Resorption Process Research Articles

Role of food fortification with vitamin D and calcium in the bone remodeling process in postmenopausal women: a systematic review of randomized controlled trials

Foods containing vitamin D reduce the deficiency of this vitamin and improve bone turnover. To discuss effects of the intake of vitamin D-fortified foods in isolated form or associated with calcium on bone remodeling in postmenopausal women. PubMed, Lilacs, Scopus, and Bireme databases. OpenThesis and Google Scholar were searched as "grey literature". Medical subject headings or similar terms related to food fortified with vitamin D and bone in postmenopausal women were used. Information was collected on study methodology and characteristics of studied populations; dosage; the food matrix used as the fortification vehicle; duration of intervention; dietary intake; 25-hydroxyvitamin D [25(OH)D] levels; serum parathyroid hormone (PTH) concentrations; bone resorption and/or formation markers (ie, carboxy terminal cross-linked telopeptide of type I collagen [CTX], tartrate-resistant acid phosphatase isoform 5b [TRAP5b], and procollagen type 1 N-terminal propeptide [P1NP]); main results; and study limitations. Five randomized controlled trials involving postmenopausal women were included. The mean ages of participants ranged from 56.1 to 86.9 years. Daily consumption of soft plain cheese fortified with 2.5 µg of vitamin D3 and 302 mg of calcium for 4 weeks resulted in a mean increase of 0.8 ng/mL in 25(OH)D and 15.9 ng/mL in P1NP levels compared with baseline, and decreased CTX, TRAP5b, and PTH values. A similar intervention for 6 weeks, using fortified cheese, showed a reduction only in TRAP5b values (-0.64 U/L). Yogurt fortified with 10 µg of vitamin D3 and 800 mg of calcium did not change P1NP values after 8 weeks of intervention, but was associated with decreases of 0.0286 ng/mL and 1.06 U/L in PTH and TRAP5b, respectively. After 12 weeks of eating the fortified yogurt, 25(OH)D levels increased by a mean of 8.8 ng/mL and PTH levels decreased in by a mean of 0.0167 ng/mL. The interventions contributed toward the improvement of the bone resorption process but not to the bone formation process in postmenopausal women. CRD42019131976.

External cervical resorption: Radiological diagnosis and literature (Review).

External cervical resorption (ECR) is a relatively unknown and insidious pathology characterized by the loss of hard dental tissues such as: Enamel, cementum and dentine due to clastic function. It begins as a localized resorptive process that initiates on the area of the root beneath the epithelial attachment and the coronal part of the alveolar process, involving vital and non-vital tissues. Despite the fact that there are several potential predisposing factors related to ECR, its aetiology still remains poorly understood and more research is needed to establish the cause-and-effect relationship of all the etiological factors. Improved radiographic detection using cone-beam computed tomography (CBCT) is required in order to correctly classify and assess this entity. This provides a three-dimensional insight into the lesion, regarding the location, the size, the depth and the circumferential spread of the ECR defect. It also allows establishment of the most efficacious treatment plan and management. The purpose of this literature review is to cover the relevant literature concerning the etiology, pathogenesis, clinical and radiological presentation and management of ECRs (based on the CBCT findings).

Impact of Cadmium Mediated by Tobacco Use in Musculoskeletal Diseases.

Tobacco use has a negative impact on health due to its relationship with the development of high-mortality diseases, such as pulmonary cancer. However, the effect of cadmium (Cd), present in tobacco smoke, on the development of joint diseases has been scarcely studied. The objective of this review is to discuss the evidence regarding the mechanisms by which Cd exposure, through tobacco smoke, may lead to the development of osteoarthritis (OA), osteoporosis (OP), and rheumatoid arthritis (RA). There's evidence suggesting a string association between moderate to severe OA development and tobacco use, and that a higher blood concentration of Cd can trigger oxidative stress (OS) and inflammation, favoring cartilage loss. At the bone level, the Cd that is inhaled through tobacco smoke affects bone mineral density, resulting in OP mediated by a decrease in the antioxidant enzymes, which favors the bone resorption process. In RA, tobacco use promotes the citrullination process through Cd exposure and increases OS and inflammation. Understanding how tobacco use can increase the damage at the articular level mediated by a toxic metal, i.e., Cd, is important. Finally, we propose prevention, control, and treatment strategies for frequently disabling diseases, such as OA, OP, and RA to reduce its prevalence in the population.

