Profound T Lymphocyte and DNA Repair Defect Characterizes Schimke Immuno-Osseous Dysplasia.

Schimke immuno-osseous dysplasia is a rare multisystemic disorder caused by biallelic loss of function of the SMARCAL1 gene that plays a pivotal role in replication fork stabilization and thus DNA repair. Individuals affected from this disease suffer from disproportionate growth failure, steroid resistant nephrotic syndrome leading to renal failure and primary immunodeficiency mediated by T cell lymphopenia. With infectious complications being the leading cause of death in this disease, researching the nature of the immunodeficiency is crucial, particularly as the state is exacerbated by loss of antibodies due to nephrotic syndrome or immunosuppressive treatment. Building on previous findings that identified the loss of IL-7 receptor expression as a possible cause of the immunodeficiency and increased sensitivity to radiation-induced damage, we have employed spectral cytometry and multiplex RNA-sequencing to assess the phenotype and function of T cells ex-vivo and to study changes induced by in-vitro UV irradiation and reaction of cells to the presence of IL-7. Our findings highlight the mature phenotype of T cells with proinflammatory Th1 skew and signs of exhaustion and lack of response to IL-7. UV light irradiation caused a severe increase in the apoptosis of T cells, however the expression of the genes related to immune response and regulation remained surprisingly similar to healthy cells. Due to the disease's rarity, more studies will be necessary for complete understanding of this unique immunodeficiency.

Differential diagnosis of cemento-osseous dysplasia and periapical cyst using texture analysis of CBCT.

BACKGROUND: Radiolucencies found at the root apex in patients with cemento-osseous dysplasia (COD) may be mistaken for periapical cysts (PC) of endodontic origin. The purpose of this study was to examine the utility of quantitative texture analysis using cone-beam computed tomography (CBCT) to differentiate between COD and PC. METHODS: Patients who underwent CBCT at Wonkwang University Daejeon Dental Hospital between January 2019 and December 2022 and were diagnosed with COD and PC by clinical, radiologic, and, if necessary, histopathologic examination were included. Twenty-five patients each were retrospectively enrolled in the COD and PC group. All lesions observed on axial CBCT images were manually segmented using the open-access software MaZda version 4.6 to establish the regions of interest, which were then subjected to texture analysis. Among the 279 texture features obtained, 10 texture features with the highest Fisher coefficients were selected. Statistical analysis was performed using the Mann-Whitney U-test, Welch's t-test, or Student's t-test. Texture features that showed significant differences were subjected to receiver operating characteristics (ROC) curve analysis to evaluate the differential diagnostic ability of COD and PC. RESULTS: The COD group consisted of 22 men and 3 women, while the PC group consisted of 14 men and 11 women, showing a significant difference between the two groups in terms of sex (p=0.003). The 10 selected texture features belonged to the gray level co-occurrence matrix and included the sum of average, sum of entropy, entropy, and difference of entropy. All 10 selected texture features showed statistically significant differences (p<0.05) when comparing patients with COD (n=25) versus those with PC (n=25), osteolytic-stage COD (n=11) versus PC (n=25), and osteolytic-stage COD (n=11) versus cementoblastic-stage COD (n=14). ROC curve analysis to determine the ability to differentiate between COD and PC showed a high area under the curve ranging from 0.96 to 0.98. CONCLUSION: Texture analysis of CBCT images has shown good diagnostic value in the differential diagnosis of COD and PC, which can help prevent unnecessary endodontic treatment, invasive biopsy, or surgical intervention associated with increased risk of infection.

No NFATC2 fusion in simple bone cyst of the jaw.

