Rehabilitation of Bell's palsy patient with complete dentures.

Facial nerve disorders may be of sudden onset and more often of unknown etiology. Edema of the facial nerve within the fallopian canal results in Bell's palsy. This causes compression of the nerve and affects the microcirculation. Many authors have suggested treatment for facial nerve paralysis ranging from simple physiotherapy to complicated microvascular decompression. It more often results in symptoms like synkinesis and muscle spasm after the decompression surgery of the nerve because of the inability to arrange the nerve fibers within the canal. The treatment choice also depends on patient's age, extent of the nerve damage, and patient's needs and desires. Many patients who cannot be rehabilitated functionally can be treated for esthetics of the involved muscles. This case report elaborates about a patient who was rehabilitated for esthetics and to some extent for function.

Bell's palsy is defined as idiopathic paralysis of the facial nerve of sudden onset.[1] It is a disorder caused by compression or damage of the 7th cranial nerve (facial nerve) which is characterized by drooping of the eyelids and corner of the mouth. This condition was first described by Sir Charles Bell who noted the difference between sensory and motor nerves.[2] The causes of the facial nerve paralysis can be viral infections herpes simplex virus-1, rheumatic swelling, ischemia, immunological reasons, trauma to the nerve, and due to idiopathic reasons.[1] The palsy occurs due to inflammation of the facial nerve in the narrow fallopian canal. The muscles commonly involved are orbicularis oris, buccinator, orbicularis oculi, occipitofrontalis, corrugator supercili, levator anguli oris, and platysma.[3] The prevalence of the disease is more common in females than in males.[2] The treatment options for the facial nerve paralysis include steroid therapy, surgical intervention, acupuncture, and physiotherapy.

Case Report

A 59-year-old female patient reported to the hospital for replacement of missing teeth. On examination, the patient had lost all her teeth and her one side of the face was paralyzed. The patient gave a history of trauma before some years and gradually lost all her teeth due to periodontal problems. The patient underwent medical treatment for the same in a general hospital. The paralysis was noted both in upper and lower regions of the face and the patient was unable to smile and close her eyes on her left side. The patient was unable to lift her left eyebrow and complained of reduced taste sensation, but was not insisting on the symptoms. The patient had spasms in her facial muscles with synkinesis, which developed gradually [Figures 1 and 2] and was not clear of the time period over which it developed. There was an asymmetry of her face when she tried to smile or close her eyes with a maximal effort. The diagnosis was Bell's palsy Grade IV[4] on the left side of the patient's face which involved the ipsilateral part of the facial nerve. The patient was not willing for the invasive treatment for the same. The patient was given an option of complete dentures with cheek plumpers,[5] which can somewhat improve her facial appearance. The patient readily accepted the treatment plan and primary impressions were made for the upper and lower edentulous arches.

Figure 1

Preoperative view

Figure 2

Left side of the patient affected

The diagnostic casts showed normal arch form without any pathologic conditions. The labial and buccal flanges of the dentures were planned to be enhanced as the circumoral muscles were weak. A simple way of enhancing the labial flanges with wax and later processing with acrylic resin was planned due to time and economic factors. Proper physiologic impressions were made after explaining the treatment plan to the patient with her consent. The occlusal rims were fabricated from the master casts with additional wax on the labial and buccal flanges. The jaw relations were made and try-in verification was done at a later date. Wax was added more on the right side and less on her left side to reproduce the symmetry of her face [Figures 3–5]. After satisfactory results with the patient's consent, the denture was fabricated with high impact acrylic resin. The upper and lower dentures were inserted in a later appointment [Figures 6 and 7]. The patient was taught to use the prosthesis and proper instructions were given to the patient. Oral hygiene was emphasized to avoid food entrapment between the dentures and the cheek. The patient was further referred to an ophthalmologist for corneal protection.

Figure 3

Wax enhancement on the labial and buccal side

Figure 5

Try-in verification extra oral view

Figure 6

Post operative, intra oral view

Figure 7

Post operative extra oral view

Try-in verification, intra oral view

Discussion

Facial nerve innervates the 18 paired muscles and 1 single facial muscle, which causes facial expressions. Damage to the nerve affects the appearance of the patients and their facial esthetics. Buccal branch of the facial nerve supplies the zygomaticus minor, orbicularis oris, buccinator, risorius, nasalis, and levator labii superioris, which play a major role in smiling and chewing. The treatment goals of surgically intervening the nerve are to restore (a) corneal damage, (b) normal resting tone of the face and (c) a symmetrical smile.[6] Recovery from the nerve damage depends on the age of the patient, extent of nerve damage and the precession of surgery. Since the condition is idiopathic more often, and the reason for paralysis of the face cannot be traced, surgery is abandoned by plastic surgeons in many Bell's palsy cases. And the treatment choice does not end here, as the patients can be considered for esthetic rehabilitation by the prosthodontists and by the ophthalmologists for corneal protection and can improve patient's psychological quotient, who are affected by the disfigurement caused by the nerve damage.

Rehabilitation of such compromised conditions involves both technical and artistic skills as the patient is compromised of both function and esthetics. Since there were well-formed ridges Implant prosthesis would have been a better option but due to collapse of the cheek on the affected side the longitivety of implant will be questioned. And implant supported prosthesis may restore function better than the removable complete dentures; the tissue support needed for neurologically disabled persons can be given only by the later.[78] The main disadvantage of undetachable cheek plumpers is food impaction resulting from the weak buccinator and resulting candidiasis. The patient should be reviewed once in a month initially and once in 3 months thereafter. Other methods to enhance the muscle support like surgical correction, detachable cheek support prosthesis, intraoral splints and neutral zone technique are practiced, but a simple method of extended denture bases provided a useful solution in this case. Since the patient had adequate mouth opening and well-formed ridges, an undetached cheek plumper prosthesis was preferred. Though enhancing the flanges with resin may cause overweight of the denture,[9] it was within the patient's tolerable limits.

Summary

The ultimate treatment for any unrecovered facial paralysis will be a surgical intervention of the damaged nerve. When most of the cases are abandoned from surgery due to complications and other reasons, the oral prosthesis plays an important role in patient's well-being. The goal of the prosthetic treatment should be to support the weakened muscles like buccinator, orbicularis oris, and levator anguli oris and provide comfort and esthetics to the patient over a long period of time.