18.3 Dental Management of Hematologic and Oncology Patients
Key Takeaways
Hemophilia A is factor VIII deficiency and hemophilia B factor IX deficiency; invasive treatment, including an inferior alveolar nerve block, needs hematologist-planned factor replacement or desmopressin plus tranexamic acid because of the risk of a deep hematoma.
A platelet count of about 50 x 10^9/L or more is generally adequate for simple extractions with local measures, while lower counts need medical consultation and possible platelet transfusion.
Sickle cell crises are triggered by hypoxia, dehydration, infection, cold and stress, so dental care uses short, stress-free appointments, good analgesia and prompt treatment of infection.
Patients with G6PD deficiency should avoid oxidant drugs such as sulfonamides, dapsone and high-dose aspirin, and methylene blue is contraindicated if methemoglobinemia occurs.
Teeth with a poor prognosis in the radiation field should be extracted at least about 2 weeks before head and neck radiotherapy, and irradiated patients need lifelong fluoride and caution with extractions because of osteoradionecrosis.
The blueprint subsection hematologic and oncologic disease expects you to identify and manage these patients in a dental setting, recognize their oral manifestations and manage complications. Several hereditary blood disorders are common in Saudi Arabia, so they appear frequently in vignettes.
Coagulation Tests
| Test | Measures | Prolonged by |
|---|---|---|
| Platelet count | Number of platelets (normal about 150-450 x 10^9/L) | Thrombocytopenia (leukemia, ITP, chemotherapy, hypersplenism) |
| PT / INR | Extrinsic and common pathways (factors VII, X, V, II, fibrinogen) | Warfarin, liver disease, vitamin K deficiency |
| aPTT | Intrinsic and common pathways (factors XII, XI, IX, VIII) | Hemophilia, heparin |
| PFA or bleeding time | Platelet function | Aspirin, von Willebrand disease, uremia |
Inherited Bleeding Disorders
- Hemophilia A (factor VIII) and hemophilia B (factor IX) are X-linked; severity is graded by factor level (severe below 1%, moderate 1-5%, mild above 5%).
- von Willebrand disease is the most common inherited bleeding disorder; type 1 (partial deficiency) is most common.
Dental management (always with the hematologist):
- Excellent prevention to avoid extractions and surgery.
- For invasive care: factor replacement to a planned level, or desmopressin (DDAVP) for mild hemophilia A and type 1 von Willebrand disease, plus tranexamic acid (systemic and as a mouthwash).
- Avoid an inferior alveolar nerve block without factor cover: bleeding into the pterygomandibular space can track into the neck and threaten the airway. Use buccal infiltration (articaine), intraligamentary or intraosseous techniques instead.
- Local measures: atraumatic technique, oxidized cellulose or gelatin sponge, sutures, pressure.
- Analgesia: paracetamol; avoid NSAIDs and aspirin.
Thrombocytopenia and Platelet Disorders
A platelet count of about 50 x 10^9/L or more is generally adequate for simple extractions with good local hemostasis; more extensive surgery may need higher counts, and counts below this level need medical consultation and possibly platelet transfusion. Spontaneous gingival bleeding and petechiae suggest severe thrombocytopenia.
Red Cell Disorders
| Disorder | Dental relevance |
|---|---|
| Iron deficiency anemia | Pallor, atrophic glossitis, angular cheilitis, Plummer-Vinson syndrome |
| Vitamin B12 or folate deficiency | Beefy red smooth tongue, burning mouth, ulceration |
| Sickle cell disease (prevalent in the Eastern and Southwestern regions of Saudi Arabia) | Crises triggered by hypoxia, dehydration, infection, cold, acidosis and stress; pallor and jaundice; delayed eruption; radiographic "step-ladder" trabeculation of the mandible, hair-on-end skull; osteomyelitis risk; possible functional asplenia (infection risk) |
| Thalassemia | Marrow expansion giving "chipmunk" facies, maxillary protrusion and spacing; iron overload from transfusions; splenectomy increases infection risk |
| G6PD deficiency (common in Saudi Arabia) | Hemolysis triggered by oxidant drugs (sulfonamides, dapsone, primaquine, nitrofurantoin, high-dose aspirin) and fava beans; prilocaine and benzocaine can cause methemoglobinemia, and methylene blue is contraindicated |
For sickle cell disease: short morning appointments, good pain control, keep the patient warm and hydrated, treat infections promptly, and use oxygen-rich nitrous oxide sedation only with adequate oxygen and medical advice. Local anesthetic with epinephrine in normal dental doses is generally acceptable.
