Репозиторий Университета

Background: The aim of this paper was to systematically review the root canal configuration (RCC) and morphology literature of the mandibular second premolar (Mn2P). Methods: Systematic research of five electronic databases was performed to identify published literature concerning the root canal configuration (RCC) of the Mn2P up through July 2020. Studies were selected according to predefined search terms and keywords inclusion criteria: “root canal configuration”, “root canal system”, “root canal morphology”, “mandibular second premolar”, “mandibular premolars”, “morphology” and “anatomy”. Further possible studies were identified by cross-referencing and screening the bibliographies of the selected articles. Results: From 1622 retrieved studies, 44 studies investigating the internal morphology of 17,839 Mn2Ps were included. Most examined Mn2Ps were single-rooted (89.5–100%); two-rooted (0.1–8%) and three-rooted (0.1–3.5%) Mn2Ps at lower frequency. Most frequent RCCs reported were 1–1–1/1 (55.3–99.6%) followed by 1–1–2/2 (0.5–57%) and 2–2–2/2 (0.6–18%). The meta-analysis of seven studies demonstrated that a significantly higher number of RCC type 1–2–1/1 (OR [95%CI] = 2.05 [1.27, 3.33]) and 2–2–2/2 (OR [95%CI] = 2.32 [0.65, 8.63]) were observed in male than in female patients. Conclusions: Different RCC research methods have been reported. Whereas clearing and radiographs were commonly used in the past, CBCT has been prevalent in recent years. A globally high frequency of a 1–1–1/1 RCC in the Mn2P has been reported. Nevertheless, the probability that different, more complicated RCCs can appear in Mn2Ps should not be underestimated and, thus, should be taken into consideration when making decisions during an endodontic treatment.

© 2019 American Association of Endodontists Introduction: Pulp stones are mineral structures that develop in the pulp tissue triggered by several clinical conditions. The exact biochemical process behind the occurrence of pulp stones is uncertain. This study aimed to perform a structural and crystallographic characterization of pulp stones and dentin from extracted human teeth. Methods: The sample consisted of 13 erupted and unerupted permanent human teeth diagnosed with pulp stones. The teeth were analyzed with scanning electron microscopy with secondary and backscattered electrons, energy-dispersive spectroscopy, micro-Raman spectroscopy, micro–X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy. Results: The pulp stones revealed a heterogeneous morphology and structure compared with each other. Compared with the adjacent dentin, the pulp stones had a similar structure. From a chemical point of view, oxygen, calcium, carbon, and phosphorus were the most prevalent chemical elements in the inner part of the stones, whereas on the surface carbon, nitrogen, sulfur, chlorine, aluminum, potassium, zinc, copper, and lead were the most prevalent. Copper, iron, and zinc were higher in the stones than the dentin (P < .05). Statistically significant differences between the chemical structure of stones from erupted and unerupted teeth were not detected (P > .05). Conclusions: Pulp stones have structural and chemical properties that are similar to dentin. Variations in morphology are common.

© 2019 Special Care Dentistry Association and Wiley Periodicals, Inc. Aims: This study aimed to investigate the morphology of the palate, palatal rugae pattern, and dental arch form in patients with schizophrenia. Methods and results: An observational case-control study was designed following the STROBE statement and checklist. The sample consisted of 132 patients (39 diagnosed with schizophrenia and 93 controls). Dental casts of the patients were classified based on the pattern of their palatal rugae, their dental arch form, and the area of their palate. The palatal rugae in patients with schizophrenia had a more random distribution and shape compared to the control group (P =.027). Oval dental arches were the most prevalent in both groups (P =.473). The palate area was slightly larger in the control group (3.2318 ± 0.549 mm2) compared with the group of patients with schizophrenia (3.060 ± 0.470 mm2) (P =.090). Conclusion: Palatal rugae pattern may feature as a potential minor physical anomaly for schizophrenia. Additional studies with alternative sampling and classification systems are necessary to understand this finding and its applications in practice.

