DNA methylation profile discriminates sporadic giant cell granulomas of the jaws and cherubism from their giant cell-rich histological mimics

Sporadic giant cell granulomas (GCGs) of the jaws and cherubism-associated giant cell lesions share histopathological features and microscopic diagnosis alone can be challenging. Additionally, GCG can morphologically closely resemble other giant cell-rich lesions, including non-ossifying fibroma (NOF), aneurysmal bone cyst (ABC), giant cell tumour of bone (GCTB), and chondroblastoma. The epigenetic basis of these giant cell-rich tumours is unclear and DNA methylation profiling has been shown to be clinically useful for the diagnosis of other tumour types. Therefore, we aimed to assess the DNA methylation profile of central and peripheral sporadic GCG and cherubism to test whether DNA methylation patterns can help to distinguish them. Additionally, we compared the DNA methylation profile of these lesions with those of other giant cell-rich mimics to investigate if the microscopic similarities extend to the epigenetic level. DNA methylation analysis was performed for central (n = 10) and peripheral (n = 10) GCG, cherubism (n = 6), NOF (n = 10), ABC (n = 16), GCTB (n = 9), and chondroblastoma (n = 10) using the Infinium Human Methylation EPIC Chip. Central and peripheral sporadic GCG and cherubism share a related DNA methylation pattern, with those of peripheral GCG and cherubism appearing slightly distinct, while central GCG shows overlap with both of the former. NOF, ABC, GCTB, and chondroblastoma, on the other hand, have distinct methylation patterns. The global and enhancer-associated CpG DNA methylation values showed a similar distribution pattern among central and peripheral GCG and cherubism, with cherubism showing the lowest and peripheral GCG having the highest median values. By contrast, promoter regions showed a different methylation distribution pattern, with cherubism showing the highest median values. In conclusion, DNA methylation profiling is currently not capable of clearly distinguishing sporadic and cherubism-associated giant cell lesions. Conversely, it could discriminate sporadic GCG of the jaws from their giant cell-rich mimics (NOF, ABC, GCTB, and chondroblastoma).

Case report: golimumab-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw is an uncommon but highly morbid adverse event of certain medical therapies. Although classically induced by bisphosphonates, the recent advent of monoclonal antibodies is contributing to a rise in cases. In this case report, we present a rare case of golimumab-associated medication-related osteonecrosis of the jaw and discuss the possible mechanisms of pathogenesis.

Radiologic findings of osteonecrosis, osteoradionecrosis, osteomyelitis and jaw metastatic disease with cone beam CT

PURPOSE

The purpose of this study was to assess CBCT scans of patients with medication related osteonecrosis of the jaws (MRONJ), osteoradionecrosis (ORN), osteomyelitis (OM) and jaw metastatic disease (JM), evaluate the presence and extent of radiologic findings, identify radiologic parameters that may distinguish the four entities and last, introduce a new modified radiographic index (CRIm), in order to contribute to the diagnosis of these conditions.

METHODS

Τwo major databases were retrospectively searched for fully documented and diagnosed CBCT scans of MRONJ, ORN, OM and JM from 2006 to 2019. 335 CBCT scans met the inclusion criteria and were assessed under standardized viewing conditions blindly by 2 observers. The CRIm index proposed in this study evaluates: lytic changes, sclerosis, periosteal bone formation, sequestration, non-healing extraction sockets and other findings which included: sinus implication, inferior alveolar canal implication and jaw fracture. Lytic changes, sclerosis, periosteal bone formation, sequestration and non-healing extraction sockets were scored as: absent (0), localized/single (1) and extensive/multiple (2). Each one of other findings were scored individually as: absent (0) and present (1). For statistical analysis t-test, Pearson's r correlation coefficient, one-way ANOVA and Bonferonni were performed.

RESULTS

Extensive lytic changes were the most common finding, especially for ORN, where it occurred in all CBCT scans (100%). The mean value of the CRIm index differs significantly between CBCT scans with MRONJ and JM, as well as between those with OM and JM (Bonferroni p < 0.001).

CONCLUSIONS

The new modified Composite Radiographic Index introduced in this study, appears to have improved an objective approach to the previously used Composite Radiographic Index by means of cumulative radiologic features. Τhe predominance of certain radiologic features in one or more of these entities may lead the diagnostician towards the correct diagnosis.

Alterations in macrophage polarization in the craniofacial and extracranial skeleton after zoledronate application and surgical interventions - an in vivo experiment

Purpose

Medication-related osteonecrosis occurs exclusively in the jaw bones. However, the exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) and the unique predisposition of the jaw bones have not been elucidated, making its treatment a challenge. Recent evidence indicates that macrophages might play a pivotal role in MRONJ pathogenesis. The aim of the present study was to compare the macrophage populations between the craniofacial and extracranial skeleton and to investigate the changes induced by zoledronate (Zol) application and surgical interventions.

Materials and methods

An in vivo experiment was performed. 120 wistar rats were randomized to 4 groups (G1, G2, G3, G4). G1 served as an untreated control group. G2 and G4 received Zol injections for 8 weeks. Afterwards, the right lower molar of the animals from G3 and G4 was extracted and the right tibia osteotomized followed by osteosynthesis. Tissue samples were taken from the extraction socket and the tibia fracture at fixed time points. Immunohistochemistry was conducted to determine the labeling indexes of CD68+ and CD163+ macrophages.

Results

Comparing the mandible and the tibia, we observed a significantly higher number of macrophages and a heightened pro-inflammatory environment in the mandible compared to the tibia. Tooth extraction caused an increase of the overall number of macrophages and a shift toward a more pro-inflammatory microenvironment in the mandible. Zol application amplified this effect.

Conclusion

Our results indicate fundamental immunological differences between the jaw bone and the tibia, which might be a reason for the unique predisposition for MRONJ in the jaw bones. The more pro-inflammatory environment after Zol application and tooth extraction might contribute to the pathogenesis of MRONJ. Targeting macrophages might represent an attractive strategy to prevent MRONJ and improve therapy. In addition, our results support the hypothesis of an anti-tumoral and anti-metastatic effect induced by BPs. However, further studies are needed to delineate the mechanisms and specify the contributions of the various macrophage phenotypes.

A new TRPV4 mutation in a case of multiple central giant cell granulomas of the jaws

Sporadic central giant cell granulomas of the jaws (GCGJ) are often solitary lesions, characterized by KRAS, FGFR1, and TRPV4 somatic mutations. Multifocal lesions may occur and are associated with hyperparathyroidism or underlying syndromes such as cherubism, which is marked by SH3BP2 mutations, and RASopathies, which are caused by mutations in the FGFR-RAS-RAF-MEK-ERK signaling cascade. The diagnosis of multiple GCGJ can be challenging. The present case reports a 14-year-old boy with multiple central GCGJ and no obvious syndromic trait. Sanger sequencing-based analysis revealed wild-type sequences for SH3BP2 (exon 9), KRAS (exons 2-4), and FGFR1 (exons 9 and 10) genes. A rare TRPV4 somatic mutation (p.Val708Met) was detected in the lesion on the right side of the mandible, whereas the other tumor and the normal oral mucosa revealed wild-type TRPV4 sequences. This report expands the spectrum of TRPV4 somatic mutations in central GCGJ.