AIMS: Simple Bone Cysts (SBCs) predominantly occur in long bones and 59% harbour NFATC2 rearrangements. Jaw SBC is rare and was previously referred to as traumatic bone cyst. It can rarely occur in association with cemento-osseous dysplasia (COD). To determine whether jaw SBCs represent the same entity as SBC of the long bones, or if they have a different molecular signature, we collected 48 jaw SBC cases of 47 patients to assess NFATC2 rearrangement. METHODS AND RESULTS: Out of the 48 cases, 36 could be used for fluorescence in-situ hybridization (FISH), of which nine (two of which associated with COD) were successful using an NFATC2 split probe. The remaining cases failed to show adequate FISH signals. All nine cases lacked NFATC2 rearrangement and five of these showed no detectable gene fusions using Archer FusionPlex. CONCLUSION: In our study, NFATC2 rearrangement is absent in solitary jaw SBC (n = 7) and COD-associated SBC (n = 2). Our findings suggest that SBC presenting in the jaw is molecularly different from SBC in long bones. Future molecular studies may confirm the absence of clonal molecular aberrations in SBC of the jaw which would support a non-neoplastic, reactive origin.

Clinical course of post-kidney transplant Schimke immuno-osseous dysplasia.

BACKGROUND: Schimke immuno-osseous dysplasia (SIOD) is a rare systemic disease characterized by short stature, proteinuria, and recurrent infections. Patients usually have spondyloepiphyseal dysplasia, and progressive steroid-resistant nephropathy that leads to kidney failure. However, their clinical course after kidney transplantation (KT) is not yet well known. Here, we present our experience with cases of SIOD treated at our institute. CASE PRESENTATION: Since 2014, three children have been diagnosed with nephropathy resulting from SIOD. They presented with proteinuria in the nephrotic range at 7, 5, and 3 years of age. Focal segmental glomerulosclerosis was confirmed and progressed to kidney failure approximately 2 years after proteinuria was detected. These patients underwent living-donor KT from their parents. After KT, Case 1 lost his graft within 7 months due to multi-organ failure caused by disseminated adenovirus infection and died. Case 2 experienced graft failure 5 years after KT due to acute rejection from poor compliance. In Case 3, the allograft was still functioning 6 years after KT with low-dose tacrolimus single medication (trough level < 5 ng/mL). Extra-renal manifestations progressed regardless of KT, namely, right renal vein thrombosis and pulmonary hypertension in Case 1, severe bilateral hip dysplasia and Moyamoya syndrome in Case 2, and neutropenia and thrombocytopenia in Case 3, in addition to recurrent infection. CONCLUSION: In SIOD patients, KT is complicated with recurrent infections due to their inherent immune dysfunction. Additionally, extra-renal symptoms may render the patients morbid despite the recovery of kidney function.

Successful low-dose immunotherapy after kidney transplantation in a 10-year-old girl with Schimke immuno-osseous dysplasia.

BACKGROUND: This case report highlights a successful steroid-free, low-dose immunosuppressive protocol for renal transplantation in a pediatric patient with Schimke immuno-osseous dysplasia with excellent 7-year patient and graft survival. Schimke immuno-osseous dysplasia is a rare multisystem disorder involving the kidney. Renal transplantation is a therapeutic option, but posttransplant mortality is high due to severe infections and posttransplant lymphoproliferative disease. METHODS: A 10-year-old girl diagnosed with Schimke immuno-osseous dysplasia and end-stage renal disease underwent an AB0-compatible living-related kidney transplantation, with no donor-specific antibodies. Our standard immunosuppression protocol was modified due to the risk of infection. Basiliximab was used as induction therapy, and a reduced dose of mycophenolate mofetil and tacrolimus was initiated following transplantation, maintaining the patient on a low tacrolimus target (3-5 µg/L). Mycophenolate mofetil was discontinued after 8 weeks due to neutropenia and the patient was kept on tacrolimus as monotherapy. Five years posttransplant the patient developed acute onset of neurological symptoms, consisting of ataxia, lack of voluntary coordination, balance, aphasia and dysphagia, and diplopia. She recovered without neurological deficits within 6 weeks. Extensive evaluation revealed no pathology. To avoid a possible a component of tacrolimus-induced cerebral vasoconstriction, the immunosuppressive therapy was changed to everolimus. RESULTS: Seven years posttransplant, the patient has experienced no serious infections, no rejections, and had excellent graft function, and no de novo donor-specific antibodies. CONCLUSIONS: The present results indicate that low-dose immunosuppressive therapy after renal transplantation with low immunological risk should be considered for patients with Schimke immuno-osseous dysplasia.

