Oral manifestations of renal osteodystrophy: case report and review of the literature

Brown Tumour in Chronic Kidney Disease: Revisiting an Old Disease with a New Perspective

Osteitis fibrosa cystica (OFC) and Brown Tumours are two related but distinct types of bone lesions that result from the overactivity of osteoclasts and are most often associated with chronic kidney disease (CKD). Despite their potential consequences, these conditions are poorly understood because of their rare prevalence and variability in their clinical manifestation. Canonically, OFC and Brown Tumours are caused by secondary hyperparathyroidism in CKD. Recent literature showed that multiple factors, such as hyperactivation of the renin-angiotensin-aldosterone system and chronic inflammation, may also contribute to the occurrence of these diseases through osteoclast activation. Moreover, hotspot KRAS mutations were identified in these lesions, placing them in the spectrum of RAS-MAPK-driven neoplasms, which were until recently thought to be reactive lesions. Some risk factors contributed to the occurrence of OFC and Brown Tumours, such as age, gender, comorbidities, and certain medications. The diagnosis of OFC and Brown Tumours includes clinical symptoms involving chronic bone pain and laboratory findings of hyperparathyroidism. In radiological imaging, the X-ray and Computed tomography (CT) scan could show lytic or multi-lobular cystic alterations. Histologically, both lesions are characterized by clustered osteoclasts in a fibrotic hemorrhagic background. Based on the latest understanding of the mechanism of OFC, this review elaborates on the manifestation, diagnosis, and available therapies that can be leveraged to prevent the occurrence of OFC and Brown Tumours.

Uremic Leontiasis Ossea: Theoretical Concepts and Practical Considerations

Leontiasis ossea (LO) in chronic kidney disease patients, also known as Sagliker syndrome, is an exceptionally uncommon uremic complication of long-lasting and severe secondary hyperparathyroidism. The prominent features of uremic LO (ULO) encompass the characteristic clinical trial of massive thickening of maxillary and mandibular bones, widening of interdental spaces, and flattening of nasal bridges and nares. Moreover, during the transformation of craniofacial architecture, significant structural and functional consequences may appear, including upper airway patency, visual and hearing acuity, oral phase of swallowing as well as various neurological and psychiatric disorders. Only few cases of ULO have been reported in the literature until now, making challenging not only the traditional diagnostic procedures but also the optimal therapeutic approach. In this narrative review, we aim to explore the underlying pathophysiological mechanisms, summarize the evidence for adverse outcomes, and highlight the current therapeutic strategies for ULO prevention and treatment, given that precise genetic determinants remain elusive.

Renal Osteodystrophy due to Secondary Hyperparathyroidism in a Cat

A 6 yr old neutered male mixed-breed cat presented for renal transplantation (RTx) for chronic kidney disease. Severe periodontal disease was identified, and before initiation of immunosuppressive therapy, a comprehensive oral health assessment and treatment procedure was performed to reduce the burden of existing oral infection. Dental radiography revealed diffuse, severe bone demineralization across the mandible and maxilla, with thinning of the cortices. Nasal turbinates were easily visualized owing to the decreased opacity of maxillary bone. Generalized bone resorption left teeth to appear minimally attached. A Vitamin D panel revealed a severely elevated parathyroid hormone level. Full mouth extractions were performed. Seven days following this procedure, RTx was performed. Serum creatinine concentration was within normal limits by 48 hr after surgery and remained normal until discharge 12 days after RTx. At 3.5 mo after RTx, the cat was mildly azotemic, and the parathyroid hormone level was elevated but significantly decreased from the original measurement. Secondary hyperparathyroidism is a common abnormality in cats with chronic kidney disease. However, clinical manifestations of hyperparathyroidism are rare in this species. This is a novel presentation of a cat demonstrating bone loss in the oral cavity as a result of renal secondary hyperparathyroidism.

Evaluation of renal osteodystrophy in the dental clinic by assessment of mandibular and phalangeal cortical indices

OBJECTIVES

Secondary hyperparathyroidism (SHPT) is a disease that affects patients with chronic kidney disease, and is characterized by mineral disturbance and bone loss, known as renal osteodystrophy. The aim of this study was to assess the validity of using intraoral phosphor storage plates to take radiographs of the middle phalanges to evaluate bone loss resulting from SHPT during follow-up of these patients.

