Endogenous Regeneration of Alveolar Bone by Decellularized Tooth Matrix.

The efficiency of bone tissue regeneration by decellularized tooth matrix, demineralized tooth matrix, and commercial xenograft Bio-Oss Spongiosa was compared on the model of a critical-size circular defect in the alveolar bone of the upper jaw of adult Wistar rats. The defect healing dynamics was assessed using histological, histomorphometrical, and immunohistochemical methods on days 30 and 60. In contrast to demineralized matrix and commercial xenograft, decellularized matrix induces the formation of the new bone tissue by day 60. Decellularized matrix can be considered as a biomaterial for cell-free tissue engineering for alveolar bone restoration in dentistry and maxillofacial surgery.

[Alveolar distraction osteogenesis: possible complications and methods of their treatment]. / Al'veolyarnyi distraktsionnyi osteogenez: vozmozhnye oslozhneniya i sposoby ikh ustraneniya.

OBJECTIVE: The aim of the study. Analysis of emerging complications during the method of alveolar distraction osteogenesis in patients with jaw defects. A retrospective analysis of foreign and domestic literature was carried out. A systematic literary search was carried out in the electronic bibliographic databases Web of Science (for foreign articles) and Elibrary and Dissercat (for domestic). MATERIAL AND METHODS: In the period from 2005 to 2019 in the clinic of the Department of Maxillofacial and Plastic Surgery of the Moscow State Medical University. Evdokimov conducted an examination and comprehensive treatment of 490 patients with primary and secondary adentia of the upper and lower jaws, accompanied by a significant deficiency of bone tissue of the alveolar ridge vertically. A comprehensive dental rehabilitation of patients with jaw defects by the method of distraction osteogenesis was carried out. RESULTS: The most common complications are: exposure of the fixation modules of the distraction apparatus - 24% of cases, failure of bone regenerate - 13%, inflammatory phenomena - 13%, displacement of the distraction vector - 43%, paresthesia - 7%. CONCLUSION: Based on our analysis of the identified complications during the distraction osteogenesis method, it was found that these complications are not critical in the treatment of patients with jaw bone deficiency and do not jeopardize the success of rehabilitation. With diagnosis and timely approach to treatment, complications are avoidable.

[Clinical example of complex diagnostic and treatment of patient with temporomandibular joint internal derangements with arthroscopic surgery]. / Klinicheskii primer effektivnosti kompleksnogo algoritma diagnostiki i lecheniya patsientov s vnutrennimi narusheniyami visochno-nizhnechelyustnogo sustava s primeneniem artroskopicheskoi khirurgii.

OBJECTIVE: Improvement and evaluation of effectiveness of the arthroscopic surgery based on individual anatomical sizes in the treatment of patients with the temporomandibular disorders (TMD). MATERIAL AND METHODS: The article presents the results of complex treatment of patient with TMJ internal derangements and osteoarthritis using arthroscopic surgery. In the pre- and postoperative period, the patient was examined clinically, as well as by computed tomography (CT) and magnetic resonance imaging (MRI). In the preoperative period, the individual sizes of anatomical structures and their localization were determined according to MRI data. That made it possible to carry out surgical intervention with minimal risk. During the operation, fibrous adhesions inside the joint were eliminated with a cold plasma coblator, the disc was mechanically moved to its normal position. At the end of the operation, blood plasma and hyaluronic acid were injected into the joint. RESULTS: As a result of the treatment, an increase in mouth opening by 80% of the initial state, disappearance of crepitus sounds, and complete relief of pain syndrome were documented. According to objective examination methods (MRI, CT), the elimination of internal disorders, restructuring and regeneration of intra-articular elements were recorded. CONCLUSION: No complications were revealed during the surgery. Arthroscopic TMJ surgery performed according to the described protocol is an effective and safe procedure that allows quickly restore the mobility of intra-articular elements, eliminate pain and improve the patient's quality of life.

SURGICALLY ASSISTED RAPID MAXILLARY EXPANSION: RETROSPECTIVE ANALYSIS OF COMPLICATIONS 2012-2017.

