Disease associated with a decreased incidence of dental caries

# Which of the following diseases is associated with a decrease in caries?
A. Sjogren's syndrome
B. Cystic fibrosis
C. Cerebral palsy
D. Down syndrome

The correct answer is B. Cystic fibrosis.

** Important: There is a significantly reduced caries rate in patients with cystic fibrosis. This is probably the result of alterations in saliva and the long-term use of antibiotics. Cystic fibrosis is a congenital metabolic disorder that causes the exocrine glands (which are glands that secrete fluids into a duct) to produce abnormal secretions, resulting in several symptoms, the most important of which affect the digestive tract and the lungs. In some glands, such as the pancreas and those in the intestines, the secretions are thick or solid {an excessively viscous mucous) and may block the gland completely. The mucous producing glands in the airways of the lungs produce abnormal secretions that clog the airways and allow bacteria to multiply. The sweat glands secrete fluids that have high sodium and chloride content. Note: The staining of the teeth is most likely due to the fact

that patients with cystic fibrosis are usually subjected to large amounts of tetracyclines during childhood.

Symptoms of CF include:

• Poor growth despite a good appetite

• Malabsorption and foul, bulky stools: steatorrhea

• Chronic bronchitis (COPD) with cough

• Recurrent pneumonia: respiratory infections

• Clubbing of fingers and toes

• Barrel-chested appearance 

Severe hypothyroidism in a child

# Severe hypothyroidism in a child is called:
A. Dwarfism
B. Myxedema
C. Cretinism
D. Acromegaly

The correct answer is C. Cretinism.

Hypothyroidism refers to a condition in which the amount of thyroid hormone in the body is below normal. This is the most common form of thyroid function abnormality and is far more common than hyperthyroidism. This condition is considerably more common in women than in men. The most common cause of hypothyroidism is Hashimoto's thyroiditis.

The second most common cause is the treatment of hyperthyroidism. Hypothyroidism is characterized by the puffiness of the face and eyelids and swelling of the tongue and larynx. The skin becomes dry and rough and the hair becomes sparse. The individual has a low basal-metabolic rate and a low body temperature. The affected individuals also have poor muscle tone, low strength and get tired very easily. Mentally they are very sluggish. The treatment of hypothyroidism is straight forward and consists of administering thyroid hormone (thyroxin).

Severe hypothyroidism in a child is called cretinism. Due to a lack of thyroid hormone, there is a retardation of growth and abnormal development of bones. Mental retardation is caused by the improper development of the CNS. If this condition is recognized early, it can be markedly improved with the use of thyroid hormones. Note: Extreme hypothyroidism in adults is called myxedema.

Note: Dental findings in a child with hypothyroidism include an underdeveloped mandible with an overdeveloped maxilla, enlarged tongue which may lead to malocclusion, delayed eruption of teeth, and deciduous teeth being retained longer.

Treatment of Parathyroid hormone deficiency

# A deficiency of parathyroid hormone can be treated with:
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K

The correct answer is C. Vitamin D.

Hypoparathyroidism is a rare disorder associated with insufficient production of parathyroid hormone, the inability to make a usable form of parathyroid hormone or the inability of kidneys and bones to respond to parathyroid hormone production.

Hypoparathyroidism can result from congenital disorders, iatrogenic causes (e.g., drugs, removal of the parathyroid glands during thyroid or parathyroid swge1y. radiation), infiltration of the parathyroid glands (e.g., metastatic carcinoma. Wilson disease, sarcoid), suppression of parathyroid function, HIV/AIDS, or idiopathic mechanisms.

Hypocalcemia is the most important consequence of hypoparathyroidism. Symptoms occur when ionized calcium level drops to less than 2.5-3 mg/1 00 mL. The clinical manifestation is tetany. A positive Chvostek's sign (twitching of the facial muscles when tapped on the facial nerve near the parotid gland) is characteristic of hypoparathyroidism.

Important: The dental manifestations of hypoparathyroidism (i.e., delayed eruption. enamel hypoplasia and blunted root apices) may be prevented by early treatment with vitamin D.

Cleft Palate occurs during which week of gestation?

# Cleft palate occurs in the ___________ of embryonic life.
A. First to third week
B. Fourth to sixth week
C. Eighth to tenth week
D. Twelfth to fourteenth week

The correct answer is C. 8th to 10th week.

Cleft palate occurs in the eighth to tenth week of embryonic life. Isolated clefts of the palate are more common in females. It is characterized by a fissure in the midline of the palate, resulting from the failure of the two sides to fuse during embryonic development.

The most severe handicap imposed by cleft palate is an impaired mechanism preventing normal speech and swallowing. 

Note: It affects approximately 1 in 2000 births.

Cleft lip results when the medial nasal process fails to fuse with the lateral portions of the maxillary process of the first branchial arch. Fusion normally occurs during the sixth and seventh weeks of embryonic development. The maxillary lip is most commonly affected.

It may be bilateral (20%) or unilateral (80%). Clefts of the lip are more frequent in males. Lip cleft involvement is more frequent on the left side than the right.

Note: It affects approximately 1 in 1000 births, but varies with race.