Ossification Of Bones Research Articles

Pathogenesis of thoracic ossification of the ligamentum flavum

Thoracic ossification of the ligamentum flavum (TOLF) is characterized by ectopic ossification of the ligamentum flavum in the thoracic spine and is considered the main cause of thoracic spinal stenosis and spinal cord disease. Osteoblast specific transcription factor Osterix (Osx) is required for bone formation, and there is no bone formation or ossification without Osx. Surgical intervention is recognized as the only effective method for TOLF treatment with set of complications. However, underlying mechanisms of TOLF are not well understood. This paper summarizes the pathogenesis of TOLF. Some relevant factors have been discussed, such as mechanical stress, genetic susceptibility genes, endocrine and trace element metabolism abnormalities, which may associate with TOLF. More recent studies using proteomics technology and RNA sequencing approach have discovered that some new factors participate in TOLF by upregulation of Osx gene expression including inflammatory factors. TOLF is a unique disease involving multiple factors. On the other hand, studies on TOLF pathogenic mechanism may provide new ideas for finding possible upstream regulatory factors of Osx and further developing novel drugs to stimulate new bone formation to treat osteoporosis.

Chronic toxic effects of chloroxylenol exposure on Rana chensinensis: Insights from endochondral ossfication

Chloroxylenol (para‑chloro-meta-xylenol, PCMX), is a widely used antimicrobial agent and can remain in the aquatic environment. Although toxicity studies related to PCMX on the aquatic animals like zebrafish and Brachionus koreanus have been reported, there are few reports in the ecological risk of amphibians. In this study, the toxicity of different concentration (143, 14.3, 1.43 μg/L) of PCMX treatments on the endochondral ossification and body condition of Rana chensiensis tadpoles was investigated at environmentally relevant concentrations during metamorphosis. The chronic exposure of PCMX decreased bone length and ossification of limbs, caused changes of thyroid gland structure and ossification related gene expression levels. Besides, we found that R. chensiensis developed rheumatoid arthritis. Therefore, these results provided valuable evidence that the ecological risk of PCMX that will negatively affect the body condition, thyroid hormones homeostasis and skeletal development of R. chensiensis tadpoles.

The Prevalence and the Clinical Importance of os vesalianum pedis.

Os vesalianum pedis (OVP) is a rare accessory bone of the foot located at the base of the fifth metatarsal bone. It is usually asymptomatic and incidentally seen on radiographs. When symptomatic, it manifests itself with lateral foot pain. OVP, which can become symptomatic as a result of traumatic injuries, can also be confused with fracture. The aim of this study is to determine the prevalence and morphometric characteristics of OVP in the Turkish population. Radiographic images of 5268 individuals aged 16 years and older (mean 39.65±17.21) who completed ossification of the fifth metatarsal bone were evaluated for OVP. Of the cases included in the study, 44.8% were female and 55.2% were male. The general and sex-based prevalence of OVP was calculated, and morphometric measurements were done. OVP prevalence in the Turkish population was found to be 0.15% regardless of sex. OVP prevalence was calculated to be 0.24% in men and 0.04% in women. Anatomy, radiology, orthopedics and emergency medicine physicians are frequently encountered with foot disorders in clinical and educational practices. It is important to keep in mind the rare presence of OVP (0.15%), in the preliminary diagnosis. os vesalianum pedis, accessory ossicle, foot, radiography.

Downregulation of Krüppel-like factor 15 expression delays endochondral bone ossification during fracture healing

