3Radiographic Features The general changes include the following:1. A change in size and shape of the bone2. A change in the number, size, and orientation of trabeculae3. Altered thickness and density of cortical structures4. An increase or decrease in overall bone densityChanges to teeth and associated structures include thefollowing:1. Accelerated or delayed eruption2. Hypoplasia3. Hypocalcification4. Loss of a distinct lamina dura
4HYPERPARATHYROIDISM Radiographic Features Only about one in five patients with hyperparathyroidism has radiographicallyobservable bone changes.General Radiographic Features. The following are the majormanifestations of hyperparathyroidism:1. The earliest and most reliable changes of hyperparathyroidism are subtle erosions of bone from the subperiosteal surfaces of the phalanges of the hands.2. Demineralization of the skeleton results in an unusual radiolucent appearance.3. Osteitis fibrosa cystica are localized regions of bone loss produced by osteoclastic activity resulting in a loss of all apparent bone structure.4. Brown tumors occur late in the disease and in about 10% of cases. These peripheral or central tumors of bone are radiolucent. The gross specimen has a brown or reddish-brown color.5. Pathologic calcifications in soft tissues have a punctate or nodular appearance and occur in the kidneys and joints.6. In prominent hyperparathyroidism, the entire calvarium has a granular appearance caused by the loss of central (diploic) trabeculae and thinning of the cortical tables
5Axial and, B, sagittal computed tomographic images with bone algorithm of a case of secondary hyperparathyroidism. Note the lack of normal cortical bone at the inner and outer tables of the skull, internal granular bone pattern, and generalized lack of defined outer cortical boundary of the osseous structures.
6HYPERPARATHYROIDISMPanoramic image. The loss of bone in hyperparathyroidism results in the radiopaque teeth standing out in contrast to the radiolucent jaws.
7Axial and coronal computed tomographic images 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.
8the loss of a distinct lamina dura and the granular texture of the bone pattern in this periapical film
9Granular bone pattern that was characteristic in all intraoral films Granular bone pattern that was characteristic in all intraoral films. Note the loss of a distinct lamina dura and floor of the maxillary antrum.This view of the same case reveals a brown tumor related to the apical region of the second and third molars.
10HYPOPARATHYROIDISM AND PSEUDOHYPOPARATHYROIDISM Most often this includes sharp flexion (tetany) of the wrist and ankle joints (carpopedal spasm).Some patients have sensory abnormalities consisting of paresthesia of the hands, feet, or the area around the mouthThe principal radiographic change is calcification of the basal ganglia. On skull radiographs this calcification appears flocculent and paired within the cerebral hemispheres on the posteroanterior view.
11Radiographic examination of the jaws may reveal dental enamel hypoplasia, external root resorption, delayed eruption, or root dilaceration
12HYPERPITUITARISM Acromegaly and Giantism A, An example of acromegaly manifesting as excessive growth of the mandible, resulting in a class III skeletal relationship of the jaws. B, A portion of a lateral skull view of the same patient demonstrating enlargement of the sella turcica.
13Radiographic Features of the Jaws The increase in the length of the dental arches results in spacing of the teethIn acromegaly the angle between the ramus and body of the mandible may increasein combination with enlargement of the tongue (macroglossia), may result in anterior flaring of the teeth and the development of an anterior open biteclass III skeletal relationship between the jaws. The thickness and height of the alveolar processes may also increase.The tooth crowns are usually normal in size, although the roots of posterior teeth often enlarge as a result of hypercementosis.
14HYPOPHOSPHATASIAHypophosphatasia is a rare inherited disorder that is caused by either a reduced production or a defective function of alkaline phosphatasethe large pulp chambers in the deciduous dentition and the premature loss of the mandibular incisors.
