The word “anterior” means to be in the front (the “posterior” being the opposite). In regards to hair terminology, the anterior scalp consists of the frontal regions. From a top-down perspective, this area includes the hairline, the temples, the forelock, and regions immediately behind the hair line. The anterior ends at what’s known as the midscalp.
It is important to note that the forehead and the anterior scalp are two separate structures, though muscles in the forehead called the paired frontalis connect to the superficial fascia of the scalp itself. These muscles pull on the superficial fascia, which is what allows the forehead to wrinkle or furrow as a facial expression. The scalp itself has no muscle fibers, which is why a person can wrinkle their forehead but not their scalp.
A forelock refers to the patch of area that begins at the mid-scalp (this is called a central forelock) and grows downwards towards the anterior scalp (this is called a frontal forelock). The frontal forelock is a prominent lock of hair located just above the forehead around the center of the anterior hairline. In a balding pattern known as the “widow’s peak” – which especially affects males – the forelock is the area that retains a partial amount of hair.
Hair loss typically begins at the anterior hairline or the whorl (a patch of hair that is not located on the anterior scalp – it helps determine the hair’s pattern and geometry). According to a 2009 overview, there are two major classifications for an anterior hairline:
It is important to note that these are not the only two styles of anterior hair growth, but rather two opposite ends of a wide spectrum of hair growth. That is to say, there are many anterior hairstyles that are not classified as “low” or “high”, but as somewhere in between.