Endocrine Pituitary and Thyroid PDF

Endocrine Disorders Introduction Hormones are substances that released from cells, circulate and affect distant organs The main physiologic functions of hormones are 1. Growth 2. Maintenance of homeostasis 3. Reproduction Hierarchical arrangement Hypothalamus controls the pituit...

Endocrine Disorders Introduction Hormones are substances that released from cells, circulate and affect distant organs The main physiologic functions of hormones are 1. Growth 2. Maintenance of homeostasis 3. Reproduction Hierarchical arrangement Hypothalamus controls the pituitary gland which in turn regulates other endocrine glands. Pituitary Gland The anterior lobe of pituitary gland produces 1. Adreno corticotrophic hormone (ACTH). 2. Melanocyte stimulating hormone (MSH). 3. Thyroid stimulating hormone (TSH). 4. Growth hormone (GH). 5. Follicle stimulating hormone (FSH). 6. Luteinizing hormone (LH). 7. Prolactin. Posterior lobe? (ADH) antidiuretic hormone. Hypothalamus and pituitary gland cascade Hypothalamus controls the pituitary gland which in turn regulates other endocrine glands. Ex. The hypothalamus and pituitary gland stimulate the secretion of cortisol from adrenal cortex While cortisol inhibits hypothalamus and pituitary gland secretion All endocrine systems function as a closed loop. In most endocrine system, negative feedback regulates their function. Other factors?( intrinsic biologic clock, light dark cycle, menstrual cycle)  Disorders of pituitary gland A- Hypopituitarism Etiology: 1- Congenital. 2- Infection. 3- Tumor, trauma or irradiation. 4-Idiopathic General manifestations 1. Impaired growth of child. ( GH). 2. Hypoadrenocorticism ( ACTH). 3. Hypothyroidism ( TSH). 4. Failure of ovulation, amenorrhoea ( FSH). 5. Impotence, defective spermatogenesis ( LH). 6. Failure of lactation ( prolactin). Functions of Growth hormone (GH) Acts on the liver, stimulating it to release several polypeptide hormones (IGF-1). Stimulates amino acid uptake and protein synthesis in target cells. Ultimately stimulates cell growth (cell size and number), especially in muscle and bone. Also stimulates fat breakdown. Growth hormone deficiency (Dwarfism ) General manifestations Short stature of the affected patient and the low growth velocity for age with normal body proportions.(Bone age in children with pituitary dwarfism is usually 2 or more years delayed than the actual chronological age. This means that if a child with pituitary dwarfism is 10 years old, his bones will look like those of a child of 8 years.) Oral manifestations Growth of the alveolar regions of the jaws are abnormal. If occurs before odontogenesis will result in Microdontia, Delayed shedding and eruption of teeth. If occurs after odontogenesis : Crowding and malocclusion with normal size of teeth. This leads to high tendency to plaque accumulation and difficulty in maintaining good oral hygiene( increased gingivitis and periodontitis). Dental implication of hypopituitrism ❖ Stress, surgery, GA, infection, sedatives, and trauma may precipitate hypopituitary coma. ❖ Hypopituitary coma is related to decreased TSH and ACTH, so that the patient cannot tolerate stress. Hypopituitary coma is managed by: 1. 200 mg hydrocortisone sodium succinate I.V. 2. 25-50 mg dextrose (hypoglycemia). 3. Oxygen. 4. Call ambulance for hospital admission. B-Hyperpituitarism Children “before epiphyseal closure” Gigantism 1- Well proportioned individual but huge. 2- Teeth: Spacing (if occur after odontognesis) Adult “after epiphyseal closure” Acromegaly 1- Large: Hand, feet, malar bone, supraorbital ridges, tongue, lip, mandible (prognathism). 2- Teeth: Spacing → Food impaction 3- Hypercementosis → Teeth fracture, or difficulty in extraction. General features of acromegaly: 1. Marked thickened (prominent) of the supra-orbital ridge 2. Hypertrophy of the soft tissue of pharynx and larynx 3. Hypertrophy of sweat and sebaceous glands 4. Cardiomegaly and hypertension 5. Abnormal glucose tolerance test 6. Large nose , sinus ,jaws ,hands and feet 7. Galactorrhea and sexual dysfunction Oral features of acromegaly: 1. Overgrowth of the mandible, Macrognathia 2. prognathism ( Class III malocclusion) 3. Teeth spacing that leads to Food impaction 4. Hypercementosis that leads to Teeth fracture, or difficulty in extraction 5. Lips enlargement 6. Enlarged tongue (macroglosia) with tongue identation marks. Dental implication 1. Systemic problem associated with hyperpituitarism may complicate the dental treatment: ❖ Hypertension. ❖ Diabetes mellitus. ❖ Cardiomegaly and heart failure. ❖ Hypercalcemia, osteoartherosis 2. Hazards of GA related to breathing problem : ❖ Tongue is enlarged ❖ Epiglottic opening is narrow So it is better to avoid supine position.  Thyroid Gland Position and Embryology: Two lateral lobes connected by an isthmus closely attached to the thyroid cartilage and moves on swallowing It originates from the base of the tongue and descend to the midline of the neck Remnants of thyroid tissue can be found at the base of the tongue (lingual thyroid) Physiologic effect of thyroid hormones ❖ With very few exceptions, every cell in the body has thyroid hormone receptors and respond to the action of the thyroid hormone, ❖ T3 is the active hormone that binds to the thyroid hormone receptors and brings about many physiologic actions of thyroid hormone. 