ObjectiveThe role of Krüppel-like zinc finger transcription factor 15 (KLF15) in endochondral ossification during fracture healing remains unexplored. In this study, we aimed to elucidate the impact of KLF15 in a mouse model of tibial transverse fracture. MethodsWe created tamoxifen-inducible, cartilage-specific KLF15 knockout mice (KLF15 KO). KLF15 fl/fl Col2-CreERT mice from the same litters as the KLF15 KO mice, but not treated with 4-hydroxytamoxifen, were used as controls (CT). At 10 weeks, male KLF15 KO and CT mice underwent tibial fracture followed by intramedullary nailing. Both groups were administered tamoxifen at days 0, 3, and 7 after surgery. The tibiae were harvested on post-surgery days 7, 10, and 14 for radiological assessment using micro-computed tomography. Histological staining (Safranin-O) and immunohistochemistry for KLF15, SOX9, Indian hedgehog (IHH), RUNX2, and Osterix were performed. Additionally, cartilage from mouse fetus was cultured for qRT-PCR and western blot analyses of KLF15, SOX9, IHH, Col2, RUNX2, Osterix, TGF-β, SMAD3, and phosphor-SMAD3. ResultsThe radiological assessment revealed that immature callus formation was delayed in KLF15 KO, compared with that in CT, peaking on day 14 compared with that on day 10 in CT. KLF15 KO mice exhibited delayed fracture healing and reduced Safranin-O staining at days 7 and 10 post-surgery. The ratio of cells positive for KLF15 and SOX9 was significantly lower in KLF15 KO than in CT, whereas the ratios for IHH, RUNX2, and Osterix showed no significant difference. RT-PCR revealed reduced expression of KLF15, SOX9, and COL2, with no significant changes in IHH, Osterix, RUNX2, TGF-β, and SMAD3. Western blot analysis indicated decreased SMAD3 phosphorylation in KLF15 KO mice. ConclusionKLF15 regulates SOX9 via the TGF-β-SMAD3-SOX9 pathway, independent of IHH, in endochondral ossification. The KLF15 deficiency decreases SOX9 expression through reduced SMAD3 phosphorylation, subsequently delaying fracture healing.

IL-4 promotes chondrogenesis of bone marrow mesenchymal stem cellsand blockade of IL-4Rα retards the endochondral ossification during rat embryonic bone development.

Interleukin-4 (IL-4)/IL-4 receptor alpha (IL-4Rα) signalling pathways play important roles in the complex process of bone formation and bone remodelling. However, whether IL-4/IL-4Rα participates in skeletogenesis during embryonic development is not completely understood. We used the anti-IL-4Rα monoclonal antibody (anti-IL-4Rα mAb) as a powerful investigational tool to evaluate the potential roles of IL-4/IL-4Rα in the chondrogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Simultaneously, we explored the effect of IL-4/IL-4Rα on bone ossification during rat embryo-fetal development. In this study, we found that, compared to the control group, IL-4 can significantly promote the chondrogenic differentiation of BMSCs. Furthermore, following exposure to anti-IL-4Rα mAb in pregnant rats, unexpected phenomena were observed in fetal bone development, including non-ossification of the fetal sternum, an incomplete ossification centre in long bones and a reduced number of ossification points in digit (toe) bones. To further investigate the underlying mechanism of the phenotype, we studied the rat sternum as the target organ, starting from different time points of sternum development in the embryonic stage. The results indicated that the retardation mainly occurred in the middle and late stages of embryonic development. This retardation was characterized by the inhibition of the differentiation process of mesenchymal stem cells into chondrocytes, resulting in reduced angiogenesis near the ossification centre, failure of osteoblasts to invade the centre of the cartilage body with the blood vessels and delayed formation of the primary ossification centre (POC). Overall, our study demonstrated the significant function of IL-4/IL-4Rα in chondrogenic differentiation of BMSCs and bone ossification during embryo-fetal development.

Resources for innovative learning of anatomy and foot ossification: Graphic design and virtual reality.

This study addresses the ossification process of the foot, a topic of great relevance within podiatry courses. Understanding the chronology of foot bone formation is essential for evaluating pathological processes and establishing appropriate therapeutic actions to improve patient quality of life. The main objectives of this work are to understand the ossification process of the foot bones and to propose an appropriate didactic methodology for effective learning of this process. The individual ossification sequences of the foot bones were established and virtually recreated to make these processes more didactic and usable as teaching aids. The literature search was conducted using the PRISMA statement, focusing on terms, such as "bone ossification," "foot," and "bone development," and included relevant studies from medical databases. Updating the ossification ages and providing previously unavailable visual teaching material offers a useful tool for improving the teaching of this subject. It was found that, in general, the tarsal bones show significant differences in ossification ages between sexes, with later and slower ossification in males. These differences are statistically analyzed and presented in detailed comparative tables. The use of innovative teaching tools, such as virtual anatomical models, helps students to better understand the ossification process of foot bones. Implementing these tools in the podiatry curriculum not only facilitates knowledge acquisition but also enhances the quality of teaching and, consequently, the future clinical practice of students.