Florid cemento-osseous dysplasia-related osteonecrosis: A series of cases.

OBJECTIVE: The aim of this study was to assess the clinicopathological features of florid cemento-osseous dysplasia (FCOD)-related osteonecrosis highlighting their histopathological aspects and bone structure. METHODS: Twenty-two FCOD-related osteonecrosis cases were evaluated retrospectively. Osteonecrosis, osteomyelitis, bacterial colonization, bone resorption, reactive bone, osteon-like structure, lamellar bone, and basophilic lines were analyzed. Specific staining and fluorescence and polarized light microscopy analyses were also performed. RESULTS: The mandible was more affected by FCOD-related osteonecrosis. There was a predominance of African-Brazilian women in the fifth and seventh decades of life. Osteomyelitis was present in 82 % of cases whereas bone resorption and bacterial colonization were present in 100 % of FCOD-related osteonecrosis cases. Thick basophilic lines were seen in all cases (100 %). Actinomycosis and osteoclasts were not often. CONCLUSIONS: This study showed female adult preference, mandibular location, and some findings such as osteomyelitis, bone resorption, and bacterial colonization were histopathological features more frequent in FCOD-related osteonecrosis. In the absence of a close clinical and radiographic correlation, the morphology of the necrotized bone similar to cementum could help to recognize FCOD.

Terminal osseous dysplasia with pigmentary defects and cardiomyopathy caused by a novel FLNA variant.

Terminal osseous dysplasia with pigmentary defects (TODPD), also known as digitocutaneous dysplasia, is one of the X-linked filaminopathies caused by a variety of FLNA-variants. TODPD is characterized by skeletal defects, skin fibromata and dysmorphic facial features. So far, only a single recurrent variant (c.5217G>A;p.Val1724_Thr1739del) in FLNA has found to be responsible for TODPD. We identified a novel c.5217+5G>C variant in FLNA in a female proband with skeletal defects, skin fibromata, interstitial lung disease, epilepsy, and restrictive cardiomyopathy. This variant causes mis-splicing of exon 31 predicting the production of a FLNA-protein with an in-frame-deletion of 16 residues identical to the miss-splicing-effect of the recurrent TODPD c.5217G>A variant. This mis-spliced transcript was explicitly detected in heart tissue, but was absent from blood, skin, and lung. X-inactivation analyses showed extreme skewing with almost complete inactivation of the mutated allele (>90%) in these tissues, except for heart. The mother of the proband, who also has fibromata and skeletal abnormalities, is also carrier of the FLNA-variant and was diagnosed with noncompaction cardiomyopathy after cardiac screening. No other relevant variants in cardiomyopathy-related genes were found. Here we describe a novel variant in FLNA (c.5217+5G>C) as the second pathogenic variant responsible for TODPD. Cardiomyopathy has not been described as a phenotypic feature of TODPD before.

Florid Cemento-osseous Dysplasia: A Report of Two Cases and Literature Review.

AIM: This report aims to provide the clinical and radiographic features of two symptomatic Indian patients with florid cemento-osseous dysplasia (FCOD), along with a discussion of the differential diagnosis, potential challenges, and therapeutic implications. BACKGROUND: FCOD is a rare, multifocal, periapical, and bilateral condition involving the premolar and molar region of the posterior mandible and sometimes the maxilla. CASE DESCRIPTION: The first patient is a 30-year-old female with a recent history of dental pain. The patient was otherwise healthy and the medical history was unremarkable. The second patient is a 50-year-old female with a history of orthodontic therapy. Radiographic evaluation using cone-beam computed tomography (CBCT) revealed bilateral involvement of the posterior mandible, sparing the entire maxilla in both patients Clinical significance: For a pathognomonic condition like FCOD, a radiology survey alone is often sufficient to arrive at the final diagnosis, and therefore surgical interventions should ideally be avoided.