A meta-analysis on the presentation of Unicystic Ameloblastoma in the jaws and the consequences for their treatment

INTRODUCTION

This meta-analysis provides reliable data on the prevalence of unicystic ameloblastomas (UA's) among solid/multicystic ameloblastomas (SMA's), as well the ratio of their presence in the maxilla and mandible and in the tooth-bearing area versus the posterior regions of the mandible, including the third molar region and ascending ramus.

MATERIAL AND METHODS

A systematic review and meta-analysis was performed according to PRISMA guideline using the strategy ((unicystic ameloblastoma) OR (((ameloblastoma) OR (solid ameloblastoma)) OR (multicystic ameloblastoma))) NOT ((((systematic review) OR (literature review)) OR (case report)) OR (Immunohistochemical)).

DISCUSSION

The study included 3856 SMA's and 1537 UA's, which amounted to 28.5% UA's. Of the 380 cases of UA from twelve articles that mentioned the involved jaws, 355 were in the mandible and 25 in the maxilla. The preponderance for the mandible is much higher than reports from previous studies of smaller series. Only five articles mentioned the location within the mandible. The vast majority was in the posterior area.

CONCLUSION

The consequences for treatment were discussed, with an emphasis on the approach to unicystic lesions in the posterior part of the mandible for which a protocol is suggested.

Manifestations of hyperparathyroidism in the jaws: Concepts, mechanisms, and clinical aspects

Hyperparathyroidism is one of the most common endocrine disorders worldwide. In countries where routine biochemical screening is not common, symptomatic hyperparathyroidism predominates. Its manifestations include skeletal alterations, calcification of soft tissues, kidney stones, and functional alterations in other systems. Notably, jaw alterations can be the first clinical sign of hyperparathyroidism, including brown tumor, renal osteodystrophy, osteitis fibrosa, and leontiasis ossea, and knowing such conditions is of core importance for the multidisciplinary diagnosis and management of hyperparathyroidism. We aimed to perform a concise review, systematizing the concepts and mechanisms underlying hyperparathyroidism and associated gnathic alterations. In addition, a detailed description of the clinical aspects of the jaw manifestations is presented.

Osteonecrosis of the Jaws in Patients with Hereditary Thrombophilia/Hypofibrinolysis-From Pathophysiology to Therapeutic Implications

Osteonecrosis of the jaws (ONJ) usually has a clear etiology. Local infection or trauma, radiotherapy and drugs that disrupt the vascular supply or bone turnover in the jaws are its major contributors. The thrombotic occlusion of the bone’s venous outflow that occurs in individuals with hereditary thrombophilia and/or hypofibrinolysis has a less known impact on jaw health and healing capability. Our research provides the most comprehensive, up-to-date and systematized information on the prevalence and significance of hereditary thrombophilia and/or hypofibrinolysis states in ONJ. We found that hereditary prothrombotic abnormalities are common in patients with ONJ refractory to conventional medical and dental treatments. Thrombophilia traits usually coexist with hypofibrinolysis traits. We also found that frequently acquired prothrombotic abnormalities coexist with hereditary ones and enhance their negative effect on the bone. Therefore, we recommend a personalized therapeutic approach that addresses, in particular, the modifiable risk factors of ONJ. Patients will have clear benefits, as they will be relieved of persistent pain and repeated dental procedures.

Clinicopathological and genetic study of a rare occurrence: Malignant transformation of fibrous dysplasia of the jaws

BACKGROUND

Malignant transformation of fibrous dysplasia (FD) is very rare and little is known about this occurrence.

METHODS

We present the detailed clinical course of three cases of osteosarcoma arising from FD of the jaws and explore the genetic aberrations by Sanger sequencing, whole-exome sequencing (WES) and immunohistochemistry (IHC). A literature review of important topics related to this occurrence was also performed.

RESULTS

It was observed that patients with secondary sarcoma from FD showed a wide range of ages, with most during the third decade. Female and males were equally affected. Craniofacial bones and femurs were the most affected sites. High-risk factors for this occurrence included polyostotic FD, McCune-Albright syndrome and excess growth hormone. Notably, a potential relationship between thyroid hormones and sarcoma development was suggested in one patient, who began to show malignant features after hypothyroidism correction. Sanger sequencing revealed GNAS mutations of FD retained in all malignant tissues. Additionally, abnormal TP53 was demonstrated in all three cases by WES and IHC. WES also revealed two other driver mutations, ROS1 and CHD8, and large amounts of somatic copy number alterations (CNAs) where various oncogenes and tumour suppressors are located.

CONCLUSION

This study demonstrated and reviewed the clinical features and risk factors for a rare occurrence, secondary sarcoma from FD, and provided important new knowledge about its genetics.

The Effects of NF-kB Inhibition with p65-TMD-Linked PTD on Inflammatory Responses at Peri-implantitis Sites

The objective of this study was to find out if suppression of NF-kB complex function by p65-TMD-linked PTD could reduce host inflammation and bone resorption at peri-implantitis sites in rats. Twenty-one male 5-week-old SD rats were divided into three groups: untreated control group (A), silk-induced peri-implantitis group (B), and nt (nucleus transducible)-p65-TMD-treated, silk-induced peri-implantitis group (C). Implant sulcus of a rat in group C were divided into two groups, namely group Cp and Cb. Palatal implant sulcus where nt-p65-TMD solution was applied with an insulin syringe were assigned to group Cp. Buccal implant sulcus without topical nt-p65-TMD application were assigned to group Cb. H&E staining, TRAP staining, and immunohistological staining were done. The crestal bone levels of group A were significantly higher than those of group B at p<0.01. The crestal bone levels of group Cp were significantly higher than those of group Cb at p<0.05. H-E staining showed increased apical migration of junctional epithelium and inflammatory cells in group Cb. TRAP staining revealed more multinucleated osteoclasts in group Cb. As for immunohistological staining, group Cb showed many IL-6-positive cells while group Cp had none. In this study, p65-TMD-linked PTD inhibited NF-kB functions and reduced inflammation and bone resorption at peri-implantitis sites in rats.