Surgically assisted rapid maxillary expansion (SARME) is a common technique developed to treat skeletally mature patients with transverse maxillary deficiency. Although SARME is supposed to be a relatively safe procedure, it is not completely free of complications. The purpose of this study was to reveal the most typical postoperative SARME complications. Retrospective evaluation of the clinical cases of 665 patients (247 males and 418 females, mean age 25,3 years) with the diagnosis of maxillary transverse deficiency, who underwent SARME in period between 2012 and 2017 at the Clinical Center of Maxillofacial, Plastic Surgery and Dentistry, Moscow. According to the results of the research, the most typical complications of SARME are paresthesia of the infraorbital nerve branches and nasopalatine nerve (198/665), distraction device dislocation (61/665), inflammation in the distraction device area (57/665), insufficient expansion of the maxilla (42/665), asymmetric expansion (27/665). The number of complications revealed indicates that SARME is an operation associated with the risks of postoperative complications. Careful treatment planning, following the operation protocol and performing the minimally invasive access can help to avoid the majority of complications.

[Clinical assessment of the effectiveness of botulinum toxin A in the treatment of temporomandibular joint pain dysfunction syndrome]. / Opyt klinicheskogo primeneniya botulinicheskogo toksina tipa A v algoritme lecheniya patsientov s sindromom bolevoi disfunktsii visochno-nizhnechelyustnogo sustava.

AIM OF THE STUDY: Assessment of the effectiveness of botulinum toxin A in the treatment of temporomandibular joint pain dysfunction syndrome. MATERIAL AND METHODS: In accordance with the diagnostic and treatment guidelines for TMJPDS, 20 patients with TMJPDS with pronounced pain on palpation of the chewing muscles, discoordination of the chewing muscles according to the EMG, and degenerative changes in the temporomandibular joint according to the MRI were examined. The patients had no contraindications to the use of botulinum toxin. Exclusion criteria: 1) age under 21 years, 2) somatic pathology, 3) refusal of the steps of the proposed diagnostic and treatment algorithm. Methods used: clinical, psychometric (visual analogue scale (VAS) - for pain assessment), X-ray, electromyographic and statistical methods. RESULTS: An objective reduction in the tone of the chewing muscles was observed after treatment In both groups. However, 30 days after the injection of BtA the IMPACT indicator in the first group was reduced by 403.5 µV or more (38.5%, p<0.05), while in the second group it decreased by 201.5 µV or more (25%, p<0.05). A correlation was identified between the VAS index (mean 7 points, severe pain level) and IMPACT (p<0.05). The onset of a significant pain reduction was observed one week after BtA injection, the most pronounced effect was achieved after 2 weeks and lasted for about 3 months. CONCLUSION: The use of BtA as part of the temporomandibular joint pain dysfunction syndrome treatment algorithm contributes to the creation of a «therapeutic window¼ for comprehensive rehabilitation of patients in this group. It increases the efficacy of the conducted treatment and contributes to a significant prolongation of the TMJPDS remission.

[Treatment features of odontogenic cystic formations of the mandible using cystotomy]. / Osobennosti lecheniya odontogennykh kistoznykh obrazovanii nizhnei chelyusti metodom tsistotomii.

AIM: The aim of the study was to improve the types of surgical intervention when performing biopsy of large-sized cystic formations of the lower jaw by cystotomy. MATERIAL AND METHODS: 44 patients were examined and surgeries were performed: 12 patients with ameloblastoma, 14 - with keratoxystone tumor, 18 - with dentigerous cyst. All patients had a retained tooth in the cyst cavity. RESULTS: For histological verification of cystic formations of large sized it is necessary to perform cystotomy-typed biopsy with bone tissue and shell fragment collection, using epithelialized flap method. CONCLUSION: Cystotomy-typed biopsy using the method of epithelialized flap can significantly reduce the rehabilitation period and allows to decide on the choice of further method of surgical treatment.

[Virtual planning and intraoperative control using computer navigation systems in orthognatic surgery]. / Virtual'noe planirovanie i intraoperatsionnyi kontrol' s ispol'zovaniem sistem komp'yuternoi navigatsii v ortognaticheskoi khirurgii.

