Asymmetry of the Receding Hairline in Men With Early Androgenetic Alopecia.

[BACKGROUND] The Norwood classification system is commonly used to ascertain the progress of androgenetic alopecia (AGA) 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 AGA.

[METHODS] Here, we used a quantitative system to evaluate the progress of AGA 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 AGA-affected patients is asymmetrical, a hitherto unnoticed disorder-associated phenomenon with unknown biological causality.