The Hypothyroid Patient with an Aching Jaw

Correct answer: B. Accelerated dental eruption

• A. This IS a feature. Reduced gut motility produces constipation.
• B. CORRECT — this is the EXCEPTION. Hypothyroidism DELAYS dental eruption and exfoliation, it does not accelerate it. Thyroid hormone drives skeletal and dental maturation; when it is deficient in childhood (cretinism), the result is delayed eruption, retained primary teeth, delayed epiphyseal closure and short stature. Accelerated eruption is a feature of HYPERthyroidism.
• C. This IS a feature. Reduced metabolic rate and reduced sweating produce dry, cool, coarse skin and cold intolerance.
• D. This IS a feature. Reduced basal metabolic rate and fluid retention (myxoedema) produce weight gain despite unchanged appetite.

Note: Oral features of hypothyroidism: macroglossia, delayed eruption, enamel hypoplasia, and delayed wound healing. In HYPERthyroidism you see accelerated eruption, premature exfoliation, osteoporosis of the jaws, burning mouth and increased caries. ⚑ Note also that EXOPHTHALMOS is a feature of GRAVES DISEASE specifically — an autoantibody-driven orbitopathy — and NOT of thyroid hormone excess in general.

Correct answer: D. Elevated alkaline phosphatase

• A. Haemoglobin is unrelated to osteomalacia.
• B. Serum phosphate is typically LOW, from the phosphaturic effect of the raised PTH.
• C. Serum calcium is typically LOW or low-normal, which is what drives the compensatory rise in PTH.
• D. CORRECT. ELEVATED ALKALINE PHOSPHATASE is the hallmark. Osteomalacia is defective MINERALISATION of osteoid, usually from vitamin D deficiency. The osteoblasts remain active and continue laying down unmineralised matrix, and alkaline phosphatase — an osteoblast product — rises accordingly. The characteristic panel is: LOW or low-normal calcium, LOW phosphate, HIGH alkaline phosphatase, HIGH parathyroid hormone (secondary hyperparathyroidism) and LOW 25-hydroxyvitamin D.

Note: The parallel disorder in children is RICKETS, where the same defect affects the growth plate and produces bowing of the long bones, a rachitic rosary and delayed fontanelle closure. Dental features of both: enamel hypoplasia, delayed eruption, large pulp chambers with high pulp horns, and hypomineralised dentine.

Correct answer: B. A stepladder trabecular pattern between the roots of posterior teeth

• A. GROUND-GLASS describes FIBROUS DYSPLASIA, and also appears in hyperparathyroidism.
• B. CORRECT. The STEPLADDER pattern — horizontal, coarse trabeculae running between the roots of the posterior teeth — is the classic jaw finding in sickle cell anaemia. It results from marrow hyperplasia: chronic haemolysis drives compensatory expansion of the marrow spaces, which resorbs the fine trabeculae and leaves a coarser, more horizontal pattern. Generalized osteoporosis, a widened diploë with a 'hair-on-end' skull appearance, and delayed eruption accompany it.
• C. COTTON-WOOL describes PAGET DISEASE of bone in its later mixed and sclerotic phases, and is also used for chronic diffuse sclerosing osteomyelitis.
• D. PUNCHED-OUT radiolucencies with no corticated rim are characteristic of MULTIPLE MYELOMA, classically in the skull and jaws.

Note: Dental management in sickle cell disease: avoid anything that precipitates a crisis — hypoxia, dehydration, acidosis, infection and stress. Use profound local anaesthesia, keep appointments short, use nitrous oxide with at least 50% oxygen, treat infections aggressively, and avoid general anaesthesia where possible.

Correct answer: B. Factor VIII

• A. Factor VII is the extrinsic pathway factor measured by the PT and INR. It has no relationship to vWF.
• B. CORRECT. FACTOR VIII. Von Willebrand factor has two distinct jobs: it mediates PLATELET ADHESION to exposed subendothelial collagen at the site of injury, and it acts as the CARRIER PROTEIN that stabilises factor VIII in the circulation. Without vWF, factor VIII is degraded rapidly and its level falls — which is why von Willebrand disease produces a combined defect of primary haemostasis (prolonged bleeding time, abnormal platelet function) and a secondary reduction in factor VIII activity with a prolonged aPTT.
• C. Factor IX deficiency is haemophilia B (Christmas disease). It is unrelated to vWF.
• D. Factor XIII cross-links fibrin to stabilise the clot; its deficiency causes delayed bleeding with a normal PT and aPTT.

Note: Von Willebrand disease is the COMMONEST inherited bleeding disorder, usually autosomal dominant. Dental management: DESMOPRESSIN (DDAVP) releases stored vWF and factor VIII from endothelium and is effective in Type 1, the commonest form. Add tranexamic acid, local haemostatic measures, and avoid aspirin and NSAIDs.

Correct answer: B. Microglossia

• A. This IS expected. Eruption is delayed and irregular in both dentitions, and the sequence is frequently abnormal.
• B. CORRECT — this is the exception. Down syndrome is associated with MACROglossia, not microglossia — a relatively large, often fissured tongue in a small oral cavity with maxillary hypoplasia, which contributes to the open-mouth posture and mouth-breathing.
• C. This IS expected. Intellectual disability of variable degree is a defining feature of trisomy 21.
• D. This IS expected, and it is the most clinically important dental issue. Periodontal disease is early-onset, rapidly progressive and severe, driven by impaired neutrophil chemotaxis and phagocytosis. It affects the mandibular anteriors particularly.

Note: Other features: hypodontia and microdontia, a Class III tendency from maxillary hypoplasia, a fissured tongue, atlantoaxial instability (which matters for head positioning under sedation or GA), and congenital cardiac defects in roughly 40–50% — which used to but no longer automatically indicates antibiotic prophylaxis. Trisomy 21 is the CHROMOSOME most commonly involved in a viable trisomy.