Expanding digits of a maxillofacial prosthodontist.

Complete or partial loss of a finger is the most commonly encountered problem in prosthetic dentistry. The etiology of missing digit may either be congenital or acquired. Trauma is the most common cause for acquired defect of the digit. Loss of a digit results in functional and psychological impact on quality-of-life of the patient. This article portrays about the prosthetic management of a patient with an acquired defect of finger.

A finger is a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates. The palm has five bones known as metacarpal bones, one to each of the five digits. Human hands contain 14 digital bones, also called phalanges or phalanx bones: Two in the thumb (the thumb has no middle phalanx) and three in each of the four fingers. These are the distal phalanx, carrying the nail, the middle phalanx, and the proximal phalanx. They enable us to interact with our environment and help in many day to day functions.[1]

“Amputation,” derived from the Latin word “amputare” (to excise, to cut out) has been defined as the “removal of part or all of a body part enclosed by skin” (Online Medical Dictionary). There are various types of amputations some of which are self-amputation, congenital amputation, and traumatic amputation. Whatever the indication of an amputation, the result is a limb stump.[2]

The main goal of prosthetic rehabilitation of a lost finger is to decrease pain and to maintain the sensation at the tip of the stump. The factors involved in the restoration of a finger are the amount of tissue involved, the bone lost and bone available for support of prosthesis and level of involvement of remaining fingers.[3]

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.[4] Individuals who desire for finger replacement usually have high expectations for the appearance of the prosthesis.[5] Various methods like titanium implants, osteointegration abutment, silicone elastomers are in use for replacing missing finger. Passing through various materials, the acceptance rate has been much higher when an individually sculpted custom restoration using a silicone elastomer.[5]

Case Report

A 70-year-old male patient reported to the Department of Prosthodontics with a chief complaint of missing part of his left index finger. Patient was employed in sugarcane juice business and had trauma to his left index finger in the juice extract machine. The patient was operated, and the stump was prepared to receive the prosthesis. On clinical examination, the patient had missing middle and distal phalanx of the left index finger. The residual stump was free from any signs of inflammation [Figure 1]. The other fingers were intact and functionally normal.

Figure 1

Preoperative

After a brief discussion with the patient, the esthetic and functional demands of the patient were evaluated. The patient was more concerned about the esthetics and demanded a prosthesis which matches the texture and color of his normal portion of the finger. Based on patient's need and economic factors, it was decided to fabricate silicone prosthesis. As protocol demands, informed consent was obtained from the patient.

Fabrication

Step 1: Impression making

After careful examination of the patient, petroleum jelly was applied to the finger stump which is to be restored.

Addition silicone impression material was employed to make the impression followed by a wash impression [Figure 2].

Figure 2

Impression making

Step 2: Model of stump

Dental stone was employed to make the model of the stump [Figure 3].

Figure 3

Model of stump

Step 3: Impression of the donor finger was made

A donor is selected according to the finger size of the recipient, and the impression is made as explained in step 1 [Figure 4]

Figure 4

Impression of the donor finger

Step 4: Wax up procedure

Using the donor finger as index, wax was poured into it, and the stump was then placed [Figure 5].

Figure 5

Wax up of stump using donor finger

Step 5: Flasking procedure

Dental varsity flask was employed to process the prosthesis. The waxed up prosthesis was placed on the base of the flask and counter was poured. After dewaxing, color matching was done during daylight. Separate color matching was done for the dorsal and ventral surface of the finger. Room temperature vinyl silicone was used to fabricate the final prosthesis. For final prosthesis, the flask is placed in hot air oven for 1-h at 45°C [Figure 6].

Figure 6

Flasking

Step 6: Placement of nail

Acrylic nail was fabricated using tooth-colored acrylic resin material. The fabricated nail shell was trimmed to conform to the nail bed that had been created on the silicone finger prosthesis. Once verified it was smoothened and polished. Single part silicone was dispensed onto the nail bed over which the finished nail shell was positioned and secured in place until it sets [Figure 7].

Figure 7

Placement of nail

Step 7: Final prosthesis

The final prosthesis is inserted to the patient and the fit is evaluated. In certain cases, where more retention is required, medical adhesives can be used [Figure 8].

Figure 8

Preoperative and postoperative

Discussion

Amputation of a digit or a portion of a digit has a deleterious effect on the functional capability as well as the psychology of the patient. It affects the quality-of-life of the patient and restrains the patient from any social activities. The prosthesis must be fabricated with patient's esthetic and functional demands on mind. In certain cases, microvascular surgery can be performed to restore the amputated part; however, economic factor plays a role in deciding the treatment plan. In this case, addition silicone impression material was used due to the superior accuracy of the material. The donor finger was not of the same patient and donor who had similar dimension of recipient finger was selected. This is because, the index finger has a slight distal curvature when extended and hence the right index finger of the patient was not used as the donor finger. Room temperature vulcanizing silicone was the material of choice for the prosthesis as the patient's esthetic demands were high when compared to the functional demand. Wood, leather, polyurethane, and polyvinyl chloride have been used to produce esthetic prosthesis, but silicone rubber has proved to be the most promising in achieving the desired life-like effects.[6] The overall durability and stain resistance of silicone are far superior to any other material currently available for finger restorations. Color matching was done in broad daylight for the dorsal and ventral aspect of the finger. Artificial nail was fabricated using cold-cure acrylic resin and shade matching was done. Once the nail conforms to the nail bed created in the prosthesis, it placed in a position using silicone and pressed until it sets. Over time, various materials have been used and developed further. The acceptance of the prosthesis has been much higher with the use of custom restoration using a silicone elastomer.[5]