1. T3 regulates the rate of metabolism in all cells 2. They accelerate carbohydrate utilization and enhance lipolytic reaction 3. They exert calorigenic effect (increased oxygen consumption and heat production) increasing BMR 4. Important for normal physical and mental development and growth 5. Help Protein synthesis in the body. 6. Important for bone growth 7. Permissive to adrenaline in body cells 8. They are cardiovascular stimulants. Disorders of thyroid gland Goiter: Is a non specific term denoting thyroid gland enlargement The patient with enlarged gland may be: Hypothyroid: (endemic goiter as the gland is increasingly stimulated by TSH causing hyperplasia and hypertrophy of thyroid gland) Hyperthyroid Goiter is more common in women and may be either physiological (puberty, pregnancy) or pathological  1- Hyperthyroidism: (Thyrotoxicosis) (toxic goiter) Etiology: -Immunologic cause -severe emotional trauma or infection, Types a. Grave’s disease: Characterized by: Diffused enlargement of thyroid gland. Exophthalmos. b. Nodular goiter: Characterized by: Less severe nodular enlargement of thyroid gland. Grave’s disease: Is an autoimmune disease present with hyperthyroidism, goiter and eye symptoms. Diagnosis: overproduction of T4 and/or T3, suppression of TSH The best test for hyperthyroidism is low TSH. N.B: Thyroid hypofunction test: Increase TSH Decreased T3, T4 Other diagnostic methods a. Ultrasonography b. Computed tomography c. MRI d. Fine needle biopsy e. Auto antibody profile General manifestations 1. Warm moist skin (hot while others are cool) 2. Excessive sweating. 3. Increased appetite but losing weight. 4. Tremors of hands and tongue 5. Exophthalmos which may persist even after treatment. 6. Nervousness and anxiety. 7. Tachycardia due to increase BMR. Treatment: Decreasing the symptoms by beta blockers for cardiac symptoms and anti- thyroid medications Then either surgery or radioactive iodine. Oral manifestations 1. Normal growth of jaw. 2. Early shedding of deciduous. 3. Early eruption of permanent teeth. 4. Osteoporosis: due to increase osteoclastic activity. Dental implication Detection of patient with thyrotoxicosis by history and clinical examination and referral for evaluation and treatment Avoidance of elective dental treatment for patients with thyrotoxicosis until good medical control Emergency dental care only should be done for patients with thyrotoxicosis patients with thyrotoxicosis a. Sedation b. Analgesics to control pain c. Antibiotics to control acute infection d. Avoid GA  e. local anesthesia should be free from adrenaline. f. Avoid any surgical procedure for untreated or incompletely treated patients Patients under good medical management Or treated thyrotoxic patient present no problem in dental treatment. Antithyroid drugs induce agranulocytosis which may cause oral and oropharyngeal ulceration. Thyroid Crisis Definition It is an exaggerated manifestation of hyperthyroidism. Precipitating factors: a. Stress. b. Infection. c. Surgery d. Pain e. trauma Clinical manifestations ❖ Thyroid crisis is manifested as: Nausea, vomiting Profuse sweating Tremors Tachycardia Fever Hypotension. How to manage thyroid crisis (thyroid storm)? Medical treatment will include: a. Hydrocortisone 200 mg IV b. Glucose IV. c. Ice pack, wet pack, fans. d. Antithyroid drugs and adrenergic antagonizer (propanolol).  2-Hypothyroidism Includes 2 types: Cretinism, In children with congenital gland absence or low Iodine content in mother diet) Myxedema, In young juvenile and adult) Hypothyroidism In childhood (Cretinism). ❖ Clinically there is: 1. Growth retardation 2. Mental retardation. 3. Delayed eruption of teeth. 4. Micrognathia. 5. Macroglossia. 6. Malocclusion, anterior open bite. 7. Puffy, enlarged, protruded lip. 8. Short and flat nose. Hypothyroidism In adult (Myxedema). is characterized by: 1. Cold intolerance. 2. Decreased sweating. 3. Loss of hair 4. Dry cold skin. 5. Decreased appetite. 6. Weight gain. 7. Slowed reaction. 8. Bradycardia. 9. Hoarseness of voice. 10. Poor memory. 11. Psychosis. 12. Chronically fatigue Oral manifestations: 1. Facial edema. 2. Macroglossia. 3. Compromized periodontal health. N.B: Hashimoto’s thyroiditis (autoimmune destruction of the gland) has been associated with xerostomia and impaired salivary output. Factors complicating dental treatment 1. Diminished respiratory rate could increase risk of aspiration of dental materials 2. Delayed wound healing. 3. Patients are susceptible to cardiovascular diseases so, Local anesthesia or retraction cord with epinephrine should be used cautiously Dental implication Myxedema coma. Precipitating factor Trauma, surgery, infection, GA. Manifestations Hypothermia. Hypotension. Bradycardia. Epileptic seizures. Management 1. Call ambulance for hospitalization. 2. Artificial respiration. 3. 200 mg hydrocortisone. Thanks, A. Prof. Dr. Souzy Kamal Anwar