ABSTRACT
Background: The safe excision density (SED) is the total number of grafts that can be excised from a given donor area without affecting the cosmetic density. It prevents overharvesting from safe donor areas (SDAs). To determine SED, the hair coverage value (HCV) of donor hair needs to be calculated. HCV represents the scalp area covered by the hair mass unit and can be calculated manually or using a software-based system such as Erdogan’s KE-Bot.
Objective: This study aims to estimate HCV and determine SED of a given SDA, comparing the coverage value calculated by a manual system and the KE-Bot software-based system.
Materials and Methods: Hair caliber and donor area density were measured manually and by the KE-Bot system. Ten patients were selected for the study, and hair caliber and density in five zones of the SDA were examined. HCV for each area was calculated using both methods.
Results: The KE-Bot system calculated an average coverage value 1.68 times higher than the manual system. SED calculated by the manual system was 33 grafts per square centimeter, while the KE-Bot system calculated 38 grafts per square centimeter. The KE-Bot system showed a more consistent standard deviation and range for total safe excision, indicating better performance. Using the KE-Bot system would result in 13.3% more grafts harvested compared to the manual method.
Conclusion: HCV and SED are important parameters in preventing overharvesting. We found the KE-Bot system allowed for higher safe excision and harvesting rates compared to the manual system.
- hair coverage value (HCV)
- hair diameter index (HDI)
- hair mass index (HMI)
- hair shaft diameter (HSD)
- hair volume index (HVI)
- safe excision density (SED)
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