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.

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.

[The role of an imbalance of sex and calcium-regulating hormones in osteoarthrosis deformans in women]. / O roli disbalansa polovykh i kal'tsiireguliruiushchikh gormonov pri deformiruiushchem osteoartroze u zhenshchin.

AIM: Determination of essential changes in hormonal background in evaluation of sex and calcium-regulating hormones levels in women of different age with osteoarthrosis deformans (OAD). MATERIALS AND METHODS: 30-34-year-old and 45-60-year-old females (60 premenopausal and 51 menopausal) with x-ray confirmed OAD and 34 control healthy women (23 premenopausal and 11 in menopause) were examined with radioimmunoassay for the baseline serum levels of calcitonin, parathyrine, osteocalcin, estradiol, testosterone, progesterone, dehydroepiandrosterone-sulfate (DHAS). RESULTS: Both age-groups patients had abnormal levels of testosterone and its metabolite DHAS. Significant deviations were found in menopausal women. With age, both patients and healthy women exhibited increasing levels of parathyrine and calcitonine. Compared to controls, OAD women had lower parathyrine, osteocalcine and higher calcitonine levels. With OAD progression, serum osteocalcin tended to lowering while testosterone was on the increase. CONCLUSION: Changes in blood levels of calcium-regulating hormones observed in osteoarthrosis may result in stimulation of cartilage degeneration. Calcitonine was low in premenopausal and menopausal OAD patients indicating impairment of bone metabolism in osteoarthrosis.

[A cryoultratomy method and its use in immunocytochemistry]. / Metod krioul'tratomii i ego primenenie v immunotsitolhimii.

A method of frozen ultrathin sectioning for tissues and suspension material is presented. Practical aspects and results in the field of cryoultratomy are observed in detail. An example of a good preservation of tissue ultrastructure and application of cryosections to immunocytochemical investigations is given.

[Quantitative determination of the infectivity of nuclear polyhedrosis virus DNA on honeycomb moth (Galleria mellonella) larvae]. / Kolichestvennoe opredelenie infektsionnosti DNK virusa iadernogo poliédroza na lichinkakh bol'shoi voshchinnoi moli (Galleria mellonella).

The possibility of using honeycomb moth larvae for titration of nuclear polyhedrosis virus (NPV) infectious DNA and determinations of transfection effectiveness was studied. Honeycomb moth larvae were shown to be a sensitive system for NPV DNA titration. DEAE-dextran used as a protector increased NPV DNA infectivity 1000-fold, LD50 in this instance being 2 X 10(8) molecules per larva. The method of NPV DNA infectivity determinations by the number of larvae with polyhedreae in the fatty tissue is more sensitive than infectivity determinations by the number of dead larvae and permits titrations of low DNA concentrations. The curve of DNA titration in the presence of DEAE-dextran by the number of larvae with polyhedrae in the fatty tissue allows to quantitate native DNA within the range of 0.01 to 5 micrograms/ml.