Iranian Journal of Orthodontics
Volume:16 Issue: 1, Mar 2021

Rotations are very common components of malocclusions. Couple forces bring about a quick and an efficient correction but the two anchorage units from which the force is being derived should be stable in order to prevent the reaction forces. In this case report, derotation of a central tooth with a couple force system appliance without deleterious effects on the surrounding teeth has been presented.

The objective of the current study was to compare the amount of separation obtained by two various elastomeric separators, as well as the pain perception and gingival health. 

A randomized split-mouth study was performed on 60 patients receiving fixed orthodontic treatment who were put randomly in one of two separator groups (Group 1: Elastomeric separators; Group 2: Safe-T separators). At the end of the 5-day study, the amount of separation was evaluated using a feeler gauge. Qualitative and quantitative pain assessment was performed using a patient-filled VAS (visual analogue scale) score and a questionnaire. Loe and Silness gingival index was used to examine gingival health at the time of placement and removal of separators. Student t-Test was used to compare mean VAS scores and the amount of separation followed by repeated measures of ANOVA and Bonferroni’s post hoc analysis. Chi Square Test was utilized to compare gingival index scores followed by the marginal homogeneity test comparing the 1st and 5th day. Reproducibility of measurements underwent assessment using intra-class correlation coefficients. 

Greater statistically significant amounts of separation (0.126 mm) was achieved by Safe-T separators than conventional elastomeric separators. Patients experienced maximum pain and discomfort with the use of conventional elastomeric separators. Amount of soft tissue injury and bleeding was greater with elastomeric separators with a mean gingival score of 3.

Safe-T separators separate teeth optimally with minimal injury and discomfort to soft tissues, which makes them the better choice for clinicians.

Determining the factors involved in selecting a specialist dentist from patient’s point of view helps dentists to improve the quality of their services and responds to patients' needs. Therefore, this study is aimed to determine the factors affecting the selection of an orthodontist by individuals.

In this study, 384 patients who had been referred to the orthodontist office participated. Individuals were interviewed separately using a questionnaire. Data were collected after completing the questionnaire and analyzed using SPSS software version 21.

Findings revealed that the orthodontist's work experience and reputation among the patients (34.1%), their attention and explanation with details to patients (45.6%), referral through another dentist, friends or other patients (46.1%), the good behavior of the staff and the  cleanliness of the office (58.1%), the use of non-extraction treatment based on each patient’s needs (47.9%) and having a payment plan and low cost of treatment (24.2%) were the most substantial issues and greatest priorities in the decision making process of patients.

Our findings indicated that some of the factors and priorities have a high impact on the selection of dentists. The knowledge of these priorities and reasons for patients to choose a dentist can be used in marketing strategies by dentists.

Debonding of orthodontic metal bracket is a routine part of fixed orthodontic treatment. The purpose of this in vitro study was to evaluate the direction of enamel cracks before and after debonding the metal orthodontic brackets in five different techniques.

Two hundred extracted human premolars were randomly divided into five groups in this in vitro study. Metal brackets were bonded with Transbond XT (3 M Unitek, Monrovia, CA, USA) light-cured adhesive. Then the brackets were removed with one of these

ultrasonic scaler, ligature cutter plier, bracket removal plier, how plier, crown remover. Direction of the enamel cracks were examined by stereomicroscope and compared. Statistical analysis was done with Paired t-test and Chi-squared test. P < 0.05 was considered as significant.

After debonding, mixed type had the highest frequency (80.9 %) and no specimens were observed with horizontal crack. There was no significant change in the pattern of directions in before-after comparison (p=0.007. Mixed pattern was less common in ultrasonic group compared to crown remover and ligature cutter groups (p=0.007 and 0.035 respectively).

All of the five debonding methods in the current study had no significant change on the microcrack patterns and there were no horizontal cracks after debonding. Ultrasonic device had the least number of mixed cracks after debonding.

Palatal expansion can be done with tooth-borne and bone-borne appliances; Bone maturity is one of the factors required placing a mini-screw in the palate for expansion. Expansion with bone-based appliance also has two dental and skeletal responses; Part of the skeletal response can be to increase the size of the airway. The present study evaluates the effect of Miniscrew-assisted palatal expansion on airway volume.

Search was conducted for articles published between January 2010 to January 2021 in PubMed, Embase, Google Scholar, and Cochrane using the following inclusion criteria: 1) patients whose treatment with Miniscrew-assisted palatal expansion and who with transverse discrepancy 2) all languages, 3) Randomized clinical trials (RCTs) or non-randomized clinical trials (Non-RCTs) and retrospective studies were considered.

