Periosteal fenestration vestibuloplasty procedure for sulcus deepening in a hemimandibulectomy patient following implant therapy.

Ablative surgery of the jaws may be necessary when malignant disease or destructive benign disease occurs. Surgical reconstruction needs to include the restoration of masticatory function so that the quality of life after the operation is optimal. When resection includes part of the upper or lower jaw, the aim of reconstruction should encompass not only the restoration of aesthetics, speech and swallowing, but also the recreation of an alveolar ridge suitable for prosthetic rehabilitation of the dental occlusion. In the present case, depth of vestibule was inadequate following implant placement thereby severely compromising prosthetic rehabilitation. Hence vestibuloplasty was done with periosteal fenestration operation, which provided retention and stability of mandibular prosthesis and hence greatly improved his overall quality of life.

INTRODUCTION

Neoplasms, which are associated directly or indirectly with the mandible usually require surgical removal of the lesion and extensive resection of the bone.[12] Smaller lesions, which are removed without discontinuity of the bone are relatively simple to restore with a prosthesis. Larger lesions that extend into the floor of the mouth may be more difficult to restore with prosthesis, even though the continuity of the mandible is maintained.[3] Success of the edentulous mandibular resection prosthesis is related directly to the amount of the remaining bone and soft tissue.[4567] Segmental mandibulectomy results in special physiological and aesthetic problems.[8] Frequently, the edentulous mandible requires reconstructive plastic surgery to create a buccal or lingual sulcus depth to provide a favorable attached tissue foundation for an acceptable mandibular denture.[910] We present a case of hemimandibulectomy which was treated at our institute successfully with implant supported dentures.

CASE REPORT

The present case report is about a 73-year-old man who was referred to I.T.S College of Dental Studies and Research Murad Nagar with the chief complaint of difficulty in eating and speaking. He gave a history of a tobacco smoking habit since 50 years. He was diagnosed with squamous cell carcinoma of the right buccal mucosa about 14 years back. His medical history revealed that he had undergone hemimandibulectomy of the right side with modified radical neck dissection 14 years back [Figure 1]. Intraoral examination revealed thick, freely movable soft-tissue with scar formation, the loss of the alveolar ridge and the obliteration of the buccal and the lingual sulcus in the entire right half of the mandibular region. The patient was completely edentulous present on the left half of the mandible. The scarring of the tissue after surgery caused severe deviation of the mandible to the resected side. The patient complained of inability to eat and wanted restoration of the missing teeth. Rehabilitation was planned with fabrication of an implant supported denture to aid in retention and stability of the denture on the resected mandible.

Figure 1

Pre-operative patient profile

Total three implants were placed, in which two were anterior to the mental foramen and one was posterior. Amongst the two anterior implants, the 1st was placed 5 mm from the resected site on the right side and the 2nd was placed 5 mm from the mental foramen toward the midline on the left side. The 3rd posterior implant was placed near 2nd premolar. At the time of prosthetic rehabilitation, it was noted that the patient required a mandibular labial vestibuloplasty procedure as his labial sulcular depth was not adequate [Figure 2]. A mucosal incision was made 3-5 mm away from the mucobuccal fold [Figure 3]. A lip-cheek mucosal flap and a mucosal alveolar flap were raised and muscles and fibrous tissues were dissected to the required depth [Figure 4]. The lip-cheek mucosal flap and the muscles were then sutured and reattached to the periosteum at the inferior border. The alveolar mucosa was fenestrated by 4-5 oblique full-thickness incisions, stretched to cover most of the labial raw periosteum and fixed to it. Finally, a pre-operatively prepared stent [Figure 5] with overextended flanges was lined with soft-liner and secured in place [Figure 6]. Adequate sulcus depth was obtained post-operatively and the patient was referred to the Department of Prosthodontics for rehabilitation and was provided with interim denture [Figure 7].