Zebrafish Models for Skeletal and Extraskeletal Osteogenesis Imperfecta Features: Unveiling Pathophysiology and Paving the Way for Drug Discovery.

In the last decades, the easy genetic manipulation, the external fertilization, the high percentage of homology with human genes and the reduced husbandry costs compared to rodents, made zebrafish a valid model for studying human diseases and for developing new therapeutical strategies. Since zebrafish shares with mammals the same bone cells and ossification types, it became widely used to dissect mechanisms and possible new therapeutic approaches in the field of common and rare bone diseases, such as osteoporosis and osteogenesis imperfecta (OI), respectively. OI is a heritable skeletal disorder caused by defects in gene encoding collagen I or proteins/enzymes necessary for collagen I synthesis and secretion. Nevertheless, OI patients can be also characterized by extraskeletal manifestations such as dentinogenesis imperfecta, muscle weakness, cardiac valve and pulmonary abnormalities and skin laxity. In this review, we provide an overview of the available zebrafish models for both dominant and recessive forms of OI. An updated description of all the main similarities and differences between zebrafish and mammal skeleton, muscle, heart and skin, will be also discussed. Finally, a list of high- and low-throughput techniques available to exploit both larvae and adult OI zebrafish models as unique tools for the discovery of new therapeutic approaches will be presented.

Effect of Platelet-Rich Fibrin Combined With Hyaluronic Acid on Bone Formation in Dental Implant Sockets: An In Vivo Study in Sheep.

The goal was to evaluate the effect of the combined growth factor of hyaluronic acid (HA) and advanced platelet-rich fibrin (A-PRF)on acceleration and maturation of bone formation around titaniumdental implants in the bone-free space (jumping distance) of anover-preparation socket. Thirty-two titanium dental implants were placed in four sheepand distributed into one control group (A) and three experimental groups (B, C, and D) in two different time periods.Each sheep received eight implants. The eight implants in each sheep were distributed into four groups. The first period was one month after the initial placement, 16 implants were used in two sheep. The second period was three months after the initial placement; another 16 implants were used in the other two sheep.All implants were placed in over-prepared implant sockets, resulting in minimal primary stability. In Group A: the space between the dental implant and the bone of the inner wall of the socket was left without a growth substrate material. In Group B: we added HA between the dental implant and the bone of the inner wall of the socket. In Group C: we added A-PRF between the dental implant and the bone of the inner wall of the socket. In Group D: we added a combination of HA and A-PRF between the dental implant and the bone of the inner wall of the socket. Data was collected for each group at one month and three months at the same time. A high-resolution, desktop micro-CT system (Bruker Skyscan 1275, Kontich, Belgium) was used to scan the specimens. The NRecon software (ver. 1.6.10.4, SkyScan) and CTAn (SkyScan) were used for the visualization and quantitative measurement of the samples. One-way analysis of variance (ANOVA) was used to compare the means of the four study groups in the same period. A post hoc test was used after ANOVA to compare the means of two samples at the same time. A p-value of ≤ 0.05 was considered statistically significant. After one month and three months of using combined HA and A-PRF on Group D, significant acceleration was observed in bone formation in all tests around dental implants compared with other groups, while no significant acceleration was observed when they were used separately; all three study groups showed significant results when compared with thecontrol group. Our data showed that using a combination of HA and A-PRF had a significanteffect on the acceleration of the bone formation and ossification process when added to bone-free space (jumping distance) around implants while leaving space without any growth substrates might delay the boneossification process.