Deep learning neural networks to differentiate Stafne's bone cavity from pathological radiolucent lesions of the mandible in heterogeneous panoramic radiography

This study aimed to develop a high-performance deep learning algorithm to differentiate Stafne’s bone cavity (SBC) from cysts and tumors of the jaw based on images acquired from various panoramic radiographic systems. Data sets included 176 Stafne’s bone cavities and 282 odontogenic cysts and tumors of the mandible (98 dentigerous cysts, 91 odontogenic keratocysts, and 93 ameloblastomas) that required surgical removal. Panoramic radiographs were obtained using three different imaging systems. The trained model showed 99.25% accuracy, 98.08% sensitivity, and 100% specificity for SBC classification and resulted in one misclassified SBC case. The algorithm was approved to recognize the typical imaging features of SBC in panoramic radiography regardless of the imaging system when traced back with Grad-Cam and Guided Grad-Cam methods. The deep learning model for SBC differentiating from odontogenic cysts and tumors showed high performance with images obtained from multiple panoramic systems. The present algorithm is expected to be a useful tool for clinicians, as it diagnoses SBCs in panoramic radiography to prevent unnecessary examinations for patients. Additionally, it would provide support for clinicians to determine further examinations or referrals to surgeons for cases where even experts are unsure of diagnosis using panoramic radiography alone.

Jawbone fibrous dysplasia: retrospective evaluation in a cases series surgically treated and short review of the literature

BACKGROUND AND AIM OF THE WORK

Fibrous dysplasia is a fibro-osseous osteopathy in which the normal bone architecture is replaced by fibrous tissue and non-functional trabeculae-like osseous structures. In head and neck area monostotic or polyostotic lesions cause a progressively expanding destructive bone swelling producing cosmetic deformities and functional impairments. The aim of this article is to present a retrospective review of a clinical case series with pathologically confirmed jawbone fibrous dysplasia for over an 8-year-period.

MATERIAL AND METHODS

Clinical presentation and radiographic features of fibrous dysplasia affecting the jawbone skeletal area, surgical procedures performed including the reconstructive methods employed and clinical outcomes were analysed for each patient.

RESULTS

Seven cases were classified as having monostotic fibrous dysplasia while the others four cases were classified as having polyostotic form. The mandible was most commonly involved. The most common presenting features included marked facial deformity, intraoral bulging, malocclusion and dental alterations. Aesthetic and/or functional impairments were the major indications for surgical treatment in all the patients of this series. Six patients underwent bone remodelling while in the remaining cases subtotal or total resection was performed. Bone reconstruction by means of autologous free bone grafts or revascularized free bone flaps was made in three cases.

CONCLUSION

The choice of the tailored therapeutic approach should be evaluated according the patient's age, rate of growth, anatomic location, type of involvement and the presence or not of functional disturbances and cosmetic alterations. Surgery remains the best therapeutic option.

Overexpression of microRNA-141 inhibits osteoporosis in the jawbones of ovariectomized rats by regulating the Wnt/β-catenin pathway

OBJECTIVE

This work was aimed to investigate the effect of microRNA-141 (miR-141) overexpression in the jawbones of ovariectomized-induced osteoporosis rats and investigate the role of miR-141 in the Wnt/β-catenin pathway.

METHODS

Twenty-four female rats were randomly divided into the sham group, ovariectomized osteoporosis group (OP), miR-141 agonist group (miR-141), and miR-141 scramble group (Scramble). Bone mineral density (BMD) and pathological changes of the jaw were detected. Serum receptor activator of nuclear factor-B ligand (RANKL), osteoprotegerin, tartrate-resistant acid phosphatase (TRAP), and bone gla protein (BGP) levels were tested by ELISA. The expression of Runt-related transcription factor 2 (Runx2), and Osterix measured by immunohistochemistry and the expression of Wnt, β-catenin, and Dickkopf1 (DKK1) proteins was measured by Western blot. Furhter, the Wnt agonist DKK2-C2, Wnt inhibitor Endostar were used to verify the effect of miR-141 overexpression on the Wnt/β-catenin pathway.

RESULT

Compared with the OP group, the content of osteoprotegerin increased while the levels of RANKL, BGP, TRAP decreased in the miR-141 and DKK2-C2 groups (p < 0.05). The levels of Runx2 and Osterix increased significantly in the miR-141 and DKK2-C2 groups when compared to the OP group (p < 0.05). Interestingly, the protein expression of Wnt and β-catenin increased while DKK1 was remarkably down-regulated in the miR-141 and DKK2-C2 groups when compared to the OP group (p < 0.05). In contrast to the miR-141 group, the above results were reversed after treatment with the Endostar (p < 0.05).

CONCLUSION

Overexpression of miR-141 could inhibit the osteoporosis of jawbones in ovariectomized rats by activating the Wnt/β-catenin pathway.

Assessment of simulated osteoporosis in alveolar bone using optical coherence tomography

Steoporosis is a skeletal disorder that compromises bone resistance and its diagnosis is usually performed using dual energy X-ray absorptiometry. Thus, the search for efficient diagnostic methods that do not involve the emission of ionizing radiation is necessary. This study proposed to use the Optical Coherence Tomography (OCT) to evaluate osteoporosis in alveolar bone. Osteoporosis lesions is simulated in vitro in porcine bones, and imaging is performed by OCT and micro-computed tomography (micro-CT). A developed algorithm is proposed to calculate the optical attenuation coefficient ( μ _t ), mean optical attenuation coefficient ( μ¯t ), integrated reflectivity (ΔR) and bone density ( BD). The μ¯t , ΔR and BD parameters shows a good correlation to micro-CT parameters (bone volume/tissue volume and total porosity). The μ _t and μ¯t methods are negatively impacted by non-uniform intensities distribution in osteoporosis images. In conclusion, BD and ΔR analysis demonstrates to be potential techniques for diagnosis and monitoring of osteoporosis using OCT.

[Exploration of destructive lesions of the jaws]

The destructive lesions of the jaws destroying the normal bone structure with involvement of the cortex are mostly diagnosed incidentally during a dental examination. or imaging examination for another pathology. The rest of the time they are suspected in front of an aesthetic deformation of the face, in particular of the cheek or the chin. In order to explore these lesions we use the Panoramic Radiography, Computed Tomography (CT) without and with intravenous injection of contrast medium, Cone Beam Computed Tomography (CBCT) and nuclear Magnetic Resonance Imaging (MRI). This article aims to determine the diagnostic range of destructive lesions of the jaws by CT, especially by CBCT, and to propose a diagnostic algorithm according to the circumstances of discovery of these lesions.

Reversible dysphagia due to gabapentin-induced jaw myoclonus

Supplemental Digital Content is available in the text

Everolimus-induced osteonecrosis of the jaw in the absence of bisphosphonates: a case report

Osteonecrosis of the jaw (ONJ) is a rare, but severe, condition that has traditionally been associated with the use of bisphosphonates. We report what is, to our knowledge, the first case of ONJ secondary to the use of everolimus, in the absence of treatment with bisphosphonates in a 65-year-old man who was given it for immunosuppression after a renal transplant. After 18 months of treatment, he was diagnosed with severe ONJ and underwent radical debridement of the palate and complete dental clearance of the maxilla.