© 2018 Contemporary Clinical Dentistry | Published by Wolters Kluwer - Medknow. Background: The success of endodontic treatment depends on the knowledge of root canal system. The root canals have complex morphology and wide individual variations. The aim of this study was to evaluate the root canal morphology of the maxillary first molars among residents of the Moscow region using cone-beam computed tomography (CBCT) scanning. Materials and Methods: Three hundred CBCT images of patients aged 20-70 years old were analyzed to study the root canal system (the number of canals and the configuration according to Vertucci's classification) of the maxillary first molars. The prevalence of a second mesiobuccal (MB2) in the mesiobuccal root (MB) was recorded in each age group. Results: three separated roots of the maxillary first molar were observed in 100% of cases. MB2 canals were found in 59.8% of cases. A second distobuccal canal was observed in 0.5% of cases. The canal morphology in the MB root was 40.2% in Type I, 22.4% in Type II, and 37.3% in Type IV. Conclusion: The prevalence of MB2 canals was 59.8%, and the most common canal morphology was Vertucci's Type I. Using CBCT scanning is a useful technique to evaluate and analyze the root canal system.

© 2018 Ophthalmology Publishing Group. All rights reserved. Purpose: creation of working classification of morphologic variations of postoperative lens capsule opacity after Micro-Invasive cataract surgery. Material and methods: Morphologic study of the lens capsule (LC) has been conducted on 4 artiphakic cadaveric eyes. A specimen of an isolated anterior lens capsule, obtained during the repeated operation with changes characteristic for anterior capsular contraction syndrome has been studied too. The obtained specimens have been researched with the method of semithin sections. Results: The analysis of the morphologic cadaveric LC specimens revealed the polymorphism of secondary cataract (SC). Besides well known "classic" SC forms, which were caused by fibroplasias processes or pseudo-regeneration a new type of postoperative LC opacity not represented in the available literature before has been revealed. The given variant of opacities was called "pseudo-hyaloid" form and characterized by the absence of clear LC borders, changes of its normal structure, the appearance of loose fibrillar structure with microslit spaces and exfoliations, that possibly was the consequence of acustic cavitation, arising in the result of ultrasonic effect. As a result the LC lost characteristic for it the role of the dense bed and made impossible adhesion and migration on its changed surface the proliferative fibrocellular elements characteristic for "classic" SC forms. The microscopy results of the isolated anterior LC specimen in the area of capsulotomic aperture showed the presence of altered abundant loose fibrillar tissue with microporous structure and expressed forming of folds. Making layers of fibrous tissue exceeded the thickness of the normal anterior LC in 10 and more times and considerably reduced the diameter of capsulotomic aperture. Conclusion: The variety of postoperative LC opacities confirmed by the results of morphologic studies afforded to suggest a new working classification in which all possible morphologic variants and the stages of the secondary pathologic changes forming of anterior LC. The suggested classification is convenient for the understanding and must promote to make a right algorithm in the choice of optimal and safe technology of laser reconstructive interventions.

© 2018 Media Sfera. All rights reserved. The anterior capsular contraction syndrome (ACCS) in pseudophakic patients is known to be accompanied by postoperative opacity of anterior lens capsule (ALC) and partial or full closure of anterior capsulotomy opening. Purpose: to perform complex morphological assessment of ALC in patients with ACCS. Material and methods. The study involved complex analysis of ALC that was removed due to ACCS in the pseudophakic eye in the setting of diabetes mellitus and past vitreoretinal surgery. The following examination methods were used: light-optical microscopy of ALC samples in the form of polychrome-colored semifine sections using optical microscope Leica DM-2500 (Germany), scanning microscopy of ALC surface with EVO LS10 (Carl Zeiss, Germany) microscope, analysis of chemical element composition and its variation of the ALC sample with energy-dispersive spectrometer Oxford X-Max50 (Oxford, UK). Results. Light-optical microscopy showed altered state and plication of ALC induced by proliferation from inner surface of the fibrocellular tissue, which gradually thickens (up to 360 µm) towards center and causes reduction of anterior capsulotomy opening. Scanning electron microscopy revealed presence of tissue with uneven micro-relief and a porous three-dimensional structure uncharacteristic for capsule on the surface of ALC. Thickness of the fibrous deposition significantly exceeded the thickness of ALC. Evaluation of elemental composition of the fibrocellular tissue showed elevated concentration of sulfur and phosphorus, which indicates high activity of the regenerative process. In the observed case, the regenerative process was of substitute nature because an attempt to restore the lens was accompanied by formation of connective tissue structurally different from original. Conclusion. Complex assessment of an isolated ALC sample allowed revelation of the chain of pathological processes accompanying the development of ACCS.