15Radiographic Features long bones show irregular defects in the epiphysis, and the skull is poorly calcified.In older children with premature closure of the skull sutures, multiple lucent areas of the calvarium may exist, called gyral or convolutional markings. These markings resemble hammered copperskull may assume a brachycephalic shapeA generalized reduction in bone densityJaws. A generalized radiolucency of the mandible and maxilla is evident. The cortical bone and lamina dura are thin, and the alveolar bone is poorly calcified and may appear deficient.Teeth. Both primary and permanent teeth have a thin enamel layer and large pulp chambers and root canals
16HYPOPHOSPHATEMIA Vitamin D – resistant rickets and hypophosphatemic rickets Hypophosphatemia represents a group of inherited conditions that produce renal tubular disorders resulting in excessive loss of phosphorus.A panoramic image of hypophosphatemia. Note the radiolucent appearance of thejaws and hence the lack of bone density and the large pulp chambers
17These periapical films of a different case of hypophosphatemia demonstrate apparent bone loss around the teeth, a granular bone pattern, large pulp chambers, and external root resorption.
18OSTEOPETROSIS Albers-Schönberg and marble bone disease Osteopetrosis is a disorder of bone that results from a defect in the differentiation and function of osteoclasts. The lack of normally functioning osteoclasts results in abnormal formation of the primary skeleton and a generalized increase in bone massautosomal recessive type (osteopetrosis congenita)autosomal dominant type (osteopetrosis tarda).
19Osteopetrosis, showing dense calcifi cation of all the bones. A, Skull and facial bones. B, Chest.C, Pelvis and femurs (note the fracture of the proximal right femur).
20A panoramic fi lm of a patient with osteopetrosis; note the increased density of the jaws, lack of eruption of the mandibular second bicuspids, narrow inferior alveolar nerve canal, and development of osteomyelitis in the body of the left mandible with periostitis
21Differential Diagnosis The differential diagnosis includes other sclerosing bone dysplasiassclerosteosis,infantile cortical hyperostosis,pyknodysostosis,craniometaphyseal dysplasia,diaphyseal dysplasia, melorheostosis,osteopathia striata.Osteosclerosis from fluoride poisoning and secondary hyperparathyroidism from renal disease also may have a general sclerotic appearance.
22PROGRESSIVE SYSTEMIC SCLEROSIS Scleroderma Progressive systemic sclerosis (PSS) is a generalized connective tissue disease that causes excessive collagen deposition resulting in hardening (sclerosis) of the skin and other tissues.
23Progressive systemic sclerosis demonstrating a loss of bone in the region of the angle of the mandible (arrows) and at the right coronoid process (arrow), which are locations of muscle attachments.
24Two periapical fi lms of two different patients with PSS; note the widening of the periodontal membrane space around some of the teeth.
25SICKLE CELL ANEMIASickle cell anemia is an autosomal recessive, chronic hemolytic blood disorder. Patients with this disorder have abnormal hemoglobin (deoxygenated hemoglobins), which under low oxygen tension results in sickling of the red blood cells.
26SICKLE CELL ANEMIARadiograph of a patient with sickle cell anemia showing a thickened diploic space and thinning of the skull cortex. B, Normal skull for comparison.
28THALASSEMIA Cooley ’ s anemia, Mediterranean anemia, and erythroblastic anemi Thalassemia is a hereditary disorder that results in a defect in hemoglobin synthesisα - or β –globulin genes.The heterozygous form (thalassemia minor) is mild.The homozygous form (thalassemia major) may be severe. A less severe formThalassemia intermedia
29A skull radiograph of a patient with thalassemia showing a granular appearance of the skull and thickening of the diploic space. B, An axial CT image of the skull of a patient with thalassemia; note the thickened diploic space and that there is hint linear orientation of the trabeculae, especially in the frontal bone
30A panoramic film of a patient with thalassemia; note the thickened body of the mandible and the sparse trabeculae and lack of maxillary antra.B, Radiograph of a different patient with thalassemia with thick trabeculae and large bone marrow spaces.