Inactivating Mutation in IRF8 Promotes Osteoclast Transcriptional Programs and Increases Susceptibility to Tooth Root Resorption

This is the first study to our knowledge to report a novel mutation in the interferon regulatory factor 8 gene (IRF8G388S ) associated with multiple idiopathic tooth root resorption, a form of periodontal disease. The IRF8G388S variant in the highly conserved C-terminal motif is predicted to alter the protein structure, likely impairing IRF8 function. Functional assays demonstrated that the IRF8G388S mutant promoted osteoclastogenesis and failed to inhibit NFATc1-dependent transcriptional activation when compared with IRF8WT control. Further, similar to subjects with heterozygous IRF8G388S mutation, Irf8+/- mice exhibited increased osteoclast activity in the mandibular alveolar bone surrounding molar teeth. Immunohistochemistry illustrated increased NFATc1 expression in the dentoalveolar region of Irf8-/- and Irf8+/- mice when compared with Irf8+/+ controls. Genomewide analyses revealed that IRF8 constitutively bound to regulatory regions of several thousand genes in osteoclast precursors, and genetic aberration of IRF8 significantly enhanced many osteoclast-specific transcripts. Collectively, this study delineates the critical role of IRF8 in defining osteoclast lineage and osteoclast transcriptional program, which may help in better understanding of various osteoclast-mediated disorders, including periodontal disease. © 2019 American Society for Bone and Mineral Research.

Invasive Oral Procedures and Events in Postmenopausal Women With Osteoporosis Treated With Denosumab for Up to 10 Years

CONTEXT

Antiresorptive therapy has been associated with osteonecrosis of the jaw (ONJ), an infrequent but potentially serious adverse event.

OBJECTIVE

To assess information on invasive oral procedures and events (OPEs)-dental implants, tooth extraction, natural tooth loss, scaling/root planing, and jaw surgery-during the 7-year Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months (FREEDOM) Extension study and to present details of positively adjudicated ONJ cases.

DESIGN

Randomized, double-blind, placebo-controlled, 3-year trial (FREEDOM) followed by 7 years of open-label denosumab (FREEDOM Extension). At Extension Year 3, women were asked to record their history of invasive OPEs since the start of the Extension to Year 2.5 and oral events in the prior 6 months. The questionnaire was then administered every 6 months until the end of the Extension.

SETTING

Multicenter, multinational clinical trial.

PATIENTS

Postmenopausal women with osteoporosis.

INTERVENTIONS

Subcutaneous denosumab 60 mg or placebo every 6 months for 3 years, then 7 years of open-label denosumab.

MAIN OUTCOME MEASURES

Self-reports of OPEs and adjudicated cases of ONJ.

RESULTS

Of respondents, 45.1% reported at least one invasive OPE. The exposure-adjusted ONJ rate in FREEDOM Extension was 5.2 per 10,000 person-years. ONJ incidence was higher in those reporting an OPE (0.68%) than not (0.05%).

CONCLUSIONS

Although invasive OPEs were common in these denosumab-treated women and were associated with an increased ONJ incidence, the overall rate of ONJ was low, and all cases with complete follow-up resolved with treatment.

Comparison of alveolar ridge splitting and autogenous onlay bone grafting to enable implant placement in patients with atrophic jaw bones

Objective:

To compare alveolar ridge splitting (ARS) and autogenous onlay bone grafting (AOBG) in atrophic jaw bones.

Methods:

Forty patients were included in this retrospective, parallel-group study conducted at the Istanbul Medipol University School of Dentistry, Istanbul, Turkey, between 2012-2015. The initial bone thickness was measured by cone beam computed tomography (CBCT). Patients were allocated into ARS (n=17) and AOGB (n=23) groups on the basis of ridge thickness and shape. Follow-up CBCT measurements to assess horizontal bone were repeated 4 to 6 months post augmentation. The diameters of the implants were recorded. Implant bone resorption was measured at one year post implant placement on panoramic radiography. Surgical complications and implant survival were evaluated.

Results:

The final bone width in the AOBG group was significantly higher than that in the ARS group (p=0.029). Forty-four implants were inserted in the AOGB group, whereas 33 implants were inserted in the ARS group. There was no significant difference regarding implant diameter (p=0.920). Implant survival rate was 93.9% in the ARS group and 93.1% in the AOGB group. Peri-implant bone resorption at one year was higher in the AOBG group than in the ARS group (p=0.032). There were minor surgical complications, including bad split and wound dehiscence.

Conclusion:

The incidence of peri-implant bone resorption for the AOGB technique was higher than that for the ARS technique, but their implant survival rates were similar.

Comparison of Beta and ANB Angles for Evaluation of Sagittal Skeletal Discrepancy: A Cephalometric Study

AIM

Diagnosis in orthodontic cases and treatment planning is a precise assessment of sagittal jaw relationship. A number of angular and linear measurements have been used to attain correct diagnosis. The present study is done to compare beta angle and A point-nasion-B point (ANB) angle for sagittal skeletal discrepancies.

MATERIALS AND METHODS

A total of 105 subjects were included in between the age group of 18 and 24 years and were categorized based on the skeletal patterns as class I, class II, and class III having a sample of 35 in each group. Based on the ANB angle and patients' profile, the sample was divided into different skeletal groups. Beta angle is the angle amid the perpendicular from C to B line through point A and the A-B line. Analysis of variance (ANOVA) and post hoc Scheffe's test were applied to analyze dependent variables. The level of significance was set at p-value 0.05.

RESULTS

The mean scores of ANB for class I skeletal pattern were 2.46 ± 0.460, for class II, 5.64 ± 1.258, and for class III, -1.03 ± 1.618. Similarly, significant differences were observed in beta angle for class I skeletal pattern as 31.71 ± 3.885, for class II, 24.97 ± 2.162, and for class III, 39.26 ± 3.649.

CONCLUSION

Both ANB and beta angle showed significant differences with different skeletal patterns.

CLINICAL SIGNIFICANCE

Both ANB and beta angle are awfully supportive diagnostic measurements to scrutinize sagittal jaw relationship.

Comparative Assessment of Facial Asymmetry in Malocclusion using Posteroanterior View

AIM

The study was conducted to assess facial asymmetry in various dental malocclusions and to determine asymmetry in lower, mid, and upper face and jaws using posteroanterior cephalometric analysis.

MATERIALS AND METHODS

Overall, 120 posteroanterior cepha-lograms were taken of individuals between 12 and 25 years of both sexes, and were divided into four groups: Angle's class I excellent occlusion, Angle's class I malocclusion, Angle's class II malocclusion, and Angle's class III malocclusion. These cepha-lograms were traced and Grummon's analysis was performed.

RESULTS

In Angle's class I occlusion and Angle's class II malocclusion, the results obtained showed asymmetry present in the upper face. Correlation was found between occlusion, maloc-clusion, and facial asymmetry.

CONCLUSION

Facial asymmetry was found in all dental occlusions whether excellent or malocclusion group, with maximum asymmetry having upward trend toward upper face starting from lower.

CLINICAL SIGNIFICANCE

For the success of the orthodontic treatments in various types of malocclusion and to determine the facial asymmetry, posteroanterior view can be very helpful, as it gives additional information which can be utilized to augment treatment planning and improve prognosis in terms of relapse prevention.

