Overlapping Phenotypes in Osteopetrosis and Pycnodysostosis in Asian-Indians

Osteopetrosis is a disorder characterized by high bone density, hepatosplenomegaly, visual and hearing loss, and anemia. Pycnodysostosis presents with short stature, acroosteolysis, and dense bones. We, hereby, present here a family with autosomal dominant osteopetrosis and also children with recessive osteopetrosis and pycnodysostosis. The molecular confirmation was done in 3 cases. Genetic heterogeneity in clinical presentation is discussed here. Further studies will help in identifying epigenetic alterations and population-specific variants and also developing targeted therapies.

Florid cemento-osseous dysplasia: a contraindication to orthodontic treatment in compromised areas

ABSTRACT Florid cemento-osseous dysplasia is a sclerosing disease that affects the mandible, especially the alveolar process, and that is, in most cases, bilateral; however, in some cases it affects up to three or even four quadrants. During the disease, normal bone is replaced with a thinly formed, irregularly distributed tissue peppered with radiolucent areas of soft tissue. Newly formed bone does not seem to invade periodontal space, but, in several images, it is confused with the roots, without, however, compromising pulp vitality or tooth position in the dental arch. There is no replacement resorption, not even when the images suggest dentoalveolar ankylosis. Orthodontists should make an accurate diagnosis when planning treatments, as this disease, when fully established, is one of the extremely rare situations in which orthodontic treatment is contraindicated. This contraindication is due to: (a) procedures such as the installment of mini-implants and mini-plaques, surgical maneuvers to apply traction to unerupted teeth and extractions should be avoided to prevent contamination of the affected bone with bacteria from the oral microbiota; and (b) tooth movement in the areas affected is practically impossible because of bone disorganization in the alveolar process, characterized by high bone density and the resulting cotton-wool appearance. Densely mineralized and disorganized bone is unable to remodel or develop in an organized way in the periodontal ligaments and the alveolar process. Organized bone remodeling is a fundamental phenomenon for tooth movement.

“Omics” Signatures in Peripheral Monocytes from Women with Low BMD Condition

Postmenopausal osteoporosis (PMO) is a result of increased bone resorption compared to formation. Osteoclasts are responsible for bone resorption, which are derived from circulating monocytes that undertake a journey from the blood to the bone for the process of osteoclastogenesis. In recent times, the use of high throughput technologies to explore monocytes from women with low versus high bone density has led to the identification of candidate molecules that may be deregulated in PMO. This review provides a list of molecules in monocytes relevant to bone density which have been identified by “omics” studies in the last decade or so. The molecules in monocytes that are deregulated in low BMD condition may contribute to processes such as monocyte survival, migration/chemotaxis, adhesion, transendothelial migration, and differentiation into the osteoclast lineage. Each of these processes may be crucial to the overall route of osteoclastogenesis and an increase in any/all of these processes can lead to increased bone resorption and subsequently low bone density. Whether these molecules are indeed the cause or effect is an arena currently unexplored.

The role of amylin in the development of diabetic osteopathy

Diabetes mellitus adversely affects the bone. Basically, it is related to weakening of the anabolic effect of insulin and other pancreatic hormones. Mechanisms underlying the decrease in bone density are not fully understood. However, many of the systemic changes related to metabolic abnormalities in diabetes have a damaging effect on the bone tissue. Inadequate compensation of glycemic profile in this disease, both directly (non-enzymatic glycosylation of proteins, activation of polyol pathway of glucose metabolism, oxidative stress) and indirectly (violation of gene expression), damages the bone structure. Another anabolic hormone produced by β-cells of the pancreas is amylin. It is a potent hypoglycemic and antiresorptive hormone affecting calcium homeostasis and influencing the preservation of bone density. The studies have shown that amylin, on the one hand, stimulates osteoblast proliferation, and on the other hand, inhibits osteoclast motility, thus acting similar to calcitonin. Inefficient redistribution of bone mass occurs. This may explain the increased incidence of fractures in patients with type 2 diabetes on the background of high bone density according to densitometry. In this regard, further studies are required to clarify the effect of amylin deficiency on the development of osteoporosis.