THE AIM: To evaluate versality and accuracy of computer navigation in orthognathic surgery, analyzing the position of osteotomized bone fragments on virtual and postoperative 3D models. MATERIAL AND METHODS: During our study we operated 27 patients with different asymmetric deformations of facial skeleton (13 patients with Class III Angle, 11 patients with Class II Angle and 3 patients with hemifacial microsomia). In 7 clinical cases optical navigation stations BrainLab 18070 Kick («BrainLab¼, Germany) and Stryker CranialMap CMF Version 2.0 («Stryker¼, USA) were used for preoperative virtual planning. In other clinical cases (20 patients) preoperative planning performed with using of 3D-cephafolometric programs Dolphin Imagin¼ and Blender 2.79. Intraoperative control of osteotomized bone fragments performed with using of optical navigation stations BrainLab 18070 Kick («BrainLab¼, Germany) and Stryker CranialMap CMF Version 2.0 («Stryker¼, USA). RESULTS: Mean surgical time was 181 minutes (150-210 min). Mean time of registration procedure was 5 minutes (3-8 min). Mean target registration error (TRE) was 0.9±0.18 mm. Absolute difference values between actual and virtual movements of maxilla was from 0.72 to 1.12 mm in vertical, from 0.56 to 0.94 mm in sagittal (COP) and from 0.39 to 0.58 mm in transversal (MSP) planes. CONCLUSION: Intraoperative control of maxilla-mandibular complex with using of computer navigation in orthognathic surgery allows to simplify bone fragments positioning, reduce surgery time, obtain a satisfactory aesthetic treatment result with occlusion restoration.

[Controlled sclerosing in the treatment of venous maxillofacial malformations]. / Primenenie metoda kontroliruemogo sklerozirovaniia v lechenii venoznykh mal'formatsii cheliustno-litsevoi oblasti.

The aim of the study was to assess the effectiveness of ultrasound-guided use of the foam form of ethoxysclerol for the treatment of venous malformations of the maxillofacial area. The study involved clinical and ultrasound examination data of 60 patient allowing to determine treatment tactics and optimal volume of injected foam sclerosant as well as the role of ultrasound for monitoring of the treatment. The results proved the efficacy of 3% foam ethoxysclerol for less invasive treatment of venous maxillofacial malformations.

World's First Clinical Case of Gene-Activated Bone Substitute Application.

Treatment of patients with large bone defects is a complex clinical problem. We have initiated the first clinical study of a gene-activated bone substitute composed of the collagen-hydroxyapatite scaffold and plasmid DNA encoding vascular endothelial growth factor. The first patient with two nonunions of previously reconstructed mandible was enrolled into the study. Scar tissues were excised; bone defects (5-14 mm) between the mandibular fragments and nonvascularized rib-bone autograft were filled in with the gene-activated bone substitute. No adverse events were observed during 12 months of follow-up. In 3 months, the average density of newly formed tissues within the implantation zone was 402.21 ± 84.40 and 447.68 ± 106.75 HU in the frontal and distal regions, respectively, which correlated with the density of spongy bone. Complete distal bone defect repair with vestibular and lingual cortical plates formation was observed in 6 and 12 months after surgery; thereby the posterior nonunion was successfully eliminated. However, there was partial resorption of the proximal edge of the autograft entailed to relapse of the anterior nonunion. Thus, the first clinical data on the safety and efficacy of the gene-activated bone substitute were obtained. Given a high complexity of the clinical situation the treatment, results might be considered as promising. NCT02293031.

Ordinary and Activated Bone Grafts: Applied Classification and the Main Features.

Bone grafts are medical devices that are in high demand in clinical practice for substitution of bone defects and recovery of atrophic bone regions. Based on the analysis of the modern groups of bone grafts, the particularities of their composition, the mechanisms of their biological effects, and their therapeutic indications, applicable classification was proposed that separates the bone substitutes into "ordinary" and "activated." The main differential criterion is the presence of biologically active components in the material that are standardized by qualitative and quantitative parameters: growth factors, cells, or gene constructions encoding growth factors. The pronounced osteoinductive and (or) osteogenic properties of activated osteoplastic materials allow drawing upon their efficacy in the substitution of large bone defects.

[Analysis of a change in the position of the hyoid bone when displacing the lower jaw in patients with dentofacial malformations].

OBJECTIVE: To estimate the magnitude of a change in the position of the hyoid bone when displacing the lower jaw during surgical treatment in patients with dentofacial abnormalities. MATERIAL AND METHODS: Fifty patients with dentofacial abnormalities (25 and 25 patients with distal and mesial occlusion, respectively) were examined and treated. All the patients underwent multislice spiral computed tomography before and 6 months after surgery. The authors developed linear quantities to analyze the position of the hyoid bone with respect to the skull base and cervical spine. The paired Wilcoxon signed-rank test was used. RESULTS: None of the examined groups was noted to have a statistically significant change in the distance between the basihyoid and the vertebral column, suggesting that the datum was moderately changed. No case of worse respiratory function was found. CONCLUSION: Our investigation has revealed that mandible displacement during orthognathic surgery causes no critcal change in the position of the hyoid bone and hence it has no significant impact on upper airway patency in this area.