Leukemia and Neutropenia
- Oral signs of leukemia: gingival enlargement (especially acute myeloid leukemia with monocytic features), spontaneous bleeding, petechiae, ulceration, candidiasis and herpetic infections; these may be the first signs.
- Absolute neutrophil count (ANC): elective invasive care is generally deferred when the ANC is below about 1.0 x 10^9/L, and severe neutropenia (below about 0.5 x 10^9/L) carries a high infection risk; antibiotic cover is decided with the oncologist.
- Coordinate dental treatment between chemotherapy cycles when blood counts recover.
Head and Neck Radiotherapy
Before radiotherapy: full dental assessment; extract teeth with a poor prognosis in the radiation field at least about 2 weeks before radiotherapy (to allow initial healing); treat caries and periodontal disease; fabricate fluoride trays; teach oral hygiene and trismus exercises.
During radiotherapy: oral mucositis, pain, candidiasis, loss of taste and xerostomia; bland rinses (saline and bicarbonate), analgesia, antifungals, nutritional support.
After radiotherapy:
| Complication | Management |
|---|---|
| Xerostomia | Saliva substitutes, sugar-free stimulation, pilocarpine when appropriate |
| Radiation caries (cervical, incisal) | Daily high-fluoride gel in trays, fluoride toothpaste, diet control, frequent recall |
| Trismus | Jaw-stretching exercises and devices |
| Osteoradionecrosis (ORN) | Risk rises with doses above about 60 Gy, the mandible, extractions after radiotherapy and trauma; prevent by avoiding extractions in the field (root canal treatment or decoronation instead), atraumatic surgery when unavoidable, specialist protocols (hyperbaric oxygen or pentoxifylline-tocopherol regimens are used in some centers) |
Chemotherapy
Myelosuppression usually reaches its lowest point (nadir) about 7-14 days after a cycle; mucositis, bleeding and infection risk peak then. Perform necessary dental treatment before chemotherapy starts or when counts recover, maintain gentle oral hygiene with a soft brush, and treat viral and fungal infections early. Antiresorptive drugs used in cancer create MRONJ risk (covered in the medically compromised chapter).
Exam Traps
- An inferior alveolar nerve block in severe hemophilia without factor cover is dangerous.
- NSAIDs are poor analgesic choices in bleeding disorders and thrombocytopenia.
- Extractions after radiotherapy in the field risk osteoradionecrosis; plan extractions before radiotherapy.
A patient with severe hemophilia A needs a pulpectomy on tooth 46. Which local anesthetic approach is safest if factor replacement has not been given?
Use a Gow-Gates block, because high blocks never bleed in hemophilia patients
Give a standard inferior alveolar nerve block, because hemophilia affects only extraction sockets
Use general anesthesia instead, because local anesthetic is contraindicated in hemophilia
Articaine buccal infiltration or intraligamentary anesthesia instead of a nerve block
A patient of Saudi origin with G6PD deficiency needs antibiotics and analgesics after an extraction. Which drug should be avoided?
Paracetamol at normal therapeutic doses
Amoxicillin in standard adult doses
A sulfonamide such as co-trimoxazole
Clindamycin for a penicillin-allergic patient
A patient will start radiotherapy for oral cancer covering the posterior mandible. Tooth 47 has a hopeless periodontal prognosis. When should it be extracted?
Six months after radiotherapy, once mucositis and xerostomia have settled
At least about 2 weeks before radiotherapy starts, to allow initial healing
Never; leave it until it exfoliates because extraction always causes necrosis
During radiotherapy, because healing is faster while the tissues are irradiated
Sections you finish are checked off in the contents.