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Year : 2014  |  Volume : 6  |  Issue : 1  |  Page : 65-68

Prosthodontic management of a completely edentulous microstomia patient

Department of Prosthodontics, Sibar Institute of Dental Sciences, Thakkellapadu, Guntur, Andhra Pradesh, India

Date of Web Publication15-May-2014

Correspondence Address:
O. Swetha Hima Bindu
Department of Prosthodontics, Sibar Institute of Dental Sciences, Thakkellapadu, Guntur - 522 509, Andhra Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0975-8844.132590

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Prosthodontic management of a completely edentulous patient with microstomia is challenging for both the operator and the patient. Limited mouth opening can be caused by the head and neck radiation, surgically treated head and neck tumors, connective tissue diseases, facial burns, reconstructive lip surgeries and the most common factor oral submucous fibrosis. It is often difficult to apply conventional clinical procedures to construct dentures for patients who demonstrate limited mouth opening, as it is difficult to insert or remove the custom trays, denture bases and the final prosthesis is in one piece because of the constricted opening of the oral cavity. However, with careful treatment planning and designing, many of the apparent clinical difficulties can be overcome. This article deals with a case report of treatment procedure and sectional prosthesis design for a patient with microstomia. All the procedures were intended for better function, health, esthetics and overall well-being of the patient.

Keywords: Flexible tray, microstomia, oral submucous fibrosis, sectional denture, sectional trays

How to cite this article:
Sandeep C, Hima Bindu OS, Sreedevi B, Prasad KS. Prosthodontic management of a completely edentulous microstomia patient. J Orofac Sci 2014;6:65-8

How to cite this URL:
Sandeep C, Hima Bindu OS, Sreedevi B, Prasad KS. Prosthodontic management of a completely edentulous microstomia patient. J Orofac Sci [serial online] 2014 [cited 2020 Sep 19];6:65-8. Available from:

  Introduction Top

Oral submucous fibrosis is a precancerous condition, affecting any part of the oral cavity and is caused by prolonged use of tobacco, areca nut, spices, etc. This condition is characterized by a burning sensation of the mouth, stiffening of certain areas of the oral mucosa with difficulty in opening the mouth.

This condition hinders conventional prosthetic treatment of edentulous patients. [1] Particularly the fabrication of complete denture is complicated by the loss of resiliency of tissues, limited tongue movements and the constant adjustments required accommodating the changing periphery. [2] Various treatment modalities include surgery, [3] dynamic opening devices called microstomia orthoses [4] and modification of denture design. [5]

  Case report Top

A 45-year-old male patient was referred to Department of Prosthodontics, for replacement of missing teeth. Case history revealed that patient had a habit of smoking two packets of cigarettes per day, since 7 years. On extra oral examination, the patient's mouth opening was only 26 mm vertically and 30 mm horizontally [Figure 1]. This posed a practical challenge for the fabrication of the complete dentures in a conventional way. Intraoral examination revealed moderately resorbed maxillary and mandibular completely edentulous ridges. Mucosa appeared blanched with palpable fibrotic bands extending all over the oral mucosa up to soft palate region. On palpation, the mucous membrane was firm. There was a minimal to zero resiliency of the tissues.
Figure 1: Mouth opening of the patient

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Mandibular primary impression and cast

For making the mandibular impression the smallest available stock tray (size-0) was selected whose flanges were modified as required until it could be inserted in patients mouth and the impression was made with alginate impression material and the primary cast was obtained.

Maxillary primary impression and cast

It was impossible to make an impression with stock tray for maxillary arch. Hence a flexible tray was prepared by manually dispensing silicone putty impression material intra-orally. After dispensing, it was carefully positioned onto denture-bearing areas and molded to appropriate contour using functional and manual manipulation and was kept in place until it set completely. Later, a wash impression was made using light body elastomer over the molded putty tray [Figure 2]. The cast was poured by stabilizing the flexible tray in a non-displacing mix of dental stone as a supporting base prior to pouring it in dental plaster to obtain the primary cast.
Figure 2: Maxillary primary impression with flexible tray

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Final impressions and casts

An auto polymerizing acrylic resin custom tray was fabricated for maxillary arch, however, it could not be introduced in the patient's mouth in one piece therefore, it was planned to section the tray into two halves to insert into the mouth. Press buttons were fixed to the handle of the sectional custom tray so that the tray could be exactly reassembled [Figure 3]. Border molding was done alternatively for the right and left halves of the sectional tray using low fusing compound and final impression of the two halves was made separately using light body elastomer. After the impression was completed, the sectional trays were separated intra-orally and reassembled externally. The impression was boxed and poured using dental stone.
Figure 3: Maxillary sectional custom tray with snap button attachments

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A single piece auto polymerizing acrylic custom tray was used for mandibular arch, as it could be inserted and removed with little difficulty. The border molding and final impression was done conventionally. The master cast was poured by inversion method with dental stone.

Jaw relations and try in

For better stability permanent denture bases were planned for recording jaw relations. Mandibular denture base was fabricated in a conventional way, but the maxillary denture had to be sectioned, hence a special metallic inlay structure was designed to be incorporated into the denture base, which consisted of two parts, right and left that were joined length-wise by a custom-made inlay structure at the overlapping metal base (5 mm wide) along the midline.

