What are some dental considerations in managing pediatric patients with leukemia?

Commentary by Dr. Mike Casas, Sickkids Hospital, University of Toronto

For children with leukemia, the oral cavity can be a source of bleeding and infection as a consequence of leukemia or the chemotherapy prescribed to treat it. Good oral health can mitigate the risks of leukemia and chemotherapy as well as improve oral comfort during therapy.

Kholoud et al. recommend treating all teeth likely to produce complications 10-14 days prior to chemotherapy. Oncology teams are unlikely to wait to start chemotherapy until after the mouth is optimized. Improved outcomes for leukemia have been demonstrated for patients receiving expedited chemotherapy. It is more likely that oral care would be coordinated to occur between cycles of chemotherapy so that the dentist can provide comprehensive and definitive care at a time while minimizing risk to the child. Dental interventions are commonly timed to coincide with the completion or initiation of a chemotherapy cycle when the child’s platelet and white blood cell counts are most favourable to reduce the risk of sepsis and uncontrolled bleeding.

Oral mucositis is the most significant source of oral morbidity during leukemia therapy and is exacerbated by poor oral hygiene. Due to the neutropenia and thrombocytopenia experienced by some children during chemotherapy, regular brushing and flossing may not be consistently achievable.  The alcohol in chlorhexidine rinse may worsen the pain of mucositis. Hygiene may be managed instead with sodium bicarbonate based mouth rinses. Mouth rinses containing topical anaesthetics can reduce pain. Cryotherapy (ice chips) may reduce the incidence of mucositis as well as provide some pain relief.  There is some weak evidence for the efficacy of Palifermin (recombinant keratinocyte growth factor) and low level laser therapy for reduction of mucositis in adults, but as yet, efficacy has not been demonstrated in children.

The general considerations put forward by Kholoud et al. for providing care to children with leukemia are sound: healthy mouths reduce the risks of leukemia. Contemporary practice, however, may diverge from some of the specific recommendations provided in the paper.

Leukemia is a malignant disease affecting the bone marrow that causes the production of large numbers of immature blood cells. The classification of leukemia is based upon the duration (acute or chronic) and cell type that it affects (lymphocyte, monocyte or myelocyte). While the etiology of the disease is unknown, factors such as genetic mutation , inherited susceptibility, smoking and alcohol consumption by the parents, chemicals, infections as well as exposure to radiation and non-ionizing electro-magnetic and electric fields may play a role in developing leukemia.

A diagnosis is usually made after careful physical examination, complete blood cell count and bone marrow biopsy. If confirmed, treatment is usually in the form of chemotherapy, radiation and bone marrow transplant.

Oral Findings

Patients with leukemia often present with generalized gingival bleeding and hyperplasia. They are more susceptible to opportunistic infections and may present with bone alterations. One of the most consistent findings is gingival swelling due to leukemic infiltration.

Cancer treatments also lead to further complications such as oral mucositis that typically follows chemotherapy and radiation. The developing dentition as well as orofacial growth can also be affected. During the induction phase of treatment, it has been noted that the oral health status, of the child can deteriorate as a result of the change in quality and quantity of the saliva produced. Other studies have shown that patients treated for Acute Lymphoblastic Leukemia (ALL) have greater incidences of agenesis, microdontia, tapering roots as well as short roots.

For children treated with bone marrow transplantation, complications such as graft-versus-host-disease, other oral manifestations may include: erythema, xerostomia, mucosal ulcerations, erosion and lichenoid changes. Other rare issues have been noted in the literature also such as leukemic infiltration in the mandible, trismus, oral aspergillosis and mucormycosis.

Dental Management

Prior to cancer treatment:

A thorough dental examination must be performed.

• Any teeth with a questionable prognosis should be extracted 10-14 days prior to chemotherapy.
• Scaling and other preventive measures including fluoride or pit and fissure applications should be completed.
• Teeth with caries should be temporized and final restorations should be placed once the patient is in remission.
• Patients and parents should be instructed and educated in proper oral hygiene care (brushing, flossing, gentle gum massage).

Care during treatment:

As mentioned above, complications such as mucositis, xerostomia and infections may develop.

• In situations where the child complains that brushing his/her teeth is painful, a chlorhexidine (CHX) rinse can help to prevent oral mucositis
  • .12% CHX rinse for 1 minute, twice a day
• Fungal infections can be treated with nystatin
  • Nystatin suspension 100,000 units 4 times daily

(Nystatin and chlorhexidine should not be used together as they inhibit the action of the other – there should be a sufficient time gap between the two medications.)

• Cold sores caused by the herpes simplex virus are also commonplace and can be treated topically with Acyclovir.
• Xerostomia can be treated with the use of saliva substitutes and sugar-free chewing gum.

Post-cancer treatment care:

Once in remission, children can be treated like any other healthy patient unless invasive treatment is required. In this latter situation, bloodwork may be considered.

• Patients should continue brushing with fluoridated toothpaste rather than the CHX rinse.
• For any patients with dental anomalies, enamel hypoplasia, disturbances in tooth development or maturity, other treatments including esthetic restorations, orthodontic appliances or endodontic treatments may be necessary.

Some studies have shown that children treated for leukemia may be at a higher risk for developing mucoepidermoid carcinoma and squamous cell carcinoma secondary to an allogenic bone marrow transplant. As such, dental professionals may play a role in the long-term observation of these patients. 

Reference

Kholoud A, Alaizari AA, Tarakji B, Petro W, Hussain KA, Altamimi MAA. Dental Considerations for Leukemic Pediatric Patients: An Updated Review for General Dental Practitioner. Mater Sociomed. 2015 Oct; 27(5): 359-362.