parathyroid glands are located behind the thyroid gland that produces parathyroid hormones ( pth ) .
pth has a main role in bone formation , vitamin d activation occurred in the kidney by pth that leads to intestinal absorption of calcium and phosphate re - absorption .
the primary function of pth is to maintain the extracellular fluid calcium concentration , which is done by pth effect on bone and kidney directly and on the intestine through its effects on synthesis of 1 , 25 ( oh)d , indirectly .
primary hyperparathyroidism ( phpt ) is a generalized disorder of calcium , phosphate , and bone metabolism due to excessive secretion of pth .
secondary hyperparathyroidism ( shpt ) is caused by impaired phosphate excretion , and failure to activate vitamin d. hypocalcemia is caused by elevated levels of the fibroblast growth factor 23 ( fgf-23 ) , and reduced synthesis of calcitriol , which is the active form of vitamin d. elevated phosphate level , decreased ionized calcium level , and reduced serum calcitriol lead to continuous stimulation of the parathyroid glands that causes increased pth release .
tertiary hpt is defined as long - time shpt leads to autonomous parathyroid glands that lead to hypercalcemia , pruritis and extra - skeletal calcification , bone involvement despite aggressive treatment to suppress pth .
hpt leads to bone involvement that include generalized osteoporosis , multiple focal areas of demineralization of the skull , and brown tumor .
the brown tumor or osteitis fibrosa cystica is a benign bone lesion that caused by hpt .
pelvis , ribs , clavicle , mandible and the extremities are most commonly affected bones in brown tumor , whereas maxillary involvement is rare ( 0.1% ) .
this case report was unique due to the presentation of brown tumors in the maxillofacial region .
in july 2012 , a 29-year - old man was referred to internal medicine clinic , al zahra hospital , isfahan , iran with chief complaint of generalized bone pain that started seven months ago and , swelling in the cheek regions , which initiated three months ago and gradually increased in size .
the patient 's medical history revealed that he had end - stage renal disease ( esrd ) for about eight years , due to systemic lupus erythematous ( sle ) that suppressed after renal failure .
hyperparathyroidism was diagnosed 15 months ago with elevated pth levels that vitamin d and calcium had been recommended for treatment .
other medications were as follows : carbonate calcium 2 g / day , calciteriol 1g / day , vitamin d 50000 units weekly , losartan 50 mg 2  daily . on oral examination ,
displaced teeth without normal alignment was seen , teeth were loose [ figure 1 ] .
bilateral swelling in the cheek regions . increased distance between teeth and irregular alignment with displaced teeth the patient compliance was poor and his follow - up laboratory test programs were not periodically in accordance with his medical condition .
result of routine laboratory tests were as follows : pth : 3552 pg / ml ( 8 - 60 ) , calcium : 8.7 mg / dl ( 8.5 - 10 ) , phosphorus : 6.3 mg / dl ( 2.5 - 5 ) , alkaline phosphatase : 2800
u / l ( 55 - 200 ) , hemoglobin : 8.5 mg / dl ( 14 - 18 ) , creatinin : 6.5 mg / dl ( 0.7 - 1.2 ) , potassium : 5.5 mg / dl ( 3.5 - 5 ) , alb : 3.5 mg / dl ( 3.5 - 4 ) .
the level of pth began to increase from 15 months that was 350 pg / ml , and so the dose of carbonate calcium and and pearl vitamin d was added to the patient 's medications that did not respond to treatment .
carbonate calcium was started with two tabs daily and increased every two week that reached to eight tabs in divided dose .
tc-99 m sestamibi of the parathyroid glands scan was advised two weeks before admission , which showed a normal uptake inminute 30 and 240 .
panoramic radiograph , shows multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in the body of the mandible bone [ figure 2 ] .
computed tomography ( ct ) scan of the head and neck region , showed multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in zygoma , maxilla , palate and mandibular bones [ figure 3 ] .
also , a generalized diffuse severe osteoporosis in maxillofacial bone with salt and pepper pattern was seen [ figure 3 ] .
