, with the anterior strap designed to be wide and flat and the posterior bar narrow and thin, can be used in modification Class II cases.[\/caption]\r\n\r\n[caption id=\"attachment_172\" align=\"alignnone\" width=\"319\"]\"Figure<\/a> Figure 5-5. <\/strong> A double palatal srap can also be used in modification Class III cases with long edentulous ridges.[\/caption]\r\n\r\n2. In the presence of a torus palatinus,\r\n\r\n3. Patients who cannot tolerate a full palatal plate.\r\n\r\n4. The palatal strap is extended anteriorly in Class IV cases to support the anterior edentulous region (Figure 5-6).\r\n\r\n \r\n\r\n[caption id=\"attachment_173\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-6. <\/strong> In Class IV cases, the anterior portion of the double palatal bar is extended to the anterior edentulous ridge. The lateral portions of the major connector should be positioned at least 6 mm away from the gingival margins of the teeth.[\/caption]\r\n

          U-shaped palatal connector<\/h3>\r\nU-shaped palatal connector<\/strong> (U-plate) covers the anterior palatal region and extends to the posterior lateral areas in a horseshoe shape (Figure 5-7).\r\n\r\n \r\n\r\n[caption id=\"attachment_174\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-7.<\/strong> U-shaped palatal connector[\/caption]\r\n\r\nTo avoid discomfort to the patient, it should be at least 0.5 mm thick. The anterior palate's anatomical reliefs are accurately replicated on the tissue-surface to reduce speech interruption.\r\n\r\nIndications:<\/strong>\r\n
            \r\n \t
          1. Modified Class I cases requiring restoration of the anterior teeth,<\/li>\r\n \t
          2. Cases requiring restoration of both anterior and posterior teeth,<\/li>\r\n \t
          3. Presence of torus palatinus,<\/li>\r\n \t
          4. When stabilization (splinting) of anterior teeth with weak periodontal support is required,<\/li>\r\n \t
          5. In patients with a strong gag reflex and\/or in cases where posterior palatal coverage cannot be tolerated.<\/li>\r\n<\/ol>\r\nContraindications:<\/strong>\r\n\r\nIn distal extension cases, it is not recommended to use U-shaped major connector with a narrow midline area without extending to the anterior teeth, as this reduces its rigidity and prevents adequate force distribution (Figure 5-8).\r\n\r\n \r\n\r\n[caption id=\"attachment_175\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-8. <\/strong> In distal extension cases, the use of the U-shaped plate is not recommended without extending to the anterior teeth, as the reduction in rigidity at the midline area prevents adequate force distribution.[\/caption]\r\n

            Full palatal plate<\/h3>\r\nThe full palatal plate<\/strong> is a major connector that covers the hard palate as widely as possible and provides maximum mucosal support. It distributes functional loads across a wide region, reducing the amount of load per unit area, thus offering physiological advantages. The movement of the distal extension denture base under functional forces decreases due to the increased retention and stability.\r\n\r\nTo replicate the natural anatomical structure of the hard palate on the tissue-surface of the plate, it should be thin; a thickness of 0.35 mm is sufficient. The prosthesis borders are shaped similarly to the complete denture base boundaries in the posterior region. The posterior borders can be completed with metal (Figure 5-9) or made from acrylic (Figure 5-10).\r\n\r\n[caption id=\"attachment_176\" align=\"alignnone\" width=\"300\"]\"Figure<\/a> Figure 5-9.<\/strong> The posterior part of the full palatal plate is located at the junction of the soft and hard palate, while the anterior part is supported by singulum rests.[\/caption]\r\n\r\n[pbcaption type=\"table\" caption=\"Figure 5-10. <\/strong>Full palatal plates with posterior borders completed with acrylic. (a) and (c) Rings are created at the junction of the metal substructure and acrylic for retention. (b) and (d) The junctions between the metal and acrylic provide a smooth transition.\"]\r\n\r\n\r\n\r\n\r\n
            \r\n\r\n[caption id=\"attachment_177\" align=\"alignleft\" width=\"300\"]\"a\"<\/a> a<\/strong>[\/caption]<\/td>\r\n\r\n\r\n[caption id=\"attachment_178\" align=\"alignleft\" width=\"300\"]\"\"<\/a> b<\/strong>[\/caption]<\/td>\r\n<\/tr>\r\n
            \r\n\r\n[caption id=\"attachment_179\" align=\"alignleft\" width=\"300\"]\"\"<\/a> c<\/strong>[\/caption]<\/td>\r\n\r\n\r\n[caption id=\"attachment_1829\" align=\"alignleft\" width=\"300\"]\"\" d<\/strong>[\/caption]<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n[\/pbcaption]\r\n

            Acrylic resin palatal part of the major connector provides superior physical retention compared to metal denture borders. In such cases, a mesh framework that allows adequate retention of the acrylic must be provided (Figure 5-10 a and c).<\/p>\r\n

            Indications:<\/strong><\/p>\r\n\r\n

              \r\n \t
            1. \r\n

              Cases where the majority of the periodontal support of the natural teeth has been lost,<\/p>\r\n<\/li>\r\n \t

            2. \r\n

              When residual ridges have undergone extreme vertical resorption,<\/p>\r\n<\/li>\r\n \t

            3. \r\n

              Cases where the anatomical form of the hard palate is flattened,<\/p>\r\n<\/li>\r\n \t

            4. \r\n

              Treatment of patients with cleft palate using removable partial dentures.<\/p>\r\n<\/li>\r\n<\/ol>\r\n

              Contraindication:<\/strong><\/p>\r\n\r\n