In the name of GOD

Sajad farokhi

HYPERPARATHYROIDISM

The general changes that can be seen in the jaws include thefollowing:

• 1. Change in size and shape of the bone

• 2. Change in the number, size, and orientation of trabeculae

• 3. Altered thickness and density of cortical structures

• 4. Increase or decrease in overall bone density

• Hyperparathyroidism is an endocrine abnormality in which there is an excess of circulating parathyroid hormone (PTH)

• PTH increases bone remodeling

• PTH increases renal tubular reabsorption of calcium and renal production of the active vitamin D metabolite 1,25(OH)2D

Primary hyperparathyroidism

• usually results from a benign tumor (adenoma) of one of the four parathyroid glands (80% to 85%)

• Hyperparathyroidism–jaw tumor syndrome

• Hyperplastic parathyroid glands

• incidence of primary hyperparathyroidism is about 0.1%

Secondary hyperparathyroidism

• esults from a compensatory increase in the output of PTH in response to hypocalcemia

• This condition produces clinical and imaging features similar to primary hyperparathyroidism.

Clinical Features• Primary hyperparathyroidism affects females two to three times more commonly than males

• occurs mainly in adults 30 to 60 years old

• Clinical manifestations of the disease cover a broad range

• These clinical symptoms are mainly related to hypercalcemia

• The combination of hypercalcemia and an elevated serum level of PTH is diagnostic of primary hyperparathyroidism

• Laboratory test

Imaging Features

• Only about one in five patients with hyperparathyroidism has observable bone changes

subtle erosions of bone from the subperiosteal surfaces of the phalanges of the hands

General Features :

The arrow indicates early subperiosteal erosion on the third phalanx.

• Demineralization of the skeleton results in an unusual radiolucent appearance (generalized osteopenia)

Generalized rarefaction and loss of cortical margins in the thoracic vertebrae.

Generalized rarefaction and loss of cortical margins in the cervical vertebrae and mandible

• Osteitis fibrosa cystica is seen in advanced cases

• In about 10% of cases, brown tumors occur late in the disease

.Brown tumors of hyperparathyroidism may appear in any bone but are frequently found in the facial bones and jaws, particularly in cases of long-standing disease

.These lesions may be multiple within a single bone

.If solitary, the tumor may resemble a central giant cell granuloma or an aneurysmal bone cyst

Axial (A) and coronal (B) MDCT images with bone algorithm of a case of secondary hyperparathyroidism with a brown tumor involving the maxilla. This tumor has features of a central giant cell granuloma with a granular expanded cortex of the maxilla and very subtle and ill-defined internal septa

.The histologic appearance of a brown tumor is identical to giant cell granuloma

• The increased levels of serum calcium result in precipitation of the mineral in the soft tissues forming punctate or nodular calcifications in the joints and kidneys

Radiograph depicting bilateral nephrocalcinosis in an adult male patient who initially presented with features of pancreatitis. Ultimately, hyperparathyroidism was diagnosed

• In prominent hyperparathyroidism, the entire calvaria has a granular appearance classically known as the “salt and pepper” skull. This appearance is caused by loss of the central (diploic) trabeculae and thinning of the cortical tables

Axial (A) and sagittal (B) MDCT images with bone algorithm of a case of secondary hyperparathyroidism

Demineralization and thinning of cortical boundaries often occur in the jaws,

Jaws

A, Panoramic image. The loss of bone in hyperparathyroidism results in the radiopaque teeth standing out in contrast to the radiolucent jaws. B, Periapical film of a different case demonstrates the loss of a distinct lamina dura and the granular texture of the bone pattern.

The elevated rate of bone remodeling can cause an abnormal bone

Teeth and Associated Structures

.loss of the lamina dura

A and B, Granular bone pattern that was characteristic in all intraoral films. Note the loss of a distinct lamina dura and floor of the maxillary antrum. C, This view of the same case reveals a brown tumor related to the apical region of the second and third molars

Management

After successful surgical removal of the causative parathyroid adenoma, almost all changes revert to normal.

The only exception may be the site of a brown tumor, which often heals with bone that is more sclerotic than normal

Many people with this disease are being diagnosed earlier, resulting in fewer severe cases

THE END