Light and electron microscopic analysis of controlled injury to follicular unit grafts.

[BACKGROUND] Careful manipulation of hair units is essential for a good yield of transplanted hair.

[OBJECTIVE] To analyze the morphology of dissected follicular units submitted to crushing, stretching, bending, and drying.

[METHODS] Follicular units were either crushed, bent, stretched with forceps, or left drying on surgical gloves for 3 minutes. The specimens were fixed and prepared for observation with light microscopy or transmission and scanning electron microscopy.

[RESULTS] No alterations were detected in follicular units that had been crushed, bent, or stretched. Major damage occurred in samples that were left to dry on gloves.

[CONCLUSION] Letting the follicular unit dry appears to be the worst mishandling to which the follicular units may be subjected during routine hair transplantation.