Management of Mucormycosis Resultant Hemimaxillectomy Defect from Interim Hollow Obturator to Definitive Two-Piece Magnet Retained Prosthesis - A Case Report

Introduction

Maxillary obturator prosthesis plays a vital role in situations where the acquired defects are large to be managed surgically. Intervention with maxillary obturator prosthesis recreates a functional separation between oral and nasal cavity and restores the lost anatomy of the resected soft palate. Insertion and removal of such prosthesis is one of the major hurdles for patients having trismus or decreased mouth opening. Such cases can be managed either surgically or prosthodontically through various two-piece obturator prosthesis prostheses.^1,2 This case report describes the management of mucormycosis-affected edentulous patient who underwent hemimaxillectomy using a twopiece prosthesis attached with magnets.

Case Report

A 62-year old male patient reported to the Department of Prosthodontics with chief complaint of nasal regurgitation of liquids and food pieces while having food. The patient furnished history of rhino cerebral mucormycosis four months back. The patient underwent hemimaxillectomy for the treatment of rhino cerebral mucormycosis. Extraoral examination revealed distortion of facial contour on the left side of the face (Figure 1A). Intraoral examination revealed a large hemimaxillectomy defect of the left side alveolus involving the premaxilla and posterior part of the hard palate (Figure 1B). Mouth opening was restricted and there was a through and through communication between oral and nasal cavities. Considering the clinical situation, a treatment plan was made to fabricate an interim obturator prosthesis first, followed by a two-piece definitive obturator prosthesis.

Clinical procedures

a) Fabrication and insertion of hollow interim obturator prosthesis

The defect was blocked out and the impression was made with irreversible hydrocolloid impression material (Algitex DPI, India). Plaster beading of the impression was done and a two-piece dental stone model was obtained (Figure 2A, B).

Modelling wax of approximately 2 mm was adapted all around the defect. A silicone putty index was made by adapting the putty consistency polyvinyl siloxane impression material into the defect (3M ESPE Seefeld; Germany). Markings were scribed onto the silicone putty index for relocation while making the hollow obturator (Figure 3A, B). 

A replica of glycerine soap (Pears Natural Glycerine Soap bar, India) was made in the exact same manner as that of silicone putty index. Wax-up for the interim obturator was done and flasking was performed, keeping the silicone putty in position. Following dewaxing, silicone putty was retrieved (Figure 3C). Heat cure acrylic (DPI, India) resin in the dough stage was packed followed by placement of silicone putty index and first trial closure was done (Figure 3D).

After first trial closure, flask was reopened and silicone putty index was retrieved and a hollow cavity was obtained (Figure 4A). Subsequent placement of gylcerine index was done into the hollow cavity created by silicone putty index (Figure 4B). Second layer of heat cure resin was placed onto the glycerine index and final flask closure was done. Curing was carried out in a conventional manner. The prosthesis obtained following curing was along with the glycerine soap index intact within it. To remove the glycerine soap, holes were made onto anterior and posterior aspects of the bulb and gylcerine was removed using orthodontic wires and three-way syringe. Prosthesis was finished and polished and insertion was done (Figure 4C). Regular follow-up was done. Post insertion instructions regarding prosthesis and oral care were explained to the patient (Figure 4D).

a) Definitive obturator prosthesis fabrication

Existing interim obturator prosthesis was relined after three months. Modelling wax was added in the form of maxillary edentulous arch form onto the existing interim plate. Curing was carried out and a single plate along with anatomy of edentulous ridge was obtained. Next, the interim plate with ridge anatomy was picked up using irreversible hydrocolloid impression material (Figure 5A). Interim plate was removed from the impression and impression was poured to obtain the master stone model (Figure 5B, C). Temporary denture base with occlusal rims was made and jaw relation was recorded (Figure 5D). 

Monoplane or zero-degree cusp teeth (Premadent, India) were arranged and try-in of the trial denture was done (Figure 6A). Trial denture was evaluated for vertical dimension, esthetics, speech & soft tissue support (Figure 6, B). After try-in of the denture, it was cured in a conventional manner. Finishing and polishing of the denture was done (Figure 6 C, D).

A trough was made into the hollow piece prosthesis, one in the anterior central portion and two bilaterally into posterior maxillary region. Three magnets (Neodymium close fields magnets) were secured into the trough using self-cure acrylic resin. For exact pick up of the location of magnets into the cured denture, articulating paper was used. Trough was ascribed at the articulating paper marking and magnets were secured using selfcure acrylic resin (Figure 7 A, B). Hollow bulb piece was relined using soft tissue reliner and inserted into position. Onto that, cured denture along with magnet attachments were inserted into the oral cavity (Figure 7 C, D). Patient was instructed about denture and oral hygiene care and regular follow-up.

Discussion

Patients with maxillofacial defects require physical as well as psychological rehabilitation. This can be achieved through multidisciplinary team approach. In the patient with maxillary defect, surgical procedures alone cannot provide satisfactory esthetic, functional and psychological care. Here comes the role of an obturator; a single piece or two-piece obturator provides excellent care in terms of function, esthetics as well as psychological benefits.^3,4

In this case, the defect was large and mouth opening of the patient was restricted; hence a decision was made to fabricate a two-piece prosthesis. The hollow obturator with palatal plate covered the defect and created separation between oral and nasal cavities that prevented nasal regurgitation of liquid and food particles while having the food. There was a marked difference in the speech production before and after prosthesis insertion.⁵

Increased weight of obturator makes the prosthesis bulky and non-retentive for the patient, hence jeopardizing its function. To overcome this, bulb part of the two-piece prosthesis was kept hollow through innovative use of silicone putty index and glycerine soap index.⁶

Monoplane teeth were used opposing the natural dentition. Advantages of using the monoplane teeth are less horizontal forces, freedom of movement and they can be easily adapted to situations prone to denture base dislodgement during the denture functioning. In the present case, magnets were chosen due to ease of placement, strong attractive forces, automatic reseating and easy replacement if needed in future.^7,8,9

Conclusion

Prosthetic rehabilitation was aimed to achieve masticatory and functional efficiency along with esthetic harmony. Two-piece obturator with hollow bulb could help in achieving optimal function in situations where surgical defects are large and cannot be rehabilitated through surgical approach. In this case report, optimal results were obtained in terms of function and esthetics by adequately supporting facial soft tissue to overcome facial disharmony and hence boosting the psychological aspect of the patient.

Consent

Informed consent for medical photographs was obtained from the patient.