Is Corticalization in Radiographs Related to a Higher Risk of Bone Loss around Dental Implants in Smoking Patients? A 5-Year Observation of Radiograph Bone-Texture Changes.

BACKGROUND: Currently, the topic of dental implants is widely researched. However, still compromising are the factors that can affect implant loss as a consequence of marginal bone loss. One of the factors is smoking, which has a devastating effect on human health and bone structure. Oral health and jaw condition are also negatively affected by smoking. The aim of this study was to evaluate the peri-implant jawbone corticalization phenomenon in tobacco smokers. METHODS: A total of 2196 samples from 768 patients with an implant in the neck area were checked, and texture features were analyzed. The corticalization phenomenon was investigated. All analyses were performed in MaZda Software. The influence of corticalization was investigated as a factor on bone structure near the implant neck. The statistical analysis included a feature distribution evaluation, mean (t-test) or median (W-test) comparison, analysis of regression and one-way analysis of variance or Kruskal-Wallis test as no normal distribution or between-group variance was indicated for the significant differences in the investigated groups. Detected differences or relationships were assumed to be statistically significant when p < 0.05. RESULTS: The research revealed that MBL was correlated with smoking after 5 years (0.42 mm ± 1.32 mm 0 mm ± 1.25 mm), the Corticalization Index was higher in the smoker group on the day of surgery, and it became higher after 5y of observation (185.98 ± 90.8 and 243.17 ± 155.47). The implant-loss frequency was higher in the group of smokers, too, compared to non-smokers (6.74% and 2.87%). The higher the torque value during the implant placement, the higher the Corticalization Phenomenon Index. CONCLUSIONS: The research revealed a correlation between smoking and changes in bone structure in radio textures near the implants. The corticalization phenomenon is important, may be detected immediately after implant placement and may be one of the indicators of the implant success rate.

Evaluation of the Value of Perfusion-Weighted Magnetic Resonance Imaging in the Differential Diagnosis of Sellar and Parasellar Tumors.

The purpose of this study was to assess the value of perfusion-weighted imaging (PWI) in the differential diagnosis of sellar and parasellar tumors, as an additional sequence in the magnetic resonance imaging (MRI) protocol. Analysis was based on a substantial group of subjects and included 124 brain and pituitary MRI examinations with a dynamic susceptibility contrast (DSC) PWI sequence. The following perfusion parameters were determined for the tumors: relative cerebral blood volume (rCBV), relative peak height (rPH) and relative percentage of signal intensity recovery (rPSR). To ensure greater repeatability, each of the aforementioned parameters was calculated as: arithmetic mean of the values of the whole tumor, arithmetic mean of the maximum values on each axial slice within the tumor and maximum values derived from the whole tumor. In our study, we established that meningiomas compared to both non-functional and hormone-secreting pituitary adenomas (pituitary neuroendocrine tumors-PitNET) had significantly higher values of rCBV with cut-off points set at 3.45 and 3.54, respectively (mean rCBV). Additionally, meningiomas presented significantly higher maximum and mean maximum rPH values compared to adenomas. DSC PWI imaging adds significant value to conventional MRI examinations and can be helpful in differentiating equivocal pituitary tumors.

Are Torque-Induced Bone Texture Alterations Related to Early Marginal Jawbone Loss?

The reason why marginal bone loss (MBL) occurs after dental implant insertion without loading has not yet been clearly investigated. There are publications that confirm or reject the notion that there are factors that induce marginal bone loss, but no research investigates what exactly occurs in the bone surrounding the implant neck. In this study, 2196 samples of dental implant neck bone radiographs were analyzed. The follow-up period was 3 months without functional loading of the implant. Marginal bone loss was evaluated in relation to the torque used during the final phase of implant insertion. Radiographic texture features were also analyzed and evaluated. The analyses were performed individually for the anterior and posterior part of the alveolar crest in both the mandible and maxilla. After 3 months, an MBL relation with higher torque (higher than 40 Ncm; p < 0.05) was observed, but only in the lower jaw. The texture features Sum Average (SumAverg), Entropy, Difference Entropy (DifEntr), Long-Run Emphasis (LngREmph), Short-Run Emphasis (ShrtREmph), and discrete wavelet decomposition transform features were changed over time. This study presents that MBL is related to the torque value during dental implant insertion and the location of the procedure. The increasing values of SumAverg and LngREmph correlated with MBL, which were 64.21 to 64.35 and 1.71 to 2.01, respectively. The decreasing values of Entr, DifEntr, and ShrtREmph also correlated with MBL, which were 2.58 to 2.47, 1.11 to 1.01, and 0.88 to 0.84, respectively. The analyzed texture features may become good indicators of MBL in digital dental surgery.

