Alkebsi A, Al-Maaitah E, Al-Shorman H, Abu Alhaija E Three-dimensional assessment of the effect of micro-osteoperforations on the rate of tooth movement during canine retraction in adults with Class II malocclusion: A randomized controlled clinical trial. Am J Orthod Dentofacial Orthop. 2018 Jun;153(6):771-785. doi: 10.1016/j.ajodo.2017.11.026.
Attri S, Mittal R, Batra P, Sonar S, Sharma K, Raghavan S, Rai KS Comparison of rate of tooth movement and pain perception during accelerated tooth movement associated with conventional fixed appliances with micro-osteoperforations - a randomised controlled trial. J Orthod. 2018 Dec;45(4):225-233. doi: 10.1080/14653125.2018.1528746. Epub 2018 Oct 3.
Sivarajan S, Doss JG, Papageorgiou SN, Cobourne MT, Wey MC Mini-implant supported canine retraction with micro-osteoperforation: A split-mouth randomized clinical trial. Angle Orthod. 2019 Mar;89(2):183-189. doi: 10.2319/011518-47.1. Epub 2018 Oct 29.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.