Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_701_Библиотеки_им_академика_М_И_Перельмана

– Swellings arising from the bone proper (bony

– Fibro-sarcomatous form: This results from

malignant transformation.

Myelomatous epulides arise from the osteoblas­tic layer of the periosteum or from the alveolus itself. A myelomatous epulis contains osteoclasts and is considered an osteoclastoma of the alveo­lar margin. It is divided by septa into lobules and contains osteoclasts, giant cells, spindle cells, and broblasts. It usually affects patients aged between 30 and 40years but can occur at any age.

A carcinomatous epulis is now considered an “alveolar carcinoma” arising from the mucous membrane covering the gum (squamous epi­thelium). It is a rapidly growing mass with necrosis and ulceration. Characteristically, it does not metastasize but gradually eats up the underlying bone. The patient usually presents with a painful, infected, fungating, or ulcerat­ing mass that may invade the bone and spread to the cervical lymph nodes (LNs). A biopsy is a must for diagnosis. Treatment usually involves a combination of surgery and radio­therapy (RT) according to full assessment and staging.

Both dental and dentigerous cysts show a slowly growing, painless swelling, hard in consistency (covered by the bone), expanding the bone inter­nally and externally, and resulting in an “eggshell crackling sensation.” Table 4.1 summarizes the differences between both cysts.

lium. It is reported to constitute about 1–3% of tumors and cysts of the jaws and is known to be the most common tumor of the lower jaw in Egypt. Ameloblastoma affects the mandible more than the maxilla (5:1), particularly the angle of the mandible, but it can grow forward toward the body of the mandible and/or upward toward the ascending ramus.

results in asignicantly higher rate of recur­rence [4].

Bony swellings affecting the jaw are mainly clas­sied into inammatory and neoplastic swell­ings; the latter may be benign or malignant, whether primary or metastatic, as shown in Table4.2.

This may occur in the form of a giant cell granu­loma, which represents failure to repair a hema­toma of the jaw. It affects females more than males, usually below the age of 20years. A plain X-ray (occlusal view) will demonstrate an expansile radiolucency in the anterior portion of the mandible, producing an even, regular swell­ing of the buccal cortical plate (arrows) and intru­sion of a canine tooth (C) (Fig.4.5).

and/or abscess may be present. Delayed seques­trum formation and delayed healing may occur due to inadequate rest (continuous motility of the jaw) and recurrent infection of the mouth.

uctuate. The mass is clearly xed to the under­lying bone. Upper cervical lymph nodes (LNs) are enlarged and tender.

The pathological types include squamous cell carcinoma (SCC), adenocarcinoma, minor sali­vary gland tumor, and undifferentiated carci­noma. It spreads locally in all directions, by lymphatics to the upper deep cervical, retropha-

ryngeal, or submandibular LNs and hematologi­cally to the lungs, bone, and brain.

The disease has a predilection for males within an age range of 38–89 years [5]. Diagnosis is usually made at a late stage where most of the patients have been long treated for sinusitis or blocked nose. The denitive presentation depends on the site and direction of growth of the tumor, as shown in Table4.3.

Burkitt’s lymphoma of the head and neck region usually involves the cervical LNs. Primary involve­ment of the nasal cavity and paranasal sinuses is uncommon. In paranasal Burkitt’s lymphoma, the maxillary sinus is most commonly involved fol­lowed by the sphenoethmoidal sinuses [6].

These articial devices are designed and implanted to t into a mandibular defect. The relative ease of procedure and the potential for aesthetic reconstruction without donor site mor­bidity have led many to the search for suitable alloplastic materials. Although these implants offer some restoration of continuity and bulk in the short term, the long-term results, and thus the overall success, have been disappointing. Currently, these devices are not favored and should be avoided, especially when applied in previously irradiated areas of the head and the neck [9].

This reconstructive option does not provide actual structural restoration of the bony mandi­ble. A soft tissue pedicled ap, commonly the pedicled pectoralis major myocutaneous ap, was widely used to cover titanium plates to pre­vent extrusion. Although this reconstructive option was essentially designed to provide a soft tissue pad for the reconstruction plates, the most common complication was still plate exposure [12]. Moreover, failure to deliver autogenous bone to reconstruct the mandible will eventually lead to reconstruction plate fatigue as the contra­lateral molar loading exerts a torsional force, which is more likely to cause plate fracture [13]. As dental rehabilitation would not be possible, this option represents an alternative for patients who have lateral mandibular continuity defects with a poor prognosis, in whom dental rehabilita­tion is neither desired nor planned.

The use of free tissue transfer and microvascular reanastomosis for reconstruction has been a rela­tively recent practice. Prior to the past three decades, the majority of head and neck defects were closed with either local tissue or random skin aps. Free aps have revolutionized recon­struction. Even when these aps are transferred from distant sites into areas of irradiation, com­promised blood ow and even salivary contami­nation, healing and support of functional loads are the usual results [14]. Together with their ability to stand the osseointegrated implants for later dental rehabilitation, free bone aps have

The eld of regenerative medicine promises new alternatives to surgical reconstruction through harnessing the regenerative capacity of the human body to repair itself. In the last few decades, the rapid expansion of knowledge about the biologi­cal basis of wound healing and the role of cells, signals, and biological scaffolds led to a paradigm shift from “tissue reconstruction” to “tissue regen­eration.” New strategies started to emerge aimed at mimicking the normal healing process in regen­erating lost or damaged tissues. The term “tissue engineering” was ofcially coined at a National Science Foundation workshop in 1988 to mean “the application of principles and methods of engineering and life sciences toward fundamental understanding of structure- function relationships in normal and pathological mammalian tissues and the development of biological substitutes to restore, maintain or improve tissue function” [24].