Association of Polymorphism CHRNA5 and CHRNA3 Gene in People Addicted to Nicotine.

Smoking is a chronic and relapsing addictive trait that harms public health. Among the many identified genetic variants of nicotine dependence, the variants in the CHRNA5/A3/B4 gene cluster on chromosome 15 that encode the α5, α3, and ß4 subunits have recently received a lot of attention. Importantly, variants in this gene cluster have been associated with nicotine addiction. Among the many significant variants in this cluster, the polymorphism SNP rs16969968 seems to be the most interesting factor in nicotine addiction. This polymorphism causes an amino acid change from aspartate to asparagine at position 398 of the α5 nicotinic receptor protein sequence. Our study aimed to analyze three polymorphic variants: the rs16969968 located in the CHRNA5 gene, the rs578776 and rs1051730 located in the CHRNA3 gene in nicotine-addicted subjects, and in controls. Our study encompasses an association analysis of genotypes and haplotypes. A group of 401 volunteers was recruited for the study and divided into two groups: the study group consisted of addicted smokers and a control group of 200 unrelated non-smokers who were not dependent on any substance and healthy. A statistically significant difference was observed in the frequency of genotypes of the rs1051730 polymorphism of the CHRNA3 gene (χ2 = 6.704 p = 0.035). The T/T genotype was statistically significantly more frequent in the group of nicotine-dependent subjects. The haplotypes rs16969968, rs578776, and rs1051730 were distinguished, of which the G-T-T and G-C-T haplotypes were present only in the study group. With differences in frequencies, statistical significance was noted-for the G-T-T haplotype p = 0.01284 and the G-C-T haplotype p = 0.00775. The research stated that novel haplotypes G-T-T and G-C-T, though with very low-frequency variants in CHRNA3, were associated with nicotine addiction.

Application of susceptibility weighted imaging (SWI) in diagnostic imaging of brain pathologies - a practical approach.

Susceptibility weighted imaging (SWI) has been broadly incorporated to MR protocols as it provides unique additional diagnostic information in a wide variety of neurological conditions. SWI exploits local field inhomogeneities created by various paramagnetics (deoxyhaemoglobin, blood breakdown products), diamagnetics (calcium) or oxygenated blood, hereby provides contrast based on magnetic susceptibility. In this review we present various examples from everyday clinical practice including, among others, acute stroke, neurodegenerative disorders, haemorrhagic lesions, vascular malformations, mycotic intracranial aneurysm, primary central nervous system vasculitis, neoplasms in which SWI was essential for diagnosis. The strongest indications for SWI applications are the neurodegenerative and neuro-vascular diseases, therefore this review is aimed at a wide range of clinicians, mainly neurologists, neurosurgeons and radiologists.

Evaluation of Common Factors of Periodontitis and Cardiovascular Disease in Patients with the Acute Coronary Syndrome.

Periodontitis is a multifactorial disease causing inflammatory destruction of supporting structures of the dentition and eventually leading to its loss. This study was designed to evaluate common risk factors for periodontitis and acute coronary syndrome in the study population and demonstrate the systemic impact of periodontitis on the occurrence of acute coronary syndrome. A total of 160 patients (35 female and 125 male) were enrolled in the study. Considering the age range, the largest group of patients (118 patients) was between 55 and 65 years, which accounted for 73.8% of the total study population. There were 35 patients (21.9%) in the age group of 45 to 54 years, while the youngest age group of 35 to 44 years had as many as seven patients. Medical history and physical examination, including periodontal status, were performed. API, PD, CAL, and CPITN were evaluated. Common risk factors for periodontitis and acute coronary syndrome were assessed. The study assessed risk factors such as hypertension, diabetes, dyslipidemia, general health, smoking, height, weight, and hip circumference. In light of the above-described etiopathogenesis of atherosclerotic disease and its association with periodontal disease, it is important to emphasize preventing and treating periodontitis, especially in patients in the so-called high-risk group for cardiovascular disease. Dentists' introduction of an appropriate prophylactic and therapeutic plan may constitute both primary and secondary prevention of cardiovascular diseases.