FEATURES OF TROPHISM OF BONE TISSUE AFTER THE INSTALLATION OF DENTAL IMPLANTS

Relevance. The most important condition for a successful result of dental implantation is high-quality osseointegration of dental implants. In the literature, the issue of the quality of osseointegration is widely covered, which directly depends on the primary stability of dental implants. In the area of bone tissue remodeling, surrounding the installed dental implants, there are permanent processes of bone resorption and its restoration [1][2].The aim is to reveal the reactivity of alkaline phosphatase and osteocalcin in the biological fluid (saliva) in patients after dental implants.Materials and methods. The collection and analysis of clinical material was carried out on the basis of the Clinics of the Samara State Medical University of the Ministry of Health of Russia. Dental implantation surgery was performed in 184 patients aged 32 to 65 years. The gender ratio was 2:3 (40 men and 60 women). The teeth were lost due to poor oral hygiene and caries complications.Results and discussion. At the time of admission of patients to the department of the Department of Prosthetic Dentistry of the Clinics of the Samara State Medical University of the Ministry of Health of Russia, the bulk of the patients had a low hygienic status. The OHI-S index averaged 2.74 ± 0.33 conventional units. (control – 0.50 ± 0.07 c.u.). In order to reduce the negative influence of microorganisms in the supra- and subgingival dental deposits, all patients underwent professional oral hygiene, as well as antimicrobial therapy. At the time of installation of dental implants, the average OHI-S and Müllemann-Cowell index was 0.72 ± 0.06 and 0.57 ± 0.06 conventional units, respectively.Conclusions. 1. The increase in the titer of alkaline phosphatase and osteocalcin during dental implantation is not statistically significant. 2. TCRF in the oral fluid (saliva) exhibits maximum activity by the 14th day, exceeding the initial three times. This indicator remains at an increased level in the period up to six months from the beginning of the operation. 3. Revealing the values of the TRKF titer after the operation of dental implantation is advisable to use as an assessment of the state of trophic processes occurring in the bone tissue.

FEATURES OF TROPHISM OF BONE TISSUE AFTER THE INSTALLATION OF DENTAL IMPLANTS

Relevance. The most important condition for a successful result of dental implantation is high-quality osseointegration of dental implants. In the literature, the issue of the quality of osseointegration is widely covered, which directly depends on the primary stability of dental implants. In the area of bone tissue remodeling, surrounding the installed dental implants, there are permanent processes of bone resorption and its restoration [1, 2]. The aim is to reveal the reactivity of alkaline phosphatase and osteocalcin in the biological fluid (saliva) in patients after dental implants. Materials and methods. The collection and analysis of clinical material was carried out on the basis of the Clinics of the Samara State Medical University of the Ministry of Health of Russia. Dental implantation surgery was performed in 184 patients aged 32 to 65 years. The gender ratio was 2:3 (40 men and 60 women). The teeth were lost due to poor oral hygiene and caries complications. Results and discussion . At the time of admission of patients to the department of the Department of Prosthetic Dentistry of the Clinics of the Samara State Medical University of the Ministry of Health of Russia, the bulk of the patients had a low hygienic status. The OHI-S index averaged 2.74 ± 0.33 conventional units. (control – 0.50 ± 0.07 c.u.). In order to reduce the negative influence of microorganisms in the supra- and subgingival dental deposits, all patients underwent professional oral hygiene, as well as antimicrobial therapy. At the time of installation of dental implants, the average OHI-S and M ü llemann-Cowell index was 0.72 ± 0.06 and 0.57 ± 0.06 conventional units, respectively. Conclusions. 1. The increase in the titer of alkaline phosphatase and osteocalcin during dental implantation is not statistically significant. 2. TCRF in the oral fluid (saliva) exhibits maximum activity by the 14th day, exceeding the initial three times. This indicator remains at an increased level in the period up to six months from the beginning of the operation. 3. Revealing the values of the TRKF titer after the operation of dental implantation is advisable to use as an assessment of the state of trophic processes occurring in the bone tissue.

