Rehabilitation of an edentulous posterior maxilla with dental implants is challenging, and sinus floor augmentation could be considered as an important surgical procedure for bone augmentation in this region before implant placement. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with simplified processing: its application in sinus floor augmentation has been widely investigated in literature. However, the biological properties and actual efficacy of this product remain controversial. This study assessed the effect of sinus floor augmentation with PRF versus freeze-dried bone allograft (FDBA) on stability of one-stage dental implants. This split-mouth randomized clinical trial evaluated 10 patients who required bilateral sinus floor augmentation. PRF and L-PRF membrane were used in one quadrant while FDBA and collagen membrane were used in the other quadrant. Implant stability was assessed by resonance frequency analysis (RFA) immediately, and 2, 4, and 6 months after implant placement. The implant stability quotient (ISQ) was compared over time and between the two groups using repeated measures ANOVA and independent sample t-test. The mean ISQ significantly increased over time in both groups (p < 0.001). The increase was greater in the PRF group (p < 0.05). Within the limitations of this study, PRF yielded superior results compared with FDBA regarding the stability of one-stage dental implants.

Background The shape of the forehead is primarily determined by the frontal bone, which holds significance for health and aesthetics. This study evaluated the morphology of the frontal bone in different age groups and genders using computed tomography (CT). Methods This cross-sectional study was conducted on CT scan results of 220 patients divided into three age groups: 20–29.27, 29.27–47.54, and 47.54–95 years. The investigation explored the lower and upper angles compared with the Sella–Nasion (SN) line, the maximum frontal projection with Nasion in the SN plan, and the variations in frontal thickness across different angles (15, 30, 45, 60, 75, and 90 degrees) relative to the SN plane. All data were analyzed using R software, considering the significance level p < 0.05. Results Of 220 patients, 119 were men, and the mean age of the participants was 41.09 ± 18.06 years. The average upper frontal slope (UFS) angle was 56.96 ± 8.17 degrees, which was 59.35 ± 7.92 degrees in females and 54.94 ± 7.86 degrees in males. The mean lower frontal slope (LFS) angle was 86.30 ± 7.96 degrees, which was 90.71 ± 6.67 degrees in females and 82.55 ± 7.00 degrees in males. The average contour nasion (C–N) distance was 7.51 ± 3.72 mm. Also, the frontal thickness at an angle of 15 degrees had the highest value of 13.08 ± 2.68 mm and at 30 degrees had the lowest value of 5.81 ± 1.56 mm. A significant difference was observed between the UFS and LFS among males and females (p < 0.001). Across all age groups, men exhibited a steeper angle, indicating a greater posterior inclination than women. Moreover, males with upper ages reported a significant increase in C–N distance and frontal projection (p < 0.05). Conclusion Our findings emphasize the importance of considering gender-specific variations in frontal bone structure when planning cosmetic or reconstructive procedures involving the forehead. The study was approved by the medical ethics committee of the Qazvin University of Medical Sciences, Qazvin, Iran (IR.QUMS.REC.1402.075). All methods were performed in accordance with relevant guidelines and regulations that is Declaration of Helsinki. All subjects gave their informed consent to participate in the study. The datasets used and/or analyzed in the current study are available from the corresponding author upon reasonable request. A.H.B, A.N., A.K., and M.T. participated in the research design. A.H.B., F.T-D., and A.N. participated in writing the first draft. A.H.B., M.T., and A.A. participated in the performance of the research and analytic tools. A.H.B., A.A., and A.K. participated in data analysis. All authors reviewed and confirmed the final manuscript. ^* These authors contributed equally to the article. Article published online: 11 November 2024 © 2024. Thieme. All rights reserved. Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

Background: The transcutaneous electrical nerve stimulation (TENS) stimulus inhibits the activity of nociceptive neurons of the central nervous system. Pain relief is achieved by increasing the pulse amplitude of TENS to induce a non -painful paranesthesia beneath the electrodes. This study aimed to assess the effect of TENS on acute pain, edema, and trismus after surgical removal of impacted third molars. Material and Methods: This randomized, double blind, split -mouth clinical trial was conducted on 37 patients with bilaterally impacted mandibular third molars. The angle and body of mandible at the site of surgery in one randomly selected quadrant underwent TENS immediately after surgery (50 Hz, 100-mu s short pulse, 15 minutes for 6 days). The TENS stimulator device was used in off mode for the placebo quadrant. The pain score (primary outcome) was measured for 7 days postoperatively, and edema and trismus (secondary outcomes) were assessed at 2, 4 and 7 days, postoperatively. The results were analyzed by repeated measures ANOVA using R software (alpha=0.05). Results: The overall mean pain score was significantly lower in the TENS than the placebo group (P<0.05). The number of taken analgesics in the first 3 days was significantly lower in the TENS group (P.05). The inter-incisal distance, as an index to assess trismus, was not significantly different between the two group at day 2, but it was significantly higher in the TENS group after the second day (P<0.001). Conclusions: TENS effectively decreased pain and trismus following impacted third molar surgery, and may be recommended as a non -pharmaceutical method to relieve postoperative symptoms.