METHODS

The sample consisted of 24 patients with chronic kidney disease, 12 with parathyroid hormone (PTH) levels ≥500 pg/ml, and 12 with PTH levels <500 pg/ml, who underwent hemodialysis weekly. For each patient, a panoramic radiograph and digital radiographs of the ring, index, and middle fingers of both hands were taken. The Mandibular Cortical Index (MCI) and the Trabecular Bone Pattern Index (TBP) were applied to the panoramic radiographs, while the Phalangeal Cortical Index (PCI) was applied to the digital radiographs of the phalanges. Three evaluators performed all analyses.

RESULTS

Significant correlations were found between the PTH levels and the MCI (p = 0.023), the PCI (p = 0.039) and the TBP index (p = 0.032). These parameters were also significantly interrelated (MCI × PCI = 0.001; MCI × TBP = 0.004 and PCI × TBP = 0.009). The PCI was shown to have the highest correlation with PTH levels.

CONCLUSION

In patients with chronic renal disease, it is clinically relevant to use panoramic and digital radiographs using intraoral storage plates to assess a number of quantitative parameters that can be linked to PTH levels.

Dental Manifestations of Pediatric Bone Disorders

PURPOSE OF REVIEW

Several bone disorders affecting the skeleton often are manifest in the maxillofacial region. This review presents the most common bone disorders in children and their dental-oral manifestations: fibrous dysplasia, Paget's disease, osteogenesis imperfecta, renal osteodystrophy, hypophosphatasia, and osteoporosis. The specific intraoral characteristics will reviewed in detail.

RECENT FINDINGS

Recent studies confirmed the close relationship between the mandible and the maxilla with the most prevalent systemic bone disorders in children. This review will help practitioners to integrate the oral health into the systemic health and improve the multidisciplinary approach of pediatric patients between medicine and dentistry.

Analysis of mandibular changes using panoramic-based indices in patients with chronic renal failure

INTRODUCTION

Chronic renal failure (CRF) is a progressive disease affecting many systems and causing dental and periodontal problems, in particular a decrease or loss in the amount of cortical bone that is visible on radiographs. Panoramic radiography is useful for determining these changes. The aim of this study was to evaluate cortical parts of the mandible using panoramic-based indices in patients with CRF.

METHODS

70 subjects with CRF were included in the study. The measurements of panoramic indices were made according to the visibility (mandibular cortical index, MCI) and thickness (mental index, MI) of the inferior cortex of the mandible. Then, these indices, obtained from 70 healthy controls of the same age and gender, were assessed and the results were compared. The effects of dental status and hemodialysis duration on MCI and MI were also investigated.

RESULTS

The frequency of an eroded cortex was significantly elevated in patients with CRF (p<0.05). The mean MI was lower in patients with CRF than in healthy subjects (5.53 ± 1.62 and 5.73 ± 1.31 mm, respectively), but the difference was not statistically significant (p>0.05). No correlation was found between hemodialysis duration and mandibular indices (p>0.05). Dental status was not associated with mandibular indices (p>0.05).

CONCLUSIONS

These results suggest that MCI might be a useful radiographic parameter for evaluating changes occurring in the cortical parts of the mandible in CRF patients. Clinicians should be aware of these changes while planning invasive dental treatments in CRF patients.

Severe maxillofacial renal osteodystrophy in two patients with chronic kidney disease

Renal osteodystrophy (ROD) is the bone pathology that occurs as an uncommon complication related to the several alterations in mineral metabolism present in patients with chronic kidney disease (CKD). This paper describes two cases of severe ROD affecting the maxilla and mandible and causing facial disfigurement of a young and a middle-aged female patient with CKD. Both patients had a history of secondary hyperparathyroidism, previously treated by surgery. The pathogenesis of the disease, as well as its clinical, imaging, and histopathological features, and management of the patient are discussed.

The osseous and dental changes of patients with chronic renal failure by CBCT

OBJECTIVES

The aim of the present study was to evaluate the osseous changes of the jaws of patients with chronic renal failure (CRF) by CBCT.

METHODS

On CBCT scans obtained from 15 patients with CRF and 15 control patients (7 males and 8 females), the mean was calculated for the antegonial index (AI), mental index (MI), panoramic mandibular index (PMI) and mandibular cortical index (MCI). The MI, AI and PMI, pulp chamber size, number of teeth with pulp calcification and lamina dura loss were compared using the paired t-test, and the MCI values were analysed using the χ(2) test.

