Investigation of the variability of the pterygomandibular space from the point of view of the target point of the inferior alveolar nerve block.

INTRODUCTION: A thorough knowledge of the anatomy and variability of the pterygomandibular space (PMS) is essential to the success of local anesthesia. This study is aimed at determining the volume of the PMS depending on the shape of the skull, face and mandible using the computed tomography (CT). MATERIALS AND METHODS: anonymized computed tomograms of 48 adult patients were analyzed, the indicators of the cranial index (CI), facial index (FI) according to Yzard, the high lengthy index of the mandible (HLI), the latitudinal-altitude index of the mandible (LAI), the longitudinal latitude index of the mandible (LLI) were calculated. RESULTS: Differences in the volume of the PMS were found depending on the shape of the skull, face and mandible. When determining the CI, the largest volume of space on the right was observed with brachycrania (2.05 ml), on the left - with mesocrania and brachycrania (2.0 ml each). With regard to the FI, the largest volume of space was obtained with medium face on the right side (2.03 ml) and broad and medium types of faces (2.0 ml each) on the left. When calculating the indicators for the shapes of mandible, the largest volume of space was found in the brachygenic (2.05 ml), leptogenic (1.98 ml) and platigenic (1.97 ml) shapes on the right and leptogenic and platigenic shapes on the left (2.0 ml each). There were statistically significant differences in the volume of the right side of the PMS between different shapes according to the cranial index (F = 5.075; p = 0.0095). The most pronounced difference was present between samples with brachycrania and dolichocrania: 0.35 mm³ (95% CI 0.05-0.65); p = 0.0188. There was a statistically significant correlation with sex for parameters on both the right and left sides. The values of indicators in men exceeded those of measurements obtained from women. CONCLUSION: The data obtained determine the differences in the volume of the PMS in individuals with different shapes of the skull, face and mandible, as well as sex differences. Thus, indicating the need to take into account these features when choosing the required amount of anesthetic in clinical practice. The average volume of the PMS space, according to our data, is 1.8-2.0 ml, which is consistent with the clinical data described in the literature.

The influence of social and medical factors on the quality of life in elderly and senile people.

The object of the study was senile people, who sought dental orthopedic care in municipal healthcare institutions of the town of Cheboksary, the Chuvash Republic. The sample size was 1 000 people. The obtained quantitative indicators were subjected to statistical processing using parametric and nonparametric statistical methods. The analysis of mounted orthopedic dent prosthetic structures manufactured and installed in elderly and senile patients shows that the choice of material and method of manufacture is largely determined by such a social factor as the average monthly income. This, in turn, largely depends on income-generating employment and the possibility of obtaining additional financial support from family members in which the patient lives. Social factors have a significant impact on the quality of life in elderly and senile people.

Choosing the optimal mandible position for inferior alveolar nerve block (IANB) using finite element analysis.

BACKGROUND: One of the most popular methods of local anesthesia in dentistry, inferior alveolar nerve block (IANB) involves the blockade of the inferior alveolar nerve (IAN) and lingual nerve (LN) in the pterygomandibular space. Despite the large number of works describing the contents of this space, the spatial displacements of the anatomical structures of this area at different positions of the mandible have not been sufficiently studied. The aim of our study was to study the spatial movements of the IAN and inferior alveolar artery (IAA) at various positions of the mandible using computer simulation and finite element analysis to find the safest way to conduct IANB. MATERIALS AND METHODS: Reverse engineering was used to create a model of the cranial base and the mandible based on computed tomography (CT) data obtained from patient N (male, 24 years old), the arteries of the head and neck were designed from the data of multiphase angiography of patient M (female, 61 years old). Masticatory muscles, sphenomandibular ligament, temporomandibular joint and mandibular nerve were modeled in the SolidWorks software package based on an open database of anatomical structures. The finite element grid was generated in the Solidworks software. In the first series of experiments, the displacement of the mandible was modeled along the vertical axis down by 48 mm (maximum opening of the mouth), in the second series, the jaw was displaced vertically by 48 mm with a simultaneous transversal movement of 10 mm, in the third series, the jaw was displaced along the vertical axis down by 34 mm and transversally by 22 mm. RESULTS: The largest distance between IAN and IAA was noted in the third series of experiments. The distance between the nerve and the vessel was minimal in the first series, with an open mouth without lateral displacements. CONCLUSION: The generated computer model opens new possibilities for studying the dynamic anatomy of the pterygomandibular space. The results of this study can be used for further experimental and clinical trials to find the safest approach to the implementation of IANB, as well as applied in the practice of the educational process.

