Introduction: In Orthodontic treatment, adequate Anchorage is necessary to move the intended teeth. In some cases, just anterior teeth are malaligned, while posterior occlusion is acceptable. Therefore, the posterior teeth could be integrated by fiber-reinforced composite (FRC) to provide a rigid Anchorage. This method proved advantageous since brackets are bonded just to anterior segment, while posterior segments remain intact. Case description: The current article presents the Orthodontic treatment of an adolescent girl with malalignment and rotation of upper incisors and canines. Posterior occlusion was admissible. Posterior Anchorage was provided by FRC bars, while anterior teeth alignment was performed by routine fixed Orthodontic appliances. Orthodontic treatment was completed within six months. It is worthy to note that the posterior occlusion was maintained as before treatment.

Background. The design of an Orthodontic mini-implant is a significant factor in determining its primary stability and its clinical success. The aim of this study was to measure the relative effect of mini-implant design factors on primary stability of Orthodontic mini-implants. Methods. Thirty-two 3-dimensional assemblies of mini-implant models with their surrounding bone were generated using finite element analysis software. The maximum displacement of each mini-implant model was measured as they were loaded with a 2-N horizontal force. Employing Taguchi’ s design of experiments as a statistical method, the contribution of each design factor to primary stability was calculated. As a result of the great effect of the upper diameter and length, to better detect the impact of the remaining design factors, another set of 25 models with a fixed amount of length and diameter was generated and evaluated. Results. The diameter and length showed a great impact on the primary stability in the first set of experiments (P<0. 05). According to the second set of experiments, increased taper angle in the threaded and non-threaded area decreased the primary stability. There was also an optimum amount of 2. 5 mm for threaded taper length beyond which the primary stability de-creased. Conclusion. It is advisable to increase the diameter and length if primary stability is at risk. In the second place, a minimum amount of taper angle, both in the threaded and non-threaded area with an approximate proportion of 20% of threaded taper length to MI length, would be desirable for MIs with a moderate size.

Introduction: The aim of this study was to perform a systematic review and meta-analysis to compare the effect of bone-borne expansion (BBE) and tooth-borne expansion (TBE) in patients with maxillary constriction. Methods: Electronic databases, including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, were searched up to February 2019. Eligible clinical trials and cohort studies that studied the effects of bone-borne and tooth-borne expansion appliances on patients with constricted maxilla were selected. The study selection, data extraction, and risk of bias assessment were independently performed by two authors. Then, the random-effects meta-analysis and post-hoc heterogeneity tests were performed. Results: In the end, four studies were included in the present meta-analysis (i. e., a randomized clinical trial, two prospective controlled clinical trials, and a cohort study) that collected data from 117 patients. The mean differences between TBE and BBE were 0. 38 mm and-0. 28 mm for premolar and molar apices, 0. 67 mm and 1. 18 mm for premolar and molar crowns, 0. 19 mm and 0. 17 mm for alveolar bone in premolar and molar areas, and-0. 61 mm and 0. 02 mm for nasal and maxillary bones, respectively. Moreover, the differences between TBE and BBE for dental angulation were 3. 84◦ and 1. 52◦ for left and right molars, as well as 4. 85◦ and 3. 46◦ for left and right premolars, respectively. Conclusion: The BBE appliances do not have any advantages over tooth-borne devices with regard to the amount of skeletal or dental expansion; however, it seems to produce less tipping in posterior teeth.

Background and Aim: Considering the importance of skeletal Anchorage in Orthodontic treatment, this study aimed to assess the frequency and pattern of skeletal Anchorage usage by Iranian orthodontists. Materials and Methods: In this cross-sectional study, 301 Iranian orthodontists filled out a questionnaire consisting of 10 questions, 5 about miniscrews and 5 about miniplate usage. It also asked for the demographic information of the participants. The relationship between the participants' demographic information and their responses to the questions was also analyzed. Statistical analysis was conducted by the Chi-square test, one-way ANOVA, t-test, and Mann-Whitney test (alpha=0.05).  Results: There were 46.7% males and 53.3% females with a mean age of 38.9 years and a mean work experience of 8.95 years. Of all, 89.7% of the participants used miniscrews and 16.3% of them used miniscrews and miniplates. Generally, participants not using skeletal Anchorage were significantly older (P=0.002) and had a significantly longer work experience (P=0.000). Also, there was no significant association between gender and skeletal Anchorage usage (P=0.204). From the perspective of the orthodontists, the main indication of Anchorage devices was to provide optimal Anchorage. Conclusion: The results showed that a high percentage of Iranian orthodontists used different types of skeletal Anchorage devices. They preferred to use miniscrews more frequently than miniplates, mostly due to difficulties associated with their surgical insertion. Also, it was observed that older orthodontists used skeletal Anchorage less frequently than younger orthodontists.