Figure 2

Inadequate sulcus depth in the mandibular anterior region

Figure 3

Incision placed

Figure 4

Tissues exposed to adequate depth with periosteum exposed

Figure 5

Stent for maintaining the vestibular depth modified with greenstick compound

Figure 6

Stent placed at its site

Figure 7

Post-operative patient profile (1 month)

DISCUSSION

Malignant tumors of the oral cavity can cause more destruction to innumerable adjacent tissues when compared to any other parts of the body. The surgical management for neoplastic lesions of the oral cavity often requires resection involving several anatomical structures such as mandible, floor of the mouth, tongue and palate etc., In hemimandibulectomy cases mandibular deviation occurs due to loss of continuity of mandible, the related altered muscle function will clinically result in facial asymmetry causing significant esthetic deformities, functional compromise and psychological sequel.[11] The residual mandible deviates medially and inferiorly, the amount of deviation will be more or less evident depending on the location and extent of the resection, the remaining amount of soft-tissue, nerve innervation and the presence of remaining natural teeth.[1213]

When mandibular continuity is lost in segmental mandibulectomy, masticatory function is compromised because of muscular imbalance that results from unilateral muscles removed, loss of grinding table due to teeth lost, altered maxilomandibular relation and decreased teeth to teeth contact which results in a significant decrease in occlusal force. The rehabilitation objective in mandibulectomy cases is to re-educate mandibular muscles to re-establish an acceptable occlusal relationship for residual hemimandible and hence that the patient can control the opening and closing mandibular movements and minimize the scar formation, because the scar will make deviation more severe and less favorable for the prosthetic intervention.[14]

In hemimandibulectomy procedure, half of the mandible and teeth are excised together with the surrounding soft-tissues. The extent of resection varies with the size of the lesion and access for surgery may be intraoral or transcutaneous, which requires lip splitting and mandibular swing. The procedure results in a large degree of soft-tissue loss intraorally. When the excised segment is located posteriorly, closure of the defect is achieved either primarily or by pedicled or free soft-tissue transfer and microvascular anastomosis, depending on the requirements of each individual case. Primary osseous augmentation is not normally undertaken. The patient may be given a conventional or implant-borne dental prosthesis, but in most cases this requires a vestibuloplasty procedure[15] to deepen the buccal and lingual sulci and to enable the fabrication of an adequately functional prosthesis. Anterior edentulous areas usually display unusual soft-tissue configurations and compromised bone support in patients with marginal mandibulectomy. Vestibuloplasty is a surgical modification of the gingiva-mucous membrane relationships including deepening of the vestibular trough, altering the position of the frenulum or muscle attachments and widening of the zone of attached gingiva. Pre-operative evaluation of the maxillofacial patient reveals that this procedure is required in most of the cases for optimal preparation of the patient and planning of the treatment. This surgical procedure to restore alveolar ridge height by lowering muscles attaching to the buccal, labial and lingual aspects of the jaws can greatly enhance the patients’ post-surgical adjustment to the prosthesis.

Prior to the fabrication of a dental prosthesis many patients need pre-prosthetic surgical procedures including vestibuloplasty. The goal of these procedures is to increase the vestibular depth. This increased depth aids in denture retention by limiting traction produced by muscular and fibrous attachments. A variety of surgical techniques have been used for vestibuloplasty including submucosal vestibuloplasty, secondary epithelization vestibuloplasty, Edlan-Mejchar vestibuloplasty and soft-tissue grafting vestibuloplasty. Various types of grafts such as split-thickness skin grafts, buccal mucosal grafts and palatal grafts can be used for these procedures.[16]

In marginal mandibulectomy patients with anterior defected areas, the edentulous segment usually displays unusual soft-tissue configurations and compromised bone support. In large defects, the lack of attached mucosa and the obliteration of vestibules may require a vestibuloplasty and skin graft.[17] Unless a vestibuloplasty is performed and denture bearing surfaces are created, bands of scar tissue are easily irritated by the prosthesis.

CONCLUSION

Dental rehabilitation of the hemimandibulectomy patient remains a challenge until date. Immediate or delayed prosthetic treatment depends not only on the timing of healing of the defect site, but also on the knowledge that the tumor has been completely eradicated. The philosophical approach to the treatment and rehabilitation of edentulous patients with resected mandible is not in what has been sacrificed in the eradication of the disease, but rather in taking the full advantage of the remaining structure. In our case report, we have attempted to do the same, whereas keeping in mind the needs of the patient and have achieved a satisfactory result.