[Role of multislice spiral computed tomography in the evaluation of changes in upper airway volume during surgical treatment in patients with dentomaxillary abnormalities].

OBJECTIVE: To assess the role of multislice spiral computed tomography in the calculation of upper airway volume and its change in patients with different types of dentomaxillary abnormalities after orthognathic surgery. MATERIAL AND METHODS: Twenty-five patients with dentomaxillary abnormalities (19 and 6 patients with Classes III and II dentomaxillary abnormalities, respectively) were examined. All the patients underwent two-jaw operations. Facial skeleton computed tomography was performed before treatment initiation and 6 months after surgery. The DICOM data were loaded in Dolphin Imaging 11.5 and a special program package was applied to calculate the volume of air space in the upper airway. The hard tissue and soft tissue points used to construct the planes setting the detection limits of air space in the upper airway were determined. RESULTS: After surgery, the patients with Class II dentomaxillary abnormalities display unilateral changes in our measured upper airway values (by increasing or reducing the air space); the majority of cases exhibiting higher values. Half of the patients with Class III had unilateral hanges, the increase or reduction in air space values varying in approximately equal proportions. CONCLUSION: Computed tomography permits the calculation of upper airway volumes before and after orthognathic treatment in patients with dentomaxillary abnormalities, which is in its turn of significant scientific and practical interest.

[Compressive-distractive method for complex lower and upper jaw defects restoration in preparative procedures before implant placement].

Distraction method in reconstructive maxillofacial surgery allows achieving optimal aesthetic and functional results. The study included 198 patients with various alveolar bone defects and 224 dental implants placed after successful alveolar bone distraction. Complex oral rehabilitation was possible after 4 month retention period.

[Evaluation of reparative regeneration of the jaw bone by microfocus roentgenography in an experiment].

In experiment on 16 grown-up chinchilla rabbits the dynamic of reparative regeneration was evaluated by digital microfocal rontgenography in the terms of 1, 2 and 4 months. Bone defect of the 8capital CHE, Cyrillic8 mm size in the region of mandible angle was caused by surgical laser Smart 2940 D+ on the right side and by physiodespenser Surgec XT on the left side. Surgical laser use let to reduce intact mother bone traumatisation and to improve remote results of bone tissue regeneration. After bone defect creation bone tissue regeneration was put into effect by all 3 callus types - endosteal, periosteal and intermediary.

PCR amplification on a microarray of gel-immobilized oligonucleotides: detection of bacterial toxin- and drug-resistant genes and their mutations.

PCR amplification on a microarray of gel-immobilized primers (microchip) has been developed. One of a pair of PCR primers was immobilized inside a separate microchip polyacrylamide porous gel pad of 0.1 x 0.1 x 0.02 (or 0.04) micron in size and 0.2 (or 0.4) nL in volume. The amplification was carried out simultaneously both in solution covering the microchip array and inside gel pads. Each gel pad contained the immobilized forward primers, while the fluorescently labeled reverse primers, as well as all components of the amplification reaction, diffused into the gel pads from the solution. To increase the amplification efficiency, the forward primers were also added into the solution. The kinetics of amplification was measured in real time in parallel for all gel pads with a fluorescent microscope equipped with a charge-coupled device (CCD) camera. The accuracy of the amplification was assessed by using the melting curves obtained for the duplexes formed by the labeled amplification product and the gel-immobilized primers during the amplification process; alternatively, the duplexes were produced by hybridization of the extended immobilized primers with labeled oligonucleotide probes. The on-chip amplification was applied to detect the anthrax toxin genes and the plasmid-borne beta-lactamase gene responsible for bacterial ampicillin resistance. The allele-specific type of PCR amplification was used to identify the Shiga toxin gene and discriminate it from the Shiga-like one. The genomic mutations responsible for rifampicin resistance of the Mycobacterium tuberculosis strains were detected by the same type of PCR amplification of the rpoB gene fragment isolated from sputum of tuberculosis patients. The on-chip PCR amplification has been shown to be a rapid, inexpensive and powerful tool to test genes responsible for bacterial toxin production and drug resistance, as well as to reveal point nucleotide mutations.

