Paget’s Disease

Fibrous Dysplasia, Paget's Disease of Bone, and Other Uncommon Sclerotic Bone Lesions of the Craniofacial Bones

Imaging studies of the brain, head and neck, sinuses, and dental computed tomography are among the most frequently performed procedures in radiologic departments. Systematic evaluation in the bone window may reveal common and uncommon sclerotic osseous abnormalities of the craniofacial skeleton.Most of these findings are incidental and unrelated to the initial clinical indications. Sporadically symptoms may arise due to lesional mass effect with compression on adjacent structures and neuroforaminal encroachment, resulting in proptosis, vision, or hearing loss. Other symptoms include craniofacial deformity, mandibular occlusion deformity, and local pain.This article reviews the most common disorders characterized by an increased bone density involving the craniofacial bones including fibrous dysplasia, Paget's disease of bone, meningioma with associated hyperostosis, and osteoma. Finally, typical examples of rarer sclerosing bone dysplasias are discussed as well.Emphasis is placed on imaging features and the differential diagnosis.

Clinical and Microstructural Findings in Paget Disease of the Entire Mandible

Paget disease of bone (PDB) is a chronic progressive bone disorder characterized by localized increased bone turnover and focal areas of woven bone formation. Although skull involvement is common, PDB very rarely affects the mandible. This report describes the clinical and histologic findings in a 75-year-old patient with PDB involving the mandible. Microstructural analyses showed an altered quality of the bone microstructure and calcium depletion of the affected bone. Differential diagnosis of PDB affecting the mandible is discussed.

Paget's disease with craniofacial and skeletal bone involvement

Paget's disease is a metabolic disorder of bone caused due to defect in the remodelling process and is very common in western countries but is very rare in Asians and Africans. It was first described by a British scientist Sir James Paget in 1877. It can be monostotic or polyostotic depending on the number of bones involved. It most commonly affects older people of more than 50 years. Disease involvement can be symptomatic or asymptomatic depending on the extent of the disease process. Diagnosis of Paget's disease can be made by raised serum alkaline phosphatase levels, radiological examination and by radioisotope bone scans.

Multiple radiopaque mandibular lesions in a patient with Apert syndrome

INTRODUCTION

Apert syndrome (acrocephalosyndactyly) is a rare congenital malformation characterized by craniosynostosis, craniofacial anomalies, and symmetric syndactyly of the hands and feet. Oral manifestations usually include bifid uvula, a Byzantine arch palate associated with lateral swellings of the palatine processes, severe maxillary dental crowding associated with teeth malposition, severe open bite, dental caries, and gingival and periodontal disorders. Florid osseous dysplasia is an asymptomatic lesion mostly encountered during casual dental radiographic examinations as multiple sclerotic masses in 2 or more quadrants, usually in tooth-bearing regions.

METHODS

A 32-year-old woman diagnosed with Apert syndrome was seen in our department for a routine dental examination. Radiographic evaluation showed multiple radiopaque lesions in the mandible. All teeth with radiopaque lesions gave positive responses to vitality tests, and the patient did not report any symptoms. Based on the clinical and radiographic findings, the diagnosis of florid osseous dysplasia in a patient with Apert syndrome was made. Because there were no signs of an intraoral infectious process or endodontic needs, the patient was followed during revisions for Apert syndrome, and the only treatment provided was conservative management of the many carious lesions observed during the clinical examination.

CONCLUSIONS

To our knowledge, this is the first study reporting the occurrence of florid osseous dysplasia in a patient with Apert syndrome. Conservative management should be performed in asymptomatic cases. Although rare, our case report highlights the importance of florid osseous dysplasia as a condition that may mimic lesions with an endodontic origin in patients with Apert syndrome.

Regional aggressive root resorption caused by neuronal virus infection

During orthodontic treatment, root resorption can occur unexplainably. No clear distinction has been made between resorption located within specific regions and resorption occurring generally in the dentition. The purpose is to present cases with idiopathic (of unknown origin) root resorption occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root resorption were investigated clinically and radiographically. Anamnestic information revealed severe virus diseases during childhood, meningitis in one case and whooping cough in the other. One of the patients was treated with dental implants. Virus spreading along nerve paths is a possible explanation for the unexpected resorptions. In both cases, the resorptions began cervically. The extent of the resorption processes in the dentition followed the virus infected nerve paths and the resorption process stopped when reaching regions that were innervated differently and not infected by virus. In one case, histological examination revealed multinuclear dentinoclasts. The pattern of resorption in the two cases indicates that innervation is a factor, which under normal conditions may protect the root surface against resorption. Therefore, the normal nerve pattern is important for diagnostics and for predicting the course of severe unexpected root resorption.