Maxillary and Mandibular Displacement in Hemifacial Microsomia: A Longitudinal Roentgen Stereometric Study of 21 Patients with the Aid of Metallic Implants

Objective

To record maxillary and mandibular displacement with articular growth and in response to bimaxillary surgical repositioning in patients with hemifacial microsomia (HFM) and to observe ipsilateral corpus/ramus growth in severely affected children.

Design

Prospective roentgen stereometric analysis (mean age 7 years 10 months to 18 years 0 months) and retrospective profile and panoramic roentgenograms. Mean total observation period was 9 years 1 month.

Setting

Department of Plastic and Reconstructive Surgery, Malmö University Hospital (Malmö, Sweden).

Patients

Twenty-one patients consecutively diagnosed from 1976 through 1988 with HMF, five of whom had bimaxillary surgery.

Interventions

Surgery was performed at the Department of Plastic and Reconstructive Surgery. Implants were inserted at the initial reconstructive surgical procedure under general anesthesia. Roentgen examinations were performed in connection with continued clinical evaluations and treatment.

Main Outcome Measures

Stereo roentgenograms were digitized at the Department of Orthopedic Surgery, Malmö University Hospital (Malmö, Sweden).

Results

Displacement of the jaws with articular growth and in response to bimaxillary surgical repositioning varied interindividually with no apparent common pattern. Relapse displacement occurred several years after bimaxillary surgery. Mandibular growth changes were found in the corpus/ramus area and alveolar process on the affected side.

Conclusions

A marked interindividual variability of maxillary and mandibular displacement indicates that the relevance of statistical analysis of HFM growth data may be questioned. We would suggest that precise and accurate longitudinal recordings of growth and response to surgery in individual HFM patients be more appropriate.

Markers of proliferation and cytokeratins in the differential diagnosis of jaw cysts

We conducted a retrospective study to analyze the histologic and immunohistochemical findings in three main types of odontogenic cyst. We studied 90 archived cystic jaw lesions: 30 dentigerous cysts, 30 keratocystic odontogenic tumors, and 30 radicular cysts. The cyst types were identified on the basis of clinical, radiologic, and histopathologic findings. Immunohistochemical analyses included staining with Ki-67, p53, epidermal growth factor receptor (EGFR), cytokeratin (CK) 8, CK14, CK17, and CK18. Cell immunopositivity was evaluated for the entire epithelium. The criteria for Ki-67 and p53 positivity were dense and/or faint nuclear staining, and cells were considered EGFR-positive if they exhibited membrane staining and/or cytoplasm staining. For the cytokeratins, cells exhibiting cytoplasm staining were considered positive. Five representative fields of each lesion were selected and identified in each of the Ki-67- and p53-stained slides. We found a statistically significant difference in the ratio of Ki-67-positive cells in the entire layer between the keratocystic odontogenic tumors and both the dentigerous cysts and the radicular cysts. A statistically significant difference was observed in the ratio of p53-positive cells between the keratocystic odontogenic tumors and the radicular cysts. Cytokeratins proved to be useful in differentiating radicular cysts from other types of cystic jaw lesions because of their CK8-positive and CK17-negative immunolabeling.

Ewing's Sarcoma Family Tumors in the Jaws: Case Report, Immunohistochemical Analysis and Literature Review

Due to the low incidence of the Ewing's Sarcoma (ES) family tumors, the available epidemiology is likely to be unreliable, and at present, there are no standard diagnostic or clinical guidelines outlining their management. This report describes a case of peripheral primitive neuroectodermal tumor (ES/pPNET) which initially mimicked cystic lesions, and describes a comparison between ES and ES/pPNET in the jaws by the World Health Organization classification. This review addressed 63 cases published in the English literature between 1950 and 2016. The majority of cases were ES. Both ES and ES/pPNET mimicked other benign entities such as traumatic, cystic and inflammatory lesions. The patients who died of their disease had a history of metastatic tumors, and primary tumor located in the mandible and maxilla for ES and ES/pPNET, respectively. The differentiation of the ES family tumors from other small blue-cell tumors may be difficult and requires familiarity with histological and immunohistochemical features.

Impact of Rantes from jawbone on Chronic Fatigue Syndrome

This study elucidates the question of whether chronic inflammation in the jawbone contributes to the development of Chronic Fatigue Syndrome (CFS). Fatty degenerative osteonecrosis in jawbone (FDOJ) may contribute to CFS by induction of inflammatory mediators. We examined seven cytokines by multiplex analysis in jawbone samples from two groups of patients. In order to clarify neurological interrelations, specimens from 21 CFS patients were analyzed from areas of previous surgery in the retromolar wisdom tooth area. Each of the retromolar jawbone samples showed clinically fatty degenerated and osteonecrotic medullary changes. As control, healthy jawbone specimens from 19 healthy patients were analyzed. All fatty necrotic and osteolytic jawbone (FDOJ) samples showed high expression of RANTES and fibroblast growth factor (FGF)-2. FDOJ cohorts showed a 30-fold mean overexpression of RANTES and a 20-fold overexpressed level of FGF-2 when compared to healthy controls. As RANTES is discussed in the literature as a possible contributor to inflammatory diseases, we hypothesize that FDOJ in areas of improper and incomplete wound healing in the jawbone may hyperactivate signaling pathways. Constituting a hidden source of “silent inflammation” FDOJ may represent a hitherto unknown cause for the development of CFS.

The Use of Hyperbaric Oxygen for the Prevention and Management of Osteoradionecrosis of the Jaw: A Dana-Farber/Brigham and Women's Cancer Center Multidisciplinary Guideline

BACKGROUND

Osteoradionecrosis of the jaw (ORN) is an infrequent yet potentially devastating complication of radiation therapy to the head and neck region. Treatment options include antimicrobial therapy, local sequestrectomy, resection, and the use of hyperbaric oxygen (HBO). Published data on ORN are difficult to compare because of the lack of a universally accepted classification and staging system, and the literature on the use of HBO to either prevent or successfully manage ORN is controversial and inconclusive. Therefore, we aimed to establish a standard approach for using HBO at our institution.

MATERIALS AND METHODS

A literature search was conducted of articles published in the English language between January 1980 and January 2016. Retrieved articles were evaluated by two independent reviewers. Isolated case reports, abstracts, case series, review articles, and cohort studies without a control group were excluded; summary data were extracted from the remaining studies. A panel of experts from Head and Neck Oncology and Oral Medicine from the Dana-Farber Cancer Institute and Brigham and Women's Hospital reviewed the summary data and established multidisciplinary guidelines on the use of HBO for the prevention and management of ORN.

RESULTS

Seven studies were evaluated and reviewed by the multidisciplinary panel. There was no consistent evidence in support of HBO for either the prevention or management of ORN.