Prenatal exposure to ethion caused maternal and foetal toxicity in rats

Ethion is a class II moderately toxic organothiophosphate pesticide. The main objective of this study was to evaluate the maternal and foetal toxicity of ethion in rats. Pregnant rats were divided into 5 groups. Group I served as control. Group II, III, IV, and V were orally administered with 0.86, 1.71, 3.43, and 6.9 mg/kg of ethion respectively, from gestational day (GD) 6–19. Dams were sacrificed on GD 20. Maternal toxicity was assessed by body weight gain, foetal resorptions, oxidative stress, liver and kidney function tests, and histopathology. Foetal toxicity was assessed by physical status, gross, teratological and histopathological examination. Ethion caused dose-dependent reduction in maternal body weight gain, increased resorptions, and reduced gravid uterine weights. Elevated MDA levels and altered levels of GSH, SOD and catalase were recorded in pregnant dam serum and tissues. SGOT, SGPT, total bilirubin, urea, uric acid, and creatinine were elevated in ethion groups indicating liver and kidney toxicity. Histology of uterus revealed myometrial degeneration and mucosal gland atrophy in uterus of pregnant dams and degenerative changes in placenta. It showed histological alterations in liver, kidney, and lungs. There was reduction in the foetal body weights and placental weights, and degenerative changes in the foetal liver and kidney. Gross evaluation of foetuses showed subcutaneous hematoma. Skeletal evaluation showed partial ossification of skull bones, costal separation, and agenesis of tail vertebrae, sternebrae, metacarpals and metatarsals. The findings reveal that prenatal exposure to ethion caused maternal and foetal toxicity in rats.

Developmental milestones in captive Galago moholi.

Systems of the body develop in a modular manner. For example, neural development in primates is generally rapid, whereas dental development varies much more. In the present study, we examined development of the skull, teeth, and postcrania in a highly specialized leaping primate, Galago moholi. Eighteen specimens ranging from birth to adult were studied. Bones, teeth, and the cranial cavity (i.e., endocast) were reconstructed with Amira software based on microCT cross-referenced to histology. Amira was also used to compute endocast volume (as a proxy for brain size). Reconstructions of the wrist and ankle show that ossification is complete at 1 month postnatally, consistent with the onset of leaping locomotion in this species. Endocranial volume is less than 50% of adult volume at birth, ~80% by 1 month, and has reached adult volume by 2 months postnatal age. Full deciduous dentition eruption occurs by 2 weeks, and the young are known to begin capturing and consuming arthropods on their own by 4 weeks, contemporaneous with the timing of bone and ankle ossification that accompanies successful hunting. The modular pattern of development of body systems in Galago moholi provides an interesting view of a "race" to adult morphology for some joints that are critical for specialized leaping and clinging, rapid crown mineralization to begin a transitional diet, but perhaps more prolonged reliance on nursing to support brain growth.

Does cranial bone ossification differ in children with developmental dysplasia of the hip?

This study aims to compare cranial bone ossification between patients with developmental dysplasia of the hip (DDH) and healthy individuals. Between September 2021 and April 2022, a total of 60 healthy female individuals (median age: 24.5 months; range, 18 to 36 months) and 56 female DDH patients (median age: 23 months; range, 18 to 35 months) were included. Age, head circumference, weight, height, and patency of the anterior fontanel were measured in groups. Percentiles were classified as very low, low, normal, high and very high. All patients were female and those with abnormal thyroid function test, vitamin D, calcium, phosphate and alkaline phosphatase values were not included in the study. For those diagnosed with DDH, they were included in the group regardless of the type of treatment. No statistically significant difference was found between the groups in terms of age and weight (p>0.05). The very low and very high head circumferences were more frequent, and the normal head circumferences were less frequent in the DDH group (p<0.05). There was no significant difference between groups in terms of fontanel closure (p>0.05). In open fontanels, no significant difference was found in both groups in terms of age (p>0.05). Our study results showed no significant difference between the fontanel ossifications of children with and without DDH; however, we found that the ossification of the skull bones of children with DDH was different compared to healthy children.

