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Maxillary Prostheses (Palate Reconstruction; Maxillectomy)

last modified on: Tue, 02/27/2024 - 08:56

Note: last updated before 2013

SURGICAL OBTURATOR

  1. A surgical obturator replaces missing dentoalveolar and/or palatal structures. They are usually used to close oronasal and/or oroantral communications following ablative cancer surgery or trauma.
    1. The prosthodontist should be consulted preoperatively.
      1. Surgical obturators may be manufactured prior to surgery.
      2. Prosthetic and surgical providers should collaborate regarding the proposed resection.
    2. Objectives
      1. Aid in the initial maintenance of skin grafts designed to replace respiratory mucosa.
        1. The surgical obturator is generally removed following seven to 10 days
      2. Facilitation of PO nutrition and hydration
      3. Facilitation of intelligible speech
      4. Diminish patient anxiety
        1. The allowance of more normal oral function
        2. The presence of the prosthesis may delay patient appreciation of the extent of the defect
    3. Dentate surgical obturator retention
      1. Removable partial denture (RPD) clasps
        1. 18-gauge round stainless steel wire retention
      2. Dental ligatures
        1. The interproximal dental extensions of the obturator's polymethylmethacrylate (PMMA) major connector can be perforated to accommodate the passing of stainless steel ligature wire through the gingival embrasures for labial or buccal tying.
      3. Sutures
        1. Suture material can be placed through resilient prosthodontic lining material bonded to the obturator's PMMA surface and the buccal or labial soft tissues.
      4. Palatal screws
        1. 15 to 17 mm screws passed through a hole in the palatal aspect of the obturator's PMMA and into the remnant hard palatal shelf
        2. Beware of dental roots and/or succedaneous tooth buds
    4. Edentulous surgical obturator retention
      1. Sutures
        1. Suture material can be placed through resilient prosthodontic lining material bonded to the obturator's PMMA surface and the buccal or labial soft tissues.
      2. Palatal screws
        1. 15 to 17 mm screws passed through a hole in the palatal aspect of the obturator's PMMA and into the remnant hard palatal shelf.
      3. Ligature wire
        1. The passage of wire through holes bored into the obturator's lateral flanges and remnants of the zygomatic processes or zygoma can aid in prosthetic retention.
        2. The passage of wire through holes bored in the obturator's palatal and labial or buccal flanges and the remaining alveolar bone can aid in prosthetic retention.
    5. Prosthodontic design considerations
      1. Palatal contours should be reconstructed.
      2. Alveolar contours should be reconstructed.
      3. Occlusion should not be restored inferior to the defect.
        1. Prosthetic teeth are not usually placed on surgical obturators.
      4. Existing complete dentures or RPDs can be modified to function as surgical obturators provided they fit adequately.
      5. The obturator should not place undue pressure in the area of a skin graft/mucosal surface union.
    6. Surgical recommendations
      1. Removal of any exposed inferior turbinate, regardless of oncologic necessity
        1. Facilitates superior prosthetic extension and retention
        2. Prohibits the potential for subsequent inferior turbinate edema and descent into the oral cavity
      2. Resect the entire velum if more than two-thirds of the anterior soft palatal tissue has been resected.
        1. An exception to this recommendation should be considered for edentulous patients in that the remnant velar tissue may be engaged for improved obturator retention.
      3. Resect the entire velum if the resection of lateral lesions extend to the uvula.
        1. This prevents the contralateral levator palatini muscle from pulling the remnant velum away from the pharyngeal extension of an obturator.
      4. Transalveolar resections in dentate patients should be as distant as possible from the nearest tooth to be retained.
        1. Extracting the tooth within the proposed alveolar resection line prior to making the section facilitates this by allowing the alveolar incision to pass through the tooth socket distant or remote to teeth that will remain.
        2. This diminishes the potential for radicular dehiscence on teeth adjacent to transalveolar resection lines.
      5. The premaxillary anatomy should be preserved provided the preservation does not compromise the oncologic objective to provide greater prosthetic support and stability.
      6. Replace exposed respiratory mucosa with a skin graft.
        1. Keratinized tissue provides a better prosthetic bearing area than respiratory mucosa.
        2. Promotes the development of a cicatricial band at the juncture between the skin graft and the mucosa.
        3. The superior aspect of this band can subsequently be engaged to improve obturator retention.
      7. Reflect a maintained margin of palatal mucosa superiorly across the exposed palatal bony surface to prevent respiratory mucosal granulation at the juncture of oral cavity and nasal or perinasal surfaces.