Serotonin Receptor HTR3A Gene Polymorphisms rs1985242 and rs1062613, E-Cigarette Use and Personality.

We nowadays record growing numbers of e-cigarette users. The development of nicotine dependence is a result of many factors, including genetics and personality. In this study we analyzed two polymorphisms-rs1985242 and rs1062613-in the serotonin receptor HTR3A gene in a group of e-cigarette users (n = 135) and controls (n = 106). Personality traits were measured using the NEO Five-Factor Inventory. The comparison of e-cigarette users with the control group indicates that the former showed significantly higher scores on the neuroticism scale and lower scores on the scales of extraversion and conscientiousness of the NEO-FFI. Homozygote variants of rs1985242 were more frequent in the study group. The results of the 2 × 3 factorial ANOVA for e-cigarette users and the control group as well as interaction between the HTR3A rs1985242 variants were found for the NEO-FFI conscientiousness scale. These results allow us to conclude that the combination of psychological factors and genetic data creates a possibility for making more complete models of substance use disorders.

GALNTL6 Rs558129: A Novel Polymorphism for Swimming Performance?

The enzyme polypeptide N-acetylgalactosaminyltransferase like 6, encoded by the GALANTL6 gene, plays a role in the gut microbiome regarding regulation of short-chain fatty acids and their anti-inflammatory and resynthesis functions. It was hypothesized that the T allele of the GALNTL6 rs558129 polymorphism could have a positive effect on anaerobic metabolism. Thus, this study was performed to investigate the association between GALNTL6 rs558129 polymorphism and athletic performance in swimmers. A total of 147 Polish short distance (SDS) and 49 long distance swimmers (LDS) of national or international competitive levels and 379 controls were genotyped using the real-time polymerase chain reaction (real-time PCR). We found that the carriers of the T allele (CT+TT) had a 1.56 times higher chance of being SDS (odds ratio (OR): 95%CI 1.06-2.29) than the CC homozygotes. The T allele was overrepresented in the SDS compared with controls (33.7% vs. 25.7%, p = 0.025, OR 1.40, 95% CI 1.04-1.87), but no statistically significant differences were found for LDS. This study provides evidence for an association between the GALNTL6 rs558129 polymorphism and short distance swimming athlete status. Although more replication studies are needed, the preliminary data suggest an opportunity to use the analysis of GALNTL6 polymorphism along with other variants of candidate genes and standard phenotypic assessment in power-oriented sports selection.

In Vivo Imaging-Based Techniques for Early Diagnosis of Oral Potentially Malignant Disorders-Systematic Review and Meta-Analysis.

OBJECTIVES: Oral potentially malignant disorders (OPMDs) are lesions that may undergo malignant transformation to oral cancer. The early diagnosis and surveillance of OPMDs reduce the morbidity and mortality of patients. Diagnostic techniques based on medical images analysis have been developed to diagnose clinical conditions. This systematic review and meta-analysis aimed to evaluate the efficacy of imaging-based techniques compared to the gold standard of histopathology to assess their ability to correctly identify the presence of OPMDs. DESIGN: Literature searches of free text and MeSH terms were performed using MedLine (PubMed), Scopus, Google Scholar, and the Cochrane Library (from 2000 to 30 June 2020). The keywords used in the search strategy were: ("oral screening devices" or "autofluorescence" or "chemiluminescence" or "optical imaging" or "imaging technique") and ("oral dysplasia" or "oral malignant lesions" or "oral precancerosis"). RESULTS: The search strategy identified 1282 potential articles. After analyzing the results and applying the eligibility criteria, the remaining 43 papers were included in the qualitative synthesis, and 34 of these were included in the meta-analysis. CONCLUSIONS: None of the analyzed techniques based on assessing oral images can replace the biopsy. Further studies are needed to explore the role of techniques-based imaging analysis to identify an early noninvasive screening method.

MRI Protocol for Pituitary Assessment in Children with Growth or Puberty Disorders-Is Gadolinium Contrast Administration Actually Needed?