Investigating surface integrity and mechanical behavior of selective laser melting for dental implants

AbstractSelective laser melting (SLM) is a contemporary manufacturing method that offers numerous advantages for producing various components. This research focuses on the examination of a dental implant sample fabricated using the SLM method. The investigation encompasses multiple aspects, including hardness, dimensional accuracy, strength, and surface properties. The results demonstrate that the hardness of the SLM sample is comparable to that of machined samples, establishing it as a viable alternative to traditional production methods. Dimensional tests reveal that the SLM sample adheres to the required acceptance limits for critical dimensions. The strength of the sample, with a value of 700 MPa, proves to be acceptable for medical applications. The presence of surface porosity and holes in the SLM sample highlights its potential for enhanced bone ossification. However, challenges associated with thread construction in the SLM process require further attention. Overall, this research showcases the promising aspects of the SLM method for dental implant production, while also identifying areas for future investigation and improvement.

Effects of long-term voluntary wheel running and selective breeding for wheel running on femoral nutrient canals.

The nutrient artery provides ~50%-70% of the total blood volume to long bones in mammals. Studying the functional characteristics of this artery invivo can be difficult and expensive, so most researchers have measured the nutrient foramen, an opening on the outer surface of the bone that served as the entry point for the nutrient artery during development and bone ossification. Others have measured the nutrient canal (i.e., the passage which the nutrient artery once occupied), given that the external dimensions of the foramen do not necessarily remain uniform from the periosteal surface to the medullary cavity. The nutrient canal, as an indicator of blood flow to long bones, has been proposed to provide a link to studying organismal activity (e.g., locomotor behavior) from skeletal morphology. However, although external loading from movement and activity causes skeletal remodeling, it is unclear whether it affects the size or configuration of nutrient canals. To investigate whether nutrient canals can exhibit phenotypic plasticity in response to physical activity, we studied a mouse model in which four replicate high runner (HR) lines have been selectively bred for high voluntary wheel-running behavior. The selection criterion is the average number of wheel revolutions on days 5 and 6 of a 6-day period of wheel access as young adults (~6-8 weeks old). An additional four lines are bred without selection to serve as controls (C). For this study, 100 female mice (half HR, half C) from generation 57 were split into an active group housed with wheels and a sedentary group housed without wheels for 12 weeks starting at ~24 days of age. Femurs were collected, soft tissues were removed, and femora were micro-computed tomography scanned at a resolution of 12 μm. We then imported these scans into AMIRA and created 3D models of femoral nutrient canals. We tested for evolved differences in various nutrient canal traits between HR and C mice, plastic changes resulting from chronic exercise, and the selection history-by-exercise interaction. We found few differences between the nutrient canals of HR versus C mice, or between the active and sedentary groups. We did find an interaction between selection history and voluntary exercise for the total number of nutrient canals per femur, in which wheel access increased the number of canals in C mice but decreased it in HR mice. Our results do not match those from an earlier study, conducted at generation 11, which was prior to the HR lines reaching selection limits for wheel running. The previous study found that mice from the HR lines had significantly larger total canal cross-sectional areas compared to those from C lines. However, this discrepancy is consistent with studies of other skeletal traits, which have found differences between HR and C mice to be somewhat inconsistent across generations, including the loss of some apparent adaptations with continued selective breeding after reaching a selection limit for wheel-running behavior.

Knockdown of best1 Gene in Zebrafish Caused Abnormal Neuronal and Skeletal Development - A Subtype of Craniovertebral Junction Malformation?