Podocytic infolding in Schimke immuno-osseous dysplasia with novel SMARCAL1 mutations: a case report.

BACKGROUND: Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive disorder characterized by spondyloepiphyseal dysplasia, progressive renal insufficiency and defective cellular immunity. Podocytic infolding glomerulopathy (PIG) is a newly proposed disease entity characterized by microspheres or microtubular structures associated with podocytes infolding into the glomerular basement membrane (GBM) on electron microscopy (EM). CASE PRESENTATION: A 4-year-old boy was admitted to our ward due to proteinuria and edema lasting 1 month. He had a short trunk and demonstrated subtle dysmorphology, with a triangular shape, a broad nasal bridge and a bulbous nasal tip. The laboratory findings were as follows: lymphocytes, 0.5 × 109/L; urine protein, 3.67 g/d; albumin, 9.8 g/L; and cholesterol, 11.72 mmol/L. Skeletal X rays showed small iliac wings, small ossification centers of the capital femoral epiphyses, shallow dysplastic acetabular fossae and mildly flattened vertebrae. The specimen for light microscopy (LM) suggested focal segmental glomerulosclerosis (FSGS). EM revealed a focal thickness of the GBM with some cytoplasmic processes of podocyte infolding into the GBM. Gene sequencing showed novel compound heterozygous mutations in the SMARCAL1 gene (c.2141 + 5G > A; c.2528 + 1G > A) that were inherited from his parents. Finally, we established the diagnosis of SIOD and treated him with diuretics and angiotensin-converting enzyme inhibitors (ACEIs). CONCLUSION: The pathogenic mechanism of PIG has not been clarified. Further studies are required to understand whether gene mutations, especially those related to podocytes, contribute to the pathogenesis of podocytic infolding.

Craniofacial bone alterations in patients with neurofibromatosis type 1.

Osseous manifestations of neurofibromatosis 1 (NF-1) occur in a minority of the affected subjects but may be because of significant clinical impairment. Typically, they involve the long bones, commonly the tibia and the fibula, the vertebrae, and the sphenoid wing. The pathogenesis of NF-1 focal osseous lesions and its possible relationships with other osseous NF-1 anomalies leading to short stature are still unknown, though it is likely that they depend on a common mechanism acting in a specific subgroup of NF-1 patients. Indeed, NF-1 gene product, neurofibromin, is expressed in all the cells that participate to bone growth: osteoblasts, osteoclasts, chondrocytes, fibroblasts, and vascular endothelial cells. Absent or low content of neurofibromin may be responsible for the osseous manifestations associated to NF-1. Among the focal NF-1 osseous anomalies, the agenesis of the sphenoid wing is of a particular interest to the neurosurgeon because of its progressive course that can be counteracted only by a surgical intervention. The sphenoid wing agenesis is regarded as a dysplasia, which is a primary bone pathology. However, its clinical progression is related to a variety of causes, commonly the development of an intraorbital plexiform neurofibroma or the extracranial protrusion of temporal lobe parenchyma and its coverings. Thus, the cranial bone defect resulting by the primary bone dysplasia is progressively accentuated by the orbit remodeling caused by the necessity of accommodating the mass effect exerted by the growing tumor or the progression of the herniated intracranial content. The aim of this paper is to review the neurosurgical and craniofacial surgical modalities to prevent the further progression of the disease by "reconstructing" the normal relationship of the orbit and the skull.

Cone-beam computed tomography analysis of cemento-osseous dysplasia-induced changes in adjacent structures in a Brazilian population.

