**1. Introduction**

Following ablation of a tumor that is the primary lesion or metastatic tissue, facial reconstruc‐ tion is needed to restore and replace both hard and soft tissue losses. Ideally, reconstruction should strive to restore the maxillofacial form, quality of tissues, oral competence, and oral cavity functions, allowing the patient to return and adapt to society. Each area to be recon‐ structed must be considered individually to define the characteristics needed to provide the structural bed for total functional return. To focus on the reconstructive approaches and goals, an anatomic list should be compiled that includes:


In general, goals of the reconstructive surgeon revolve around the restoration of functions, including normal deglutition with tongue and pharyngeal components; adequate oral competence; adequate mandibular mobility for functional mastication, with complete dental rehabilitation; airway support and patency after a tracheotomy to allow decannulation; fluent speech function paralleling deglutition; protective sensory function, especially sensations of the tongue, corneal blink reflexes, and trigeminal facial sensory nerves; and overall movement of the head and neck region, including shoulder lift and the muscles of the face [2]. As with all aspects of life, form usually follows function. Special attention must be paid to the preoperative facial aesthetic units that can be redefined, such as the mandibular symphysis, angle of the jaw, malar regions, nose, and teeth. The end result is a patient who is able to return to a normal lifestyle, engaging in routine activities of family life, work, and society. Reconstructive

principles have been formulated to increase the predictability of successful surgery. They include the use of a team approach to decrease operative time by synchronous resection and flap preparation; avoidance of multiple flaps and vein grafts whenever possible; minimizing of flap ischemia by shaping the flap while still vascularized; and slight overcorrection of the soft tissue deficiency with well-vascularized soft tissues [3]. The ideal technique must be fast, reliable, and cost efficient, imposing minimal morbidity on the patient [4]. Considerable debate involving immediate versus delayed reconstruction continues. The reconstructive process may involve multiple staged surgical procedures, for which the patient will require extensive preoperative counseling.

**Advocates of delayed treatment** wait months to years after the original surgical resection [5]. Factors that disfavor an immediate approach include the covering of the primary site and therefore the inability to detect a recurrence, a longer surgical time, the possibility of seeding cancer cells in newly dissected tissue planes, and an increased risk of graft infection from the contaminated salivary environment [6]. In contrast, Markowitz and colleagues [7] were not able to demonstrate any advantage for delayed reconstruction. In fact, secondary surgery, or two-stage reconstruction, is associated with higher overall complication rate, longer hospital stay, and greater cost [8]. Heller and associates [9] studied the long-term benefits in 47 patients who underwent immediate reconstruction of the mandible and found acceptable functional and long-term survival results. Leaving the patient unreconstructed was advocated by those who felt that an adequate follow-up period to detect recurrence was required before complete reconstruction. Since the advent of extensive noninvasive imaging systems such as computed tomography (CT), magnetic resonance imaging (MRI), and single photon emission CT (SPECT) technology, physicians are better able to identify an early recurrence. Over the past decade, one-stage reconstructive efforts using musculocutaneous flaps and microvascular free tissue transfers have significantly improved the quality of life of such patients. When such a recon‐ struction is performed during the primary surgery, it allows postoperative radiation treatment to be administered in a timely fashion. Delaying postoperative radiation can result in increased morbidity and increase the risk of recurrence [10]. Furthermore, delayed reconstruction is preceded by considerable fibrosis and soft tissue contraction, increasing the difficulty of subsequent reconstruction and compromising functional and cosmetic restoration.

**The advantages of immediate or early reconstruction** in summary are as follows: reduction in the total number of surgical procedures, less time that the patient must endure deformity and morbidity, protection and preservation of vital structures, reduced economic cost of treatment, and rapid oral rehabilitation and return to normal social lifestyle [4]. The surgical result after cancer resection of the oral cavity and oropharynx is a significant functional and cosmetic defect. For example, a partial glossectomy leaves a patient with varying degrees of articulation and swallowing difficulties, depending on the amount of tongue tissue removed. Bony resection of the involved mandible produces masticatory problems, as well as alteration of facial contour.

