Background There are a few hypotheses for the origin of palatally impacted canines (PIC). Nevertheless, the results of different studies are controversial. Objective Considering the evidence available in the literature to determine the skeletal and dentoalveolar dimensions in patients with PIC using cone beam computed tomography (CBCT). Search methods This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement. The literature search with no publication date restriction in five databases and hand searching was performed until April 2023. Data collection and analysis Data assessing the skeletal and dentoalveolar characteristics of subjects with PIC evaluated with CBCT was extracted, and the studies’ quality was evaluated with the Newcastle-Ottawa Scale (NOS). Skeletal and dentoalveolar characteristics of subjects with PIC were compared with non-impacted subjects or non-impacted sides. MedCalc software was used to perform the meta-analysis. Statistical heterogeneity was assessed using the chi-square and I-square tests. Results The initial database search identified a total of 1153 studies. After applying the selection criteria, nine articles were included in the systematic review and meta-analysis. According to the NOS, all included articles were graded as “Good” quality. The meta-analysis showed a non-significant difference in measuring dentoalveolar height, alveolar first molar width, and basal lateral width. Controversial results were observed when evaluating both basal and alveolar first premolar widths. A significant difference was found when assessing anterior alveolar crest height and basal maxillary width. Conclusions Studies demonstrated the reduction of both dentoalveolar and skeletal maxillary parameters of the patients with PIC. The meta-analysis indicated that PIC correlates to both vertical and transverse skeletal dimensions of the maxilla. However, the results remain controversial. The findings should be interpreted with caution due to different study designs and unbalanced groups in the included studies; therefore, further research is needed for more reliable conclusions. Registration This systematic review and meta-analysis were registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42022362124)

Objective. To evaluate the efficiency of various interven­tions performed before and during orthodontic treatment which aim to reduce the incidence of WSL. Materials and methods. Using PRISMA guidelines in search of clinical trials published between 2017 and 2022, a literature analysis was performed. This search was conducted using following Medical Subject Heading (MeSH) terms in 2 databases: “prevention and control” AND “Orthodontics” AND “Tooth Demineralization”. Supplementary, a manual search was conducted in Go­ogle Scholar. Results. The literature search resulted in a total of 3626 study articles, of which 8 publications were used in the present review, according to a selection based on the pre-established eligibility criteria. The review showed that F varnish, 10% Xylitol varnish had positive outcomes in comparison with placebo. 0.44% APF formulated daily oral rinse and nanosilver mouthwash were better than 0.2% NaF weekly rinse and CHX, F mouthwashes res­pectively. NovaMin toothpaste, MIPP and MIV, exami­ned in different studies, proved no significant difference over regular F toothpaste. MIV compared to ProSeal provided no statistically significant between-group diffe­rences as well. Clinpro 5000 provided superior protection against enamel decalcification when compared to Clinpro Tooth Creme and MI Paste. Conclusion. The white spot lesions have improved, re­gressed, or eliminated with topical agents including F, Xylitol, or CPP-ACP during the fixed orthodontic treat­ment. In order to determine the most effective therapeu­tic approach for the treatment of surface and subsurface demineralization of the enamel, more research is needed to provide scientific proof.