The right half of the wax pattern was designed to have three square inlay structures and it was fabricated on a refractory cast obtained by duplicating the master cast. Following this, it was invested, casted, trimmed, polished and returned to master cast. This entire assembly was duplicated to get a second refractory cast, on which the left wax pattern was formed, which included three square-shaped holes (2 mm wide and 2 mm high) with parallel walls. The inlay structures on the right half framework could precisely fit through the holes when the segments were joined with their tops at the same level as the surface [Figure 4].
Figure 4: Custom made metal inlay structure right and left parts

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Following this, maxillary permanent denture base was fabricated incorporating the metallic inlay structure and was sectioned with care without disturbing the seal, jaw relations record was made and teeth arrangement was done conventionally on a semi-adjustable articulator developing neutrocentric occlusion. Try in was done and was found to be satisfactory. The dentures were processed in a conventional way.

Insertion and recall visits

At the insertion stage the patient was trained as to how to place and remove the sectional maxillary denture. The right segment of the maxillary denture was first inserted into the mouth. Then the left segment was inserted to join the right one by placing the inlay structures into the corresponding holes [Figure 5]. Patient was given home-care instructions on the operation of the custom-made inlay structure assembly along with other instructions. Evaluation was done at recall visits and adjustments were done as required. Patient expressed immense sense of gratification with the treatment rendered.
Figure 5: Patient inserting the right and left maxillary denture sections

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  Discussion Top

Microstomia or limited mouth opening condition poses a problem during each step of prosthetic reconstruction. Hence several methods have been put forward for impression making which includes flexible trays, modified stock trays and sectional trays with different attachments. [6],[7],[8],[9] And for connecting sectional dentures cast Co-Cr hinges, [5],[10] swing-lock attachments, [11],[12] stud attachments, [13] clasps [14] and magnets [15],[16] were used.

In this case report, we used a simple method of snap fit buttons attachment for maxillary sectional tray and later the sectional denture segments were joined by means of a custom-made inlay structure on the overlapping metal base. This was a simple and the cost-effective way. Patient was able to use this design, when inserting or removing the denture with ease [Figure 6].
Figure 6: Final denture insertion

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  References Top

1.Naylor WP, Manor RC. Fabrication of a flexible prosthesis for the edentulous scleroderma patient with microstomia. J Prosthet Dent 1983;50:536-8.  Back to cited text no. 1
2.Benetti R, Zupi A, Toffanin A. Prosthetic rehabilitation for a patient with microstomia: A clinical report. J Prosthet Dent 2004;92:322-7.  Back to cited text no. 2
3.Ichimura K, Tanaka T. Trismus in patients with malignant tumours in the head and neck. J Laryngol Otol 1993;107:1017-20.  Back to cited text no. 3
4.Khan Z, Banis JC Jr. Oral commissure expansion prosthesis. J Prosthet Dent 1992;67:383-5.  Back to cited text no. 4 LA. A simplified technique for prosthetic treatment of microstomia in a patient with scleroderma: A case report. Quintessence Int 1994;25:531-3.  Back to cited text no. 5
6.Cura C, Cotert HS, User A. Fabrication of a sectional impression tray and sectional complete denture for a patient with microstomia and trismus: A clinical report. J Prosthet Dent 2003;89:540-3.  Back to cited text no. 6
7.Whitsitt JA, Battle LW. Technique for making flexible impression trays for the microstomic patient. J Prosthet Dent 1984;52:608-9.  Back to cited text no. 7
8.Luebke RJ. Sectional impression tray for patients with constricted oral opening. J Prosthet Dent 1984;52:135-7.  Back to cited text no. 8
9.Mirfazaelian A. Use of orthodontic expansion screw in fabricating section custom trays. J Prosthet Dent 2000;83:474-5.  Back to cited text no. 9
10.Cheng AC, Wee AG, Morrison D, Maxymiw WG. Hinged mandibular removable complete denture for post-mandibulectomy patients. J Prosthet Dent 1999;82:103-6.  Back to cited text no. 10
11.Wahle JJ, Gardner LK, Fiebiger M. The mandibular swing-lock complete denture for patients with microstomia. J Prosthet Dent 1992;68:523-7.  Back to cited text no. 11
12.Suzuki Y, Abe M, Hosoi T, Kurtz KS. Sectional collapsed denture for a partially edentulous patient with microstomia: A clinical report. J Prosthet Dent 2000;84:256-9.  Back to cited text no. 12
13.Geckili O, Cilingir A, Bilgin T. Impression procedures and construction of a sectional denture for a patient with microstomia: A clinical report. J Prosthet Dent 2006;96:387-90.  Back to cited text no. 13
14.Winkler S, Wongthai P, Wazney JT. An improved split-denture technique. J Prosthet Dent 1984;51:276-9.  Back to cited text no. 14
15.Watanabe I, Tanaka Y, Ohkubo C, Miller AW. Application of cast magnetic attachments to sectional complete dentures for a patient with microstomia: A clinical report. J Prosthet Dent 2002;88:573-7.  Back to cited text no. 15
16.Matsumura H, Kawasaki K. Magnetically connected removable sectional denture for a maxillary defect with severe undercut: A clinical report. J Prosthet Dent 2000;84:22-6.  Back to cited text no. 16


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]


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