J Cutan Med Surg. 2016 Jul 15. pii: 1203475416658470. [Epub ahead of print] Asymmetry of the Receding Hairline in Men With Early Androgenetic Alopecia. Azar RP1, Thomas AH2, Maurer M3, Lindner G4. Author information 1Centre for Modern Hair Transplantation, Berlin, Germany email@example.com. 2Department of Biotechnology, Technische Universität Berlin, Berlin, Germany. 3Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Berlin, Germany. 4Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Berlin, Germany Department of Biotechnology, Technische Universität Berlin, Berlin, Germany provio GmbH, Biomedical Research and Innovation, Berlin, Germany. Abstract BACKGROUND: The Norwood classification system is commonly used to ascertain the progress of androgenetic alopecia (Androgenetic Alopecia) with a robust and quick assessment, but it lacks precision in the frontal region, notably during the onset of male pattern hair loss. OBJECTIVE: Due to the ongoing technical improvement in restorative hair transplantation practices, we aim to develop simple quantitative methods for measuring the progression of Androgenetic Alopecia. METHODS: Here, we used a quantitative system to evaluate the progress of Androgenetic Alopecia of the frontal receding hairline in a case study with 41 patients. RESULTS: We found subtle differences in the extent of frontotemporal regressions that were not captured by the Norwood classification system. The majority of patients exhibited significantly larger right-sided frontotemporal regressions. CONCLUSION: These results indicate that the quantification system used is a valuable tool in complementing the Norwood classification system to more precisely determine the recessing hairline characteristics in early stages of hair loss. Our findings also suggest that hairline regression in Androgenetic Alopecia-affected patients is asymmetrical, a hitherto unnoticed disorder-associated phenomenon with unknown biological causality. © The Author(s) 2016. KEYWORDS: Norwood classification; androgenetic alopecia; follicular unit extraction; hair follicle; hair transplantation PMID: 27421295 DOI: 10.1177/1203475416658470 [PubMed - as supplied by publisher] Any ideas to explain it?