Bentov I, Reed MJ The effect of aging on the cutaneous microvasculature. Microvasc Res. 2015 Jul;100:25-31. doi: 10.1016/j.mvr.2015.04.004. Epub 2015 Apr 24.
Hilton S, Sattler G, Berg AK, Samuelson U, Wong C Randomized, Evaluator-Blinded Study Comparing Safety and Effect of Two Hyaluronic Acid Gels for Lips Enhancement. Dermatol Surg. 2018 Feb;44(2):261-269. doi: 10.1097/DSS.0000000000001282.
Leung WC, Harvey I Is skin ageing in the elderly caused by sun exposure or smoking? Br J Dermatol. 2002 Dec;147(6):1187-91. doi: 10.1046/j.1365-2133.2002.04991.x.
Rogers GS, Gilchrest BA The senile epidermis: environmental influences on skin ageing and cutaneous carcinogenesis. Br J Dermatol. 1990 Apr;122 Suppl 35:55-60. doi: 10.1111/j.1365-2133.1990.tb16126.x.
Savoia A, Accardo C, Vannini F, Di Pasquale B, Baldi A Outcomes in thread lift for facial rejuvenation: a study performed with happy lift revitalizing. Dermatol Ther (Heidelb). 2014 Jun;4(1):103-14. doi: 10.1007/s13555-014-0041-6. Epub 2014 Jan 17.
Stojanovic L, Majdic N Effectiveness and safety of hyaluronic acid fillers used to enhance overall lip fullness: A systematic review of clinical studies. J Cosmet Dermatol. 2019 Apr;18(2):436-443. doi: 10.1111/jocd.12861. Epub 2019 Jan 12.
Zouboulis ChC [Intrinsic skin aging. A critical appraisal of the role of hormones]. Hautarzt. 2003 Sep;54(9):825-32. doi: 10.1007/s00105-003-0581-7. German.
Assessment and Augmentation of Lip Appearance in Specific Study Populations
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.
