Re: Is it a dimple on my chin or is it called a cleft chin? Why do I have it?

Dear Alson,

This is one of those questions that try as hard as I could there was no 
published information that I could rely on. So, the answer that I am 
providing is a bit shaky, although it is reaffirmed by two of my colleagues 
whose opinions I respect greatly. With this preamble of a caveat I believe 
that the dimple in the chin (or sometimes referred to as a cleft chin) is 
an inheritable phenomenon and is most probably the result of a slightly 
anomalous embryologic development. During the formation of the chin the 
right and left sides develop separately and then fuse in the midline. The 
result of this fusion (in the region of the bony aspect of the lower jaw) 
is known as the "symphysis menti." 

From this point on I am skating on thin ice because I could not find a 
published source to confirm the remainder of this note: 

If the fusion is just a little bit incomplete, a shallow depression is 
noted in the symphysis menti and is reflected as a vertical groove in the 
soft tissue cover of the bone. That is the dimple in the chin (see Kirk 
Douglas).

I am sorry that I could not give you a more concrete answer but I believe 
that this conjecture is correct and as I indicated it has been reaffirmed 
by two other faculty members of my department.

Leslie P. Gartner, Ph.D.
Associate Professor of Anatomy
Dental School
University of Maryland
Baltimore, Maryland