OBJECTIVES: To describe the effects of cemento-osseous dysplasia (COD) on anatomical structures. METHODS: CBCT scans were retrospectively selected from a database of individuals who attended an Oral Medicine service. Cases with a confirmed diagnosis of periapical, focal, or florid COD were included. Two oral and maxillofacial radiologists assessed the scans. Frequencies of the variables were described according to COD case, lesion areas, and teeth. RESULTS: Sixty COD cases affected 244 areas and 426 teeth. Florid COD was the most common (n = 48). Cortical bone (buccal, lingual, palatine, or mandibular) (n = 42) and the maxillary sinus (n = 13) were the structures most frequently affected by displacement or perforation. Thinning (n = 80), expansion (n = 62), and perforation (n = 60) of the cortical bone were common effects. The median size of the lesions was 12 mm in the mesiodistal direction, 8 mm in the buccal-lingual/palatal direction, and 9 mm in the superior-inferior direction. Root resorption was observed in 18.1% of all teeth, while tooth displacement was uncommon (0.6%). All teeth affected by COD had a discontinuous lamina dura and non-uniformly visible periodontal ligament space. CONCLUSIONS: CBCT images revealed that cortical bone, lamina dura, and periodontal ligament space were the structures most affected by COD and the effects of COD on anatomical structures were more frequent than previously described. CLINICAL RELEVANCE: CODs are fibro-osseous lesions common in the clinical practice, and relationship with anatomical structures is poorly described. CBCT is an appropriate method for the diagnosis and follow-up of patients with COD.

Odontoma associated with mandibular transmigrated canine in a geriatric patient: Second case report.

OBJECTIVE: This report discusses the clinical relevance of a novel case of an odontoma and transmigrated canine in the setting of florid cemento-osseous dysplasia (COD), hypercementosis and moderate to severe periodontitis in a 66-year-old patient. BACKGROUND: An odontoma may infrequently impede tooth eruption and rarely has been implicated with canine transmigration. COD is a benign fibro-osseous lesion associated with decreased vascularity and poorer surgical intervention. MATERIALS AND METHODS: A partially edentulous woman, in no acute distress, underwent clinical and radiographic evaluation in pursuit of comprehensive dental care. RESULTS: Radiographic assessment demonstrated multiple occult pathologies of the mandible, including compound odontoma, canine transmigration, florid COD, hypercementosis and moderate to severe periodontitis, a concurrence thought to be previously unreported. Furthermore, the presence of the odontoma and transmigrated canine is apparently the second reported case in the geriatric population. CONCLUSIONS: The attending clinician should carefully weigh removal of an impacted and transmigrated canine associated with an odontoma in the setting of COD and compromised bone, particularly in older individuals. When surgical intervention is deferred in these clinical situations, patients should continue to be monitored for clinical and radiographic development of pathologic processes.

Concomitant cemento-osseous dysplasia and aneurysmal bone cyst of the mandible: a rare case report with literature review.

BACKGROUND: Concomitant cemento-osseous dysplasia (COD) and aneurysmal bone cyst (ABC) are rare in the head and neck region. In our search of the English language literature, we found only one case report describing the simultaneous occurrence of COD and ABC in the head and neck region. Here, we report a case of COD associated with ABC. Further, we performed a systematic search of the literature to identify studies on patients with COD associated with nonepithelial lined cysts of the jaws. CASE PRESENTATION: The patient was a 32-year-old woman who was referred from a private dental clinic because of a cystic lesion below the mandibular right first molar. She had no pain or significant systemic disease. After performing panoramic radiography and cone-beam computed tomography, the imaging diagnosis was COD with a cystic lesion, such as ABC or solitary bone cyst. Excisional biopsy was performed, which revealed concomitant COD and ABC. CONCLUSION: This case of ABC associated with COD provides insight for the diagnostic process of radiographically mixed lesions with cystic changes.

Difficulties in the diagnosis of periapical translucencies and in the classification of cemento-osseous dysplasia.

