| Abstract|| |
The majority of maxillary defects can be rehabilitated with pedicled flaps. However, when there are very large resections of the maxilla and flap success is questionable, then the defect may be obturated with a conventional hollow bulb clasp retained obturator or implant retained obturator prosthesis. However, inadequate retention, stability and support may be associated with the use of a conventional obturator and in case of recurrence the success of implant is questionable. A precision attachment becomes the silver lining. They have been used to retain obturator for some time. The use of precision attachments in a dentate maxillectomy patient can yield significant functional improvement while maintaining the obturator's aesthetic advantages. This clinical report describes the successful prosthetic rehabilitation of maxillary defects with an obturator retained using two different extracoronal resilient precision attachments. Attachment retained prosthesis provides a successful closure for the defect but also better esthetics, retention, better tolerability and better mastication and speech.
Keywords: Hollow bulb, Obturator, precision attachment, prosthetic rehabilitation, retention, Rhein83 equator attachment, Rhein83 OT cap distal attachment, speech and craniomaxillary rehabilitation
|How to cite this article:|
Shetty PP, Chowdhary R, Shetty PP. A maxillofacial prosthetic obturator using precision attachments. Indian J Dent Res 2020;31:799-802
|How to cite this URL:|
Shetty PP, Chowdhary R, Shetty PP. A maxillofacial prosthetic obturator using precision attachments. Indian J Dent Res [serial online] 2020 [cited 2022 Jan 20];31:799-802. Available from: https://www.ijdr.in/text.asp?2020/31/5/799/306441
| Introduction|| |
The prosthodontic rehabilitation of patients with acquired defects of the maxilla after surgical resection is one of the responsibilities of a maxillofacial prosthodontist. To recreate an artificial barrier between the cavities and thus restore the functional capabilities of speech, mastication and swallowing. Maxillofacial defects are caused by trauma, tumour or congenital deformations. The goal of prosthetic rehabilitation for total and partial maxillectomy patients, include separation of oral and nasal cavities to allow adequate deglutition and articulation, possible support of the orbital contents to prevent enophthalmos and diplopia, support of the soft tissue to restore the midfacial contour and an acceptable aesthetic results. One of the main impacts of patients submitted to maxillectomy is the impairment of speech intelligibility and lack of good retention and stability of the prosthesis planned after the surgery. These defects caused by hemi or full maxillectomy can be repaired surgically using free microvascularized flaps or pedicled flaps. When there are very large resections of the maxilla and covered with flaps, success is questionable. Such defects need to be obturated with a dental or maxillofacial prosthesis.,, The rehabilitation of a maxillary defect with an obturator retained by a resin-bonded extracoronal attachment, which can improve both retention and aesthetics, is commonly practiced when a central or lateral incisor is the terminal abutment adjacent to a large defect.,
This present case report describes simple, economic and reliable procedure for the prosthodontic rehabilitation of a patient with mucoepidermoid carcinoma in the maxilla.
| Clinical Report|| |
A 24-year-old female patient reported to the department, complaining of a swelling in the maxillary right posterior region. After the clinical examination of the lesion, she was advised for histopathologic investigation for a confirmatory diagnosis. The histopathologic results of the sample sections revealed that the intraoral swelling was mucoepidermoid carcinoma involving the right quadrant of the maxillary posterior area. Patient was advised for surgical resection of this lesion and accordingly he underwent resection of the tumour along with the right maxillary posterior region. After the resection, the patient developed an Aramany Class I defect, which extended from the buccal mucosa to the midpalatine area medially. Anteriorly, it extended from the first premolar to the posterior extent of the hard palate including some part of the soft palate. The patient also complained of nasal twang, social stigma, loss of confidence and extreme difficulty in speech, mastication and deglutition.
Extraoral examination showed slight tissue contracture visible on the right side of face post operatory recovery. On intraoral examination [Figure 1], it was observed that the left maxillary quadrant was intact. On the right maxillary quadrant, only three anterior were intact. The mandibular arch had a full component of natural teeth, with normal mouth opening and jaw movements. Tissue around the excision showed good signs of healing. However, it was found that the left half of the patient's oral tissues, the palatal bone and the remaining residual ridge alone were incapable of supporting the prosthesis. Restoring with fixed prosthesis was ruled out due to high chance of recurrence. The remaining teeth exhibited significant periodontal and bony support and the oral hygiene was fair. A well-planned prosthesis, which does not involve any invasive procedure but functions as good as a fixed prosthesis using the remaining structure was the prime concern.
| Clinical Technique|| |
- The defect developed after the surgical excision extended from the buccal mucosa to the midpalatine area medially. Anteriorly, it extended from the first premolar to the posterior extent of the hard palate including some part of the soft palate. The defect area was packed with gauze, so as to prevent the ingress of the impression material into the nasal cavity during recording the impression. Primary impression was made with irreversible hydrocolloid (Zhermack hydrogum) and a diagnostic casts were poured using dental stone.
- Surveying was done for the diagnostic cast with the defect area and the height of contours was marked and the required prosthesis framework was designed on the model.
- Teeth 13 and 26 of the opposite quadrant of the maxilla which was intact were prepared to accommodate a metal ceramic crown.
- Border moulding of the sulcular depth followed with final impression was done such that the depth and extent of the defect area was recorded accurately by asking the patient to move her head right, left and bend downwards, which allowed to record the final impression in functional form.
- Resilient attachments were selected to provide retention, stability and long life to the prosthesis.
