Body Jaw Research Articles

Special at-rich sequence-binding protein 2 and its role in healing of the experimental mandible bone tissue defect filling with a synthetic bone graft material and electrical stimulation impact.

Aim: The purpose of the study was to identify the role of SATB2 in healing of the experimental mandible bone tissue defect filling with a synthetic bone graft material and electrical stimulation impact. Materials and Methods: An experiment was carried out on 48 mature male rats of the WAG population, which were divided into 4 groups. Each group included 12 experimental animals. Group 1 included rats that were modeled with a perforated defect of the lower jaw body. Group 2 included animals that were modeled with a perforated defect similar to group 1. In animals, a microdevice for electrical action was implanted subcutaneously in the neck area on the side of the simulated bone defect. The negative electrode connected to the negative pole of the battery was in contact with the bone defect. The battery and electrode were insulated with plastic heat shrink material. Group 3 included rats that were modeled with a perforated defect similar to previous groups, the cavity of which was filled with synthetic bone graft "Biomin GT" (RAPID, Ukraine). Group 4 included animals that were modeled with a perforated defect similar to groups 1-3, the cavity of which was filled with synthetic bone graft "Biomin GT" (RAPID, Ukraine). The simulation of electrical stimulation was the same as in group 2. The material for the morphological study was a fragment of the body of the lower jaw from the zone of the perforated defect. Immunohistochemical study was performed using rabbit anti-human SATB2 monoclonal antibody. Results: In the regenerate filling the defect in the bone tissue of the lower jaw of rats, there was an increase in SATB2 expression under conditions of electrical stimulation; filling the defect with a synthetic bone graft material; simultaneous filling the defect with a synthetic bone graft material and electrical stimulation. The most pronounced expression of SATB2 was observed under conditions of simultaneous filling the defect with a synthetic bone graft material and electrical stimulation; minimally expressed - in conditions of filling the defect with a synthetic bone graft material; moderately expressed - under conditions of electrical stimulation. In the regenerate, in cases of all treatment methods, SATB2 was expressed by immune cells, fibroblastic differon cells, osteoblasts, and in case of electrical stimulation, also by adipocytes, vascular pericytes and endothelial cells, epidermis. Conclusions: The activation of SATB2 expression identified by the authors is one of the mechanisms for stimulating reparative osteogenesis under the conditions of electrical stimulation; filling the defect with a synthetic bone graft material; simultaneous filling the defect with a synthetic bone graft material and electrical stimulation.

ОБОСНОВАНИЕ ПОДБОРА ВНУТРИКОСТНОГО ФИКСАТОРА И ТОЧКИ ЕГО ВВЕДЕНИЯ ПРИ ОСТЕОСИНТЕЗЕ МЫЩЕЛКОВОГО ОТРОСТКА НИЖНЕЙ ЧЕЛЮСТИ

This article observes the anatomical subtleties of the structure of the condylar process, branch and angle of the mandible. A retrospective study of 141 cone-beam computer tomograms of patients aged 3 to 72 years old was conducted in the period from 2014 to 2019. Among the patients who underwent CBCT were 105 adults and 36 children. The following parameters were studied: the length of the mandible branch, the presence of a bend of the mandible branch in its lower part outward at the level of tuberositas masseterica and anteriorly from it, the linear dimensions of the spongy substance in the neck of the condylar process of the mandible. All parameters were determined on both sides of the jaw. CBCT was performed on a panoramic X-ray dental device with a Gendex CB-50 tomography function. The tomograms were performed according to the standard procedure. Calculations of computer tomograms were carried out in the I-CATVision program. Statistical methods were used using Microsoft Excel 2010 to process the array of data obtained. Due to the analysis of tomograms, the linear dimensions of the spongy substance in the neck of the condyle process were determined. The nuances of the structure of the posterior part of the lower jaw body are described. Taking into account these data, the technique of intraosseous osteosynthesis of the condyle of the mandible is justified.