INFLUENCE OF NITRIC OXIDE, HYDROGEN SULFIDE, MARKERS OF ANTIOXIDANT HOMEOSTASIS AND BONE METABOLISM OF ORAL FLUID ON THE DENTAL HEALTH OF CHILDREN WITH MILD IODINE DEFICIENCY, LATENT IRON DEFICIENCY AND ASSOCIATED MICROELEMENTOSIS

The article analyzes the metabolism of nitric oxide (NO), hydrogen sulfide (H2S), markers of antioxidant protection, bone metabolism of oral fluid and features of dental status in children with mild iodine deficiency (МІD), latent iron deficiency and combined (LID); a combination of trace elements was examined.
 As a result of the study (age group from 6 to 11 years) under the conditions of МІD in boys there was an increase in the level of NO2, NO2- + NO3-, and in girls - peroxynitrite in the oral fluid. In schoolchildren with LІD changes in the studied parameters were less pronounced (in the oral fluid increased NO2 concentration regardless of gender and increased peroxynitrite content only in girls). Under conditions of combined micronutrient imbalance in the oral fluid levels of NO2 increased, the amount of NO2- and NO3-, peroxynitrite, regardless of gender, and girls, in addition, levels of arginase decreased. Such changes were observed against the background of weakening of antioxidant protection of oral fluid. In particular, acid phosphatase (АсР) was activated under the conditions of LD in boys against the background of alkaline phosphatase (АР) inhibition and reduction of total calcium levels in oral fluid. The same tendency was observed in girls of this group, in addition, they found inhibition of superoxide dismutase (SOD) activity of oral fluid. Under the conditions of LІD, regardless of gender, KF activation was observed against the background of АсР suppression (in boys), decrease in SOD activity (in girls). The most pronounced changes were observed in the oral fluid of children with combined iodine and iron deficiency: increased activity of АР regardless of gender, glutathione peroxidase (GP), LF in girls, inhibition of АсР activity in boys, decreased total calcium regardless of gender. The level of ionized calcium in the oral fluid increased only in girls.
 In children aged 12 to 18 years under the conditions of МІD, an increase in the concentration of peroxynitrite in the oral fluid regardless of gender and a decrease in arginase levels were found only in girls. In the oral fluid of boys with LІD found a decrease in L-arginine, in girls - and an increase in L-arginine, NO2 concentration on the background of a decrease in arginase and peroxynitrite. In high school students with combined microelements, regardless of gender, the content of peroxynitrite in the oral fluid and a decrease in the level of L-arginine in boys and an increase in arginase in girls. In this group, a significant increase in the concentration of H2S in schoolgirls, which can perform a protective function in oxidative stress or impaired blood supply, attracts attention. The results of the level of total, ionized calcium and phosphatase activity indicate an increase in the resorptive process in periodontal tissues in all experimental groups.
 During the dental examination, a high level of caries prevalence, a decrease in the level of hygiene, and a higher PMA index were found in older schoolchildren with a combination of microelements. The poorer level of dental health among boys concerning girls attracts attention, which can be explained by the better level of care and daily rehabilitation of the oral cavity in girls.
 Thus, under the conditions of preclinical microelements the indicators of NO metabolism change, the antioxidant reserve of oral fluid decreases, and markers of bone metabolism are disturbed. Such biochemical changes in the composition of oral fluid are compared with indicators of dental status.