panoramic radiograph , shows multiple small unilocular radioluscencies , suggestive of brown tumors ct scan ; ( a ) axial view shows multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in hard palate ( arrow ) ; ( b ) coronal view shows a well - defined radioluscency in zygoma ( arrow ) ; ( c ) axial view shows multiple small unilocular well - defined radioluscencies in the mandibular body ( arrow ) a radiograph of the forearm and elbow regions , showed a unilocular well - defined radioluscency , suggestive of brown tumor in ulnar bone , in addition to calcification of dialysis shunt and metastatic vascular calcification [ figure 4 ] .
radiograph of the forearm and elbow regions , showed a unilocular well - defined radioluscency , suggestive of brown tumor in ulnar bone .
note to the calcification of dialysis shunt and metastatic vascular calcification finally , he underwent parathyroidectomy due to tertiary hpt diagnosis .
the histopathological examination showed a chief cell proliferation of parathyroid with clear cytoplasm and small central nucleus with oxiphilic cells seen between them .
the tissue was surrounded by a thin capsule penetrated by thin septa that divided that into labels , all of these suggested hpt .
result of routine laboratory tests were as follows : pth : 3552 pg / ml ( 8 - 60 ) , calcium : 8.7 mg / dl ( 8.5 - 10 ) , phosphorus : 6.3 mg / dl ( 2.5 - 5 ) , alkaline phosphatase : 2800
u / l ( 55 - 200 ) , hemoglobin : 8.5 mg / dl ( 14 - 18 ) , creatinin : 6.5 mg / dl ( 0.7 - 1.2 ) , potassium : 5.5 mg / dl ( 3.5 - 5 ) , alb : 3.5 mg / dl ( 3.5 - 4 ) .
the level of pth began to increase from 15 months that was 350 pg / ml , and so the dose of carbonate calcium and and pearl vitamin d was added to the patient 's medications that did not respond to treatment .
carbonate calcium was started with two tabs daily and increased every two week that reached to eight tabs in divided dose .
tc-99 m sestamibi of the parathyroid glands scan was advised two weeks before admission , which showed a normal uptake inminute 30 and 240 .
panoramic radiograph , shows multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in the body of the mandible bone [ figure 2 ] .
computed tomography ( ct ) scan of the head and neck region , showed multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in zygoma , maxilla , palate and mandibular bones [ figure 3 ] .
also , a generalized diffuse severe osteoporosis in maxillofacial bone with salt and pepper pattern was seen [ figure 3 ] .
panoramic radiograph , shows multiple small unilocular radioluscencies , suggestive of brown tumors ct scan ; ( a ) axial view shows multiple small unilocular well - defined radioluscencies , suggestive of brown tumors in hard palate ( arrow ) ; ( b ) coronal view shows a well - defined radioluscency in zygoma ( arrow ) ; ( c ) axial view shows multiple small unilocular well - defined radioluscencies in the mandibular body ( arrow ) a radiograph of the forearm and elbow regions , showed a unilocular well - defined radioluscency , suggestive of brown tumor in ulnar bone , in addition to calcification of dialysis shunt and metastatic vascular calcification [ figure 4 ] .
radiograph of the forearm and elbow regions , showed a unilocular well - defined radioluscency , suggestive of brown tumor in ulnar bone .
note to the calcification of dialysis shunt and metastatic vascular calcification finally , he underwent parathyroidectomy due to tertiary hpt diagnosis .
the histopathological examination showed a chief cell proliferation of parathyroid with clear cytoplasm and small central nucleus with oxiphilic cells seen between them .
the tissue was surrounded by a thin capsule penetrated by thin septa that divided that into labels , all of these suggested hpt .
the brown tumor is a bone lesion that is caused by osteoclast activity in hpt condition .
the incidence of skeletal brown tumors in esrd ranges from 1.5 to 13% , but this complication has been decreased with novel diagnostic pth radioimmunoassay techniques and successful treatment of the disease . this unusual complication of secondary hpt is more commonly seen in young female patients , and so the patient in this report was unusual for his gender .
pelvis , ribs , clavicle , mandible and the extremities are most commonly affected bones in brown tumor , whereas involvement of the maxilla is considered rare .
elevated pth is the cornerstone of all hpt , but they differ in calcium and phosphate level . primary hpt presented with an elevated calcium level , normal or low phosphate level , secondary hpt hypocalcemia and hyperphosphatemia are dominant , while hypercalcemia and hyperphosphatemia occurred in tertiary .
hypocalcemia , hyperphosphatemia and calcitriol deficiency may be found in chronic kidney disease ( ckd ) , that can lead to pth , directly affecting the skeletal system .