Of the 123 studies on miniscrew-assisted palatal expansion, only 7 studies clinically evaluated the effect of miniscrew-assisted palatal expansion on airway dimensions. The results of studies show that the miniscrew-assisted palatal expansion increasing airway dimensions; so that, increased nasal cavity volume and nasopharyngeal volume have been observed following this treatment. However, studies have shown that this approch does not effect on oropharyngeal, palatopharyngeal, glossopharyngeal and posterior areas.

The results of the study demonstrated that Miniscrew-assisted palatal expansion is an effective and efficient treatment in increasing airway dimensions via its increasing nasal cavity and nasopharynx volume.

The aim of this study is a systematic review on the long-term stability of growth modification treatment in children with obstructive sleep apnea (SA).

At first, all the papers (n=87) related to keywords (growth modification, headgear, functional therapy, herbst, twin block, forsus, AHI, orthodontics, sleep apnea, systematic review, meta-analysis) were searched for English databases; PubMed, Scopus, Embase, google scholar and Cochrane Database of Systematic Reviews covering the period from 2000 through 2021 was studied. As a result to inclusion and exclusion criteria, papers related to growth modification treatment in children with sleep apnea were found and analyzed (n=5). Predefined inclusion and exclusion criteria were:  papers related to growth modification treatment for children with SA, Children 7 to 11 years old with SA grade 2 and above, follow-up 10 months to 11 years old, use of functional appliance and headgear, papers were English, papers were original and all the papers were free full text.

Of the 87 studies on growth modification treatment and sleep apnea, only 5 studies clinically evaluated the long-term stability of growth modification treatment on airway dimensions. Growth modification treatments for sleep apnea are very important and can play very significant role in health improvement. So, paying more attention to benefits of orthodontics therapeutic tools in sleep apnea is necessary. On important points is the orthodontist’s active role play in screening the patients for this disease and advice oral appliance therapy, if needed.

The long-term stability of using orthodontic functional appliances in the treatment of sleep apnea in children demonstrated that the utilization of these tools can increase the width of airways in the oral cavity improving the respiratory condition in children eliminating problems associated with apnea.

The aim of study was the biological assessment of cultured RAW264 macrophage exposed to nano amorphous calcium phosphate particles by analyzing of cytotoxicity and genotoxicity tests.

Nanoamorphus Calcium Phosphate particles were produced by sol -gel method, then particle size and hemogenicity was analyzed by XRD (X ray Diffraction). Cytotoxicity of nanoparticles was determinated with mouse RAW264 macrophage. The cells cultured in 37°c in DMEM medium 96 part s plates with concentration of 10000 cells in each part for 72 hours, then the medium removed and the second medium added to cells containing different concentrations of Nano particle (0, 200 and 400μg/ml). After 24 hours of incubation, MTT assay and Annexin V were used for assessing cell viability and apoptosis.

The apoptosis insignificantly increased in macrophages with 200 and 400 μg/ml NACP and for cytotoxicity, cell viability for control, 200μg and 400μg groups were 100,107,103 percent.

NACP has no cytotoxicity and genotoxicity, so it can be used as non -toxic and beneficial material for clinical use.

There is a continuous debate on the issue of comparison between extraction and non-extraction treatment results in terms of subsequent soft tissue changes in Class II division 1 patients. So far, however, little attention has been paid to the photographic evaluation of treatment results. The aim of this study was to assess the impact of extraction and non-extraction treatment of Class II division 1 malocclusion on soft tissue profile by means of pre- and post- treatment photographs

The pre- and post- treatment profile photographs of 41 borderline Class II division 1 malocclusion patients (ANB ≤5 degrees, and overjet ≤ 5 mm) were evaluated. The photographs were digitized into the computer and 19 angular measurements were evaluated. Paired t-tests and Independent-sample t-tests were performed to compare the pre- and post- treatment values between the extraction and non- extraction groups. The level of significance was set to be P < .05.

Significant differences between pre- and post- treatment values in extraction group existed for Z angle and N‑Sn‑Pog. In non-extraction group, significant differences were observed in N‑Pn‑Pog, G‑Sn‑Pog, N‑Sn‑Pog and N‑Sn‑B. When comparing the extraction and non-extraction groups before and after treatment, the results showed that the only significant difference was in PFH/AFH proportion.

The results of this study revealed that for both extraction and non -extraction groups, there were straightening and improvement of soft tissue profile without significant impact on lips or nasolabial angle.