10.1 Introduction

The most common modalities used to treat head and neck cancer are comprised of surgery, radiation therapy, and chemotherapy. These aggressive cancer treatments not only act upon tumor cells, but also produce noxious effects to normal cells, including the oral mucosa and salivary glands. The short- and long-term effects of this toxicity on the oral cavity and dentition have been well documented. ^{1 , 2} Early evaluation and treatment by a trained dental team can diminish or prevent some of these oral complications, such as mucositis, oral infection, and osteoradionecrosis (ORN). It is therefore important that patients undergo a thorough dental evaluation prior to the initiation of head and neck cancer treatment.

10.2 Nonodontogenic Considerations

As the treatment of the cancer patient is multifaceted, communication between different providers to organize and coordinate care is critical in order to improve outcomes. A focus on the concept of a multidisciplinary team has therefore become increasingly prominent over the years. For head and neck cancer patients, this team often consists of head and neck cancer surgeons, reconstructive/plastic surgeons, radiation oncologists, medical oncologists, pathologists, speech and language therapists, dietitians, social workers, and dentists. Accordingly, it is important for the dental professional to take a multidisciplinary approach and communicate with other providers as there are numerous nonodontogenic factors to consider when constructing an initial dental treatment plan for head and neck cancer patients.

10.3 Diagnosis/Patient Prognosis

The patient’s medical history, diagnosis, prognosis, and treatment plan should be obtained from the multidisciplinary team. If the patient prognosis is extremely poor or medical status extremely compromised, dental treatment may sometimes be deferred and the team may opt to address future dental sequelae as they arise.

10.4 Radiation Therapy Factors

A significant challenge to the dentist is the determination of what preexisting oral conditions or teeth require treatment in order to limit the risk of ORN following radiation therapy. ORN of the jaw is one of the most severe chronic side effects of radiation treatment to the head and neck region. First described by Regaud in Paris in 1922, ORN is defined as nonhealing exposed bone in a previously irradiated area present for over 3 months. ³ Other features include pain, halitosis, dysgeusia, food impaction in the area of exposed sequestra, pain, fractures, and fistulas. ⁴ It can occur in both dentate and edentulous patients, either spontaneously or following trauma, with most cases of ORN occurring after tooth extractions. ⁵

As proper dental management is of utmost importance for the prevention of ORN, the dentist should receive from the radiation oncologist the general radiation plan prior to the initiation of treatment. Type of radiation, total cumulative dose, and intended field of direct radiotherapy should be considered when determining a dental treatment plan. All parts of the jaws are not necessarily included in the field of radiation and if the radiation dose to the area of the mandible or maxilla is less than 50 to 60 Gy, the risk of osteonecrosis has usually been considered lower (see Chapter 41 Radiotherapy Related Side Effects in the Treatment of Oral Cavity Malignancies). ⁶

Conventional (two- and three-dimensional conformal radiotherapy) techniques can result in significant side effects and decreased quality of life. Over the last few decades, improvements have been made in radiotherapy for the treatment of cancer including intensity-modulated radiotherapy (IMRT), which manipulates photon and proton beams of radiation to conform to the shape of a tumor and reduce doses to normal tissues. Other advancements like volumetric intensity-modulated?arc therapy and image-guided radiotherapy have also helped improve IMRT further. ⁷ There has been a reduction in the rates of ORN with these newer advances, which may be attributed to more conformal dose distributions that spare parts of the mandible that would have received a high dose with more conventional techniques. Salivary gland sparing with these advancements may also decrease the risk for development of dental caries. ⁸

Finally, the scheduled time of commencement of radiotherapy and amount of time available for the dental assessment are important to take into consideration as this may influence prioritizing certain treatments if there are time constraints. In some cases, due to severity of the tumor and disease, dental treatment may be deferred so that radiation can proceed without delay. In such cases, the initial dental evaluation should be scheduled soon after cancer diagnosis in order to allow for sufficient time to complete any necessary dental treatment.

10.5 Patient-Related Factors

10.6 Oral Assessment before Treatment

Following a standard history, including medical diagnoses, a social and dental history, and current and recent complaints, a thorough oral and dental examination should be conducted. The purpose of the dental examination is to determine definitive diagnoses and prognoses for individual teeth in order to identify those that require aggressive or invasive dental treatment prior to chemotherapy and/or radiation treatment. Infection control should be instituted prior to cancer treatment in order to improve patient outcomes, as a healthy oral cavity has been shown to improve general comfort and result in fewer interruptions during treatment. ²

10.7 Radiographs

In addition to a clinical examination, a through dental evaluation should incorporate radiographic images. Select dental radiographs are a valuable diagnostic tool to aid in the assessment of areas for potential infection that may not be visually obvious. A panoramic radiograph and/or a full series of dental radiographs should be taken for dentate patients to assess for any bony pathology, screen for caries (tooth decay), and aid in the detection of periodontal disease (▶ Fig. 10.1). A panoramic radiograph should also be taken for edentulous patients in order to screen for any bony pathology, submucosal or intrabony root fragments, and impacted teeth.