|Year : 2014 | Volume
| Issue : 2 | Page : 143-146
Techniques for fabricating hollow obturator: Two case reports
Janakirama Reddy Sridevi1, Natarajan Kalavathy1, Narasimha Jayanthi2, Narasimhaiah Manjula1
1 Department of Prosthodontics, Crown and Bridge, D.A.P.M.R.V. Dental College and Hospital, Bengaluru, Karnataka, India
2 Department of Prosthodontics, Oxford Dental College and Hospital, Bommanahalli, Bengaluru, Karnataka, India
|Date of Web Publication||7-May-2014|
Department of Prosthodontics, Crown and Bridge, D.A.P.M.R.V. Dental College and Hospital, J.P. Nagar, 1st Phase, Bengaluru - 560 078, Karnataka
The most commonly seen intraoral defect is the one affecting the maxilla, through an opening into the nasopharynx. These defects can either be congenital or acquired. These are usually large openings in the palate and/or the surrounding structures. Obturators are used to close or seal these defects to restore proper mastication, speech, deglutition, and esthetics. This article presents case reports describing two different techniques for fabricating hollow bulb oburator.
Keywords: Hollow bulb, obturator, shim
|How to cite this article:|
Sridevi JR, Kalavathy N, Jayanthi N, Manjula N. Techniques for fabricating hollow obturator: Two case reports. SRM J Res Dent Sci 2014;5:143-6
|How to cite this URL:|
Sridevi JR, Kalavathy N, Jayanthi N, Manjula N. Techniques for fabricating hollow obturator: Two case reports. SRM J Res Dent Sci [serial online] 2014 [cited 2020 Sep 18];5:143-6. Available from: http://www.srmjrds.in/text.asp?2014/5/2/143/132097
| Introduction|| |
An obturator is a device that is used to close any unnatural opening intraorally. This is usually a defect in the maxilla such as cleft palate or resected maxilla.
There are numerous ways of fabricating the open and closed hollow obturator. All these techniques intend to provide a light weight prosthesis that is readily accepted by the patient. The open bulb obturator provides the advantage of easy cleans ability, but accumulation of moisture necessitates frequent cleaning.  Removable lids or the covering of the obturator prosthesis usually reduces this disadvantage.
Various methods available to fabricate a hollow bulb obturator include the fabrication of an obturator either as one piece or by processing in two halves and sealing using autopolymerizing resin.  One piece hollow bulb obturator can be fabricated by filling the hollow portion using materials such as sugar,  salt, polyurethane foam, sponge  and gas injection using argon gas.  Nondetachable screw cap can also be used to cover the opening made to pour out the sugar or salt.
This article presents two case reports describing two different techniques used to fabricate the hollow bulb obturator.
| Case reports|| |
The case we present here is about a 59-year-old female patient who came to the Department of Prosthodontics, DAPM R V Dental College, Bangalore, with the complaint of missing teeth and closure of defect in the upper arch. Patient had undergone hemimaxillectomy due to squamous cell carcinoma of the palate.
Primary impression was made using alginate [Figure 1]. Primary cast was made and special tray was fabricated. Border molding was done using green stick compound. And final impression was made using elastomeric impression material [Figure 2]. Master cast was thus, obtained over which denture base was fabricated. Jaw relation was done. Teeth arrangement was done and tried in patient's mouth [Figure 3].
Processing of the lid
Wax-up of the lid portion of the obturator was done [Figure 4]. It was flasked, dewaxed, packed and processed separately.
Processing of the trial denture
The trial denture was flasked and dewaxed [Figure 5]. Heat cure acrylic resin was packed into the mold and acrylic was processed. The lid was placed in the obturator [Figure 6] and sealed using autopolymerizing resin. The obturator was finished and polished.
The second case is about a patient 59-year-old female came to the Department of Prosthodontics, DAPM R V Dental College, Bangalore, with a complaint of replacement of missing teeth. Patient gave a history of teeth being extracted during maxillectomy due to carcinoma of maxilla. One piece hollow bulb obturator was planned to restore the defect.
Primary impression of the defect and surrounding structures was made using alginate [Figure 7]. Primary cast obtained on which special tray was fabricated. Border molding was done using green stick compound and final impression was made using elastomeric impression material. Denture base was made on the master cast obtained. Occlusal rims were fabricated and jaw relation was recorded. This was followed by a try in procedure [Figure 8].