The aim of this study was to assess the diagnostic value of non-contrast pituitary MRI in children with growth or puberty disorders (GPDs) and to determine the criteria indicating the necessity to perform post-contrast examination. A retrospective study included re-analysis of 567 contrast-enhanced pituitary MRIs of children treated in a tertiary reference center. Two sets of sequences were created from each MRI examination: Set 1, including common sequences without contrast administration, and Set 2, which included common pre- and post-contrast sequences (conventional MRI examination). The differences in the visibility of pituitary lesions between pairs of sets were statistically analyzed. The overall frequency of Rathke's cleft cysts was 11.6%, ectopic posterior pituitary 3.5%, and microadenomas 0.9%. Lesions visible without contrast administration accounted for 85% of cases. Lesions not visible before and diagnosed only after contrast injection accounted for only 0.18% of all patients. Statistical analysis showed the advantage of the antero-posterior (AP) pituitary dimension over the other criteria in determining the appropriateness of using contrast in pituitary MRIs. The AP dimension was the most significant factor in logistic regression analysis: OR = 2.23, 95% CI, 1.35-3.71, p-value = 0.002, and in ROC analysis: AUC: 72.9% with a cut-off value of 7.5 mm, with sensitivity/specificity rates of 69.2%/73.5%. In most cases, the use of gadolinium-based contrast agent (GBCA) in pituitary MRI in children with GPD is unnecessary. The advantages of GBCA omission include shortening the time of MRI examination and of general anesthesia; saving time for other examinations, thus increasing the availability of MRI for waiting children; and acceleration in their further clinical management.

Effect of Intraoral Drainage after Impacted Mandibular Third Molar Extraction on Non-Infectious Postoperative Complications.

Surgical removal of mandibular third molars is associated with non-infectious postoperative complications, including pain, swelling, trismus. Intraoral drains are noteworthy because of their ease of application, availability, and effectiveness. This study aimed to evaluate the use of latex and calcium-sodium alginate mouth flat drains on the severity of postoperative complications such as pain, trismus, and edema after surgical removal of mandibular third molars. Ninety patients who underwent surgical removal of wisdom teeth were studied. The patients were divided into three groups. Group A-with a latex flat drain, group B-with a sodium-calcium alginate (Kaltostat) flat drain, and group C-with a wound closed with knotted sutures. Patients were assessed for pain on a VAS scale every day from surgery to postoperative day 7. Before the procedure and on postoperative days 1, 2, and 7, the pain level, edema, and trismus were measured, respectively. Intraoral drainage with a flat drain after mandibular third molar removal does not significantly reduce pain, as measured by the VAS scale, or postoperative swelling, as measured by lines between craniometric points. Intraoral drainage with a latex drain after mandibular third molar removal does not significantly reduce trismus, while intraoral drainage with a calcium-sodium alginate drainage bag significantly increases trismus.

Correlation of Panoramic Radiography, Cone-Beam Computed Tomography, and Three-Dimensional Printing in the Assessment of the Spatial Location of Impacted Mandibular Third Molars.

The development of radiology, rapid prototyping techniques, and the increasingly common use of 3D printing in dentistry inspires the use of these techniques to improve diagnostic and therapeutic processes. This study aimed to conduct a retrospective comparative analysis of dental panoramic radiographs, cone-beam computed tomography, and 3D printing in preoperative assessment of the procedure's difficulty. Thirty clinical cases with a high degree of difficulty were selected, and based on evaluation with CBCT, a virtual 3D model of the region of surgical procedure was created, which was then printed using a 3D printer. The comparative analysis included the linear measurements performed in dental panoramic radiographs, cone-beam computed tomography, and 3D models in a preoperative assessment of the degree of retention and difficulty of impacted mandibular third molars in the mandible. Linear measurements performed on dental panoramic radiographs were significantly lower than in cone-beam computed tomography and 3D models. No statistically significant differences were obtained in linear measurements between 3D models and cone-beam computed tomography images except for the measurement of the lingual lamina thickness; however, due to the insignificant differences in measurements, with a mean of only 80 µm, the elective procedure of removal of the impacted third molar in the mandible may be safe.

Effect of Platelet-Rich Fibrin Application on Non-Infectious Complications after Surgical Extraction of Impacted Mandibular Third Molars.

Due to the frequent development of non-infectious complications after surgical removal of the third lower impacted tooth, many techniques are used to reduce their severity. Among them is the technique of applying platelet-rich fibrin to the post-extraction alveolus. The study included 90 consecutively enrolled patients. Eligible patients were randomly assigned to two groups: patients with and without platelet-rich fibrin introduced into the postoperative alveolus. Pain, swelling, trismus, and temperature were evaluated after the procedure. Pain intensity was significantly higher in the control group than in the study group at 6 h, 1, and 3 days after surgery. PRF application did not significantly affect the intensity of swelling. Body temperature was significantly higher in the control group than the study group on day two after surgery. The trismus was significantly higher in the control group than in the study group at one, two, and seven days after surgery. Application of the PRF allows for a faster and less traumatic treatment process. It will enable for speedier recovery and return to active life and professional duties.