Circ_0008542 in osteoblast exosomes promotes osteoclast-induced bone resorption through m6A methylation

With an increasing aging society, China is the world’s fastest growing markets for oral implants. Compared with traditional oral implants, immediate implants cause marginal bone resorption and increase the failure rate of osseointegration, but the mechanism is still unknown. Therefore, it is important to further study mechanisms of tension stimulus on osteoblasts and osteoclasts at the early stage of osseointegration to promote rapid osseointegration around oral implants. The results showed that exosomes containing circ_0008542 from MC3T3-E1 cells with prolonged tensile stimulation promoted osteoclast differentiation and bone resorption. Circ_0008542 upregulated Tnfrsf11a (RANK) gene expression by acting as a miR-185-5p sponge. Meanwhile, the circ_0008542 1916-1992 bp segment exhibited increased m6A methylation levels. Inhibiting the RNA methyltransferase METTL3 or overexpressing the RNA demethylase ALKBH5 reversed osteoclast differentiation and bone resorption induced by circ_0008542. Injection of circ_0008542 + ALKBH5 into the tail vein of mice reversed the same effects in vivo. Site-directed mutagenesis study demonstrated that 1956 bp on circ_0008542 is the m6A functional site with the abovementioned biological functions. In conclusion, the RNA methylase METTL3 acts on the m6A functional site of 1956 bp in circ_0008542, promoting competitive binding of miRNA-185-5p by circ_0008542, and leading to an increase in the target gene RANK and the initiation of osteoclast bone absorption. In contrast, the RNA demethylase ALKBH5 inhibits the binding of circ_0008542 with miRNA-185-5p to correct the bone resorption process. The potential value of this study provides methods to enhance the resistance of immediate implants through use of exosomes releasing ALKBH5.

ИННОВАЦИОННЫЙ ПОДХОД К ЛЕЧЕНИЮ ПОПЕРЕЧНЫХ ПЕРЕЛОМОВ КОРНЕЙ МОЛЯРОВ

A tooth fracture is a traumatic injury to a tooth with the disturbance of its crown or root part integrity. A root fracture is a fracture that involves cementum, dentin, periodontium and, in some cases, dental pulp. Root fractures occur in 0.2-7% of all cases of permanent teeth injuries. The aim of the study was to investigate clinical effectiveness of using a material based on hydroxyapatite «Bioplast-Dent» paste and a material based on mineral trioxide aggregate - «Rutsil» in the treatment of a transverse fracture of the medial tooth root 4.6 (clinical case). The object of the study was a patient with a fracture of the medial tooth root 4.6 and destructive processes in the tissues of the apical periodontium of tooth 4.6, who applied to the Chair of Restorative Dentistry with the course of the Faculty for Advanced Training & Retraining of «VSMU» in 2019. Temporary obturation of the root canals of the root of tooth 4.6 was performed using the material based on hydroxyapatite «Bioplast-Dent» in the form of a paste. Permanent obturation of the root canals of the root of tooth 4.6 was carried out using domestic material based on mineral trioxide aggregate (MTA) - «Rutsil». The final restoration of the tooth crown was carried out after X-ray control from the moment of permanent obturation of the root canals in 3 months. Additionally, dynamic R-control was performed in 12 months. The results of the treatment have shown that the use of hydroxyapatite-containing paste and domestic material based on mineral trioxide aggregate - «Rutsil» brings about activation of osteogenesis in periodontal tissues and stops the process of resorption in the fracture line, shortening the time of bone tissue recovery and contributing to a greater success of treatment.

Assessment of the effect of estradiol on biochemical bone turnover markers among postmenopausal women.