Objectives: Use of miniscrews has become very common in Orthodontic treatment of patients. Following tissue manipulation during miniscrew placement, bacteremia may occur, which is important in patients susceptible to infective endocarditis. This study aimed to investigate the possibility of bacteremia following Orthodontic miniscrew placement. Materials and Methods: The present quasi-experimental study was conducted on 30 Orthodontic patients, including 11 males (36. 7%) and 19 females (63. 3%) with a mean age of 23. 67±, 4. 87 years, who required miniscrew placement in their treatment plan. Two blood samples were taken from the patients for aerobic and anaerobic cultures right before and 30-60 seconds after miniscrew placement. To investigate the presence of bacteremia, the blood samples were incubated in an automated blood culture machine for five days. The standard biological methods were used for the positive sample(s) to identify the type of bacteria. Data analysis was performed using the McNemar test. Results: The blood samples of 29 patients were negative for the bacteria before and after miniscrew placement. Blood sample of one patient was positive for aerobic and anaerobic bacteria after miniscrew placement. However, bacteremia was negative in the initial (preplacement) blood samples for both aerobes and anaerobes. Conclusion: Miniscrew placement in Orthodontic patients was not associated with bacteremia.

Objective: Implants are being used in Orthodontics as a reliable mode of Anchorage.Among other factors, the cortical bone thickness plays a major role in determining the stability of these implants. The objective of this study was to study the relationship of various arch forms and the cortical bone thickness and to determine if the cortical bone thickness varies between various arch forms. This would help to determine the ideal length of an implant for a particular arch form.Materials and Methods: A cross sectional tomograph was obtained from 30 patients.Based on arch forms the patients’ tomographs were equally divided into three basic square, tapered and ovoid categories, each consisting of 10 patients. Consequently, their buccal and lingual cortical plate thicknesses were measured.Results: The results showed that there was a statistically significant difference between the three arch forms, in which the square arch form had the greatest cortical bone thickness among the three arch forms.Conclusion: Patients having a tapered arch form may require implants with greater length than patients having a square or an ovoid arch form. Since the availability of the cortical bone in square arch patients is greater, there is more stability for the implants in these cases; therefore, implants with a shorter length may be used in these cases.

Objectives This study assessed the mandibular buccal shelf (MBS) for safe miniscrews insertion in teenagers and adults. Methods Cone-beam computed tomography (CBCT) images of 30 teenagers and 30 adults were used to measure bone width and cortical bone thickness. Measurements were made at four sites buccal to the distobuccal cusp of mandibular 1st molar (D6), and mesiobuccal cusp (MB7), an area at the center of the bifurcation (Mid7), and distobuccal cusp (DB7) of mandibular second molar. Bone width was measured at four distances (4, 6, 8, and 10 mm) from the (CEJ). ANOVA was used for statistical analysis. Results The MBS was significantly different within each age group and in different age groups, tooth sites, distances from the CEJ, and cortical bone thicknesses (P<0. 001). A significant difference was detected in bone width between the two age groups in D6 at all distances from the CEJ, MB7 and Mid7 at 4 mm and 6 mm, and DB7 at 4 mm from the CEJ (P<0. 05). Cortical bone thickness was significantly different between the two groups at MB7, Mid7, and DB7 (P<0. 05). Conclusion All distances from the CEJ at DB7 offered adequate bone width for safe miniscrew implantation. Mid7 showed suitable bone width at all distances from the CEJ in teenagers. In adults, miniscrews should be implanted at 6 mm from the CEJ. Miniscrews should be inserted in at least 8 mm distance from the CEJ at MB7. D6 is unsafe for miniscrew insertion in both groups at all distances from the CEJ.

Objective: The aim of this study was to evaluate fracture characteristics of rigid twotooth segments splinted with fiber reinforced composite (FRC), with and without  application of simulated masticatory forces. Material and Methods: In this experimental study, 80 extracted maxillary bicuspids were joined in pairs from the buccal aspect using FRC. The specimens were divided into two groups. In group A, the fracture load of FRC was measured. The 20 specimens of group B were initially loaded in a chewing simulator machine for 4×105 cycles to simulate a two-year chewing period. Samples that withstood these loads were assessed for fracture load. The results were compared using student t-test. Stereomicroscopic evaluation of fracture areas was performed to determine the fracture pattern.  Results: None of the specimens in group B failed during application of simulated masticatory forces, meaning that the survival rate was 100%. Mean (standard deviation) of fracture loads in groups A and B were 195.80 (14.345) and 190.57 (24.027), respectively. No significant difference was found in mean fracture loads between the two groups. The overall fracture pattern was similar in both groups.  Conclusions: FRC bars demonstrated sufficient durability to withstand chewing forces within the chewing simulation period. The fracture loads were higher than the mean mastication forces and remained almost unchanged after application of these forces.