Assessment of Electrosensitivity of the Pulp of the Mandibular Second Molar after Surgical Removal of an Impacted Mandibular Third Molar.

Despite the frequent discussion of complications associated with surgical removal of wisdom teeth in the scientific literature, increased mobility of the second molar, which can affect the clinical status of the pulp, is often downplayed or overlooked. This study aimed to evaluate surgical removal of an impacted third molar on the change in the electrosensitivity of the pulp of the mandibular second molar. Sixty patients consecutively presenting to the Department of Oral Surgery to remove an impacted mandibular third molar were included in the study. Clinical examinations of pulp sensitivity of second molars in both the study and control groups were evaluated before the procedure, seven days after the procedure, and eight weeks after the procedure. The surgical removal of an impacted mandibular third molar significantly affected the pulp sensitivity of the second molar.

Evaluation of the Effect of Surgical Extraction of an Impacted Mandibular Third Molar on the Periodontal Status of the Second Molar-Prospective Study.

Dental injury to the second molar (SM) caused by the surgical extraction of the impacted third molar tends to be underestimated. The necessity of assessment of the impact of the removal of the wisdom tooth in the mandible on the second molar arose. The study group (n = 60) was the one with the second molar on the surgical side, and the control group (n = 60) was the one with the tooth on the opposite side of the alveolar arch. Before the surgery, the difficulty level was assessed according to the Pederson scale. The periodontal status of the SM was assessed by probing depth (PD), gingival index (GI), tooth mobility (TM) examination by the percussion method and resonance frequency. Measurements were taken before and after the surgery, 7 days and 8 weeks after the surgery. The study demonstrated the significant impact of the surgical removal of the wisdom tooth on the PD, GI and TM of the SM. The predicted degree of difficulty of the very difficult surgery had an influence on the increase in PD on the distal buccal and lingual surface of the SM, and on the GI in the proximity of the examined tooth. The results of the presented research confirm the necessity of the clinical assessment of the lower SM before and after the surgical removal of the impacted wisdom tooth in the mandible.

The Pattern of Mandibular Third Molar Impaction and Assessment of Surgery Difficulty: A Retrospective Study of Radiographs in East Baltic Population.

Classifications of impacted teeth allow defining the type and degree of retention, as well as assessing the degree of difficulty of the procedure. The aim of this study was to conduct retrospective analysis of the degree of retention and difficulty in the surgical removal of impacted mandibular third molars in the clinical material of the Department of Oral Surgery in 2013-2018. This study included 1585 dental panoramic radiographs of patients of the Department of Oral Surgery, who reported in 2013-2018, in order to perform surgical removal of the impacted mandibular third molar. Based on dental panoramic radiographs, the degree of retention was determined based on classifications according to Winter, according to Pell and Gregory, according to Tetsch and Wagner, and according to Asanami and Kasazaki. The difficulty of the procedure was also assessed based on the Pederson index. The most common types of lower wisdom tooth impaction are as follows: in Winter's classification, mesial-angular impaction; in Tetsch and Wagner's classification, oblique medial-angular impaction; in Pell and Gregory's classification, impaction grade 2A; and in Asanami and Kasazaki's classification, 3A and anterior inclination. In most cases of surgical removal of an impacted tooth, the anticipated difficulty of the procedure was rated as very difficult.

Quality of Life of Patients after Kinesio Tape Applications Following Impacted Mandibular Third Molar Surgeries.

Today, extraction of the impacted third molar is the most common procedure performed in oral surgery departments. One of the methods currently investigated-in terms reducing the severity of non-infectious complications and decreasing Quality of Life following third molar surgeries-is Kinesio Taping (KT). The aim of the study was to evaluate the impact of Kinesio Tape application on Quality of Life. A total of 100 asymptomatic patients with impacted third lower molar were included. The study participants were randomly divided into two groups: a study group with the application of KT (n = 50) and a control group (without KT) (n = 50). Removal of the impacted third lower molar was performed in each patient in a standardized fashion. For assessment of Quality of Life, the modified University of Washington Quality of Life Questionnaire (UW-QoL v4) was used. Patients with Kinesio Tape application scored higher in all domains. Statistically significant differences between the two groups were found in the following domains: "Activity", "Mood", "Health-related QoL during the past 7 days" and "Overall QoL during the past 7 days". There were no significant differences in significant problems and important issues between groups. Kinesio Taping has a significant impact on Quality of Life after impacted third molar removal. It should be considered as one of the noninvasive methods to reduce postoperative non-infectious complications.

