Prosthetic Rehabilitation Of Velopharyngeal Defect- A Case Report

INTRODUCTION

           According to the glossary of Prostho dontic terms obturator is defined as prosthesis used to close a congenital or a acquired tissue opening, primarily of hard palate and or associated alveolar structures. Palatopharyngeal insufficiency is an acquired or congenital anatomic defect of the soft palate that makes the Palatopharyngeal sphincter incomplete.1The soft palate acts as a dynamic separator between oral and nasal cavity. ² Persons with maxillary defects present themselves with many problems with speech, mastication and most importantly poor aesthetics. To overcome such problems obturator prosthesis are usually provided. Ambroise Pare was first to use obturator for the maxillary defects and since then many modifications have been made to improve the quality of these obturators³.A pharyngeal obturator is a removable maxillary prosthesis which has a posterior extension to separate oropharynx and nasopharynx.^4-5 This obturator prosthesis restores the defects of the soft palate and allows adequate closure of palatoph aryngeal sphincter. ²

CASE REPORT

           A 60 year old female patient reported to the department of Prosthodontics with complaint of inability to speak and regurgitation of nasal secretion. No significant past medical history was noted. Intra oral examination revealed absence of all teeth and cleft of soft palate (Fig 1). Patient had undergone total extraction due to periodontal problem. Patient gave history of the defect since birth and had not undergone any surgical correction or prosthetic rehabilitation. She exhibited symptoms of velopharyngeal dysfunction, so speech aid prosthesis with a speech bulb was planned. Entire procedure was explained to the patient and her consent was obtained.

           Defect was blocked with gauze piece and an impression of the maxillary arch was made using irreversible hydrocolloid impression material (Fig.2). Primary Impression was poured using dental stone Type II and primary cast was obtained. Custom tray extending into the defect was fabricated on primary cast with auto polymerizing acrylic resin after blocking the undercuts with wax. Area of the defect was functionally molded using low fusing green stick compound during which patient was instructed to swallow and rotate her head to record the velopharyngeal region. The above procedure was repeated till the defect was adequately recorded. Border molding was completed using green stick compound. Final impression was made using a medium body polysulphide impression material. A thin layer of green stick was removed from the recorded defect area and space was created for light body impression material. The tray was repositioned back in the mouth with impression material in it and patient was asked to repeat all the movements. Impression was checked for extension and retention (Fig.3). Final impression was poured with Type III dental stone and master cast was obtained. Jaw relation was recorded. Teeth selection followed by arrangement and try in was done. Margin of the defect was marked on the cast using a marking pencil extending from the posterior part of the hard palate to the anterior part of the soft palate. A small spectacle hinge was selected and placed on the posterior end of the defect. Wax up was completed after placing the hinge which connected the hard and soft palatal portion of the wax. Flasking was done. After final setting of plaster dewaxing was carried out. After dewaxing, to fabricate a hollow bulb obturator a initial mix of acrylic resin was placed on the defect area of about 2mm thickness. Sugar was packed into the defect. A permanent heat processed silicone based soft denture material (Malloplast-B) was placed in the posterior defect of the cast followed by packing of heat cure acrylic resin on the anterior defect. Denture was processed (Fig-4). Final finishing and polishing was done and the denture was delivered to the patient (Fig 5,6,7).

DISCUSSION

           As with all phases of prosthodontics, there can be considerable difference in soft palate defects from one patient to another⁷ . Prosthetic rehabilitation of the patients suffering from velopharyngeal deficits with obturator prostheses varies according to the location and nature of the defect or deficiency ^4,6,9.There are differences between the obturator prosthesis constructed for patients with developmental or congenital malformation of the soft palate as compared with the patients with acquired defects.

However the main objective of obturation are to provide a barrier for the control of nasal emission and inappropriate nasal resonance during speech, and also to prevent the leakage of material into the nasal passage during deglutition. The patient must be counseled about the shortfall or limitation of treatment, that the prosthodontist cannot restore the soft palate. The clinician can only try to provide an alternative means for oropharyngeal function.

CONCLUSION

           By using readily available material and conventional techniques simple hollow bulb obturator can fulfill the requirements and provides the marked improvement in patientsesthetic, speech and mastication. Thus it imparts a positive psychological effect on the patients personality. The prosthodontist plays a significant role in the complete rehabilitation of the palatal defect. Thorough knowledge and skills, coupled with a better understanding of the needs of the patients enable the successful rehabilitation of such patients. A prosthesis so designed provides a functional solution to the compromised state of the patient.