EXPERIMENTAL AND MORPHOLOGICAL ASSESSMENT OF THE INFLUENCE OF HYDROXYAPATITE-CONTAINING OSTEOTROPIC MATERIAL AND ELECTRICAL STIMULATION ON REPARATIVE OSTEOGENESIS OF THE LOWER JAW.

Aim: The aim of the study was to reveal the peculiarities of reparative osteogenesis in experimental lower jaw defect under the conditions of hydroxyapatite-containing osteotropic material application and electrical stimulation. Materials and Methods: An experiment was conducted on 48 mature male rats of the WAG population. All animals were divided into 4 groups (12 animals in each group). Group 1 included rats that were not subjected to any manipulations. Group 2 included rats that were modeled with a perforated defect of the lower jaw body. Group 3 included rats that were modeled with a perforated defect similar to group 2, the cavity of which was filled with synthetic bone graft "Biomin GT" (RAPID, Ukraine). Group 4 included animals that were modeled with a perforated defect similar to groups 2-3, the cavity of which was filled with synthetic bone graft "Biomin GT". In animals of group 4, a microdevice for electrical action was implanted subcutaneously in the neck area on the side of the simulated bone defect. Morphological and statistical methods were used. Results: The research carried out by the authors proved that the use of the above-mentioned bone replacement material helps to increase the regenerative potential of the bone tissue of the lower jaw, but does not lead to the formation of a full-fledged bone regenerate, as evidenced by the results of the morphometry of the regenerate (the specific volume of lamellar bone tissue accounted for 54.9%); disordered localization of bone beams, which were characterized by reduced signs of mineralization; the presence in connective, osteogenic fibroreticular and lamellar bone tissues the encapsulated bone graft granules with the presence of inflammatory cell infiltration. In cases the combined use of synthetic bone graft "Biomin GT" and electrical stimulation, the authors noted more intensive reparative osteogenesis processes in the bone defect of the lower jaw compared to cases when only one bone graft was used, but they also did not lead to the formation of a full-fledged bone regenerate. Conclusions: The experimental and morphological study conducted by the authors proved that the use of hydroxyapatite-containing osteotropic material ("Biomin GT"), especially in cases of its combined use with electrical stimulation, significantly activates reparative osteogenesis in the bone defect of the lower jaw, which does not lead to the formation of a full-fledged bone regenerate.

MORPHOLOGICAL CHARACTERISTICS OF REPARATIVE OSTEOGENESIS IN THE RATS LOWER JAW UNDER THE CONDITIONS OF USING ELECTRICAL STIMULATION.

Aim: The purpose of the study was to identify the morphological features of reparative osteogenesis in the rats lower jaw under the conditions of using electrical stimulation. Materials and Methods: An experiment was conducted on 24 mature male rats of the WAG population. Two groups were formed. Group 1 included 12 rats that were modeled with a perforated defect of the lower jaw body. Group 2 included 12 animals that were modeled with a perforated defect similar to group 1. In animals, a microdevice for electrical action was implanted subcutaneously in the neck area on the side of the simulated bone defect (a temporary Videx AG 4 battery; a constant sinusoidal electric current of an unchanging nature 1 milliampere, frequency 30 W). The negative electrode connected to the negative pole of the battery was in contact with the bone defect. The battery and electrode were insulated with plastic heat shrink material. Morphological and statistical methods were used. Results: The positive effect of electrical stimulation on reparative osteogenesis was due to a decrease in the severity of hemodynamic disorders, activation of angiogenesis in granulation tissue, which was one of the components of the regenerate that filled the bone defect, matured and turned into connective tissue; stimulation of the proliferative potential of fibroblastic cells and cells with osteoblastic activity in granulation tissue; increasing the proliferative potential of osteoblastic elements of bone tissue bordering the cavity; stimulation of macrophage cells and processes of cleansing the bone cavity from fragments of a blood clot and alteratively changed tissues; formation of clusters of adipocytes in the loci of connective and granulation tissue of the regenerate; the process of metaplasia of connective tissue into bone tissue; an increase of the foci of hematopoiesis in the intertrabecular spaces of lamellar bone tissue. Conclusions: A comprehensive clinical and experimental study conducted by the authors proved that electrical stimulation activates the reparative osteogenesis in the lower jaw, which occurs through direct osteogenesis and does not finish on the 28th day of the experiment.