[The osteoplastic efficacy of different forms of hydroxyapatite based on experimental morphological study data]. / Osteoplasticheskaia éffektivnost' razlichnykh form gidroksiapatita po dannym éksperimental'no-morfologicheskogo issledovaniia.

Time course of healing of induced defects in the femoral bone filled with various forms of hydroxyapatite (HA) was studied in experimental rats on days 30, 60, and 90 after inflicting the defect. HA granulate exerted the best effect on bone repair. In experiments with HA granulate, bone regenerate replaced up to one half of the area of defect by day 90. After insertion of a mixture of granulate and HA powder in bone defects the newly formed bone occupied a little more than one-third of the defect area. In experiments with HA powder suspension the size of bone defect by day 90 was the same as after healing under a blood clot.

Massive parallel analysis of DNA-Hoechst 33258 binding specificity with a generic oligodeoxyribonucleotide microchip.

A generic oligodeoxyribonucleotide microchip was used to determine the sequence specificity of Hoechst 33258 binding to double-stranded DNA. The generic microchip contained 4096 oxctadeoxynucleo-tides in which all possible 4(6)= 4096 hexadeoxy-nucleotide sequences are flanked on both the 3'- and 5'-ends with equimolar mixtures of four bases. The microchip was manufactured by chemical immobilization of presynthesized 8mers within polyacrylamide gel pads. A selected set of immobilized 8mers was converted to double-stranded form by hybridization with a mixture of fluorescently labeled complementary 8mers. Massive parallel measurements of melting curves were carried out for the majority of 2080 6mer duplexes, in both the absence and presence of the Hoechst dye. The sequence-specific affinity for Hoechst 33258 was calculated as the increase in melting temperature caused by ligand binding. The dye exhibited specificity for A:T but not G:C base pairs. The affinity is low for two A:T base pairs, increases significantly for three, and reaches a plateau for four A:T base pairs. The relative ligand affinity for all trinucleotide and tetranucleotide sequences (A/T)(3)and (A/T)(4)was estimated. The free energy of dye binding to several duplexes was calculated from the equilibrium melting curves of the duplexes formed on the oligonucleotide microchips. This method can be used as a general approach for massive screening of the sequence specificity of DNA-binding compounds.

Fabrication of microarray of gel-immobilized compounds on a chip by copolymerization.

The manufacturing of microchips containing oligonucleotides and proteins immobilized within gel pads, ranging in size from 10 x 10 to 100 x 100 microns, is described. The microchips are produced by photo- or persulfate-induced copolymerization of unsaturated derivatives of biomolecules with acrylamide-bisacrylamide mixture. Oligonucleotides containing 5'-allyl or 5'-butenediol units were synthesized using standard phosphoramidite chemistry. Acryloyl residues were attached to a protein by a two-step procedure. Photopolymerization was induced by illumination of the monomer solution containing initiator with UV light through the mask. The mask was applied directly over the monomer solution or projected through a microscope. Alternatively, copolymerization was carried out in drops of aqueous solution of monomers containing ammonium persulfate. Drops with different allyl-oligonucleotides were distributed on a glass slide, and the polymerization was induced by diffusion of N,N,N',N'-tetramethylethylenediamine (TEMED) from a hexane solution that covered the aqueous drops.

Parallel thermodynamic analysis of duplexes on oligodeoxyribonucleotide microchips.

A microchip method has been developed for massive and parallel thermodynamic analyses of DNA duplexes. Fluorescently labeled oligonucleotides were hybridized with oligonucleotides immobilized in the 100 x 100 x 20 mum gel pads of the microchips. The equilibrium melting curves for all microchip duplexes were measured in real time in parallel for all microchip duplexes. Thermodynamic data for perfect and mismatched duplexes that were obtained using the microchip method directly correlated with data obtained in solution. Fluorescent labels or longer linkers between the gel and the oligonucleotides appeared to have no significant effect on duplex stability. Extending the immobilized oligonucleotides with a four-base mixture from the 3'-end or one or two universal bases (5-nitroindole) from the 3'- and/or 5'-end increased the stabilities of their duplexes. These extensions were applied to increase the stabilities of the duplexes formed with short oligonucleotides in microchips, to significantly lessen the differences in melting curves of the AT- and GC-rich duplexes, and to improve discrimination of perfect duplexes from those containing poorly recognized terminal mismatches. This study explored a way to increase the efficiency of sequencing by hybridization on oligonucleotide microchips.