periapical radiographs reveal loss of lamina dura in 10% of patients with hpt . depending on duration and severity of disease , loss of lamina dura may occur around one tooth or all remaining teeth .
the result of lamina dura loss may give the root a tapered appearance because of loss of image contrasts .
the major clinical manifestations of hpt in the oral cavity are brown tumor , malocclusions , loss of bone density , soft - tissue calcifications , weak teeth , and dental abnormalities of such developmental defects , alterations in dental eruption and widened pulp chambers .
according to the examination and using panoramic radiography , the differential diagnosis is multiple myeloma , bone metastases of a carcinoma , osteosarcoma , osteomyelitis or osteonecrosis secondary to bisphosphonate therapy and paget 's disease that elevated pth level differentiate hpt from others .
brown tumor is a late manifestation and happens in advanced shpt , while they can rarely occur as an early sign of hpt . in the jaw bones
, it may present sometimes painful , hard and clearly palpable swellings , if a large deformity in affected bone occurred .
also an altered masticatory function and facial deformities can be seen , as was seen in the presented case , but it may be completely asymptomatic .
, showed that the diagnosis of brown tumor in esrd condition is suggested clinically and confirmed by the endocrinological status of the patient , and so based on history and labarotary test , brown tumor was his diagnosis .
but tc-99 m sestamibi scan can be useful for diagnosis of hpt , but normal scan in 30 and 240 minutes can be falsely negative . the scan must be done every 15 minutes , and false negative can be due to the fact that , it has been done only in 30  and 240  .
chang cw et al . , showed that imaging of parathyroid glands should be done only before to reoperation and is not usually required before initial parathyroidectomy .
according to the fact that hypocalcemia has the main role in shpt , correction of hypocalcemia and hyperphosphatemia with calcium and phosphate binders , and 1,25 dihydroxy vitamin d , is the cornerstone of treatment and prevention of secondary hpt and its complication .
patients with very severe shpt may be unresponsive to high - dose vitamin d and require parathyroidectomy as seen in the presented patient .
ishikawa y et al . , presented parathyroidectomy was a good choice for patients with high pth levels and diffuse brown tumor .
secondary hyperparathyroidism is a common complication of end - stage renal disease , on long time hemodialysis .
the scan is not required to confirm the hpt , and diagnosis of brown tumor is clinically in esrd .
it is important for general practitioner dentists , oral and maxillofacial surgeon , oral and maxillofacial radiologist , an endocrinologist and internist to be aware of shpt to diagnosis and treatment .
dentists should also be aware of possible presence of brown tumors in the jaws of patients having hpt or presented with radiologic finding of hpt to prevent fatal complications .
panoramic radiographs and ct scans were all useful radiographic methods for the correct diagnosis of brown tumour .
njp contributed in the conception of the work , conducting the study , revising the draft , approval of the final version of the manuscript , and agreed for all aspects of the work .
makh contributed in the conception of the work , drafting and revising the draft , approval of the final version of the manuscript , and agreed for all aspects of the work .
shjp contributed in the conception of the work , conducting the study , revising the draft , approval of the final version of the manuscript , and agreed for all aspects of the work .
makh contributed in the conception of the work , revising the draft , approval of the final version of the manuscript , and agreed for all aspects of the work .
 parathyroid glands produce parathyroid hormone ( pth ) . 
 pth has a main role in bone formation . 
 hyperparathyroidism ( hpt ) is explained as primary , secondary and tertiary types defined as overproduction of pth . the brown tumor or osteitis fibrosa cystica is a benign bone lesion that is caused by hpt . 
 this complication has been decreased by diagnosis and successful treatment of secondary hyperparathyroidism . 
 pelvis , ribs , clavicle , mandible and the extremities are most commonly affected bone in brown tumor , whereas maxillary involvement is rare . the present article report a 29-year - old man with chief complaints of bone pain , swelling cheeks and teeth displacement with secondary hpt . 
 parathyroidectomy was done due to bone disorder . 
 it is important for dentists and endocrinologists to understand maxillofacial manifestation of secondary hpt to prevent its complication . 
INTRODUCTION
CASE REPORT
Laboratory findings
Radiographic findings
DISCUSSION
CONCLUSION
AUTHOR'S CONTRIBUTION