ANALYSIS OF BONE DENSITY OF THE RABBIT LOWER JAW ACCORDING TO RADIOVIZIOGRAPHIYA

Nowadays, the premature loss of teeth is a serious problem not only dental but also a general medical.The results of dental prosthetics are largely determined by the condition of the bone tissue o f the jaw. Modern radiological examination methods make it possible to determine the quality of bone tissue, the biomarker of which is the mineral density indicator. Experimental methods play an important role in understanding the processes occurring in the body during the development of pathological conditions. The aim of our research was to fi nd out the peculiarities of mineral density of bone tissue in diff erent parts of the lower jaw of the intact rabbit. 10 lower jaws of sexually mature intact rabbits aged 6-7 months, weighing 2.5-3 kg were used for the study. It was established that the bone tissue density indicators of diff erent parts of the body of the lower jaw of an intact rabbit are characterized by features peculiar to each of the studied parts and caused, obviously, by diff erent loads on the bone tissue during articulatory movements. The alveolar part of the body of the lower jaw at the level of the molars has the highest density of bone tissue, the lowest one is the main part of the body o the lower jaw at the level of the incisors. The density of the bone tissue of the alveolar part of the body of the lower jaw gradually increases in the direction from the incisors to the molars, the density of the main part of the body of the lower jaw is the lowest at the incisors level of the, the highest – between the incisors and the molars. At the level of the incisors and molars, the density of the bone tissue of the alveolar part of the lower jaw body is higher, and between the incisors and the molars, it is lower than the density of the bone tissue of its main part.

CONSERVATIVE MANAGEMENT OF UNICYSTIC AMELOBLASTOMA—A CASE REPORT WITH 6 YEARS’ FOLLOW-UP

Unicystic ameloblastoma is a benign odontogenic tumor of the jaws. A 14-year-old female patient presented with a swelling located in the left jaw body. Panoramic radiograph disclosed a unilocular radiolucent lesion extending from midline mandibular to the left second molar tooth area. An exploratory punction revealed 4 mL of a yellowish fluid. Computed tomography demonstrated an extensive bone resorption tangent to the mandibular canal with expanded cortical bone, tooth displacement, and radicular resorption. The patient was initially submitted to incisional biopsy and a drain was installed. The histopathologic examination revealed unicystic ameloblastoma and with 4 months of decompression there was a decrease of lesion extension. Afterwards, under general anesthesia, the lesion was enucleated. A reconstruction plate was installed and removed after 1 year. After 5 years, 4 dental implants were installed, and the patient was rehabilitated with a fixed prosthesis. The patient is at 6-year follow-up with no signs of recurrence.

COMPARATIVE EVALUATION OF THE ANGULAR DIMENSIONS OF THE MANDIBLE WITH VARYING DEGREES OF PRESERVATION OF THE DENTITION IN MEN AND WOMEN OF THE MATURUSAGE GROUPS (FROM 35 TO 55 YEARS) AND SENILIS(OVER 56 YEARS OLD)

Resume. The study of the features of the structure of the lower jaw with preserved and with various degrees of loss of dentition is relevant from the point of view of dental implantology. Materials and methods. A craniometric study of angular dimensions was carried out on 120 3D models of the mandibles of men and women of the age groups Maturus and Senilis, divided into 10 subgroups. The degree of influence of tooth loss on angular dimensions was assessed. Results. In groups with complete acquired adentia, there was a statistically significant decrease in the angles of inclination and protrusion of the chin in men and women from 6° to 14° (p < 0,05), while in other groups with partial adentia, no statistically significant differences were observed. The angle of the lower jaw branch and the basal angle did not respond to tooth loss. Conclusions. The anterior segment of the lower jaw body undergoes maximum restructuring, which is reflected in the reaction of angular dimensions to the complete loss of teeth

