Sickle Cell Anemia

What is Sickle Cell Anemia?

• A hereditary blood disorder characterized by the production of abnormal hemoglobin (HbS) in red blood cells
• Abnormal hemoglobin causes red blood cells to become rigid, sticky, and sickle-shaped
• Hemoglobin S is a structural variant of normal adult hemoglobin (HbA) caused by a missense variant in the β-globin gene (HBB)

Inheritance and Pathogenesis

• Inherited in an autosomal recessive pattern, meaning an individual must inherit two copies of the mutated gene to have the disease
• People with only one copy of the mutated gene are carriers (sickle cell trait) and usually do not exhibit symptoms
• Hemoglobin is composed of four subunits: two α subunits encoded by HBA on chromosome 16 and two β subunits encoded by HBB on chromosome 11
• The p.Glu6Val variant in β-globin decreases the solubility of deoxygenated hemoglobin, causing it to form stiff fibrous polymers and distorting the red blood cell shape

Phenotype

• Anemia
• Splenomegaly
• Repeated infections
• Dactylitis (painful swelling of the hands or feet)
• Vasoocclusive infarctions occur in many tissues, causing strokes, acute chest syndrome, renal papillary necrosis, autosplenectomy, leg ulcers, priapism, bone aseptic necrosis, and visual loss
• Bone vasoocclusion causes painful “crises” that can persist for days or weeks if untreated

Management and Treatment

• Pain management using medications and other therapies
• Blood transfusions to reduce the number of sickle cells and increase the number of normal red blood cells
• Hydroxyurea to reduce the frequency of pain episodes and acute chest syndrome
• Bone marrow or stem cell transplant as a potential cure, typically used in severe cases
• Preventive care, including vaccinations and antibiotics to reduce the risk of infections, and regular monitoring for complications

Diagnosis

• Blood tests to check for abnormal hemoglobin and to count red blood cells
• Genetic testing to identify mutations in the HBB gene
• Newborn screening often includes testing for sickle cell disease

Oral Manifestations of Sickle Cell Anemia

• Mucosal pallor due to anemia
• Delayed eruption of teeth
• Bone changes, including "stepladder" trabecular pattern in the jawbones and generalized osteoporosis
• Orofacial pain related to sickle cell crises or bone infarctions
• Increased susceptibility to infections, including periodontitis
• Gingival enlargement due to extramedullary hematopoiesis or medication use
• Ulcerations and tissue necrosis due to reduced blood flow

Dental Management of Sickle Cell Anemia Patients

• Medical history and consultation with the patient's hematologist
• Emphasis on good oral hygiene practices to prevent infections
• Regular dental check-ups to monitor and maintain oral health
• Pain management using appropriate analgesics and nitrous oxide-oxygen sedation
• Hydration before, during, and after dental procedures to prevent sickling
• Minimization of stress and anxiety during dental visits
• Use of local anesthesia with vasoconstrictors cautiously and in minimal amounts
• Infection control measures to prevent infections and use of prophylactic antibiotics for invasive dental procedures
• Avoidance of procedures that may reduce oxygen levels
• Management of dental infections promptly to prevent systemic involvement
• Orthodontic treatment with careful planning and monitoring due to increased risk of osteonecrosis and delayed healing
• Emergency care preparedness and coordination with the patient's medical team
• Patient education on oral hygiene, regular dental visits, and management of oral pain and signs of infection