INTERIM OBTURATOR

  1. The interim obturator is placed when the surgical dressing that was supported by the surgical obturator is removed from the superior recesses of the maxillectomy defect.
  2. The interim obturator serves the patient for four to six months while the maxillectomy defect heals and matures. Teeth are frequently added to the prosthesis at this juncture to improve function and enhance cosmesis.
  3. New impressions may be generated in order to fabricate an interim prosthesis to completely replace the surgical prosthesis, or the addition of a resilient soft prosthodontic liner to the PMMA of the existing prosthesis may modify the surgical prosthesis itself. This soft liner can later be replaced with denser PMMA.
    1. Refinement of the interim obturator during healing: Modifications are frequently necessitated through several postoperative months as the hard and soft tissues of the defect mature. These modifications are usually accomplished through one of two means.
      1. Addition of soft prosthodontic liner to existing prostheses.
        1. Advantages:
          1. Consumes the least amount of time
          2. Minimizes cost in that there is no dental laboratory expense
        2. Disadvantages:
          1. Porosity of the soft liner accumulates microbes
          2. The soft liner can tear
          3. The soft liner cannot be as highly polished as PMMA
          4. The bulk of a soft liner increases the prosthetic weight
      2. Addition of PMMA to existing prostheses.
        1. Advantages:
          1. PMMA is dense and can be highly polished
          2. PMMA can readily be cleansed
          3. The obturator bulb can be hollowed and the PMMA can be appreciably thinned to decrease prosthetic weight
        2. Disadvantages:
          1. Requires dental laboratory expertise and generates a dental laboratory expense
          2. Necessitates two clinical appointments
          3. Necessitates a period of time during which the patient is without the prosthesis
          4. To mitigate this inconvenience, patients are usually appointed in the early morning so the ensuing laboratory work can be accomplished prior to a late afternoon appointment on the same day

DEFINITIVE OBTURATOR

  1. When surgical interventions are finished and healing has progressed for four to six months following the cessation of all therapy, the interim obturator can be replaced with a definitive obturator.
  2. Edentulous definitive obturators generally consist completely of PMMA, while the PMMA components of partially edentulous definitive obturators are supported by cast chrome-cobalt frameworks.
  3. Definitive obturator bulbs are usually hollowed to decrease the weight of the prosthesis.
    1. Edentulous definitive obturator fabrication sequence
      1. Primary irreversible hydrocolloid impressions
      2. Final polysulfide rubber base (PRB) impressions using compound border molded customized impression trays
      3. Fabrication of heat processed PMMA record bases in the dental laboratory; alternatively, autopolymerizing PMMA record bases may be used in situations with small maxillectomy defects
      4. Maxillomandibular relationship (MMR) and face-bow transfer (FBT) records generated from the record bases and wax rims
      5. Wax try-in of the prosthetic dentition and verification of the articulated laboratory MMR; revision of the articulated laboratory MMR and occlusion should the verification fail
      6. Prosthetic delivery
      7. 24-hour follow-up for occlusal and intaglio surface adjustments
      8. 72-hour follow-up for occlusal and intaglio surface adjustments
      9. One-week follow-up for occlusal and intaglio surface adjustments
      10. Individualized periodic follow-up
    2. Partially edentulous definitive obturator fabrication sequence
      1. Primary irreversible hydrocolloid impressions
      2. Final polyvinylsiloxame (PVS) framework impressions using compound border molded customized impression trays
      3. Chrome-cobalt framework try-in and altered cast impression of the maxillectomy defect
        1. The altered cast impression may be of PMMA and compound-supported PRB or PVS impression material or wax.
      4. MMR and FBT records generated from autopolymerizing PMMA and wax rims attached to the chrome-cobalt framework
      5. Wax try-in of the prosthetic dentition and verification of the articulated laboratory MMR
        1. Revision of the articulated laboratory MMR and occlusion should the verification fail
      6. Prosthetic delivery
      7. 24-hour follow-up for occlusal and intaglio surface adjustments
      8. 72-hour follow-up for occlusal and intaglio surface adjustments
      9. One-week follow-up for occlusal and intaglio surface adjustments
      10. Individualized periodic follow-up
    3. Prosthetic extension within maxillectomy defects to enhance obturator retention
      1. Cicatricial band engagement
        1. The band results from medial contraction at the skin graft and mucosal juncture.
        2. While the band is taut, it is resilient enough to allow an extension of the prosthesis superior and lateral to its oral line of demarcation. This resists inferior displacement of the obturator bulb
      2. Velar engagement
        1. Extension upon the nasal surface of the remaining velum resists inferior displacement of the obturator bulb.
      3. Vomerine engagement
        1. Vertical extension upon the surface of the remaining vomer resists inferior rotation of the obturator bulb to the contralateral side.