Dynamics of the mandible bone tissue condition after the dental implantation and shockwave therapy

Background. The problem of restoration the integrity of the dentition after tooth loss remains one of the most problematic dental issues. Мodern dental technologies open a promising direction in its solution, in particular - the method of dental implantation. Objective. The aim of our work was to study the changes that occur in the bone tissue of the mandible after implantation of titanium foam and to determine the effect of shock wave therapy (SWT) on its structure restoration. Methods. The study was performed on 15 adult rabbits aged 6-7 months, weighing 2.5-3 kg. The animals from the experimental groups were implanted with titanium pin, 3 mm long. The pin was implanted under combined anesthesia bilaterally into the body of the mandible. One day after the operation, the animals received SWT 500 pulses with a frequency of 5 Hz and a maximum pressure at the wavefront of 1.2 Bar per implantation site using the device Storz Medical Master Plus MP 100. The animals were removed from the experiment on 15-th day, after which the mandible was disarticulated and radiographically performed. The obtained results were statistically significant. The differences at p<0.05 were considered significant. Results. The results showed that the bone tissue of the jaws during implantation undergoes traumatic injury, the results of which, two weeks after surgery on radiographs we can clearly see a violation of the bone tissue structure and a significant increase in its density. Using the SWT method, we obtained a positive dynamics of bone density after titanium pin implantation and slight Rh-changes in bone structure compared with normal. Conclusion. Аfter implantation with titanium pin the bone density of the rabbit lower jaw body is significantly reduced, X-ray shows the heterogeneity of bone structure, areas of sclerosis are expressed. Shock wave therapy helps to restore the quality of bone tissue, this is confirmed by the fact that the density indicators are close to the norm and X-ray shows some separate small areas of restructuring of bone tissue heterogeneity, mainly due to merging the pattern of the bone trabeculae of the bone cancellous part.

А case of a lower jaw fracture treatment after lower wisdom tooth extraction

One of the most common dental surgical procedures performed in specialized oral surgery and dental practice is extractions of mandibular third molar. In this report, we look at the case of a 55-year-old patient who is receiving hospital treatment for lower jaw pain and edema. After orthopantomography, a fracture was found in the angle of the lower jaw, accompanied by an inflammatory process. In the intraoral examination, an unhealed completely extraction wound to the left of the mandible was observed in the area of the wisdom tooth, pathological mobility and bone crepitus. Mandibular angle fracture is the most common mandibular fracture, accounting for approximately 40% of all mandibular fractures. Mandibular angle fracture is defined as a fracture line between the anterior border of the mandibular ramus and the jaw body. In the present case, the patient received an additional graphy of the facial skeleton and was treated with intermaxillary fixation with rigid fixation and restraints bilaterally in the area of the upper and lower jaws and molars.

Effectiveness of the Sequential Use of Plastic and Titanium Implants for Experimental Replacement of the Mandibular Defect in Animals Using Preliminary Digital Design.

Using the templates preliminarily made by 3D design and prototyping methods, defects in the lateral area of the lower jaw of sheep were created using the piezosurgical technique. The defects were replaced by plastic implants obtained by the method of layer-by-layer fusion of the FDM printing-fusing deposition modeling and fixation with titanium screws to the jaw body. In the time interval, plastic implants are replaced by titanium implants obtained by selective laser sintering (SLS) using a 3D printer. To study the processes of reparative osteogenesis, microsamples of tissues of the preimplantation zone were analyzed. As a result, signs of osteo- and fibro-osseointegration were identified. The obtained data are regarded as a prerequisite for further clinical trials of the developed protocols for the sequential replacement of jaw defects using 3D printing.

Decompression drainage (marsupialization) in the treatment of extensive jaw cysts

Odontogenic cysts of the jaw are one of the most common diseases of the maxillofacial region, the main methods of treatment of which are cystotomy and cystectomy. Despite the widespread use of these surgical methods of treatment they are not without drawbacks. The presented clinical material shows the possibility of treating a patient with a large cavity formation of the jaw body by decompression drainage (marsupialization). The proposed surgical manual can be used either in isolation (the main method of treatment), or in combination with subsequent cystectomy. In modern domestic and foreign literature, publications devoted to this method of treatment of large and giant jaw cysts are rare, and therefore this clinical observation is presented.

