Table 1.
Modified Norwood-Hamilton classification of male pattern androgenetic alopecia
| Clinical definition | Type |
|---|---|
| I. Minimal recession of hairline along the anterior border in the FT region |  |
| II. The anterior border of the hair in the FT region has triangular areas of recession that tend to be symmetrical. These areas extend no further posterior than approximately 2 cm anterior to a line drawn in a coronal plane between the external auditory meatus on both the sides. Hair is either lost or sparse along the mid-frontal border of the scalp |  |
| IIa. The entire anterior border of the hairline lies high on the forehead. The usual mid-frontal island of hair is represented by only a few sparse hairs. The area of denudation extends no further than 2 cm from the frontal line |  |
| IIIa. The area of denudation reaches the mid-coronal line |  |
| III. Characterized by deep FT hair recession, usually symmetrical and either bald or sparsely covered with hair. These areas of hair recession extend further posterior to a point that lies approximately 2 cm anterior to a line drawn in a coronal plane between the external auditory meatus on either side |  |
| IIIv (vertex). Hair is mainly lost in the vertex. There may be some frontal recession, but it does not exceed that seen in type |  |
| IV. The frontal and FT recession is more severe than in type III. There is also sparseness or absence of hair in the vertex area. These bald areas are extensive, but separated from each other by a band of moderately dense hair that joins the fully haired fringe on each side of the head |  |
| IVa. The area of denudation extends beyond the mid-coronal line, and there may be considerable thinning of hair posterior to the actual hair line |  |
| V. The hair loss over the vertex and FT areas is larger than in type IV and the band of hair between them are narrower and sparser |  |
| Va. Most advanced degree of alopecia; however, the bald area does not reach the vertex |  |
| VI. The hair loss over the FT and vertex regions is confluent and the bridge of hair that crosses the crown is absent |  |
| VII. There is only a narrow horseshoe-shaped band of hair that begins laterally, just anterior to the ear and extends posteriorly on the sides and fairly low on the occipital area |  |
FT – Frontotemporal