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Objective This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique. Methods Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test. Results The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature. Conclusion With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.

Postoperative fistulae are one of the most significant complications of cleft palate repair. They usually has an adverse effect on patients’ oral hygiene, speech and even mental health. There has been a wide range of rates of fistula occurrence, from 0.8%-60%, with the classification and definition of fistulae differing from one author to the next. In this paper, the definition and classification of palatal fistulae and their reconstruction method are reviewed. At present, there is a lack of a consistent definition of palatal fistulae and a classification that can fully reflect the characteristics of palatal fistula. Adjacent flap is mainly used for repairing small fistulae with an adequate amount of surrounding tissue; anteriorly based dorsal tongue flaps are a safe and reliable method for large fistulae; free flap is beneficial for refractory and complicated palatal fistulae that are difficult to repair by the local and pedicle flap; and different synthetic materials are used in multilayer repair of fistulae; among them, composite polymer membrane is highly biocompatible, promoting cell attachment and proliferation in animal models, but its security in the human body needs further research.

Children born with cleft lip and palate (CLP) are at high risk of disorders involving early speech production, and these problems can persist into later childhood, leading to the emergence of compensatory articulation errors. These difficulties in early vocalization directly impact the subsequent development of children's speech and vocabulary. Studies have shown that providing naturalistic interventions, such as milieu teaching and focused stimulation, for children with CLP in the first three years of life have positive impacts on the speech development of children, such as the potential to increase phonemic inventories and the percentage of correct consonants. In addition to speech and language therapists who perform systematic speech therapy, parents can be trained and supervised to deliver early speech intervention. The percentage of correct consonants can be used to assess outcome measures of speech intervention when combined with other measures, such as consonant inventory and speech intelligibility. However, much recent research in the field has focused on older children. Therefore, it must be determined if intervening during the early phase of typical speech development leads to better results. Future research should use more robust methodological designs to determine whether early speech intervention exhibits a positive impact on the speech and future physical and mental development of children with CLP.