The Characterization of tissue responses to titanium meshes with different through porosity in the experimental study

During the experiment, three artificial defects were created on the outer surface of the jaw body of experimental animals. Two wells were filled with bone substitute materials, one well was not filled with anything and remained as a control. The defects formed and filled with materials were closed with titanium membranes with different through porosity. in order to study the effect of titanium membranes with varying degrees of porosity on osteoreparative processes in the area of defects, histological studies were carried out. As a result, it was determined that bone recovery was the same both in the group where titanium membranes with a pore diameter of 0.25 mm were used and in the group where titanium membranes with a pore diameter of 1.0 mm were used.

Comparative characteristics of the use of bone-substituting materials based on mineral and collagen

The purpose of this study was to carry out a comparative assessment of two types of bone substitute materials for targeted bone regeneration, on a mineral basis and on the basis of collagen. During the experiment, artificial defects were created on the outer surface of the jaw body of experimental animals. Two defects were replaced with osteoplastic materials with different degrees of mineralization, one defect remained under the clot. Histological examinations of biopsy specimens were performed. It was revealed that when using demineralized bone substitute materials, the processes of bone tissue repair occur more intensively.

Cephalometric features of connective tissue dysplasia manifestation in children and adolescents

Relevance. The high prevalence of dysplastic disorders involving connective tissue, and its negative effecton the development of dentoalveolar anomalies, carious and non-carious lesions of the teeth, periodontopathy, temporomandibular joint issues in the child population, lay the basis for improving diagnostics algorithms. Enhancing the already available standards is of greatest importance for children at the initial stages of diagnostics when evaluating the external signs of dysplastic disorders.Purpose – improving diagnostics algorithms for connective tissue dysplasia (CTD) in children in primary dental care facilities based on the evaluation of external phenotype signs and maxillofacial morphological features.Materials and methods. Depending on the external phenotype manifestations severity, as well as on laboratory, clinical and instrumental signs, the 92 children with CTD were divided into groups with mild, moderate and severe degrees of undifferentiated dysplasia. Gnathometric and biometric examinations of the maxillofacial area were performed through traditional methods, whereas the diagnosis was set following the generally accepted classifications. The diagnosis confirmation implied evaluation through cone beam computed imaging.Results. The nature and the intensity of morphofunctional disorders in the craniofacial structures (“small” stigmas) depend on the severity of connective tissue dysplastic disorders.Conclusions. The change direction vector in the facial and brain parts of cranium in children with CTD is aimed at increasing hypoplastic tendencies and dolichocephalia, proof to that being the following constitutional and morphological features: the prevalence of the vertical type of face skeleton growth over the horizontal and neutral ones; a convex face profile with a disproportionate general heights of the face skeleton; reduction of latitudinal with an increase in altitude facial parameters; a narrow short branch of the lower jaw; the upper jaw displaced downwards and forward; a decrease in the size of the apical basis of the lower dentition, the lower jaw body, as well as the height and width of the lower jaw branches.

UNUSUAL CASE OF MALE BREAST CANCER: A CLINICAL REPORT

A 56-year-old man started oncologic treatment in 2010 for right side breast cancer, having been submitted to radical mastectomy plus axillary emptying and concomitant adjuvant chemotherapy. Infusion of zoledronic acid was used to minimize the risk of bone metastases. In 2017, pulmonary and cerebral metastases were identified with concomitant persistent wound in the posterior edentulous residual border of the mandible. Expansion of a bone necrosis area in the jaw body was observed (right side; diagnostic hypothesis: bisphosphonate-induced osteonecrosis). Then, pharmacologic treatment was applied. Submandibular abscess (right side) with tongue projection and difficulty maintaining airway permeability were observed in 2019. Abscess drainage and complete removal of the necrotic bone fragment were performed. Histopathologic analysis of bone material and associated soft tissue indicated mouth squamous cell carcinoma. Oncologic treatment for pulmonary and cerebral metastases has not been modified by this new carcinoma, and the patient is being monitored.