BACKGROUND: Cemento-osseous dysplasia is a benign fibro-osseous lesion of the tooth-bearing region of the jaws with a periodontal ligament origin. It appears predominantly in Black and Asian middle-aged females. Its importance is that it could mimic a periapical lesion in the early, translucent stage. CASE PRESENTATION: In this report a rare case of familial cemento-osseous dysplasia is presented: a 50-years old Caucasian woman with labial paraesthesia and radiological translucency around the roots of the mandibular incisors and the first molar teeth. The lesion around the first molar was diagnosed as periapical granuloma and a root canal treatment was carried out. The diagnosis of florid cemento-osseous dysplasia and the treatment plan based on two- and three-dimensional radiographic examinations were certified histologically after surgical removal of the lesion. We screened the family members - including the patient's mother, daughter and son - and identified a periapical version of cemento-osseous dysplasia in the daughter. Our case highlights the difficulties of differential diagnosis of cemento-osseous dysplasia and other periapical pathologies. The inconsistencies in the present classification of cemento-osseous dysplasia are also discussed with a proposal for a different classification based on new aspects that would be very helpful in setting up a correct treatment plan. CONCLUSION: Differentiation of endodontic and non-endodontic origin of radiolucency and distinguishing it from anatomical landmarks by appropriate clinical evaluation and using vitality testing can give an opportunity to prevent unnecessary endodontic treatment. The current categories of cemento-osseous dysplasia classification do not cover the early stage of a hereditary florid form of cemento-osseous dysplasia. Instead of anatomical location of the lesion, clinical and genetic features may be recommended as parameters of cemento-osseous dysplasia classification.

Terminal osseous dysplasia presenting with intracytoplasmic inclusion bodies in digital fibromas.

Terminal osseous dysplasia is a rare, X-linked syndrome, presumptively embryonic lethal in males, which has recently been described with highly characteristic skin findings. The presence of intracytoplasmic inclusion bodies in fibroblasts has been considered an exclusive finding of infantile digital fibromatosis. This is the first report documenting digital fibromas with intracytoplasmic inclusion bodies in a classic case of terminal osseous dysplasia.

Successful Implant Placement in a Case of Florid Cemento-Osseous Dysplasia: A Case Report and Literature Review.

Florid cemento-osseus dysplasia (FCOD) has been described as a reactive process in which normal bone is replaced by fibrous connective tissues and cementum-like materials. Radiographically it appears as dense, lobulated masses, often occurring bilaterally with symmetric involvement. In this case report, a successful implant placement has been reported in a 62-year-old Caucasian woman with a chief complaint of mandibular partial edentulous. Radiographic images showed the bilateral radiopaque lesions in edentulous regions of mandible, and mandibular anterior teeth alike. All mandibular teeth were vital and no root resorption was detected. The findings of X-ray images were attributable to FCOD. A highly conservative step-by-step 2-stage implant surgery was performed. After 6 months the implants loaded with fixed prosthesis. 2, 4, 6, 12, and 18 months after the surgery radiographic images were taken, which revealed an optimal functional rehabilitation and complete integration of implants. This report confirms that treating the edentulous area near the FCOD lesions could be planned, if conservative step- by-step implant placement been considered. To the best of our knowledge, a case of FCOD with successful implant placement has not been reported previously. More studies in more patients are needed to confirm results of such a therapeutic modality.

Diagnosis and management of benign fibro-osseous lesions of the jaws: a current review for the dental clinician.

Benign fibro-osseous lesions of the maxillofacial skeleton constitute a heterogeneous group of disorders that includes developmental, reactive (dysplastic) and neoplastic lesions. Although their classification has been reviewed multiple times in the past, the most common benign fibro-osseous lesions are fibrous dysplasia, osseous dysplasia and ossifying fibroma. For the dental clinician, the challenges involve diagnosis and treatment (or lack thereof). A careful correlation of all clinical, radiologic and microscopic features is essential to establish a proper diagnosis and a clear treatment plan. This article aimed to review the clinical, radiologic and histopathologic characteristics of benign fibro-osseous lesions of the jaws, with emphasis on their differential diagnoses. With a deeper understanding of benign fibro-osseous lesions, clinicians will be better prepared to manage these lesions in their practice.

