Background: The high prevalence of malocclusion is a public health problem in the world and the third priority in oral care. Numerous primary studies have presented reports on the prevalence of malocclusion among Iranian children. In combination, the results of these studies using meta-analysis are highly valuable for health policy-making. Similarly, this study aimed at determining the prevalence of different types of malocclusion among Iranian children. Materials and Methods: Using relevant keywords, national and international databases were explored. After narrowing down the search strategy and leaving out the duplicates, the remaining articles were screened based on titles and abstracts. To increase search sensitivity, reference lists of the papers were examined. To identify unpublished articles and documentations, a set of negotiations were done with the people involved and research centers. Finally, the heterogeneity index between the studies was determined using Cochran (Q) and I² tests. According to the results of heterogeneity, the random effects model was used to estimate the prevalence of malocclusion in Iran. Results: In total, 25 articles were included in the meta-analysis process. The prevalence of dental malocclusion was estimated in 28,693 Iranian children aged 3-18 years. The total prevalence of Class I, II, and III malocclusion was 54.6% (46.5-62.7), 24.7% (20.8-28.7), and 6.01% (4-7.1), respectively. The prevalence of Class I, II, and III malocclusion was 44.6% (32.9-56.2), 21.5% (18.01-25.1), and 4.5% (3.2-5.9) in boys and 48.8% (36.8-60.8), 21.5% (16.9-25.1), and 5.5% (3.9-7.1) in girls, respectively. Conclusion: This study showed a high prevalence of malocclusion among Iranian children. Also, the results indicated that the prevalence is higher in girls.

Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. 'A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria 'Platelet rich plasma', 'Platelet rich fibrin', 'Stem cells', 'Natural and artificial scaffolds' from 1982-2015'. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon.