What is a double chin?
A double chin, also known as a glans or "goose neck," refers to a neck with excessive volume below the chin and jawline. This excess volume obscures the normal angle between the neck and jaw. The cervicofacial angle is not well-defined. The most common cause is fat accumulation. Liposuction is a good treatment in these cases, but sometimes the results are not as expected. Why?
Why does a double chin appear?
The most common cause of a double chin is excess submental fat. This fat is located beneath the skin and above the platysma muscle. This muscle is flat, divided into two halves, and runs from the lower lip and jawline to the clavicle. Beneath this muscle, we find another layer of fat called the subplatysmal fat. This fat is sandwiched between two muscles called digastric muscles, which connect the chin to the hyoid bone (these are the anterior bellies of the digastric; the posterior belly runs from the hyoid bone to the mastoid process, behind the ears). The position of the hyoid bone is important because it can be positioned lower, making the neck appear straighter. If we remove this submental fat, we find the mylohyoid muscle, which also forms the floor of the mouth. Above it are the tongue muscles. Lateral to the digastric muscles are the submandibular glands. All of these structures are important in shaping the neck. Its position and size determine how defined the neck is. Therefore, we can find ourselves with a (real) double chin or an obtuse neck (which is often genetic and familial). The causes can be:
Loose skin and sagging platysma muscle, presence of platysma bands in the front of the neck —one may be more prominent than the other—, excess superficial fat between the skin and the platysma, excess deep subplatysmal fat, large digastric muscles, low hyoid bone, large and/or drooping submandibular glands.
Why do I have a double chin if I'm thin?
A double chin can be more or less noticeable, and we distinguish several degrees depending on the degree of deformity. Obviously, the head must be at a 90-degree angle to the neck. We all have a double chin if we look down and tilt our heads back (like when using a mobile phone). We need to differentiate whether the double chin is due to excessive skin laxity and the platysma muscle. Palpation can give us an idea of whether it's really fat or if we're dealing with an obtuse neck. But to be absolutely sure, we perform an ultrasound. With it, we can see the anatomy and determine if there is a lot or a little superficial fat and what the internal structures are like. This is very important because it allows us to determine the best treatment and avoid dissatisfaction. If we perform liposuction and the internal structures are large, the result won't be very good, and it's quite possible that the patient's expectations won't be met.
Credits: Dr. Laura Salvador / Antiaging Group Barcelona.