[Terminological and debatable issues of the intraosseous organization of the anterior part of the mandible]. / Terminologicheskie i diskussionnye voprosy vnutrikostnoi organizatsii perednego otdela nizhnei chelyusti cheloveka.

In the scientific literature, one can find conflicting assumptions about the presence of «proper mental bone¼ and «upper and lower lingual canals¼, which make up a separate ossified area in the chin of the mandible and the system of blood supply and innervation. However, calling these lesions «lingual canals¼ or «incisal canals¼, as is often found in various articles, is incorrect based on the position of International Anatomical Terminology. This is due to the lack of topographic reference in the term, which can equally be understood as the canal of the tongue, the neurovascular bundle of the same name, and the root canal system of the teeth of the lower jaw and can also be associated with the maxilla. We searched for information in English, without time limits, in the PubMed Central database, and searched on Google and analyzed the bibliography, relevant studies and reviews. The selection of publications was carried out by request «mental spine canals¼, 58 articles were found in PubMed, of which 21 were relevant. For the analysis, publications were selected that described in detail the anatomical, clinical and radiological features of the structure of the anterior part of the mandible. As a result of previous studies and the study of literature data, the intraosseous structures of the anterior part of the lower jaw were refined and classified, which solve not only terminological disputes, but also are important clinical guidelines for endodontic treatment, dental implantation and local anesthesia.

[A classification of surgical guides application for dental implantation]. / Klassifikatsiya variantov primeneniya khirurgicheskikh napravlyayushchikh shablonov dlya dental'noi implantatsii.

In dental implantology the treatment planning is the most important item for surgery success as well as for functionality and aesthetics of denture. The current problem is to determine the implant position intraoperatively. On dental market there are many companies offering the different variants of navigation surgery, including surgical guides. The purpose of this study is to create universal classification of surgical guide application for dental implantation based on clinical setting and the individual anatomy of the patient which simplifies the medical activities and predictably performs the treatment protocol.

[C-cells of the thyroid gland in experimental osteoporosis]. / C-kletki shchitovidnoi zhelezy pri éksperimental'nom osteoporoze.

The population of thyroid C-cells of female rabbits with ovariectomy-induced osteoporosis was studied using immunohistochemical method with antibodies against calcitonin (CT) and morphometrically. The development of osteoporosis was confirmed using radiology and densitometry. 8 weeks after the operation, after the detection of hypercalcemia and hypercalciuria, some of the animals were given a correcting treatment with calcium-containing drug and vitamin D3 or with a combination of calcium drug with hormonal estrogen-containing drug. 4 weeks after the treatment was started, thyroid C-cells in animals that received the drugs, were significantly larger than in the cells of control and ovariectomized rabbits that received no treatment. Following 12 and 22 weeks, in the animals treated with hormonal drug, both calcium concentrations in blood and urine and C-cell dimensions were normalized. Large C-cells with an intensive reaction to CT were observed at weeks 12 and 22 (weeks 20 and 30 after the operation) in the thyroid gland of the animals that received no treatment and of the animals that received calcium with food. In the last case, the morphological changes of C-cells were more pronounced, despite the insignificant differences in blood calcium concentrations in both groups. These results permit to suggest that the intensity of CT synthesis by C-cells may be influenced by calcium concentrations not only in the blood, but also in the intestinal lumen.