Impact of the 25-Hydroxycholecalciferol Concentration and Vitamin D Deficiency Treatment on Changes in the Bone Level at the Implant Site during the Process of Osseointegration: A Prospective, Randomized, Controlled Clinical Trial.

INTRODUCTION: The most important factor which is responsible for the positive course of implant treatment is the process of osseointegration between the implant structure and the host's bone tissue. The aim of this study was to assess what effect the 25-hydroxycholecalciferol concentration and vitamin D deficiency treatment have on changes in the bone level at the implant site during the process of osseointegration in the mandible. MATERIALS AND METHODS: The study was with 122 people qualified for implant surgery, who were assigned to three research groups (A, B, and C). Laboratory, clinical, and radiological tests were performed on the day of surgery, and after 6 and 12 weeks. The bone level in the immediate proximity of the implant was determined by radiovisiography (RVG). RESULTS: The bone level after 12 weeks in Groups B and C was significantly higher than after 6 weeks. The bone level in the study Group B was significantly higher than in Group A. The study showed that the higher the levels of 25-hydroxycholecalciferol were observed on the day of surgery, the higher was the level of bone surrounding the implant after 6 and 12 after surgery. CONCLUSION: The correct level of 25-hydroxycholecalciferol on the day of surgery and vitamin D deficiency treatment significantly increase the bone level at the implant site in the process of radiologically assessed osseointegration.

The Impact of Using Kinesio Tape on Non-Infectious Complications after Impacted Mandibular Third Molar Surgery.

Non-infectious complications such as post-extraction pain, trismus, and swelling are extremely common after impacted wisdom tooth removal. The aim of the study was to assess the impact of using kinesio tape on the level of the postoperative swelling of soft tissues, trismus, and pain in patients undergoing the surgical extraction of an impacted mandibular third molar. One hundred patients undergoing the surgical extraction of a lower wisdom tooth were randomly divided into two groups: a study group with kinesio taping (KT) (n = 50) and a control group without kinesio taping (NKT) (n = 50). The surgical procedure was performed according to the same repeatable scheme. Kinesio tape was applied immediately after surgery in the KT group. In both groups, measurements of swelling, trismus, and pain were performed before the surgery and on the third and seventh postprocedural days. Kinesio tape had a significant effect on the decrease in facial swelling on the third day after surgery and a decrease in trismus and pain severity levels on the third and seventh days after surgery. The kinesio tape method is non-invasive, continuously active throughout the entire application period, and requires no additional patient appointments. KT application is an effective method for reducing postoperative edema, pain, and trismus after impacted mandibular wisdom teeth surgery.

Morphology and serum and bone tissue calcium and magnesium concentrations in the bones of male rats chronically treated with letrozole, a nonsteroidal cytochrome P450 aromatase inhibitor.

Purpose/Aim of the study: The role of estrogen (E) in the regulation of bone turnover in women is well established, though the contributions of E versus testosterone (T) in the control of bone turnover in men are poorly understood. The aim of this study was to examine the association between chronic treatment with letrozole, a nonsteroidal inhibitor blocking the aromatase activity and thus the conversion of androgens into estrogens, and cortical bone morphology in the femur and humerus of male adult rats.Materials and Methods: Adult male rats were treated with letrozole for 6 months and the body and femur weight, morphology, collagen structure, blood serum, and bone tissue concentrations of calcium and magnesium were examined.Results: Long-term aromatase inhibition resulted in a decrease in femur mass, a wavelike arrangement of bone and lamellae with an altered organization of collagen in compact bone, a increased concentration of calcium in blood serum, and no change in calcium bone tissue concentration, magnesium serum, or bone tissue concentration. MicroCT study of the humerus revealed significant decreases of whole bone tissue volume, cortical bone thickness, cortical bone volume, and external cortical bone thickness with letrozole treatment.Conclusion: Chronic treatment with letrozole affected cortical bone structure and produced histomorphological changes in male rat bone similar to that observed in the aging processes.