CONCLUSION

Based on the available evidence and expert opinion, routine use of HBO for the prevention or management of ORN is not recommended and is rarely used at our institution. The Oncologist 2017;22:343-350 IMPLICATIONS FOR PRACTICE: The Division of Head and Neck Oncology of Dana-Farber/Brigham and Women's Cancer Center does not recommend the routine use of HBO for the prevention or management of ORN. Adjunctive HBO may be considered for use on a case-by-case basis in patients considered to be at exceptionally high risk who have failed conservative therapy and subsequent surgical resection.

Bad to the Bone: On In Vitro and Ex Vivo Microbial Biofilm Ability to Directly Destroy Colonized Bone Surfaces without Participation of Host Immunity or Osteoclastogenesis

Bone infections are a significant public health burden associated with morbidity and mortality in patients. Microbial biofilm pathogens are the causative agents in chronic osteomyelitis. Research on the pathogenesis of osteomyelitis has focused on indirect bone destruction by host immune cells and cytokines secondary to microbial insult. Direct bone resorption by biofilm pathogens has not yet been seriously considered. In this study, common osteomyelitis pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Streptococcus mutans) were grown as biofilms in multiple in vitro and ex vivo experiments to analyze quantitative and qualitative aspects of bone destruction during infection. Pathogens were grown as single or mixed species biofilms on the following substrates: hydroxyapatite, rat jawbone, or polystyrene wells, and in various media. Biofilm growth was evaluated by scanning electron microscopy and pH levels were monitored over time. Histomorphologic and quantitative effects of biofilms on tested substrates were analyzed by microcomputed tomography and quantitative cultures. All tested biofilms demonstrated significant damage to bone. Scanning electron microscopy indicated that all strains formed mature biofilms within 7 days on all substrate surfaces regardless of media. Experimental conditions impacted pH levels, although this had no impact on biofilm growth or bone destruction. Presence of biofilm led to bone dissolution with a decrease of total volume by 20.17±2.93% upon microcomputed tomography analysis, which was statistically significant as compared to controls (p <0.05, ANOVA). Quantitative cultures indicated that media and substrate did not impact biofilm formation (Kruskall-Wallis test, post-hoc Dunne's test; p <0.05). Overall, these results indicate that biofilms associated with osteomyelitis have the ability to directly resorb bone. These findings should lead to a more complete understanding of the etiopathogenesis of osteomyelitis, where direct bone resorption by biofilm is considered in addition to the well-known osteoclastic and host cell destruction of bone.

The starting point for bisphosphonate-related osteonecrosis of the jaw: Alveolar bone or oral mucosa? A randomized, controlled experimental study

OBJECTIVE

Although over a decade has passed since first introduction of BRONJ, the exact pathophysiology of this disease is still unclear. The present experimental study aimed to determine whether the oral mucosa or alveolar bone serves as the starting point for BRONJ development.

SUBJECTS AND METHODS

Sixty male Wistar rats were randomly assigned into study and control groups (each, n = 30), and received intraperitoneal injection of 0.06 mg/kg zoledronate and saline, respectively, once a week for 12 weeks. At the end of the week 4 of the experiment, all 60 rats underwent unilateral mandibular first molar extraction. A 4 mm defect was made in the contralateral canine alveolar mucosa. At the end of the experiment, rats were sacrificed, and the three areas of interest including extraction, soft tissue defect, and the non-intervention (canine area on the same side of extraction) sites were assessed clinically for presence of bone exposure/fistula, and histologically for status of bone remodeling (only at extraction site) and osteonecrosis.

RESULTS

In the study group, the frequency of bone exposure/fistula was 80%, 0%, and 0%; and the rate of histological bone necrosis was 83.3%, 20%, and 0%; at the extraction, soft tissue defect, and non-intervention sites, respectively. No clinical and histological sign of bone necrosis was found in the control group. Normal bone remodeling was observed in 0% and 100% of the extraction sockets in the study and control groups, respectively.

CONCLUSION

Injury to alveolar bone was a stronger trigger for BRONJ development compared to oral mucosal damages.

[NF-κB signaling pathways and the future perspectives of bone disease therapy using selective inhibitors of NF-κB]

The transcriptional factor nuclear factor κB(NF-κB)regulates the expression of a wide variety of genes that are involved in immune and inflammatory responses, proliferation, and tumorigenesis. NF-κB consists of five members, such as p65(RelA), RelB, c-Rel, p50/p105(NF-κB1), and p52/p100(NF-κB2). There are two distinct NF-κB activation pathways, termed the classical and alternative NF-κB signaling pathways. Since mice lacking both p50 and p52 subunits developed typical osteopetrosis, due to total lack of osteoclasts, NF-κB is also important osteoclast differentiation. A selective NF-κB inhibitor blocked receptor activator of NF-κB ligand(RANKL)-induced osteoclastogenesis both in vitro and in vivo. Recent findings have shown that inactivation of NF-κB enhances osteoblast differentiation in vitro and bone formation in vivo. NF-κB is constitutively activated in many cancers including oral squamous cell carcinoma(OSCC), and is involved in the invasive characteristics of OSCC. A selective NF-κB inhibitor also prevented jaw bone destruction by OSCC by reduced osteoclast numbers in animal model. Thus the inhibition of NF-κB might useful for the treatment of bone diseases, such as arthritis, osteoporosis, periodontitis, and bone invasion by OSCC by inhibiting bone resorption and by stimulating bone formation.

[CLINICAL ESTIMATION OF THE PROPHYLAXIS EFFICACY FOR POSTOPERATIVE PATHOLOGICAL CICATRICES OF FACIAL SKIN]

Efficacy of combined prophylaxis of postoperative pathological cicatrices of facial skin was studied. Application of extracorporeal shock—wave therapy and the silicone gel Strataderm have had impacted the clinical characteristics of the facial skin postoperative cicatrix positively: a shock—wave therapy promoted a sutural tracks involution, аnd the silicone gel Strataderm — normalization of the postoperative cicatrix pigmentation.

Four mm-long versus longer implants in augmented bone in atrophic posterior jaws: 4-month post-loading results from a multicentre randomised controlled trial

PURPOSE

To evaluate whether 4-mm long dental implants could be an alternative to augmentation with equine bone blocks and the placement of at least 10-mm long implants in atrophic posterior jaws.

MATERIALS AND METHODS

Forty patients with atrophic posterior (premolar and molar areas) mandibles having 5 to 6 mm bone height above the mandibular canal and 40 patients with atrophic maxillae having 4 to 5 mm below the maxillary sinus, were randomised according to a parallel group design to receive one to three 4.0 mm-long implants or one to three implants, which were at least 10 mm long, in augmented bone at two centres. All implants had a diameter of 4.0 or 4.5 mm. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers. Implants were placed 4 months after interpositional grafting. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers, and implants were placed simultaneously. Implants were not submerged and were loaded after 4 months with provisional prostheses. Four months later, screw-retained reinforced acrylic restorations were delivered, and then replaced after 4 months by definitive screw-retained metal-composite prostheses. Patients were followed up to 4-months post-loading. Outcome measures included prosthesis and implant failures, any complication and peri-implant marginal bone level changes.