A multidisciplinary team is often involved in the assessment and treatment of cancer patients. This team consists of head and neck surgeons, plastic surgeons, oral and maxillofacial surgeons, maxillofacial prosthodontists, radiation oncologists, medical oncologists, radiolog‐ ists, pathologists, speech and occupational therapists, internists, and psychologists. Preoper‐ ative evaluation of the patient must include a full assessment of the patient's overall health, ability to tolerate prolonged general anesthesia and blood loss, emotional and intellectual abilities, motivation, and expectations. In addition, the status of the patient's airway and nutritional needs must be addressed. Preoperative physical examinations, endoscopies or panendoscopy, and radiologic evaluation (CT scans, MRI) must outline the tumor size, location, and tissue type (biopsy) and rule out other concomitant lesions. The choice of which reconstructive modality is used depends on the extent of the defect preoperatively. The stage of the disease, the type of node dissection, and the availability of neck vessels are determined by the surgeon. Transverse CT scan and a lateral cephalogram provide the model of the mandible in two dimensions. Enhanced three-dimensional reconstructive CT scans further outline the preoperative mandibular contours and provide a more complete model. Before surgery, it is equally important that the patient be evaluated by a prosthodontist to aid in the achievement of proper bimaxillary arch alignment for postsurgical dental rehabilitation. Angiograms or noninvasive Doppler studies of the recipient and donor vessels are obtained if their adequacy is in doubt, providing information regarding their vascular status. Successful outcome can be ensured when the overall medical condition of the patient, the extent of the disease and prognosis, and the potential donor sites are thoroughly evaluated in the preop‐ erative setting. [11]

principles have been formulated to increase the predictability of successful surgery. They include the use of a team approach to decrease operative time by synchronous resection and flap preparation; avoidance of multiple flaps and vein grafts whenever possible; minimizing of flap ischemia by shaping the flap while still vascularized; and slight overcorrection of the soft tissue deficiency with well-vascularized soft tissues [3]. The ideal technique must be fast, reliable, and cost efficient, imposing minimal morbidity on the patient [4]. Considerable debate involving immediate versus delayed reconstruction continues. The reconstructive process may involve multiple staged surgical procedures, for which the patient will require extensive

**Advocates of delayed treatment** wait months to years after the original surgical resection [5]. Factors that disfavor an immediate approach include the covering of the primary site and therefore the inability to detect a recurrence, a longer surgical time, the possibility of seeding cancer cells in newly dissected tissue planes, and an increased risk of graft infection from the contaminated salivary environment [6]. In contrast, Markowitz and colleagues [7] were not able to demonstrate any advantage for delayed reconstruction. In fact, secondary surgery, or two-stage reconstruction, is associated with higher overall complication rate, longer hospital stay, and greater cost [8]. Heller and associates [9] studied the long-term benefits in 47 patients who underwent immediate reconstruction of the mandible and found acceptable functional and long-term survival results. Leaving the patient unreconstructed was advocated by those who felt that an adequate follow-up period to detect recurrence was required before complete reconstruction. Since the advent of extensive noninvasive imaging systems such as computed tomography (CT), magnetic resonance imaging (MRI), and single photon emission CT (SPECT) technology, physicians are better able to identify an early recurrence. Over the past decade, one-stage reconstructive efforts using musculocutaneous flaps and microvascular free tissue transfers have significantly improved the quality of life of such patients. When such a recon‐ struction is performed during the primary surgery, it allows postoperative radiation treatment to be administered in a timely fashion. Delaying postoperative radiation can result in increased morbidity and increase the risk of recurrence [10]. Furthermore, delayed reconstruction is preceded by considerable fibrosis and soft tissue contraction, increasing the difficulty of

subsequent reconstruction and compromising functional and cosmetic restoration.

**The advantages of immediate or early reconstruction** in summary are as follows: reduction in the total number of surgical procedures, less time that the patient must endure deformity and morbidity, protection and preservation of vital structures, reduced economic cost of treatment, and rapid oral rehabilitation and return to normal social lifestyle [4]. The surgical result after cancer resection of the oral cavity and oropharynx is a significant functional and cosmetic defect. For example, a partial glossectomy leaves a patient with varying degrees of articulation and swallowing difficulties, depending on the amount of tongue tissue removed. Bony resection of the involved mandible produces masticatory problems, as well as alteration

A multidisciplinary team is often involved in the assessment and treatment of cancer patients. This team consists of head and neck surgeons, plastic surgeons, oral and maxillofacial surgeons, maxillofacial prosthodontists, radiation oncologists, medical oncologists, radiolog‐

preoperative counseling.

644 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

of facial contour.

Reconstruction in head and neck cancer patients requires a thorough understanding of function and tissue defects needs to be restored. Anatomically, a classification system for maxillofacial rehabilitation has been described.

**Maxillary defects** encompass minor defects of the hard and soft palate to extensive hard and soft tissue losses from resections of the maxilla, soft palate, sinuses, and adjacent structures (i.e., orbit and cheek).

**Mandibular defects** include alveolar segments with associated soft tissues, as well as portions of the tongue and floor of the mouth.

