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HAIR LOSS TYPES AND HAIR LOSS PATTERNS
The Hamilton–Norwood scale is used to classify the stages of male hair loss pattterns. The stages are described with a number from 1 to 7. This measurement scale was first introduced by James Hamilton in the 1950s and later revised and updated by O’Tar Norwood in the 1970s. It is sometimes referred to as the Norwood–Hamilton scale or simply the Norwood scale.
THE HAMILTON–NORWOOD SCALE IS USED TO CLASSIFY THE STAGES OF MALE PATTERN BALDNESS.
Let’s go through all 7 types of balding patterns.
There is minimal or no recession of the hairline.
There are triangular, usually symmetrical, areas of recession at the frontotemporal hairline.
Type 3 VERTEX
Hair loss guide
This represents the minimal extent of hair loss sufficient to be considered as baldness according to Norwood. There are deep symmetrical recessions at the temples that are bare or only sparsely covered by hair. In Type 3 Vertex, the hair loss is primarily from the vertex with a limited recession of the frontotemporal hairline that does not exceed the degree of recession seen in Type 3.
The frontotemporal recession is more severe than in type 3 and there is sparse hair or no hair on the vertex. The two areas of hair loss are separated by a band of moderately dense hair that extends across the top. This band connects with the fully haired fringe on the sides of the scalp.
The vertex hair loss region is still separated from the frontotemporal region but it is less distinct. The band of hair across the crown is narrower and sparser and the vertex and frontotemporal regions of hair loss are bigger.
The bridge of hair that crosses the crown is gone with only sparse hair remaining. The frontotemporal and vertex regions are joined together and the extent of hair loss is greater.
The most severe form of hair loss with only a narrow band of hair in a horse- shoe shape remaining on the sides and back of the scalp. This hair is usually not dense and can be quite fine.
Type A Variant Hair Loss Patterns
Norwood also defined a Type A variant from his standard classification system, which is distinguished by two major features and two minor features.
The major features are:
- The anterior border of the hairline progresses to the rear without leaving an island of hair in the mid-frontal region and
- There is no simultaneous development of a bald area on the vertex. Instead, the frontal hairline recession keeps progressing to the rear of the scalp.
The minor features are:
- There is a persistent sparse hair scattering in the area of hair loss and
- The horseshoe-shaped fringe areas of hair that remain on the side and back of the scalp tend to be wider and reach higher on the head compared to Norwood’s standard.
THE VARIOUS TYPE A VARIANTS DESCRIBED BY NORWOOD ARE AS FOLLOWS:
The hairline is anterior to the coronal plane 2 cm anterior to the external auditory meatus.
The hairline has receded back to a point between the limit of Type 2A and the level of the external auditory meatus.
The hairline has receded beyond the external auditory meatus but has not reached the vertex.
The area of denudation includes the vertex. Hair loss more severe than Type 5A cannot be distinguished from Types 6 or 7.
The Norwood classification is one of the most detailed classification systems for male hair loss patterns and is the most widely used classification worldwide.