RESULTS

No patient dropped out. In six augmented mandibles (30%), it was not possible to place implants which were at least 10.0-mm long, therefore shorter implants had to be placed instead. In particular, one mandible fractured and the patient did not want to go ahead with the treatment. One implant of the patient with the mandible fracture from the augmented group failed versus two 4.0 mm implants in two patients from the short implant group. In the maxillae, three short implants failed in two patients versus five long implants in three patients (two long implants and one short implant dropped into the maxillary sinus). Two prostheses on short implants (one mandibular and one maxillary) were placed at a later stage because of implant failures versus four prostheses (one mandibular and three maxillary) at augmented sites. In particular, three patients of the augmented group (one mandible and two maxillary) were not prosthetically rehabilitated. There were no statistically significant differences in implant failures (P (chi-square test) = 1.000; difference in proportion = 0; 95% Cl: -0.13 to 0.13 or prostheses failures (P (chi-square test) = 0.399; difference in proportion = 0.05; 95% Cl: -0.06 to 0.16). At mandibular sites, nine augmented patients were affected by complications versus one patient treated with short implants (P (chi-square test) = 0.003; difference in proportion = 0.40; 95% Cl: 0.16 to 0.64), with the difference being statistically significant. No significant differences were found for the maxillae: eight sinus lift patients versus three patients rehabilitated with maxillary short implants were affected by complications (P (chi-square test) = 0.077; difference in proportion = 0.25; 95% Cl: -0.02 to 0.52). Patients with mandibular short implants lost on average 0.40 mm of peri-implant bone at 4 months and patients with 10 mm or longer mandibular implants lost 0.52 mm. Patients with short maxillary implants lost on average 0.48 mm peri-implant bone at 4 months and patients with 10 mm or longer maxillary implants lost 0.50 mm. The difference was statistically significant in the mandibles (mean difference: -0.12 mm, 95% CI: -0.20 to -0.04, P (ANCOVA) = 0.006), but not in the maxillae (mean difference: -0.02 mm, 95% CI: -0.10 to 0.07, P (ANCOVA) = 0.711).

CONCLUSIONS

Four months after loading 4.0 mm-long implants achieved similar results, if not better, than longer implants in augmented jaws, but were affected by fewer complications. Short implants might be a preferable choice to bone augmentation, especially in mandibles, since the treatment is less invasive, faster, cheaper, and associated with less morbidity; however, 5- to 10-year post-loading data is necessary before making reliable recommendations. Conflict-of-interest statement: Global-D (Brignais, France) partially supported this trial and donated the implants and prosthetic components; however, data property belonged to the authors and by no means did Global-D interfere with the conduct of the trial or the publication of the results.

OCULOECTODERMAL SYNDROME: A NEW CASE WITH GIANT CELL GRANULOMAS AND NON-OSSIFYING FIBROMAS

Oculoectodermal syndrome (OES) is a very rare disorder with an unknown etiology and characterized by aplasia cutis congenita, epibulbar dermoid and hyperpigmentation areas on the skin. To the best of our knowledge, two cases of OES have been reported to date with recurrent giant cell granuloma in the jaw and one of them also had a non-ossified fibroma in the long bones. Herein, we report the second case with aplasia cutis congenita, epibulbar dermoid, hyperpigmentation along Blaschko lines and also giant cell granuloma in the jaw and non-ossified fibromas in the bones.

Zoledronate induces osteonecrosis of the jaw in sheep

INTRODUCTION

The treatment of bisphosphonate-related osteonecrosis of the jaw has become routine in maxillofacial hospitals. However, the etiopathology has not yet been fully understood. The aim of this study was to develop a large animal model for medication-related osteonecrosis of the jaw (MRONJ).

MATERIAL AND METHODS

Eight Swiss mountain sheep were randomly assigned into two groups. Group I received 0.075 mg/kg zoledronate (ZOL) intravenously every third week for 16 weeks. After 16 weeks, extraction of the first and second lower left premolar was performed. Group II underwent surgery and no ZOL was administered. After surgery, Group I continued to receive ZOL infusions; after 16 weeks, all animals were euthanized. The jaw bones were investigated macroscopically, radiographically (computed tomography) and histologically.

RESULTS

Osteonecrosis of the jaw was observed at all extraction sites in all the animals receiving ZOL, and at none of the sites in animals without ZOL. All ZOL-treated animals spontaneously developed exposed bone lesions in the oral cavity at sites where no surgical intervention was performed. CT imaging shows persistent alveolar extraction sockets 16 weeks after surgery in all animals of the ZOL-group, and healed alveolar extraction sockets in non-ZOL-treated animals.

CONCLUSION

Sheep treated with ZOL reproducibly demonstrated osteonecrosis of the jaw after tooth extraction, and spontaneous development of exposed bone in the oral cavity at sites where no manipulation was performed. This animal model can be used for further research in the fields of BP-ONJ etiopathology, oral implantology, bone and fracture healing and periodontology.

Restoration of Severely Atrophic Jaws

For many patients, there is no other option. The CDI is an eposteal implant that becomes firmly attached to underlying bone. More than 25 years of experience with the implant have shown that the implant is capable of supporting both removable and fixed appliances. Once the many constituent factors of this process are understood and taken into account, the CDI becomes a powerful device in the armamentarium of the implant dentist. Furthermore, it often represents the only tool that can be employed to successfully correct cases involving severely atrophic jaws.

Evaluation of the quantitative accuracy of 3D reconstruction of edentulous jaw models with jaw relation based on reference point system alignment

OBJECTIVES

To apply contact measurement and reference point system (RPS) alignment techniques to establish a method for 3D reconstruction of the edentulous jaw models with centric relation and to quantitatively evaluate its accuracy.

METHODS

Upper and lower edentulous jaw models were clinically prepared, 10 pairs of resin cylinders with same size were adhered to axial surfaces of upper and lower models. The occlusal bases and the upper and lower jaw models were installed in the centric relation position. Faro Edge 1.8m was used to directly obtain center points of the base surface of the cylinders (contact method). Activity 880 dental scanner was used to obtain 3D data of the cylinders and the center points were fitted (fitting method). 3 pairs of center points were used to align the virtual model to centric relation. An observation coordinate system was interactively established. The straight-line distances in the X (horizontal left/right), Y (horizontal anterior/posterior), and Z (vertical) between the remaining 7 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test.

RESULTS

The differences of the straight-line distances of the remaining 7 pairs of center points between the two methods were X: 0.074 ± 0.107 mm, Y: 0.168 ± 0.176 mm, and Z: -0.003± 0.155 mm. The results of paired t-test were X and Z: p >0.05, Y: p <0.05.