To investigate the developmental defects caused by knockdown of best1 gene in zebrafish as a model for a subtype of craniovertebral junction (CVJ) malformation. Two antisense morpholinos (MOs) were designed targeting zebrafish best1 to block translation (ATG-MO) or to disrupt splicing (I3E4-MO). MOs were microinjected into fertilized one-cell embryos. Efficacy of splicing MO was confirmed by reverse transcription-polymerase chain reaction. Phenotypes were analyzed and quantified by microscopy at multiple developmental stages. Neuronal outgrowth was assessed in transgenic zebrafish expressing green fluorescent protein in neurons. Skeletal ossification was visualized by Calcein staining. Knockdown of best1 resulted in zebrafish embryos with shorter body length, curved axis, low survival rate, microcephaly, reduced eye size, smaller head and brain, impaired neuronal outgrowth, and reduced ossification of craniofacial and vertebral bone. Best1 gene plays critical roles in ophthalmologic, neurological and skeletal development in zebrafish. A patient with a premature stop codon in BEST1 gene exhibited similar phenotypes, implying a subtype of CVJ malformation.

Dynamic evolutionary interplay between ontogenetic skull patterning and whole-head integration.

The arrangement and morphology of the vertebrate skull reflect functional and ecological demands, making it a highly adaptable structure. However, the fundamental developmental and macroevolutionary mechanisms leading to different vertebrate skull phenotypes remain unclear. Here we exploit the morphological diversity of squamate reptiles to assess the developmental and evolutionary patterns of skull variation and covariation in the whole head. Our geometric morphometric analysis of a complex squamate ontogenetic dataset (209 specimens, 169 embryos, 44 species), covering stages from craniofacial primordia to fully ossified bones, reveals that morphological differences between snake and lizard skulls arose gradually through changes in spatial relationships (heterotopy) followed by alterations in developmental timing or rate (heterochrony). Along with dynamic spatiotemporal changes in the integration pattern of skull bone shape and topology with surrounding brain tissues and sensory organs, we identify a relatively higher phenotypic integration of the developing snake head compared with lizards. The eye, nasal cavity and Jacobson's organ are pivotal in skull morphogenesis, highlighting the importance of sensory rearrangements in snake evolution. Furthermore, our findings demonstrate the importance of early embryonic, ontogenetic and tissue interactions in shaping craniofacial evolution and ecological diversification in squamates, with implications for the nature of cranio-cerebral relations across vertebrates.

The adverse side effects of prenatal and postnatal rats' exposure to silver nanoparticles Induced toxicity.

Silver nanotechnology is widely applied in industry and medicine, with an increased likelihood of environmental and food contamination. This study aimed to explore the adverse effects of orally administering silver nanoparticles (AgNPs) to pregnant or lactating female rats on adults and the development of their offspring. Forty female albino rats were used to assess the immediate impacts of AgNPs in two separate experiments. The experimental group received 1 ml of AgNPs, dissolved in deionized water, at doses of 0, 50, and 100 mg/kg of body weight from the 6th to the 15th day of gestation in pregnant albino rats. After a 20-day gestation period, euthanasia was performed on the female rats, followed by a gross examination post-dissection. The feti were preserved in ethyl alcohol and Poin's solution for the identification of skeletal and visceral malformations. It was noticed that feti of dams that received AgNPs showed teratogenicities such as delayed ossification and deletion of bones or ribs. Notably, dams showed necrosis and satellitosis with evidence of behavioral alteration. While rats' pups showed only brain edema and no behavioral changes. AgNPs at a dose of 50 or 100 mg/kg induced teratogenic effect in terms of delayed ossification, abnormal limb formation, and brain edema in rat pups, however, induced necrosis and satellitosis in dam rats. Hence, greater emphasis should be placed on preventing exposure to Ag-NPs, especially among pregnant females.

Potential applications of the human amniotic membrane in endodontics: A case series of three different procedures

The human amniotic membrane (hAM) is the innermost placental membrane that protects and nourishes the growing fetus. While its use in various oral and maxillofacial procedures is abundant, application in endodontics is relatively new. The present case series describes the application of this therapeutic membrane in three different endodontic procedures – pulpotomy, revascularization, and root-end surgery. In case 1 (pulpotomy), the radicular pulp returned to its uninflamed state, and the patient became asymptomatic at follow-up. In case 2 (revascularization), the patient became asymptomatic; however, there was no increase in the root length and width even after 2 years of follow-up. In case 3, the osseous bone defect was healed entirely at the 6-month follow-up. The application of hAM in different endodontic treatment protocols seems appreciable. A potential limitation of its use has been described in this report. Further clinical trials are warranted to produce better evidence for the same.

