Genetic Disorders and Bone Affecting the Craniofacial Skeleton

A Novel lncRNA Mediates the Delayed Tooth Eruption of Cleidocranial Dysplasia

Delayed eruption of permanent teeth is a common symptom of cleidocranial dysplasia (CCD). Previous studies have focused on the anomaly of osteogenesis resulting from mutations in the Runt-related transcription factor-2 gene (RUNX2). However, deficiencies in osteoclastogenesis and bone resorption, and the epigenetic regulation mediated by long non-coding (lnc)RNAs in CCD remain to be elucidated. Here, a novel osteoclast-specific lncRNA (OC-lncRNA) was identified during the osteoclast differentiation of RAW 264.7 cells transfected with a RUNX2 mutation expression cassette. We further confirmed that OC-lncRNA positively regulated osteoclastogenesis and bone resorption. The OC-lncRNA promoted the expression of CXC chemokine receptor type 3 (CXCR3) by competitively binding to microRNA (miR)-221-5p. The CXCR3–CXC-motif chemokine ligand 10 (CXCL10) interaction and nuclear factor-κB constituted a positive feedback that positively regulated osteoclastogenesis and bone resorption. These results demonstrate that OC-lncRNA-mediated osteoclast dysfunction via the OC-lncRNA–miR-221-5p–CXCR3 axis, which is involved in the process of delayed tooth eruption of CCD.

[Clinical and imaging characteristics of familial gigantiform cementoma. A review of the literature]

Familial gigantiform cementoma (FGC) is a rare benign fibro-cementum lesion, which follows an autosomal dominant inheritance pattern and presents during childhood. It is limited to the bones of the face, with a predilection for the jaw, is fast growing and painless and expands considerably over time. It is considered among the seven disorders that affect the physiognomy of the craniofacial skeleton. Radiographically, FGC occurs in three stages of maturation similar to bone dysplasia, being radiolucent, mixed and radiopaque and is described as a mixed lobular well delimited mass, which can occur in both maxillae, causing expansion of the buccal and palatal / lingual bone cortices. displacement and retention of teeth. The aim of this study was to perform a review of the literature to identify the clinical, radiographic and histopathological characteristics of FGC in the jaws and describe the imaging tools that are useful for the diagnosis and follow-up of this lesion.

Case report of osteomyelitis of the mandible in osteopetrosis and management considerations

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Management guidelines in mandibular osteomyelitis in Osteopetrosis.

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A female patient with osteopetrosis presented osteomyelitis after teeth extraction.

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Our case suggests the importance to maintain at maximum existing mandibular bone.

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Dental prevention could reduce occurrence of osteomyelitis in Osteopetrosis.

Introduction and importance

Osteopetrosis is a poorly known and probably underdiagnosed pathology. It is caused by various genetic abnormalities resulting in osteoclast dysfunction. Functional and aesthetic consequences have a major impact on the patient’s quality of life. Ten percent of osteopetrosis cases develop osteomyelitis that usually involves the mandible. Management of this complication remains complex and often unsatisfactory.

Case presentation

We report a case of a 62-year-old woman with osteopetrosis, complicated by mandibular osteomyelitis with intra-oral bone exposure and submental fistulas. Management was performed with antibiotic therapy and surgical necrotic resection. This cured the fistulas but the bone exposure persisted.

Discussion

This case report highlights the difficulty of achieving complete healing of osteomyelitis in osteopetrosis. Antibiotic therapy, surgical management, or even hyperbaric oxygen therapy are required, but must be adapted to the case. A free flap procedure is undesirable but, when it is necessary, a bone marrow transplant could be considered to restore osteoclast function.

Conclusion

The management of mandibular osteomyelitis in patients with osteopetrosis must adapt to the situation and severity. To avoid most cases of osteomyelitic complications in patients suffering from osteopetrosis, we propose that a preventive strategy of better dental care should be considered.

Maxillary osteomyelitis associated with osteopetrosis: Systematic review

Osteopetrosis is a rare condition which presents increased bone density and deficient bone remodeling. The consequential complications include cranial nerve impairment due compression, bone fractures, and osteomyelitis. Maxillary osteomyelitis is uncommon even in osteopetrosis patients. This is a systematic review of the literature regarding the management and outcomes of maxillary osteomyelitis in patients with autosomal dominant osteopetrosis (ADO) type II. A case of this specific pathology is reported. There are 18 cases of maxillary osteomyelitis associated with ADO type II reported in the literature. The mean age of the patients reported was 33.5 (SD 15.9) years, and the male:female ratio was 1:1. Antibiotic therapy was variable, and amoxicillin with clavulanic acid was the main choice (33.33%). Surgery or sequestrectomy was performed in 88.89% of the studies. Complete healing was achieved in only 44.4% of cases. The treatment protocols remain controversial and often do not lead to complete healing. In the case that we report, complete healing was achieved after prolonged antibiotic therapy, hyperbaric oxygen therapy, and partial resection. In conclusion, the management of maxillary osteomyelitis in ADO type II patients is challenging, and complete resolution of the process is dependent on multiple interventions.

Follow-up CT findings of recurrent familial gigantiform cementoma of a female child

Familial gigantiform cementoma (FGC) is a rare autosomal dominant, benign fibro-cemento-osseous lesion of the jaws that can cause severe facial deformity. True FGC with familial history is extremely rare and there has been no literature regarding the radiological follow-up of FGC. We report a case of recurrent FGC in an Asian female child who has been under our observation for 6 years since she was 15 months old. After repeated recurrences and subsequent surgeries, the growth of the tumor had seemed to plateau on recent follow-up CT images. The transition from an enhancing soft tissue lesion to a homogeneous bony lesion on CT may indicate decreased growth potential of FGC.