TREATMENT OF OSSIFYING FIBROMA ASSOCIATED WITH SIMPLE BONE CYST: A CASE REPORT

A 9-year-old male patient with melanoderma reported an increase in volume in an asymptomatic right jaw body. At the extraoral physical examination, facial asymmetry was observed with increased volume in the right submandibular region and preserved mouth opening. On intraoral examination, bulging of the buccal cortical bone was evident in the region of the teeth 44 to 46, firm to the palpation and covered by intact mucosa. At tomographic examination, it was possible to observe a well-delimited multilocular lesion partially filled by hyperdense tissue associated to the hypodense lesion in the lingual region. An incisional biopsy was performed, and histopathologic analysis confirmed the diagnosis of ossifying fibroma. The treatment was the total exeresis of the lesion; during the surgery, it was verified that the associated hypodense lesion was a degeneration, which originated a simple bone cyst. In the postoperative control of 2 years the patient had a good evolution.

CHANGES IN THE LIMIT OF THE BONE TISSUE STRENGTH OF THE MANDIBLE IN ITS VARIOUS PARTS AT THE LOSS OF TEETH IN AN ADULT

Traumatic injuries and fractures of the lower jaw are an urgent problem in maxillofacial surgery and traumatology. The strength of the bone tissue of the lower jaw has been studied on 90 lower jaws of adults. All jaws are systematized into three groups: with intact bite, partial and complete loss of teeth. To assess the architectonics of the bone tissue of the mandibular body, sagittal and frontal cuts were made in the molar region. It has been established that, in the case of a complete set of teeth, the ultimate strength of the bone tissue in the area of the incisors is 441.3 ± 32 MPa; in the area of premolars 411.9 ± 20 MPa; molars 431.3 ± 24 MPa; in the area of the base of the coronoid process 156.9 ± 14 MPa; in the area of the base of the condylar process 205.9 ± 19 MPa. To the greatest extent, with partial loss of teeth, the strength of bone tissue in the region of the molars and the angle of the lower jaw changes in Kennedy classes I and II. With the complete loss of teeth, the values of bone strength in the area of molars, angle and condylar process decreased by 22.5-27.7%, in the area of incisors by 6.7%. It was shown that with a full set of teeth, class II according to U. Lekholm and G. Zarb was most often observed - in 66.7% of cases, less often class I - in 16.7% and class III - in 13.3%, class IV was observed most rarely - in 3.3% of cases. With complete loss of teeth, the presence of mainly II and III classes is noted. It has been proven that the strength of the bone tissue of the lower jaw body decreases significantly with age with the loss of teeth in an adult, which is associated with significant changes in the quality of bone tissue.

FIBROMYXOMA IN THE MANDIBLE: CASE REPORT

A 7-year-old black male child complained of increased volume in the face with no relevant medical history. Extraoral physical examination showed an increased volume in the jaw body of the left side, hard to palpation and with unknown evolution time. A painless hard volume increase at the palpation of the vestibule was in the mouth. Computed tomography scan revealed a solid expansive lesion by inflating the vestibular cortical of the jaw body to the left. Incisional biopsy was performed, and the histologic slices stained in hematoxylin and eosin showed a pattern of spindle cells arranged in regular bundles in addition to mitochondrial areas with little cellularity. Immunohistochemistry was positive for vimentin and Ki67 (4%) and negative for smooth muscle actin, desmin, S100, CD34, and caldesmon, leading to a diagnosis of fibromyxoma. The mandibulectomy was performed associated with application of liquid nitrogen for 3 months without signs of local recurrence. A 7-year-old black male child complained of increased volume in the face with no relevant medical history. Extraoral physical examination showed an increased volume in the jaw body of the left side, hard to palpation and with unknown evolution time. A painless hard volume increase at the palpation of the vestibule was in the mouth. Computed tomography scan revealed a solid expansive lesion by inflating the vestibular cortical of the jaw body to the left. Incisional biopsy was performed, and the histologic slices stained in hematoxylin and eosin showed a pattern of spindle cells arranged in regular bundles in addition to mitochondrial areas with little cellularity. Immunohistochemistry was positive for vimentin and Ki67 (4%) and negative for smooth muscle actin, desmin, S100, CD34, and caldesmon, leading to a diagnosis of fibromyxoma. The mandibulectomy was performed associated with application of liquid nitrogen for 3 months without signs of local recurrence.