Trial denture was flasked and dewaxed. Undercuts were blocked out with 2 mm of wax in the defect area. Three tissue stops were then made in this wax. Another layer of wax was adapted on the opposing palatal surface. Autopolymerizing resin was mixed and added on the area relieved with wax on the defect and the palatal surface. The two halves of the flask were closed and the resin was allowed to polymerize. A hollow shim was thus obtained [Figure 9]. The wax used for relief was washed off using boiling water. This hollow shim was placed back in the flask using the stops as a guide [Figure 10]. Heat cure acrylic resin was mixed and packed into the flask. Shim was thus encased within the obturator. The acrylic resin was processed, finished and polished [Figure 11].
| Discussion|| |
Patients with large maxillectomy defects present a significant challenge for prosthetic rehabilitation. Retention is severely compromised in these patients resulting in difficulties in speech and mastication. The technique described in this article for the fabrication of the hollow bulb obturator was described by Chalian and Drane  The hollow bulb obturator offers many advantage of being light and reduces excessive atrophy of muscles.
Many authors have described various other techniques for the fabrication of the hollow bulb obturator. Matalon and LaFuente  described the technique of adding sugar during processing of the obturator, which is later removed by drilling a hole in the superior surface and the hole is filled with autopolymerizing resin. The opening can also be filled by using a nondetachable screw cap.
El Mahdy et al.  described the two flask technique to process the obturator and the tooth portion separately. Mc Andrew et al.  described the technique of fabricating the prosthesis in two halves and sealing them using autopolymerizing resin. Iramaneerat et al.  described the technique of injecting argon gas into the bulb of the obturator.
Buzayan et al.  described the use of hard thermoforming splint to fabricate closed hollow bulb obturator. Plaster index was used as a matrix for the fabrication of hollow obturator by Asher et al. 
The two techniques described in this article have more advantages than disadvantages. The advantages of fabricating one piece obturator are; it is hygienic, more esthetic, simple, and accurate and there are no lines of demarcation between heat cure and autopolymerizing resin. It also improves the speech by adding resonance to the voice.
The disadvantages of one piece obturator are: increased processing time, shim or polyurethane foam increases the weight of the prosthesis.
The advantages of a two piece obturator are; the thickness of the obturator can be controlled thereby reducing the weight of the prosthesis. ,, It reduces clinical time. It can be used for both completely and partially edentulous arches.
The disadvantages are; additional processing time required to process the lid, acrylic resin may seep into the hollow portion of the obturator, seepage of fluids is possible if the seal is improper. Two piece obturator is mainly used in large defects with more undercuts or in patients with reduced mouth opening.
Among the various techniques, the technique described by Chalian et al. is being followed for decades due to the advantages described above.
| References|| |
|1.||Chalian VA, Drane JB. Maxillofacial Prosthetics - Multidisciplinary Practice, Baltimore: The William and Wilkins Co.; 1972. |
|2.||McAndrew KS, Rothenberger S, Minsley GE. 1997 Judson C. Hickey Scientific Writing Awards. An innovative investment method for the fabrication of a closed hollow obturator prosthesis. J Prosthet Dent 1998;80:129-32. |
|3.||Matalon V, LaFuente H. A simplified method for making a hollow obturator. J Prosthet Dent 1976;36:580-2. |
|4.||Boucher LJ, Heupel EM. Prosthetic restoration of a maxilla and associated structures. J Prosthet Dent 1966;16:154-68. |
|5.||Iramaneerat W, Seki F, Watanabe A, Mukohyama H, Iwasaki Y, Akiyoshi K, et al. Innovative gas injection technique for closed-hollow obturator. Int J Prosthodont 2004;17:345-9. |
|6.||el Mahdy AS. Processing a hollow obturator. J Prosthet Dent 1969;22:682-6. |
|7.||Buzayan MM, Ariffin YT, Yunus N. Closed hollow bulb obturator - One-step fabrication: A clinical report. J Prosthodont 2013;22:591-5. |
|8.||Asher ES, Psillakis JJ, Piro JD, Wright RF. Technique for quick conversion of an obturator into a hollow bulb. J Prosthet Dent 2001;85:419-20. |
|9.||Tanaka Y, Gold HO, Pruzansky S. A simplified technique for fabricating a lightweight obturator. J Prosthet Dent 1977;38:638-42. |
|10.||Nidiffer TJ, Shipmon TH. The hollow bulb obturator for acquired palatal openings. J Prosthet Dent 1957;7:126-37. |
|11.||Brown KE. Clinical considerations improving obturator treatment. J Prosthet Dent 1970;24:461-6. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]