Prosthetic Rehabilitation of Parkinson’s Disease Patient with Flabby Ridge Using Modified Window Technique: A Case Report

Introduction

Complete denture construction and its performance in function depends on accurate impression of the denture supporting and limiting areas.¹ Flabby ridge is one which becomes displaceable when alveolar bone gets replaced by hyperplastic soft fibrous tissue. It is seen in both the arches with more incidence in maxillary arch (24%).² Combination syndrome is a condition where the edentulous maxilla is opposed by natural teeth in mandibular anterior region and biting forces are directed towards the anterior ridge, resulting in trauma, severe bone loss and replacement of bony alveolar ridge with fibrous hyperplastic tissue which is an important cause for flabby tissue formation.³ Other causes include trauma seen in long term complete denture patients,² and unplanned dental extractions.⁴ In the presence of fibrous hyperplastic tissue, fabrication of a stable and retentive denture becomes a great challenge. Under occlusal forces, these ridges get easily displaced due to poor support, resulting in loss of peripheral seal and retention.¹ MacEntee stated that 2 mm displacement of flabby tissue can result in compromised support for complete denture.⁵ Tremors seen in Parkinson’s disease patients can make prolonged dental treatment more challenging.

Flabby ridges are usually managed by

(1) Surgical excision of fibrous tissue

(2) Implant supported prosthesis

(i) Fixed

(ii) Removable

(3) Conventional complete denture without surgical intervention using special impression techniques.^6,7

The patients not willing for treatment options 1 and 2 need to be treated with special impression techniques. Incorrect recording of impression leads to displacement of flabby tissues that return to their original form on denture insertion, causing denture dislodgement. Flabby ridge affects retention, support, and stability of denture, if not managed appropriately with special impression techniques.⁸ Different impression methods have been explained to manage maxillary anterior flabby tissue.⁹ The techniques include, mucocompressive, mucostatic and selective pressure impression techniques.^10-12 The concept of ideal impression method for recording flabby ridges has always remained controversial.⁵ This paper discusses a modified window technique for recording the impressions of flabby tissues with better material control and application of Polyvinyl siloxane (PVS) elastomeric impression material.

Case Presentation

A female patient aged 64 years with history of Parkin son’sdisease reported to the Department of Prosthodo nticswith a chief complaint of ill-fitting maxillary denture since six months. History revealed that an immediate denture was delivered soon after the extraction one yearback and the fitting of the denture was affected due toprogression of disease. On intraoral examination, thepatient had completely edentulous maxillary arch with flabby ridge in the maxillary anterior region extending from 13 to 23 and a partially edentulous mandibular arch with missing teeth in relation to 37 and 47. Different treatment options like implant supported prosthesis as well as excision of flabby tissues were explained to the patient. But the health condition of the patient was not suitable for any surgical procedures. Therefore, the treatment opted was to fabricate a complete denture in the maxillary arch and a removable partial denture in the mandibular arch with a novel, different and special impression technique.

The diagnostic impression of the maxillary arch was made using irreversible hydrocolloid (Zhermack tropicalgin chromatic alginate impression material) with perforated edentulous stock tray. The diagnostic cast was poured using dental plaster (Type II gypsum). Spacer was placed along the midline using modelling wax and the flabby ridge area from canine to canine was blocked out with additional wax. A maxillary special tray (space 2 mm) with one handle in the mid palatine area was made using self-cure acrylic resin. The anterior window region from 13 to 23 was marked with a BP blade before curing the special tray to remove the window in the later stage. After curing, a vacuum-pressed polyethylene sheet of 0.5 mm thickness was adapted over the special tray (Figure 1).

Then the marked area on the acrylic resin was removed and two holes were prepared on the vacuum pressed sheet in the anterior window area. The tray was placed in the patient’s mouth and the borders were made 2 mm short from the sulcus using tungsten carbide bur. Sectional border molding technique was done using conventional greenstick compound (Low fusing compound, DPI Pinnacle tracing sticks). Then the wax spacer was removed and tray adhesive was applied (Adhesive polysiloxane, Coltene) on the tray. Following this, secondary impression using heavy body polysiloxane impression material (Affins, perfect impressions Coltene) was made (Figure 2). Then the impression was checked for any defects and the heavy body material present in the anterior area of flabby ridge was removed carefully using BP blade.

Then the impression was placed back in the patients mouth and light body polysiloxane material (Zhermack elite HD+) was injected through the holes made in the vacuum sheet until excess material came out through the holes (Figure 3). Final impression was removed and inspected.

After beading and boxing of secondary impression, final cast was poured with Type III dental stone. Occlusal rim was fabricated on record base and jaw relation was recorded. Following this, maxillary try-in (Figure 4) was done, the final prosthesis was fabricated in the conventional manner and was inserted in the patient’s mouth. The retention, stability, support and esthetics of the new denture were satisfactory and patient was extremely pleased with the result (Figure 5). In the recall visits, the patient expressed satisfaction and no complaints were noted.

Discussion

Impression plays a vital role in the denture fabrication, especially in flabby ridge cases.⁸ Several methods have been discussed in the literature for recording impressions of flabby ridges. Liddlelow introduced a method using two impression materials. In the special tray, Plaster of Paris was used over flabby tissues, and remaining tissues were recorded using zinc oxide eugenol.⁶ In another technique, two different custom impression trays and materials were used to record the flabby and normal tissues.¹³ Watson described the window technique, where an impression of normal tissues was made using the special tray and zinc oxide eugenol impression paste. Then an impression plaster of low viscosity was painted over flabby tissues through the window.¹⁴ Each of these methods have their own advantages and disadvantages.¹⁵ Allen stated that in order to get an accurate peripheral seal, prior to recording the secondary impression, a special tray with a spacer must be prepared and flabby tissues should be recorded in a rest position through the space after final impression.⁷

As PVS materials are available in different viscosities, they are usually used by dentists for recording flabby ridge impressions.^11,16 Heavy body polyvinylsiloxane was used to provide mucocompressive impression in the remaining areas other than the flabby alveolar ridge. This gives a stable and controlled replacement of secondary impression material with light body. Although siloxane impression provides accuracy, controlled application is very important. This technique permits controlled application and provides support for low viscosity material in accordance to little or no application of force to the flabby alveolar ridges. The initial marking of the tray using BP blade before curing helps in easy removal of window.¹⁷

This case report describes a new and modified window impression technique for recording impression in a Parkinson’s disease patient with anterior maxillary flabby area using silicon impression material. Using this modified impression technique, flabby tissues can be managed effectively.

The complete denture prosthesis should fulfil its basic objectives like retention, stability, support, aesthetics and preservation of supporting tissues. Flabby alveolar ridge gets displaced during conventional impression procedures and results in instable and non-retentive dentures. Various treatment modalities for flabby alveolar ridge include: surgical removal of flabby tissues, implant supported or conventional denture. This report describes an effective method for application of light body elastomeric impression material to obtain an accurate final impression of flabby ridge. This technique can also be used with other low viscosity impression materials like impression plaster, that are injected through the holes. With modified window technique, these ridges can be managed effectively.

Conflict of Interest

Nil