Estrogen deficiency found in postmenopausal women may lead to disturbances in the balance of bone metabolism. Study of the influence of estradiol on markers of bone turnover may help to understand the mechanisms of bone metabolism and to monitor osteoporosis therapy in postmenopausal women at high risk of fractures. The aim of the study was evaluation of the effect of estradiol on the basic markers of bone turnover in postmenopausal women. The study was conducted in a group of 92 postmenopausal women, divided into two groups: Gr-1 with low estradiol levels ≤ 10 pg/ml and Gr-2 with reference estradiol levels ≥ 25 pg/ml). Basic markers of bone turnover were examined: Ctx (C-terminal cross-linked telopeptide of type I collagen alpha chain) and OC (osteocalcin); pro-resorptive cytokines: IL-6 and TNF-α; vitamin 25(OH)D3 and lipid profile. Women was also analyzed according to demographic and clinical data. A positive relationship was found between estradiol and the main bone formation marker - OC (p = 0.041, r = 0.213) and IL-6, TNF-α (p = 0.007, r = 0.281 and p = 0.018, r = 0.246, respectivly, but only in the group with a reference hormone level. Moreover, the main markers of bone turnover: Ctx and OC showed a mutual positive correlation (p = 0.013; r = 0.257) in women with reference estradiol levels. Relationships between markers of bone remodeling, pro-resorptive cytokines and vitamin D3 depending on the level of estradiol showed no statistically significant correlation. The study showed that only in women with the reference estradiol level (≥ 25 pg/ml) were the bone formation and resorption processes balanced.

Murine Metatarsus Bone and Joint Collagen-I Fiber Morphologies and Networks Studied With SHG Multiphoton Imaging.

Chronic inflammatory disease of bones and joints (e.g., rheumatoid arthritis, gout, etc.), but also acute bone injury and healing, or degenerative resorptive processes inducing osteoporosis, are associated with structural remodeling that ultimately have impact on function. For instance, bone stability is predominantly orchestrated by the structural arrangement of extracellular matrix fibrillar networks, i.e., collagen-I, -IV, elastin, and other proteins. These components may undergo distinct network density and orientation alterations that may be causative for decreased toughness, resilience and load bearing capacity or even increased brittleness. Diagnostic approaches are usually confined to coarse imaging modalities of X-ray or computer tomography that only provide limited optical resolution and lack specificity to visualize the fibrillary collagen network. However, studying collagen structure at the microscopic scale is of considerable interest to understand the mechanisms of tissue pathologies. Multiphoton Second Harmonic Generation (SHG) microscopy, is able to visualize the sterical topology of the collagen-I fibrillar network in 3D, in a minimally invasive and label-free manner. Penetration depths exceed those of conventional visible light imaging and can be further optimized through employing decalcification or optical clearing processing ex vivo. The goal of this proof-of-concept study was to use SHG and two-photon excited fluorescence (2-PEF) imaging to mainly characterize the fibrillary collagen organization within ex vivo decalcified normal mouse metatarsus bone and joint. The results show that the technique resolved the fibrillar collagen network of complete bones and joints with almost no artifacts and enabled to study the complex collagen-I networks with various fiber types (straight, crimped) and network arrangements of mature and woven bone with high degree of detail. Our imaging approach enabled to identify cavities within both cortical and trabecular bone architecture as well as interfaces with sharply changing fiber morphology and network structure both within bone, in tendon and ligament and within joint areas. These possibilities are highly advantageous since the technology can easily be applied to animal models, e.g., of rheumatoid arthritis to study structural effects of chronic joint inflammation, and to many others and to compare to the structure of human bone.

Non-Surgical Management of an Anterior Tooth with Internal Inflammatory Resorption: A Case Report

Background: According to the Glossary of the American Association of Endodontists, resorption is definedas a condition associated with either a physiologic or a pathologic process resulting in the loss of dentin,cementum, or bone. It may present internally (pulpal origin) or externally (periodontal origin). Internalresorption is a rare, insidious, resorptive pathological process, starting from the pulp extending into thesurrounding dentin. Treatment is mainly focused on arresting the cellular activity accounting for theresorptive process.Methodology: A patient presented with an upper front tooth that was tender on percussion and a history oftrauma in her childhood which resulted in Ellis class II fracture of the tooth. Pulp sensibility testing showeda negative response suggestive of a non-vital tooth. A non-surgical endodontic therapy was carried out underthe microscope with calcium hydroxide dressings followed by the three-dimensional obturation techniqueusing thermoplasticized Gutta percha.Conclusion: The current case report discusses the etiology and symptoms of internal inflammatoryresorption, the contribution of cone beam computed tomography imaging in its diagnosis, and a step wiseprotocol for the three dimensional obturation of the resorptive lesion.