Evaluation of post-extraction alveolar regeneration time in advanced periodontal disease employing novel hydroxyapatitepolymeric (FlexiOss®Vet) in dogs.

The purpose of the study was to demonstrate bone regeneration and the time of formation of new alveolar bone based on implanted FlexiOss®Vet bone substitute material. The study attempted to determine the time taken to fill bone defects with newly formed osseous bone compared to alveoli with a standard method of filling the post-extraction alveolus with a collagen sponge. The study was conducted on a group of 12 dogs with advanced periodontal disease (stage IV) in which polymeric hydroxyapatite bone substitute material (FlexiOss®Vet) was implanted into alveoli on the right side, and collagen sponge was implanted into alveoli on the left side in the same patient. The patients underwent macroscopic inspection and X-ray examination at different periods of regeneration after the procedure. On the right side, macroscopically, the alveoli showed features of marked enlargement, and on X-ray examination they gave opacity to X-rays and there was no clear border between the alveolus and alveolar bone. On the left side, the alveoli were clearly penetrable to X-rays, and hollow alveoli filled mainly with connective tissue were observed. The study also showed a significant reduction in bone healing time in alveoli with implants compared to self-healing alveoli. These results suggest that the implanted material is significantly beneficial in the process of bone regeneration in large bone defects in dogs and notably shortens the process of bone regeneration after tooth extractions. It is presumed that this could reflect a model for the treatment of large bone defects in not only the maxilla and mandible, but also long bones, and that it could be a model for alveolar healing in humans.

Skeletal Class III phenotype: Link between animal models and human genetics: A scoping review.

This study aimed to identify evidence from animal studies examining genetic variants underlying maxillomandibular discrepancies resulting in a skeletal Class III (SCIII) malocclusion phenotype. Following the Manual for Evidence Synthesis of the JBI and the PRISMA extension for scoping reviews, a participant, concept, context question was formulated and systematic searches were executed in the PubMed, Scopus, WOS, Scielo, Open Gray, and Mednar databases. Of the 779 identified studies, 13 met the selection criteria and were included in the data extraction. The SCIII malocclusion phenotype was described as mandibular prognathism in the Danio rerio, Dicentrarchus labrax, and Equus africanus asinus models; and as maxillary deficiency in the Felis silvestris catus, Canis familiaris, Salmo trutta, and Mus musculus models. The identified genetic variants highlight the significance of BMP and TGF-β signaling. Their regulatory pathways and genetic interactions link them to cellular bone regulation events, particularly ossification regulation of postnatal cranial synchondroses. In conclusion, twenty genetic variants associated with the skeletal SCIII malocclusion phenotype were identified in animal models. Their interactions and regulatory pathways corroborate the role of these variants in bone growth, differentiation events, and ossification regulation of postnatal cranial synchondroses.

Interdisciplinary management of horizontal root fracture in middle third with osseous bone defect – A clinical report

Dental trauma are the main cause of emergencies in dental practice. Amongst these, root fractures are relatively uncommon but comprises about 0.5 to 7% of all injuries affecting permanent dentition. Most commonly, root fracture occurs from a horizontal impact mostly in oblique direction. The incidence is more common at the mid-third of the root rather at the apical and cervical thirds. Such hideous injury must be restored to normal as early as possible to retain the dental health and appearance. This report records the case of horizontal root fracture of upper anterior tooth, treated with Mineral Trioxide Aggregate (MTA) and fractured root fragments were unified with the aid of a stainless steel reamer after an endodontic treatment. Alloplastic bone graft and GTR membrane were used for osseous bone defect. Mineral trioxide aggregate (MTA) has several impending &amp; forthcomin clinical applications owing to its grander sealing property and biocompatibility. A 12 months follow-up revealed a well stabilized assembly of the root fragments and periodontal healing.