**Facial defects** include structures of the orbit, nose, ear, and/ or cheek. Defects of the oral cavity and oropharynx of small to moderate size can be successfully closed primarily, as long as tongue mobility and the gingival sulcus are not compromised. The goal of reconstructive surgery is to achieve coverage of the soft tissue defect, providing a definitive separation between the oral cavity and the neck. This can be accomplished by use of either split-thickness or full-thickness skin grafts or local, regional flaps. Functional and aesthetic outcomes become less favorable as the extent of resection increases. Large defects, depending on the location, require vascularized skin, soft tissue, and muscle. The advantages of myocutaneous flaps are abundant blood supply, greater reliability, better effectiveness and predictability. These pedicled osteomyocutaneous flaps facilitate resistance to infection and resorption, which is directly related to the osseous vascular supply. Flap geometry, bone availability, and muscle bulk restrict the degree to which the pedicled flap will adapt to the defect [12]. The use of free microvascular flaps is another option for reconstruction in this region. The free microflaps provide vascularized skin and bone to regions formerly considered impossible to reconstruct owing to limitations of the donor site tissue. The most widely used free microvascular flaps are radial forearm flaps for the floor of the mouth defects involving segments of the mandible. Flap selection is based on the quantity and contour of bone required, as well as the volume of soft tissue necessary to accommodate the patient's needs. Whenever possible, it is best to use adjacent soft tissue. If this is not feasible, then a regional flap (e.g., pectoralis major myocuta‐ neous flap or deltopectoral flap) may be required. Reconstruction of mandibular defects requires the use of myocutaneous and microvascular free flaps, in conjunction with osseoin‐ tegrated dental implants, to provide satisfactory masticatory function. The goal of recon‐ structing a tooth-bearing mandible with adequate strength, with appropriate vestibular sulci, and without excessive soft tissue bulk continues to invite surgeons to develop new treatment options. Once the mandibular segments are properly aligned to restore a normal relationship with the maxilla, oral rehabilitation is easily accomplished by a maxillofacial prosthodontist. One area of oromandibular reconstruction that has challenged reconstructive surgeons is the restoration of preoperative sensory and motor functions. Both pedicled and free tissue flaps are large, insensitive tissue blocks that are used to replace oral tissues, thus compromising swallowing and speech mechanisms. It has been difficult to reproduce the complex neurosen‐ sory and muscular activities of the oral and pharyngeal viscera. There is a need for thin, pliable, sensate tissue to facilitate oral rehabilitation. Radial forearm, dorsalis pedis, lateral thigh, lateral arm, and fibular osteocutaneous flaps all possess thin, pliable tissue and identifiable sensory nerves that may be integrated into the reconstructive plan. [4] Urken and Moscoso [13] reported 80% sensory recovery in 40 cases of mandibular reconstruction with radial forearm flaps. Reconstruction of other bony defects typically requires bone grafting (cortical versus cancellous), bone containing vascularized pedicled or free flaps, and free nonvascularized bone grafts. With the advent of rigid fixation, bone grafting techniques have been enhanced, allowing broader applications. Alloplastic materials such as silicone and hydroxyapatite have been used to "fill in" bony defects and not to replace functional and structural tissue loss. The success of bone grafting is completely dependent on adequate stabilization, immobilization, and healthy soft tissue coverage. Once tissue has been irradiated, its repair capacity is compromised. In bone, hypovascularity, damage to osteoprogenitor cells and hypoxic tissue are responsible.

When a patient has received doses greater than 5000 rads (50 Gy) after ablative tumor surgery, significant reconstructive difficulties are encountered. Grafts placed into irradiated tissue beds have high rates of complications.

**Hyperbaric oxygen (HBO)** has been reported to help poorly perfused tissues by allowing hyperoxygenation [14], providing antimicrobial activity (cidal to anaerobes and static to microaerophilic organisms) [15], increasing fibroblastic proliferative activity [16], improving neovascularization and angiogenesis [17], increasing bone matrix formation [18], increasing mineralization [19], promoting osteoclastic activity to remove necrotic bone[20]; and enhanc‐ ing the transport capacity of erythrocytes by increasing their deformability [21]. Ganstrom [22] suggested a protocol for HBO delivery: The patient is seated in a pressurized closed chamber that is above one atmospheric pressure. The patient breathes 100% oxygen, with oxygen toxicity avoided by regulating time and dose limits. Routinely, a single treatment (dive) varies from 90 to 120 minutes once or twice a day. Another protocol developed by Marx'" is as follows: 20 sessions of HBO at 2.4 atmospheres (ATA) for 90 minutes of oxygen breathing, once daily for 5 or 6 days per week. This is followed by the surgical procedure. Postoperatively, the patient undergoes 10 sessions of HBO, following the same preoperative regimen. The disadvantage of HBO is time consumption without improvement in the quantity of tissue; only the quality is enhanced. Also, HBO is expensive, ranging up to \$50,000 for a treatment sequence. There are some contraindications to receiving hyperbaric oxygen, including optic neuritis, immune deficiency states, and end-stage chronic obstructive pulmonary disease. It is therefore very important to make a thorough assessment of the patient's medical history, pulmonary status, and chest radiograph. Occasionally, pulmonary function testing and ophthalmologic evalua‐ tion are required.