Photopolymerizable precursors for degradable biomaterials based on acetal moieties

In tissue engineering (TE), artificial biomaterials have emerged over the past decade as an alternative to autotransplants. The main characteristics of these materials include good biocompatibility as well as biodegradability. Up to now, most materials used in TE are based on polyesters, which are limited in their scope of application, especially as scaffolds, due to their undesirably slow degradation behavior under acidic conditions present, e.g. during the process of hydroxyapatite resorption during bone regeneration. Furthermore, the formation of acidic degradation products can lead to tissue inflammation or even necrosis. Therefore, alternatives to ester functionalities, which show enhanced degradability under acidic conditions, are of interest. Herein, we present the synthesis of linear and cyclic acetal-based monomers for photopolymerizable materials. The reactivity and mechanical properties of polymer networks derived from these monomers were investigated. Moreover, their degradation behavior compared to ester-based polymer networks was explored. Degradation studies of the model compounds showed that the synthesized acetals degrade 80 to 200 times faster than their ester counterparts. A subsequent in vitro degradation study of polymer networks based on these compounds confirmed the potential of acetals moieties in polymeric biomaterials for bone regeneration.

Protective Effect of Indian Herbs and Physical Exercise on Osteoporosis: A Review

ABSTRACT Osteoporosis means low bone mass with higher chances of bone fracture risk. There is imbalance between bone formation and bone resorption process due to deficiency of oestrogen hormone, ageing and oxidative stress. Herbs and physical exercise both play an important role in the prevention of osteoporosis. This narrative review paper compiles the role of physical activities and Indian herbs on the molecular pathway of osteoporosis that how these are beneficial in prevention and management of osteoporosis. It can also give further lead to different researches on use of different herbs and physical activities.

The Effect of N-acetylcysteine on Periodontitis: A mini-review of literature

Recently, there is strong evidence for the beneficial role of antioxidants in the treatment of periodontal diseases. A drug that is gaining more and more focus in new research is N-acetylcysteine, an antioxidant that contributes to the increase in glutathione (GSH), used as a mucolytic agent, however, recent studies have shown its significant role in decreasing levels of reactive oxygen species and in the bone resorption process in experimental periodontitis, therefore, this review sought to elucidate whether N-acetylcysteine is effective in the treatment of periodontitis and also in the involved mechanisms already mentioned in the literature. The present study is a mini-review, in which a search was performed on Google Scholar, PubMed and Web of Science and databases for the collection of studies published in the last 10 years (2009-2020). The mini-review included studies that addressed a direct or indirect link between the effects of N-acetylcysteine on periodontitis, studies published in recent years, and in vitro and in vivo studies (animal and / or human models). Seven articles were selected from the following databases: PubMed (03) and Google Scholar (04) were subsequently analyzed. As for the language and the journal, all were published in international Journals and in English. It was concluded that N-acetylcysteine was effective in bone resorption in experimental periodontitis, but further studies are suggested in order to elucidate all the mechanisms involved in the observed results.

Histomorphometric Evaluation of Socket Preservation Using Autogenous Tooth Biomaterial and BM-MSC in Dogs.