Bisphosphonates: effects on osteoblast

PURPOSE

Bisphosphonates are synthetic analogues of pyrophosphate usually used in treating bone disorders such as osteoporosis, Paget's disease, fibrous dysplasia, hypercalcemia of malignancy, and inflammation-related bone loss. Though therapeutic effects of bisphosphonates depend primarily on their inhibitory effect on osteoclasts, increasing attention is being given to other effector cells, such as osteoblasts. This review focuses on the presumed effect of bisphosphonates on osteoblasts.

METHODS

A review of the literature was conducted to evaluate the pharmacodynamic effects of bisphosphonates including inhibition of osteoclasts and apoptosis of osteocytes and osteoblasts as well as their potential stimulatory effects on the proliferation of osteoblasts.

RESULTS

Studies have demonstrated that bisphosphonates may stimulate proliferation of osteoblasts and inhibit apoptosis of osteocytes and osteoblasts.

CONCLUSION

Considering that osteoblasts may be involved in bone disorders, such as osteoporosis, osteopetrosis, osteogenesis imperfecta, and Paget's disease, and that bisphosphonates may stimulate proliferation of osteoblasts and inhibit apoptosis of osteocytes and osteoblasts, it is conceivable that a role for bisphosphonates exists in these diseases beyond merely the osteoclast influence.

Paget's disease of the mandible

Paget's disease (PD) is a chronic progressive disease of the bone characterized by abnormal bone resorption and deposition affecting either single bone (monostotic) or many bones (polyostotic) with uncertain etiology. We report a case of isolated mandibular involvement in a 65-year-old female patient, clinically asymptomatic with abnormally increased alkaline phosphatase level (1 368.1 U/l). Although prevalence of PD is common in western countries, but rare in Asian chapter, that too isolated mandibular involvement, considering this fact, we report this case of PD for documentation.

Synchronous Paget disease of bone and hyperparathyroidism: report of a case with extensive craniofacial involvement

Paget disease of bone (PDB) and hyperparathyroidism (HPT) are metabolic osseous disorders which affect ≥2% of the population. As these diseases may share clinical, radiographic, biochemical, and histopathologic features, knowledge of their phenotypic overlap may provide diagnostic utility and improve clinical outcome. Scant information is available in the dental literature regarding patients concurrently affected with both pathologies. We present an unusual case report of a 63-year-old woman coaffected with primary HPT, attributed to a functional oxyphilic parathyroid adenoma, and PDB. Bone scintigraphy revealed pagetoid lesions of the skull, humeral head, spine, sacrum, and hemipelvis. Salient craniofacial features noted were bony involvement of the calvarium and midface, resulting in extensive maxillary overgrowth, hearing loss, telecanthus and consequent visual impairment, nasal deformity, and leontiasis ossea. The patient underwent a partial parathyroidectomy and bisphosphonate administration was to be initiated upon extraction of the remaining dentition.

Interferons and viruses: an interplay between induction, signalling, antiviral responses and virus countermeasures

The interferon (IFN) system is an extremely powerful antiviral response that is capable of controlling most, if not all, virus infections in the absence of adaptive immunity. However, viruses can still replicate and cause disease in vivo, because they have some strategy for at least partially circumventing the IFN response. We reviewed this topic in 2000 [Goodbourn, S., Didcock, L. & Randall, R. E. (2000). J Gen Virol 81, 2341-2364] but, since then, a great deal has been discovered about the molecular mechanisms of the IFN response and how different viruses circumvent it. This information is of fundamental interest, but may also have practical application in the design and manufacture of attenuated virus vaccines and the development of novel antiviral drugs. In the first part of this review, we describe how viruses activate the IFN system, how IFNs induce transcription of their target genes and the mechanism of action of IFN-induced proteins with antiviral action. In the second part, we describe how viruses circumvent the IFN response. Here, we reflect upon possible consequences for both the virus and host of the different strategies that viruses have evolved and discuss whether certain viruses have exploited the IFN response to modulate their life cycle (e.g. to establish and maintain persistent/latent infections), whether perturbation of the IFN response by persistent infections can lead to chronic disease, and the importance of the IFN system as a species barrier to virus infections. Lastly, we briefly describe applied aspects that arise from an increase in our knowledge in this area, including vaccine design and manufacture, the development of novel antiviral drugs and the use of IFN-sensitive oncolytic viruses in the treatment of cancer.

Paget's disease of bone in a Chinese patient: A case report and review of the literature

Although it is fairly common in the Western countries, Paget's disease of bone is very rare in Chinese individuals. Through an extensive literature search, only 8 Chinese Paget's disease cases were found in the English language literature and all were reported in local medical journals of Asia that may not be accessible to international readers. To enhance the awareness of the rarity of Paget's disease in Chinese individuals to pathologists worldwide, we present a case of Paget's disease in a 54-year-old Chinese male. We also compare the clinical features of Paget's disease reported in Chinese patients to Paget's disease reported in the Western countries. No familial cases and no malignant transformation are found in the reported cases of Paget's disease in Chinese patients. In addition, more often skull involvement, higher frequency of monostotic cases, and symptomatic cases are observed in this limited number of Paget's disease cases reported in Chinese individuals.