Evaluation of different stable internal fixation in unfavorable mandible fractures under finite element analysis.

The mandibular angle fracture is the most common fracture between this type of injury in jaw bone and also is the type of fracture treatment that presents a larger number of complications, and a series different osteosynthesis types have been studied over the years by the world literature. The finite element method is a form of mathematical analysis, which is based on dividing a structure into a finite number of small areas. It has the ability tomathematically model structures, making it possible to apply forces anywhere. For this study, a three-dimensional mandible with an unfavorable angle fracture was simulated. Five different types of fixations were evaluated: group 1, Champy technique with one 4-holes miniplate, 2.0 system; group 2, technique with two parallel 4-holes conventional miniplates, 2.0 system; group 3, technique with two parallel 4-holes locking miniplates, 2.0 system; group 4, technique with one reconstruction 6-holes plate, 2.8 system in base jaw; and group 5, technique with one reconstruction 6-holes plates, 2.8 system in jaw body + one parallel 4-holes conventional miniplate, 2.0 system. The results showed that strains are better distributed through the locking miniplate and screws system and presented less stress concentration when compared with the conventional ones. The Champy technique had the worst results about of all groups. The use of the locking system shows less stress compared to the non-locking system, and the presence of a reconstruction plate associated with a mini plate does not lead to increased stability compared with an isolated reconstruction plate.

Morphometry of the mandibular foramen applied to local anesthesia in hoary fox (Lycalopex vetulus)

ABSTRACT: Great part of the veterinary care in wild carnivores is intended to treat the dental disorders, and oral cavity disorders may generally affect the animal health as a whole. It is factual that knowing the location of the mandibular foramen is vital for local anesthetic block of the inferior alveolar nerve, however, there is still no data on the morphometry of the hoary fox mandibular foramen. The aim was describing morphometry of the mandibular foramen of this species and associating its position with anatomic reference points in the mandible, thus providing support for more effective local anesthetic block of the inferior alveolar nerve in such species. Four adult jaws of Lycalopex vetulus were used. Radiography and biometrics of the hemimandibulas were performed. The rostral third of the jaw body in a lateral view presented three mental foramens, being a rostral, a medium and a caudal. Each hemimandibula presented I3/C1/PM4/M3. The angle of the mandible was marked by the masseteric fossa, the angular incisure, the angular process and the mandibular foramen, and this last one located perpendicularly to the dorsal edge of the angular incisures in medial view. In this view, the crevice to the milohyoid nerve, projected in the caudodorso rostral direction, was also evidenced. The ramus of the mandible was characterized by the presence of the condylar and coronoid processes, and by the dorsal and ventral mandibular incisions. Statistical analyzes did not present significant differences between the antimeres of the studied animals, and the penetration of the needle perpendicularly to the dorsal end of the angular incision on average 8.79mm, overlapped to the medial face of the angle of the mandible could be indicated. Alternatively, the access may also be achieved by inserting the needle in an average of 17.69mm perpendicular to the dorsal end of the angular process, in contact with the medial aspect of the angle of the mandible, and in caudo-rostral projection, also allowing a better anesthetic blockade of the inferior alveolar nerve in L. vetulus. It can also be concluded that the masseteric fossa, the dorsal and ventral mandibular angles, the crevice to the milohyoid nerve, the ramus of the mandible and the mandibular foramen presented differences in their topographic descriptions when compared to the other canids.