This study is aimed at assessing the dimensional alterations occurring in the alveolar bone after premolar extraction in dogs with histomorphometric and histological analysis. After atraumatic premolar extraction, tooth-derived bone graft material was grafted in the extraction socket of the premolar region in the lower jaws of six dogs in two experimental groups. In the second experimental group, BM-MSCs were added together with the graft. The control was left untreated on the opposite side. After twelve weeks, all six animals were sacrificed. Differences in alveolar bone height crests lingually and buccally, and alveolar bone width at 1, 3, and 5 mm infracrestally, were examined. Histologic study revealed osteoconductive properties of tooth biomaterial. A statistically significant difference was detected between the test and control groups. In the test groups, a reduced loss of vertical and horizontal alveolar bone dimensions compared with the control group was observed. Tooth bone graft material may be considered useful for alveolar ridge preservation after tooth extraction, as it could limit the natural bone resorption process.

Reprint of: Relationship Between Surface and Inflammatory Resorption and Changes in the Pulp After Replantation of Permanent Incisors in Monkeys

The etiology of surface and inflammatory root resorption after the replantation of incisors was examined in green vervet monkeys. The teeth were examined histologically and histobacteriologically for pulpal healing and root resorption 2 and 8 weeks after replantation. In contrast to surface resorption, inflammatory resorption was related to infected necrotic tissue or an infected leukocyte zone in the root canal. The following theory for surface and inflammatory resorption is presented. Damaged periodontal ligament areas and damaged parts of the root surface are attacked by a resorption process whereby resorption of cementum and dentin may occur. Inflammatory resorption or surface resorption will then occur depending on the pulpal status and the depth of the resorption cavity. If the resorption cavity penetrates the intermediate layer of cementum and contacts dentinal tubules that are in communication with infected necrotic pulp tissue or an infected leukocyte zone, then inflammatory resorption will take place as a result of the diffusion of toxic elements from the pulp canal to the resorption cavity. However, if the resorption cavity is shallow and does not penetrate the intermediate layer of cementum, a tooth that displays similar pulpal changes will elicit only surface resorption because the intermediate layer of cementum will tend to arrest the diffusion of toxic elements. Finally, if the pulp contains vital, inflamed, or noninflamed tissue or if root canal treatment has been performed, surface resorption will occur regardless of the depth of the cavity.

Disturbance of osteonal bone remodeling and high tensile stresses on the lateral cortex in atypical femoral fracture after long-term treatment with Risedronate and Alfacalcidol for osteoporosis

An 83 year-old Japanese woman complained of left lateral thigh pain following a low-energy fall 4 months prior to admission. She had been treated for osteoporosis with Risedronate and Alfacalcidol for the previous five years. She was diagnosed with an atypical femoral fracture (AFF) according to the American Society for Bone and Mineral Research (ASBMR) Task Force revised criteria. Radiographs revealed cortical thickening and a transverse radiolucent fracture line in the lateral cortex of the shaft. MRI showed a high intensity signal on the T2WI image 1 cm long in the lateral cortex. The patient had normal levels of bone resorption and formation biomarkers except for low 25(OH) Vitamin D. Double fluorescent labeling was done preoperatively.Due to significant bowing, a corrective osteotomy and intramedullary nailing were performed, and the resected bone wedge was analyzed by bone histomorphometry. Three ground sections of the lateral cortex at the fracture site showed many and large pores, with or without tetracycline labeling. Histomorphometric assessment was done on intracortical pores, classified by a novel criteria, only to assess size of the pores to know prolonged osteoclastic activity and its characteristics of inner surfaces to assess whether bone formation has been occurring or not in labeling period in remodeling cycle, and coalition of multi-pores. Increased size with widespread variation of pores suggested prolonged osteoclastic activity in the reversal/resorptive phase. Bone labeling showed lamellar bone on the endocortical surface.We hypothesize that the case had developed from a regional disturbance of osteonal remodeling in the lateral cortex, in which accumulated microcracks might have initiated a resorption process resulting in resorption cavities, i.e., pores, which became larger due to prolonged activity of secondary osteoclasts. Various sized pores could form lamellar bone, still forming at the time of biopsy, some had formed lamellar bone, but stopped to form before labeling and not to start to form at all, probably due to incomplete coupling. Endocortical lamellar bone might had started to resorbed to smooth off endocortical surface, followed by formation of lamellar bone. The endocortical bone formation was assessed and its formation period is about 2.7 years.A finite element analysis using preoperative CT data revealed high tensile stresses on the lateral aspect of the femur. Histomorphometric results suggest that there might be more pores in the tensile area than the compressive area. These findings may subsequently connect accumulation of microcracks, an increase of size and number of pores and coalition and subsequent fracture in the lateral cortex.

