Side Effects of Cancer Treatment
The prevalence of chemotherapy induced oral mucositis has been shown to range from 30-75% of patients, depending upon treatment type. In about 50% of patients with mucositis, lesions can be severe causing significant pain, interfering with nutrition and often requiring modification of the chemotherapy regimen. In addition, mucositis may predispose a child to fungal infection (most commonly), viral infection such as herpes simplex virus and bacterial infection, which may lead on to life-threatening systemic infection.
This opportunistic yeast infection, usually limited to the skin and mucous membranes and most commonly caused by Candida albicans. Radiotherapy and chemotherapy may predispose a patient to candidiasis by altering their immune status. In addition, changes to the oral mucosal environment such as mucositis, xerostomia and poor oral hygiene may increase a patient’s risk of developing oral candidiasis.
Herpes simplex virus (HSV)
HSV is viral infection can cause pain and blistering on or around the lips and within the mouth. Orofacial lesions are most commonly caused by HSV type 1, although not exclusively. It is estimated that around 80% of the population are asymptomatic carriers of the virus. It is thought that approximately 50 – 90 % of bone marrow transplantation patients who are seropositive for HSV will develop HSV infections, usually within the first five weeks after transplantation. A large proportion of patients with acute leukaemia or those receiving high dose chemotherapy will reactivate HSV during periods of immunosuppression.
Salivary gland dysfunction
Cytotoxic drugs can alter both the flow and composition of the saliva, causing xerostomia (a sensation of dryness in the mouth). Radiotherapy treatment to the head and neck region can cause damage to the salivary glands. Such radiotherapy damage develops soon after the initiation of treatment, progresses during treatment (and for some time after treatment), and is essentially permanent. Both salivary gland damage and xerostomia impact a patient’s quality of life, causing oral discomfort, taste disturbances, difficulty chewing and swallowing and speech problems. In addition, patients suffering from xerostomia/salivary gland damage are at greater risk of oral infections, including oral candidiasis. Long-term consequences of salivary gland damage include dental caries.
Recommendations for the Treatment of Children with Cancer:
A- Recommendation for Oral Care at the time of cancer diagnosis:
All children should undergo a dental assessment at the time of cancer diagnosis and, if possible, before cancer treatment commences.
The possible long-term dental/orofacial effects of childhood cancer and treatment should be discussed with parent
All invasive dental treatments should be undertaken by either a consultant or specialist pediatric dentist.
Initial evaluation medical history review should include, but not be limited to:
– disease/condition, treatment protocol.
– complete blood count (CBC)], coagulation status, immuno- suppression status, presence of an indwelling venous access line, and contact of oncology team/primary care physician(s).
– For HCT patients, include type of transplant, HCT source, matching status, donor, conditioning protocol, date of transplant, and presence of GVHD or signs of transplant rejection.
– The American Heart Association (AHA) recommends that antibiotic prophylaxis for nonvalvular devices, including indwelling vascular catheters (i.e., central lines) is indicated only at the time of placement of these devices to prevent surgical site infections. The (AHA) found no convincing evidence that microorganisms associated with dental procedures cause infection of nonvalvular devices at any time after implantation. Antibiotic prophylaxis is not necessary for patients with an indwelling central venous catheter who are undergoing dental procedures.35,36 Immunosuppression is not an independent risk factor for nonvalvular device infections. Immunocompromised hosts who have those devices should receive antibiotic prophylaxis as advocated for immunocompetent hosts. 35,37 Consultation with the child’s physician is recommended for management of patients with nonvalvular devices.
Dental history review
Preventive strategies and oral hygiene instraction includes brushing of the teeth and tongue two to three times daily with regular soft nylon brush or electric toothbrush, regardless of the hematological status.38 Ultrasonic brushes and dental floss should be allowed only if the patient is properly trained.39 Patients with poor oral hygiene and/or periodontal disease may use chlorhexidine rinses daily until the tissue health improves or mucositis develops. 40
Dental practitioners should encourage a non-cariogenic diet.
Preventive measures include the use of fluoridated toothpaste or gel, fluoride supplements if indicated.