RESULTS

There were no statistically significant differences in the PMI, MI and AI values in patients with CRF and the control group. With regard to MCI, the cortical margins of the mandible were more porous in patients with CRF than in the control group, and also soft-tissue calcifications, lamina dura loss and radiolucent defects were more common in patients with CRF. There were no statistically significant differences in pulp chamber size and pulp calcifications between patients with CRF and the control group.

CONCLUSIONS

Radiographic changes in the jawbones of patients with CRF may be commonly seen. CBCT is a valuable diagnostic tool for the evaluation of osseous findings, pulp chamber, soft-tissue calcifications and MCIs and allows indices measurement in three dimensions without any superposition.

Brown tumor at the jaw in patients with secondary hyperparathyroidism due to chronic renal failure

Brown tumors are bony lesions caused by rapid osteoclastic activity, which rare involved jaws. Renal osteodystrophy (ROD) is associated with different pathogenetic mechanisms--disorder of calcium-phosphate metabolism, impaired metabolism of vitamin D, increased parathyroid activity that lead to extreme concentrations of parathormone. The authors report two cases of jaw enlargement in patients received haemodialysis with excessive increase values of alkaline phosphatase and parathormone in serum. The patients were treated surgically with corrective procedures in maxillo-facial area. ROD of the jaws could be severe complication in dialysis patients with end stage of CKD if no appropriate care aimed at correction or prevention of parathyroid hyperfunction was applied to them.

Total parathyroidectomy with autotransplantation for a rare disease derived from uremic secondary hyperparathyroidism, the uremic leontiasis ossea

SUMMARY

We described six uremic leontiasis ossea (ULO) patients who underwent total parathyroidectomy with autotransplantation. ULO demonstrated more a systemic disease than a simple craniofacial deformation. The surgery seemed an effective treatment to alleviate secondary hyperparathyroidism and to improve patients' quality of life. ULO may have a high postoperative recurrence tendency.

INTRODUCTION

ULO is a rare disease derived from uremic secondary hyperparathyroidism (SHPT). Previous studies mostly focused on the craniofacial deformations. This study aims to investigate the systemic features of the disease and the surgical outcomes.

METHODS

The present study retrospectively assessed six ULO patients who underwent total parathyroidectomy (TPTX) with autotransplantation (AT). Follow-up data were recorded. The follow-up status was considered as "effectiveness" if serum intact parathyroid hormone (iPTH) levels were <150 pg/mL in the first 3 days after surgery, or as "recurrence" if serum iPTH gradually increased >300 pg/mL during follow-up in patients whose status was initially considered as "effectiveness".

RESULTS

Craniofacial deformations, short stature, thoracocyllosis, spine malformations, osteodynia, and muscle weakness were observed in all patients. Abnormal pulmonary functions were observed in five patients. After surgery, one patient died from respiratory failure. Surgery was effective in the remaining five patients with relieved osteodynia and stopped craniofacial deformation. A mean follow-up of 7.6 (4 to 12) months was available. Three patients suffered from recurrence of hyperparathyroidism originating from autografts.

CONCLUSIONS

Our data suggests that ULO is not only a simple disease with craniofacial malformations but is a severe systemic disease leading to increased surgical risks. TPTX with AT seems an effective treatment to relieve SHPT and to improve quality of life. ULO may have a high postoperative recurrence tendency.

Severe secondary hyperparathyroidism and panoramic radiography parameters

OBJECTIVES

Renal osteodystrophy (RO) are skeletal abnormalities seen in patients with secondary hyperparathyroidism (SHPT). This study aims to evaluate the effects of RO using panoramic radiography parameters. Furthermore, the correlation between these parameters and parathyroid hormone (PTH) levels was tested.

MATERIALS AND METHODS

Qualitative (mandibular cortical index/trabecular bone pattern) and quantitative parameters (mental index/calcification and resorption foci) were applied from panoramic radiographs of chronic kidney disease (CKD) patients and controls. Frequency distribution and descriptive analysis were used to compare the results of both groups. Spearman's correlation coefficient evaluated the correlation between serum PTH levels of CKD patients and the radiographic parameters. Intra- and interobserver agreement was tested using the intraclass correlation coefficient and kappa index.