A novel compound heterozygous mutation of the SMARCAL1 gene leading to mild Schimke immune-osseous dysplasia: a case report.

BACKGROUND: Schimke immune-osseous dysplasia (SIOD, OMIM 242900) is characterized by spondyloepiphyseal dysplasia, T-cell deficiency, renal dysfunction and special facial features. SMARCAL1 gene mutations are determined in approximately 50% of patients diagnosed with SIOD. CASE PRESENTATION: The case presented here is that of a 6-year-old boy who was born at 33 weeks to healthy, non-consanguineous Chinese parents. He presented with short stature (95 cm; <3rd percentile) and proteinuria. Initially suspected of having IgM nephropathy, the patient was finally diagnosed with mild Schimke immune-osseous dysplasia. One novel mutation (p.R817H) and one well-known mutation (p.R645C) was identified in the SMARCAL1 gene. CONCLUSION: This report describes a clinical and genetic diagnostic model of mild SIOD. It also highlights the importance of molecular testing or clinical diagnosis and the guidance it provides in disease prognosis.

Florid cemento-osseous dysplasia: review of an uncommon fibro-osseous lesion of the jaw with important clinical implications.

Florid cemento-osseous dysplasia (FCOD) is a rare, benign, multifocal fibro-osseous dysplastic process affecting tooth-bearing areas of the jaw, characterized by replacement of normal trabecular bone with osseous tissue and dense acellular cementum in a fibrous stroma. It is one clinicopathologic variant in a spectrum of related non-neoplastic fibro-osseous lesions known as cemento-osseous dysplasias (CODs), thought to arise from elements of the periodontal ligament. Diagnosis primarily relies upon radiographic and clinical findings; unnecessary biopsy should be avoided, as inoculation with oral pathogens may precipitate chronic infection in these hypovascular lesions. Appropriate management of uncomplicated FCOD consists of periodic radiographic follow-up. Accordingly, it is important that both radiologists and clinicians performing endodontic interventions possess familiarity with this entity in order to prevent misdiagnosis and inappropriate intervention, which may result in a protracted clinical course. Lesions are usually asymptomatic in the absence of infection, typically discovered on routine dental radiographs or imaging performed for unrelated indications. Radiographically, the condition typically manifests as widespread non-expansile intraosseous masses of varying internal lucency and sclerosis that surround the root apices of vital teeth or edentulous areas in the posterior jaw. While all CODs share similar microscopic features, FCOD is distinguished by its multifocal distribution, involving two or more quadrants of the maxilla and mandible, often in a bilateral symmetric fashion. The vast majority of cases are sporadic, though few exhibit an autosomal dominant familial inheritance pattern. In this pictorial review, we discuss the radiologic characteristics of this entity, pertinent clinical and histologic features, differential diagnoses, and management options.

Differentiating early stage florid osseous dysplasia from periapical endodontic lesions: a radiological-based diagnostic algorithm.

BACKGROUND: Osseous dysplasia (OD) is the most common fibro-osseous lesion of the jaw affecting the periapical region. Early stages of OD can resemble periapical radiolucencies, thus mimicking the radiological aspects of an endodontic pathology. Such radiolucent lesions affecting previously decayed or treated teeth are even more complex to interpret. CASE PRESENTATION: The aim of this paper is to report a case-series of representative clinical situations describing the radiological features and illustrating the diagnostic workup of patients with florid osseous dysplasia (FOD). Emphasis is given to the endodontic implications of such periapical bone disease and the complexity of accurate diagnosis in the context of endodontic retreatment. We then propose a practical radiological-based diagnostic algorithm to assist the clinician in the diagnostic of OD periapical lesions. CONCLUSION: Periapical lesions may be confused with bone diseases such as osseous dysplasia, especially in the radiolucent initial stage. Knowledge of clinical features associated with a careful reading of cone beam CT images, such as fine opacities within the hypodense periapical lesion, may help determine the right diagnostic.