Writing scientific manuscripts: most common mistakes

I have had the privilege of serving as editor-in-chief for 11 years of two scientific journals: The Dental Press Journal of Orthodontics and the Journal of the World Federation of Orthodontists. I had the opportunity to read and correct thousands of manuscripts. This experience was greatly enriching, because reading a text professionally completely differs from the perspective of readers in general. The routine practice of correcting manuscripts has made me realize that some errors recur frequently. To help authors to improve their manuscripts before submission, these problems are discussed here in the order that they appear in conventional manuscript sections.