RESULTS

Intra- and interobserver agreement was respectively excellent (0.81-1.00) and good (0.61-0.80). Qualitative parameters demonstrate significant difference compared with the control group. Mean mental index was lower in patients with CKD (3.17 ± 1.35 mm), but the difference was not significant. Calcification/resorption foci (3.63 ± 2.07) of CKD patients were significantly more present than in the control group (p = 0.0001). PTH levels were correlated with mental index, mandibular cortical index and trabecular bone pattern (respectively, 0.0034, 0.0315, and 0.0370).

CONCLUSIONS

RO presented a number of characteristic bone metabolic effects in the jaws that could be observed on panoramic radiographs. Radiographs of CKD patients demonstrate significantly more calcification and resorption.

CLINICAL RELEVANCE

The mental index, mandibular cortical index, and trabecular bone pattern are good parameters for evaluating the effects of RO on severe secondary hyperparathyroidism.

Correlation between hand/wrist and panoramic radiographs in severe secondary hyperparathyroidism

OBJECTIVES

Hand/wrist and dental radiographs are important for osteoporosis analysis in secondary hyperparathyroidism (SHPT). This study evaluated whether a correlation exists between the effects of the disease on the hands and jaws, and investigated the association between osteoporosis progression in the hands and parathyroid hormone (PTH) levels in chronic kidney disease (CKD) patients.

MATERIALS AND METHODS

Four panoramic radiographic parameters (mental index, mandibular cortical index, trabecular bone pattern, and calcification/resorption) and four corresponding hand/wrist radiographic parameters (metacarpal cortical thickness, phalangeal cortical index, trabecular bone pattern, and calcification/resorption) were applied to investigate possible correlation between the effects of SHPT on the jaws and hands/wrists, by Spearman's correlation coefficient. PTH levels and the hand/wrist radiographic parameters were also tested by spearman's correlation coefficient (p < 0.05). The presence of brown tumors, vascular calcifications, and acroosteolysis on the hands was also evaluated.

RESULTS

Mandibular cortical index was strongly correlated with the phalangeal cortical index (p = 0.000). Phalangeal cortical index and trabecular bone pattern of hand/wrist correlated with PTH levels (0.002 and 0.000, respectively). Brown tumors occurred in four CKD patients, while both vascular calcifications and acroosteolysis were observed in 19 patients.

CONCLUSION

There is a significant correlation between the morphological changes caused by secondary hyperparathyroidism in hand and jaw bones. The morphological status can be assessed using the mandibular cortical index, besides the phalangeal cortical index. The latter correlates well with parathyroid hormone levels of advanced chronic kidney disease.

CLINICAL RELEVANCE

Panoramic images reveal morphological changes in the jaw bone, indicating likewise changes in the hand/wrist in severe secondary hyperparathyroidism. The severity of the bone changes may be a reflection of the parathyroid hormone levels in advanced chronic kidney disease.

Characterization of mandibular bone in a mouse model of chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a worldwide health problem with increasing prevalence and poor outcomes, including severe cardiovascular disease and renal osteodystrophy. With advances in medical treatment, patients with CKD are living longer and require oral care. The aim of this study is to determine the effects of CKD and dietary phosphate on mandibular bone structure using a uremic mouse model.

METHODS

Uremia (U) was induced in female dilute brown agouti/2 mice by partial renal ablation. Uremic mice received a normal-phosphate (NP) or a high-phosphate (HP) diet. sham surgeries were performed in a control group of mice; half received an NP diet, and the other half was fed an HP diet. At termination, animals were sacrificed, and mandibles were collected for microcomputed tomography (micro-CT) and histologic analysis.

RESULTS

Sera levels of blood urea nitrogen, parathyroid hormone, and alkaline phosphatase were significantly increased in U/NP and U/HP mice versus sham controls, whereas serum calcium was increased in the U/HP group, and no differences were noted in serum phosphate levels among groups. Micro-CT analyses revealed a significant reduction in cortical bone thickness and an increase in trabecular thickness and trabecular bone volume/tissue volume in U/NP and U/HP groups compared to the sham/NP group. A significant reduction in cortical bone thickness was also found in the sham/HP group versus the sham/NP group. Histologic evaluation confirmed increased trabeculation in the U groups.

CONCLUSION

CKD in mice, especially under conditions of HP feeding, results in marked effects on alveolar bone homeostasis.