A Novel Method for Retention of an Orbital Prosthesis in a Case with Continuous Maxillary and Orbital Defect

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Gunjan Pruthi,¹Veena Jain,² and Swati Sikka³

Case Report

A 55-year-old male patient had reported to the Department of Prosthodontics, AIIMS, with a chief complaint of missing right eye since 3 months and regurgitation of food from the defect site. Patient gave the history of diabetes and histopathological diagnosis revealed Rhinocerebral mucormycosis. Surgical exenteration of the right eye and right side hemimaxillectomy was done to treat Rhinocerebral mucormycosis, and was followed by protocol of maintenance chemotherapy. Extraoral examination of the patient showed a large orbital defect on right side which was continuous with intraoral maxillary defect (Fig. 1). Extra orally, tissue was healthy but no definite bony or soft tissue undercut was found to help in the retention of the prosthesis. For complete prosthetic rehabilitation of the patient, a hollow closed bulb obturator and a silicone orbital prosthesis were planned. As the intraoral and extraoral defects were continuous, so to retain the orbital prosthesis, it was plugged with the help of pin of electric plug into the socket attached to the bulb of maxillary obturator (like a patrix and matrix).

Method

Recording the Impressions

The patient was draped for impression procedures and patient’s eyebrows and eyelashes were lubricated with petroleum jelly in order to facilitate removal of the impression material and minimize discomfort to the patient. Lines were marked on the patient’s face with an indelible pencil for symmetrical placement of the orbital prosthesis. Impressions of the orbital defect and the maxillary defect were made using irreversible hydrocolloid (Zelgan, Dentsply India Ltd.) and individual casts were poured in dental stone for better surface details and strength.

Fabrication of Conformer and Attachment of Pin and Socket

A conformer of orbital defect was made with the autopolymerising resin (DPI cold cure, Dental Product of India, Mumbai, India) and was tried on patients face. A 5 mm thick sprue wax was attached to the acrylic base to provide a mechanical undercut for the retention of silicone eye prosthesis. An obturator plate was also made in cold cure acrylic resin and adjusted in patient’s mouth. A pin of electric plug was attached on the rear side of the conformer and a corresponding socket pin was attached to the bulb of the maxillary obturator plate. Both parts were snuggly fitted into each other like a matrix and patrix part of a semi precision attachment and adjusted to attain a path of insertion and removal without interference, so that the orbital prosthesis could be retained with the obturator in the absence of anatomic undercuts. The pin and socket were stabilized with sticky wax to the acrylic conformer and obturator plate, respectively. Conformer and obturator plate were flasked and dewaxed and packing was done in heat cure acrylic resin (high impact heat cure acrylic, Travelon) (Fig. 2). Pigments were added to the resin used for packing of orbital defect to match the patient’s skin color. The heat cure bases were checked on the patient for the adaptation and retentive potential (Fig. 3).

Fabrication of Silicone Orbital Prosthesis

The right eye prosthesis was carved in modeling wax using a prefabricated eye shell button selected according to the color of the left eye. It was tried on the patient’s face to check the orientation of pupil, color, size and volume of sclera visible as compared to the contra lateral eye. Once the trial was found satisfactory, flasking, dewaxing and packing were done as per Prosthodontic protocols and processed in RTV (room temperature vulcanizing) silicone material. Silicone-specific colors were used to match the color of the patient’s skin. Try-in of definitive obturator was done. It was flasked in a conventional manner and was delivered to the patient after finishing and polishing (Fig. 4a, b). Eye prosthesis was retrieved, characterized and was delivered to the patient (Figs. 5, ​,6).6). Patient could wear the prosthesis with or without spectacle (Figs. 7, ​,8).

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