AIMS AND OBJECTIVES – Maxillofacial Prosthodontics is an art and science which provides life-like appearance to the missing structures of an individual. The complete or partial loss of a finger results in significant functional deficiencies. In addition to immediate loss of grasp, strength and security, the absence of a finger may cause marked psychological trauma. CASE DESCRIPTION – A case report has been presented where a custom made finger prosthesis; comfortable in use and esthetically acceptable to the patient was fabricated; using silicone material. CONCLUSION – The retention for this patient was obtained by reducing the stump and using a ring of suitable size.
Finger and partial-finger amputations are some of the most frequently encountered forms of partial-hand losses.1 Although the most common causes of these amputations are traumatic injuries, congenital absences or malformations may present similar clinical challenges.2
Prosthesis refers to artificial replacement of an absent part of the human body. These artificial substitutes serve primarily to improve the patient’s appearance and to support them psychologically. They play an immense role in making the patient more socially acceptable.3 Reconstructive surgery cannot restore esthetics as much as prosthesis can and thus has limited role in case of lost body parts. The major role in rehabilitating the patient is thus played by the maxillofacial prosthodontist and the anaplastologist. The ideally constructed finger prosthesis must meet the following preconditions: the prosthesis must assist in grip and absorbing and transferring forces to the hand; the prosthesis should look natural, allowing expression of gestures.4,5
This article presents a case of rehabilitation of a finger defect with a silicone prosthesis and describes a method of retention for the same.
A 22-year-old female patient reported to the Department of Prosthodontics, with a chief complaint of a partially missing index finger on her right hand. A complete hand examination was carried out that revealed a residual stump on the index finger of the right hand measuring 1.5 cm in height. A solitary healed wound/scar was seen on the base of the residual stump. The surrounding area appeared to be normal with no signs of any infection or inflammation. Informed consent was obtained before beginning the treatment procedure.
The index finger of the patient’s left and right hand were lubricated with a thin layer of petroleum jelly, to prevent the hydrocolloid impression material from adhering to it. Impressions of the stump and of the index finger of the contralateral hand which correspond to the lost digit were taken using irreversible hydrocolloid. A plastic disposable cup of sufficient length and diameter was chosen to confine the impression material. The containers were tried on the patient’s fingers to provide adequate clearance of at least 5 mm around for the impression material. Regular setting alginate was mixed using cold water to increase the working time and poured into the containers. The patient was asked to dip her finger and stump vertically into the container without touching the sides or the bottom of the container. Both the impressions were made with the digits in the semiflexed and relaxed position. The material was allowed to set and the fingers were removed quickly in a jerking motion after the material was set.
The impression of the stump was poured in Type-III dental stone. The impression of the middle finger was poured with molten modeling wax. Upon cooling, the wax pattern was retrieved from alginate mold by partially incising the alginate mold with sharp instrument.
The wax pattern was then adjusted by sculpting and adapted on the working cast. Approximate length and angulations were determined on working cast and later confirmed during trial of wax pattern. The wax pattern was tried on the patients affected right hand little finger. Necessary adjustments regarding the length, contour and angulations of the finger were done at this stage of prosthetic fabrication.
A reduction of 1-1.5 mm was done on the stone casts to produce prosthesis with a smaller diameter which can be stretched over the stump to provide retention.
The pattern and the cast were then invested in a large size Hanau flask. The mold was first poured only upto half of the pattern. Tin foil substitute was applied and then the other half was poured, wax was eliminated in the conventional way.
Color matching and incorporation of nail
The most critical step was to match the color of the prostheses to the patient’s skin color. The basic skin color was observed. The colors were mixed with the silicone to obtain the base color. Maximum efforts were made to achieve the appropriate characterization for the palmer and dorsal surfaces of the prostheses. The shade matching was done using natural daylight. Artificial nail was properly shaped and trimmed to the required size. Around 1 mm of nail bed was carved in the wax pattern and the nail was incorporated in that space.
The mould created by the elimination of the wax was packed with silicone rubber. The material was allowed to bench cure overnight and for the final polymerization, it was placed in hot water, for one hour, at 45 degrees Celsius.
Once the final prosthesis was retrieved, the flash was trimmed using a sharp blade and the final finishing was accomplished using fine sand paper.
The retention for this patient was by using a ring of suitable size.
Individuals who desire finger replacement usually have high expectations for the appearance of the prosthesis.6 The polyvinyl chloride material generally used is easily and permanently stained by such common materials as ballpoint pen and newspaper ink and has not proven durable enough for active use. The acceptance rate has been much higher when individually sculpted custom restoration using silicone elastomer is provided.7 The overall durability and stain resistance of silicone is far superior to any other material currently available for finger restorations. Almost all stains can be removed easily with water and soap.8 Silicone finger restorations may have additional functional benefits. Many traumatic amputees experience painful hypersensitivity at the termination of finger remnants. The gentle, constant pressure of an elastomer prosthesis can help desensitize and protect the injured tip. Over time, scar tissue contained within a silicone prosthesis seems to become more pliant and comfortable. Recent literature speculates that silicone gel improves the hydration of the stratum corneum of immature hypertrophic scars. Placing a decorative ring over the margin of a finger prosthesis ending at the metacarpal-phalangeal joint will make the changing color of the hand less noticeable although the distal joint functions will be slightly restricted.
The custom-made finger prosthesis is esthetically acceptable and comfortable for use in patients with amputated fingers, resulting in psychological improvement and personality. An esthetic and retentive prosthesis are the primary determinant factors in the successful prosthetic restoration of a finger. The retention for this patient was obtained by reducing the stump and using a ring of suitable size.