Patients who receive radiation therapy to the masticatory muscles may develop trismus. Thus, daily oral stretching exercises/physical therapy should start before radiation is initiated and continue throughout treatment.
B. Rcommendation for dental / oral care during cancer treatment.
- A dental assessment every three to four months by a pediatric dental specialist or consultant.
- oncology/hematology protocols are divided into phases (cycles) of chemotherapy. The patient’s blood counts normally start falling five to seven days after the beginning of each cycle, staying low for approximately 14 to 21 days, before rising again to normal levels for a few days until the next cycle begins. Ideally, all dental care should be completed before cancer therapy is initiated. When that is not feasible, temporary restorations may be placed and non-acute dental treatment may be delayed until the patient’s hematological status is stable.38
- During immunosuppression, elective dental care should not be provided. If a dental emergency arises, the treatment plan should be discussed with the patient’s physician
- When all dental needs cannot be treated before cancer therapy is initiated, priorities should be infections, extractions, periodontal care (eg, scaling, prophylaxis), and sources of tissue irritation before the treatment of carious teeth, root canal therapy for permanent teeth, and replacement of faulty restorations. 40 Incipient to small carious lesions may be treated with fluoride and/or sealants until definitive care can be accomplished.
- Pulp therapy in primary teeth: Although there have been no studies to date to address the safety of performing pulp therapy in primary teeth prior to the initiation of chemotherapy and/or radiotherapy, many clinicians choose to provide a more definitive treatment in the form of extraction as pulpal/periapical/furcal infections during immunosuppression periods can become life- threatening.
- Teeth that already have been treated pulpally and are clinically and radiographically sound should be monitored periodically for signs of internal resorption or failure.
- Symptomatic non-vital permanent teeth should receive root canal treatment at least one week before the initiation of cancer treatment to allow sufficient time to assess the treatment success before the chemotherapy. 38,40 If that is not possible, extraction is indicated.
- Asymptomatic non-vital permanent teeth may be delayed until the hematological status of the patient is stable. 40
- If a periapical lesion is associated with an endodontically treated tooth and no signs or symptoms of infection are present, there is no need for retreatment or extraction since the radiolucency is more likely due to an apical scar.
- Orthodontic appliances and space maintainers should be removed if the patient has poor oral hygiene and/or the treatment protocol or HCT conditioning regimen carries a risk for the development of moderate to severe mucositis. Simple appliances (eg, band and loops, fixed lower lingual arches) that are not irritating to the soft tissues may be left in place in patients who present good oral hygiene.39 Removable appliances and retainers that fit well may be worn as long as tolerated by the patient who maintains good oral care. Patients should be instructed to clean their appliances on a daily basis, routine cleaning of appliance cases with an antimicrobial solution to prevent contamination and reduce the risk of appliance associated oral infections is also recommended.38 If band removal is not possible, vinyl mouth guards or orthodontic wax should be used to decrease tissue trauma.
- Partially erupted molars can become a source of infection because of pericoronitis therefore, overlying gingival tissue should be excised .
- Surgical procedures must be as atraumatic as possible, with no sharp bony edges remaining and satisfactory closure of the wounds. When the infection is associated with the tooth, antibiotics should be administered for about one week, 38,39 to minimize the risk of development of osteonecrosis. osteoradionecrosis, or bisphosphonate-related osteonecrosis of the jaw (BRONJ).
- Loose primary teeth should be allowed to exfoliate naturally. Nonrestorable teeth, root tips, teeth with periodontal pockets greater than six millimeters, symptomatic impacted teeth, and teeth exhibiting acute infections, significant bone loss, involvement of the furcation, or mobility should be removed ideally two weeks (or at least seven to 10 days) before initiation of cancer therapy to allow adequate healing. Some practitioners prefer to extract all third molars that are not fully erupted, particularly prior to HCT, others favor a more conservative approach, recommending extraction of third molars at risk for pulpal infection or those associated with significant infection, periodontal disease, or pericoronitis or when the tooth is malpositioned or non-functional.
- Dentist should discuss the comprehensive oral care plan with the oncology team in detale.