CONCLUSION

By using contact measurement and the reference point system alignment technique, highly accurate reconstruction of the vertical distance and centric relation of a digital edentulous jaw model can be achieved, which meets the design and manufacturing requirements of the complete dentures. The error of horizontal anterior/posterior jaw relation was relatively large.

Prospective, mono-institutional study of the impact of a systematic prevention program on incidence and outcome of osteonecrosis of the jaw in patients treated with bisphosphonates for bone metastases

The aim of our study was to investigate the occurrence of osteonecrosis of the jaw (ONJ) after implementation of dental preventive measures before starting bisphosphonates (BPs) therapy and during treatment. All consecutive patients with bone lesions eligible for BPs treatment were prospectively evaluated. Before starting BPs, each patient underwent a strict dental preventive program with a specialized odontoiatric team. The odontoiatric evaluation identified patients with oral pathologies or inadequate oral hygiene and provided a dental preventive treatment. From April 2007 to April 2012, 254 patients were enrolled. After excluding patients due to previous BPs treatment, 212 patients with a mean age of 74 years (range 37-95) were included. On average, patients received 9.7 treatment cycles (range 1-48). No ONJ was recorded (0.0 %; 95 % confidence interval [CI] 0.0-1.4). Comparing this risk with that observed in a previous cohort who did not receive dental prevention (16/186, 8.6 %; 95 % CI 4.2-15.3 %), we observed clear efficacy in preventing ONJ (relative risk reduction: 100 %, 95 % CI 86-100 %, P < 0.0001). We developed a strict three-step prevention program that is able to decrease ONJ incidence and the need for destructive surgery with permanent sequelae. We demonstrated that ONJ could be effectively prevented. We recommend a mandatory preventive program involving a multidisciplinary team for all patients starting BPs.

[Contemporary approach to diagnosis and treatment of impacted teeth]

BACKGROUND

Goal of the research was to study occurrence frequency of impacted teeth, to develop rational methods of diagnostics and treatment of denotalveolar and facial anomalies caused by impacted teeth.

PATIENTS AND METHODS

From 1989 for 2013 period of time 7172 patients with dentoalveolar anomalies, referred to our clinic for the orthodontic help were surveyed.

RESULTS

At 899 (12.53 +/- 0.39%) patients it is revealed 1405 impacted teeth, from them on the maxilla--623, on mandible--752 teeth. The most widespread impacted teeth on the maxilla were canines, on the mandible--the second premolars and the third molars. Treatment of impacted teeth by stimulation of their eruption by low-frequency ultrasound with a frequency of fluctuations of 26.5 kHz, intensity of 1 W/cm, with an amplitude of 40-60 microns and wave of 0.012 m long, daily or within 1 days, with period of 3-10 seconds with the course of treatment averaging 1-5 procedures, until a tooth eruption is carried out.

CONCLUSION

The way of stimulation developed by us for late erupted impacted permanent teeth on the basis of application physiologic for an organism low-frequency ultrasound promotes increase of efficiency and reduction of treatment terms of dentoalveolar and facial anomalies. The received positive results allow to recommend this method for adoption in orthodontic practice.

[Histomorphometric and quantitative histochemical analysis of periimplantation zone in patients with different bone mineral density within dental implantation]

BACKGROUND

The aim of the work is to study histomorphometric and histochemical properties of jaw bone loss in patients with full or partial edentulism, need to restoring their dentition integrity by dental implantation.

PATIENTS AND METHODS

Cytological studies were carried out in 83 patients, among which normal bone mass was observed in 28 patients (17 women and 11 men), osteopenia in 26 patients (17 women and 9 men), osteoporosis in 29 (19 women and 10 men) patients. Histological examination of bone biopsies were performed in 76 patients, among which normal bone mass was observed in 22 (16 women and 6 men, osteopenia in 26 patients (17 women and 9 men), osteoporosis in 28 (19 women and 9 men) patients.

RESULTS

Histomorphometric analysis of "implant-bone" contact in the entire length of the joint in patients with normal bone mass was 61.8 +/- 3.7%, with osteopenia was 51.6+/- 3.0%, with osteoporosis was 46.1 +/- 2.8%. The intensity of bone remodeling in patients with normal bone mass was 2.7 +/- 0.19, in patients with osteopenia was 2.2 +/- 0.14, in patients with osteoporosis was 1.8 +/- 0.11. This demonstrates the significant difference between the patients with normal bone mass and osteoporotic patients. The "implant-bone" interface in osteoporotic patients was significantly lower than in patients with normal bone mass.

CONCLUSION

Histomorphometric studies and quantitative histochemical analysis revealed that the decrease of bone mineral mass in patients often combined with a decrease of the "implant surface-bone" site contact area, with atrophy and with hypoplasia of perimplant tissues.

[Application of three-dimensional printing technique in repair and reconstruction of maxillofacial bone defect]

OBJECTIVE

To explore the application of three-dimensional (3-D) printing technique in repair and reconstruction of maxillofacial bone defect.

METHODS

The related literature on the recent advance in the application of 3-D printing technique for repair and reconstructing maxillofacial bone defect was reviewed and summarized in the following aspects: 3-D models for teaching, preoperative planning, and practicing; surgical templates for accurate positioning during operation; individual implantable prosthetics for repair and reconstructing the maxillofacial bone defect.

RESULTS

3-D printing technique is profoundly affecting the treatment level in repair and reconstruction of maxillofacial bone defect.

CONCLUSION

3-D printing technique will promote the development of the repair and reconstructing maxillofacial bone defect toward more accurate, personalized, and safer surgery.

The phosphorous necrosis of the jaws and what can we learn from the past: a comparison of "phossy" and "bisphossy" jaw

INTRODUCTION

The osteopathology of the jaws associated with bone resorption inhibitors is a current topic that engages a variety of clinical specialists. This has increased after the approval of denosumab for treatment of osteoporosis and skeletal-related events in patients with solid malignancy. Early after the first publications, there is a possible connection between phosphorous necrosis of the jaws, a dreadful industrial disease mentioned, and bisphosphonate-induced pathology. The nineteenth century was the prime time for phosphorus necrosis of match factory workers.

RESULTS

This occurrence provides an interesting insight into the medical and surgical profession in the nineteenth century. There are striking parallels and repetition of current and old ideas in the approach to this "new disease." There are similar examples in case descriptions when compared with today's patients of bisphosphonate-related osteonecrosis of the jaws (BRONJ).

DISCUSSION

Phosphorus necrosis was first described in Austria. Soon after this, surgeons in German-speaking countries including well-known clinicians Wegner (1872) and von Schulthess-Rechberg (1879) pioneered the analysis, preventative measures, and treatment of this disease. The tendency at this time was to approach BRONJ as a "special kind of osteomyelitis" in pretreated and metabolically different bone. Not only the treatment strategy to wait until sequestrum formation with subsequent removal and preventative measures but also the idea of focusing on the periosteum as the triggering anatomical structure may have been adopted from specialists in the nineteenth century. Therefore, phosphorous necrosis of the jaw is an excellent example of "learning from the past."