According to a new study conducted by the Plastic and Reconstructive Surgery, the journal of the American Society of Plastic Surgeons, The shape of the jaw line may indicate a person's age. In the study, it was found that the lower jaw continues to grow with age, which gives a person a more square jaw line making a person look old.

Study Highlights
a. Eight men and 8 women were studied in this research.
b. Researchers studied the radiographic images the volunteers.
c. The images were taken when the volunteers were about 16 years old and 56 years old.
d. It was seen that in all the volunteers, the lower jaw continued to grow with age.
e. This gave the jaw a larger and squarer jaw line.