- An extracoronal precision attachment (Rhein83, USA), OT cap attachment fordistal extension) was selected to the anterior area and a Rhein83, OT equator castable type to the posterior region of the prosthesis. OT EQUATOR has a low vertical profile of 2.1 mm and diameter of 4.4 mm making it the smallest attachment system on the market. This system was apt for the palatal side as the vertical space limitations was a consideration. Hence it was chosen for the palatal retention. OT Cap is a resilient distal extension attachment. It was chosen in the distal extension side as it functions as a stabilizing retentive connector. It also acts as shock absorber due to the cushioning effect obtained by the design of the sphere and the elasticity of the cap. This design of the sphere with a flat head in addition to the spherical inner surface of the elastic cap also permits vertical movement during mastication [Figure 2].
- Wax pattern were fabricated on the prepared tooth and plastic pivot posts with ball attachments were attached using a surveyor and this was casted with Ni-Cr alloy using lost wax technique [Figure 2].
- Care was taken that a minimum of 2-3mm space was present under the attachment to render it self-cleansing [Figure 3].
- Bisque try-in crowns with the attachment were temporarily cemented to the tooth and a pick up impression was made [Figure 4].
- Due to a large defect, a hollow obturator was planned.
- A three piece sectional cast was poured and a cast partial denture (cpd) framework was fabricated over the casted attachment with continuous lingual plating on all the anterior and posterior teeth. This helped as lingual guide plane, provided retention and stability and also acted as splint for the remaining dentition [Figure 5].
- An acrylic hollow bulb (trubyte lucitone 199 denture base resins; dentsply) is fabricated and attached to the groove fabricated on the cast partial framework with self cure resin and cured in a pressure pot to reduce the amount of residual monomer [Figure 6].
- The female nylon rings (Rhein83 OT cap) are finally seated in place in the framework [Figure 6].
- The prosthesis is finally checked for fit, comfort, retention, stability, function and esthetics.
| Discussion|| |
One of the most common of all intraoral defects is the maxillary defect in the form of an opening into the antrum and nasopharynx., This causes intertransportation of micro-organisms between the oral and nasal cavity. The nasal cavity is lined by pseudostratified ciliated columnar epithelium and goblet cells present there aggressively attract oral flora., The obturator prosthesis is designed such that, it seals the defect and functions efficiently as it prevents the infiltration of food, fluids, and flora from the oral to nasal chambers and vice-versa. It also tremendously improves the quality of voice and mastication as it completely seals the lateral palatal defect as well as the maxillary defect. One of the best way of closure of maxillary defects are implants. Schmidt et al., used zygomatic and standard endosseous implants to retain prostheses in near-total and total maxillectomy patients. Dilek et al., reported the case of a partial maxillectomy patient with an obturator that was supported by five mini dental implants. However, for some patients, like in our present case report, these implants are not acceptable due to their general health, personal inclination; economic reasons, poor bone quality, or high chance of recurrence. In such cases, retention of the prosthesis poses a big problem. The other ways of retaining the obturator is with conventional clasp retained prosthesis, attachment retained prosthesis, or magnet retained prosthesis.
Due to inadequate prosthesis support in the maxillectomy patient, stress distribution to both the palate and the remaining teeth should be optimal for the health of the remaining structures. Stress concentration was seen in the anterior area of the palate and the remaining teeth, especially the posterior teeth, which also supports the findings found in previous studies., Hence, we placed one attachment on the distal area of the canine and the other on the palatal position of first molar. Stress concentration was also seen at the junction of the attachment and the lingual guide plane and the anterior part of the lingual guide plane, which will reduce the life of the abutment and cause adhesion failure. This occurrence could be explained by the creation of a dynamic fulcrum line during loading. To reduce the stress on the abutment teeth, a resilient attachment was selected. In the anterior section we placed a rhein attachment and on the posterior region we placed a locator attachment. Due to ease of placement of prosthesis and to reduce the bulk in the palatal area, locator attachment was selected for the posterior palatal region. Both of them have nylon washer between the male and female parts, which not only can give a cushion effect but also be easily changed to maintain the retentive force due to wear. The use of attachment on the tooth adjacent to the defect can not only provide adequate retention, but better aesthetics of the prosthesis. The continuous lingual guide plane not only modifies abutment contours, but also splints the tooth and provides better stress distribution of the prosthesis. We have fabricated a hollow obturator as the use of a hollow maxillary obturator may reduce the weight of the prosthesis by up to 33%, depending on the size of the maxillary defect.
Hence, this designing of the hollow attachment retained obturator prosthesis not only prolongs the life of the abutment, but also leads to a successful highly retentive esthetically acceptable prosthodontic rehabilitation for maxillary defect.
| Conclusion|| |
A proper diagnosis and a well-designed treatment plan will result in successful outcomes. Rehabilitation with obturator prosthesis needs to fulfil the functional, esthetic, masticatory and phonetics demands of the patient. It is difficult to improve the quality of life for hemimaxillectomy patients when a fixed prosthesis is not possible. A fixed removable attachment retained obturator is a successful replacement for an implant retained prosthesis. This not only provides a successful closure for the defect, but also provides better esthetics, restores his speech and oration, boosts confidence – due to excellent retention, better acceptability due to better mastication without any nasal regurgitation and enhances the overall health status of the patient. The prosthesis not only rehabilitates the defect, but also restores the lost confidence and dignity of the patient. It provides him a new lease of life allowing him to continue his public life and cherish his dreams without any fear of identity rejection and social stigmas of the society.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and Sponsorship
Conflicts of interest
There are no conflicts of interest.
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Dr. Prajna P Shetty
#932, Sunderram Shetty Nagar, Vijaya Bank Layout, Behind Iimb, Bannerghatta Road, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]