Clinical and radiographic evaluation of caries depth, root resorption and furcation lesion in primary molars

Primary molars with furcation lesions have a negative impact on the child's quality of life. We determined the prevalence of furcation lesions and their influence on the root resorption process in primary molars. It is Cross-sectional study of patients aged 3 to 12 years that was apply a health questionnaire was applied and the teeth were submitted to physical examination using the International Caries Detection and Assessment System (ICDAS) and periapical radiography. Criteria for radiographic interpretation were established and assessments performed by three different specialists. The kappa coefficient measured interexaminer agreement and level of significance of 5% was adopted for all tests. The sample consisted of 26 patients and 50 primary molars. The second molar received ICDAS score 6 in 38.5% of the sample. The interexaminer agreement was almost perfect between the radiologist and pediatric dentist for caries depth on the mesial (K=0.97) and occlusal surface (K=0.97); In root resorption for mesial (K=0.89) and distal (K=0.93). The detection of furcation lesions was present in 42.3% of the sample; 50% of the teeth had at least 1/3 of the mesial root resorbed and 75% of the distal root and the presence of furcation lesions in primary molars influenced root resorption.

External Root Resorption of the Mandibular Second Molar Associated with Completely Impacted Third Molar: A Case Report and Review of the Literature

External root resorption (ERR) of permanent teeth is believed to result from mechanical or inflammatory factors, such as the force pressure of orthodontic appliances, dental trauma, cysts or tumours, chronic apical periodontitis, and poor regeneration of the periodontium in reimplanted or transplanted teeth. Another factor frequently associated with ERR of second molars is an unerupted third molar close to the root of the second molar. This type of root resorption has been observed at the site of contact with the impacted tooth, indicating that the impacted tooth's pressure participates in the resorption process. Though this resorption mechanism is not yet apparent, some investigators deem it similar to the mechanism involved in the resorption of primary teeth. This case report aims to describe a second molar resorption case triggered by an impacted third molar and perform a literature review. Key Words External Root Resorption, Mandibular third molar, Pressure resorption,

Association between shape changes and bone remodeling patterns in the middle face during ontogeny in South American populations

The morphology of facial bones is modeled by processes of bone formation and resorption induced by interactions between tissues and compensatory responses. However, the role of remodeling patterns on the morphological changes within and among populations has been scarcely explored. Here, we assess the association between facial shape and the underlying bone cell activity throughout the ontogeny in two Amerindian populations that represent the extremes of craniofacial variation in South America. The sample comprises 71 individuals (36 adults and 35 subadults) representing hunter-gatherers from Patagonia and horticulturists from Northwest Argentina. We analyzed the shape and size of the zygomatic and the maxilla, and compared them with the patterns of bone formation and resorption. Bone formation and resorption were described by quantitative histological analysis of bone surfaces. Morphological changes were described by landmarks and semilandmarks digitized on 3D surfaces obtained from CT images. The results from multivariate statistics analysis show that the patterns of bone remodeling are associated with variation in the morphology of the middle face. We found a similar pattern of facial shape variation along the ontogenetic trajectory in the two samples, and a similar trend in the amount of formation and resorption activities across ages. The main differences between samples were found in the distribution of the areas of bone formation and resorption, possibly associated with mechanical bone response to masticatory loading. These findings provide clues about the processes and mechanisms of bone development involved in the facial morphological differentiation in human populations from southern South America.