A cumulative review with a systematic approach aimed to provide a comparison of studies’ investigating the possible impact of the active form of vitamin D₃, calcitriol (CTL), on the tooth movement caused by orthodontic forces (OTM) by evaluating the quality of evidence, based on collating current data from animal model studies, in vivo cell culture studies, and human clinical trials. Methods: A strict systematic review protocol was applied following the application of the International Prospective Register of Systematic Reviews (PROSPERO). A structured search strategy, including main keywords, was defined during detailed search with the application of electronic database systems: Medline/Pubmed, EMBASE, Scopus, Web of Science, and PsycINFO. In addition, a search was carried out with the use of ClinicalTrials.gov search in order to include ongoing or recently completed trials. The Oxford Level of Evidence and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was utilized to critically evaluate the risk of bias and relative quality of studies included. Meta-analysis with the use of RevMan5 software, random effect, and inverted variable method allowed the quantification of cumulative results. Results: Twenty-seven studies were identified which fulfilled inclusion criteria, including two clinical studies. The assessed level of evidence was variable and inconsistent, predominantly being moderate or low due to a significant difference in study design, sample size, and study protocols. Data synthesis rendered from meta-analysis involving various CTL doses demonstrated slight discrepancies in tooth movement between control and experimental groups (mean difference = 0.27; 95% CI: 0.01–0.53, std mean difference = 0.49; 95% CI: 0.09–0.89), as well as relatively moderate heterogenicity. Conclusions: Although it has been suggested that CTL could accelerate OTM in animal studies and clinical context, these scarce data were supported by a low level of evidence and the studies were carried out using inadequate sample size. Well-powered RCT studies would help to overcome the lack of robustness of the research.

Background. Understanding the correlation between temporomandibular joint disorder (TMD) parameters and various occlusal features can play a significant role in diagnosing and treating occlusal problems and their potential consequences on TMD. Objectives. To investigate the relationship of occlusal features and some of the TMD parameters. Study Design and Sampling. The current cross‐sectional study was conducted on 200 TMD patients seeking dental treatment at different dental centers in Baghdad city, aged 18–35 years. All participants underwent assessment for occlusal features, which were molar and canine classifications, overjet, posterior buccal or lingual crossbites, and overbites, and TMD parameters (muscle pain, TMJ pain, and clicking) using the Chi‐square test for statistical analysis. Results. Regarding molar classification, there were strong positive correlations between subjects with TMD and having different molar classifications (class I, II, and III) bilaterally or unilaterally; furthermore, there were strong positive correlations between subjects with TMD and having different canine classifications. Moreover, there were significant correlations between subjects with increased, normal, or decreased overjet and the TMD parameters. In addition, there were weak positive correlations between TMD occurrence and buccal or lingual posterior crossbite. On the other hand, there were significant correlations between subjects with a decreased overbite and the presence of TMD parameters. Conclusion. TMD had a multifactorial background rather than dependability on a specific molar or canine classification type. There was also a correlation between overjet and TMD muscle pain, while decreased overbite was correlated to muscle and TMJ pain. Conversely, there is no vital correlation between posterior buccal or lingual crossbite occurrence and TMD parameters.

Aim: To evaluate the effectiveness of a sports dietary supplement, which is Dymatize® Elite Casein (micellar casein), as a storage medium for avulsed teeth compared to Hank’s balanced salt solution at three-time intervals. Methods: One hundred teeth freshly extracted for orthodontic treatment. Were divided into Hank’s balanced salt solution, Dymatize® Elite Casein, a Dry group, and a control that tested directly after extraction. Experimental groups' teeth were immediately immersed in the media and subdivided into three groups at time intervals (1 hr, 4 hrs, and 8 hrs). Cells of PDL were examined after being scraped, and labeled with trypan blue using a light microscope and a hemocytometer. The data were statistically analyzed, using one-way ANOVA with Graph Pad Prism 7. And, Post Hoc Tukey's test performed inferential to compare each test group to all other groups. Results: All groups showed highly significant changes, except for Dymatize® and control at one hour, which showed non-significant differences. All experimental groups had highly significant differences after 4 and 8 hours. Conclusion: The Dymatize® Elite Casein could serve effectively as a transport medium and preserve fibroblast viability over time ensuring replantation success. It is a good substitute with its superior properties.

To evaluate surface microhardness of three thermoplastic retainer materials (Essix PLUS Plastic, Zendura A, and Iconic Original) and to compare the effects of the thermoforming method (vacuum versus pressure) and subsequent thermocycling. This in vitro study tested 180 sheets (1.02 mm; n = 60/material). For each material, specimens were allocated to five conditions (n = 12/group): before thermoforming (BT), after vacuum thermoforming (AVT), after pressure thermoforming (APT), after vacuum thermoforming plus thermocycling (AVTT), and after pressure thermoforming plus thermocycling (APTT). Sheets were formed on a three-dimensionally printed maxillary cast using a vacuum former (Plast Vac P7) or a pressure-molding machine (Biostar), following the manufacturer's protocols. Formed sheets were cut into 9 × 13 mm specimens. For thermocycling, specimens were immersed in distilled water for 24 hours and thermocycled 1,500 cycles between 5°C and 55°C (20 s dwell per bath). Statistical Analysis Surface hardness was measured with a Vickers microhardness tester (100 g load for 15 s), and three indentations per specimen were averaged (VHN). SPSS v26 and GraphPad prism V11 were used. Normality and homogeneity were assessed (Shapiro-Wilk, Levene). Comparisons used one-way ANOVA with Tukey HSD, Dunnett's two-sided test versus BT, and independent samples t-tests. Zendura A showed the highest hardness, followed by Iconic Original and Essix Plus. Essix Plus showed no significant changes after thermoforming or thermocycling (p > 0.05). In Zendura A, pressure thermoforming increased hardness versus BT (p = 0.001); thermocycling increased hardness in the vacuum pathway (AVT→AVTT, p = 0.001). In Iconic Original, thermoforming reduced hardness versus BT (AVT and APT, p < 0.001), whereas thermocycling increased hardness within both, forming pathways (AVT→AVTT and APT→APTT, both p < 0.001). Vacuum versus pressure forming did not differ significantly before thermocycling for any material (p > 0.05). After thermocycling, differences were significant for Zendura A (AVTT > APTT, p = 0.030) and Iconic Original (APTT > AVTT, p = 0.031). Hardness is material-dependent and is influenced by thermoforming and thermal aging. Essix Plus was the most stable, while Zendura A and Iconic Original were more sensitive, with method-related differences becoming evident after thermocycling.