Jaw growth is not always clear cut. There is no one time and age in a human being’s life where a bone just stops growing. But, there are certain benchmarks that you can use as a base.
There is a possibility of the jaw growing after 18, especially in males. However, this growth is not significant at all. Most likely, it will be just small adjustments. By 18, the jaw’s look and size have mostly stabilized, and there is little natural growth left.
But this does not mean that the jaw is no longer capable of growing or changing. It is just that, after the initial spurt of growth in the teens, the jaw will not change much. This is why there are so many changes to the appearance that happen during the teen years.
As you may have previously noticed, people after 20 generally look the same even until their early 30’s. But the difference in the face of 1 to a 12-year old kid is much different than what they will look like at 18. These changes are because of puberty and the growth spurts that the body goes through in that time.
But if you are dead set on growing your jaw, there are procedures available for you. Most people will get surgery if they think their face is not proportional or have underlying dental problems. Specific jaw procedures can resolve these problems.
Parts of the Mandible (Lower Jaw)
The mandible is the movable part of the skull and is also called the lower jaw. It’s responsible for chewing food, and the muscles for chewing are attached to this bone. Something interesting to note is that it is a bone in the skull that is not connected to the others through sutures.
The mandible has five major parts, with the largest being the body. Like the maxilla, the mandible has processes as well. The sections vary in shape, size, and function. It is the strongest and largest bone of the face and connects to the temporal bone through the temporomandibular joints. It is also where the teeth are rooted.
The body is the largest area of the mandible. It is a rectangular horseshoe-like area that is parallel to the floor of the mandible. Two borders surround the body of the mandible, the alveolar border and the base.
After the body, the ramus (or two rami) is the most substantial part of the mandible. You can identify it as the two sides of the mandible connected to the temporal bone, usually at an angle of about 110 degrees. The ramus also has the following bony parts:
The coronoid process is the side attachment of the temporalis muscle. It helps significantly with chewing food.
The condylar process is also called the neck. It supports the head of the ramus.
The alveolar process holds the teeth and is an incredibly important part of the mandible.
Like all other body parts, the mandible also goes through many changes as a person grows. These changes happen most notably in the teen years. For men, growth will be larger and lead to a square shape. For women, it will be more triangular.
In this study by Foley et al. (1992), the researchers found that for females, the mandibular growth rate was twice as high in the ages of 14-16 than it was at 16-20. Women experience earlier growth spurts than men, so the peak growth of the mandible also stops earlier.
Alternatively, this study by Love et al. (1990) looked at it from men’s perspective. Their research resulted in the conclusion that mandibular growth goes in an upward and forward rotating motion. And in the sample subjects of the study, the growth heightens at the ages 16-18.
Habits or dental problems could also impact the growth of the mandible. For example, those with underbites or deep overbites will have a different looking jaw than those with normal bites. Also, mouth breathers will develop a recessed chin. Bad oral posture contributes to the problem of how normal a child’s bite is.
From childhood to adulthood, the mandible grows from a slanted position to a relatively vertical one. The changes from youth to adulthood are quite drastic, yet they do peak at some point. The mandible does not continue to change at that rate for the entirety of human life.
Yet, it still changes even in the later years. However, these changes are not the differences that you would expect. These changes are minute and not that obvious from the outside.
When Does the Mandible (Lower Jaw) Stop Growing?
The mandible stops growing at around the age of 18, but it continues to remodel bone throughout the lifetime. It is safe to assume that the lower jaw will stop manifesting physical growth in the late teens to the early twenties for our purposes. Beyond that, there will likely be very little difference to your lower jaw. Again, this is not an exact number. Some people’s mandibular growth will stop at a much younger age than the early twenties.
This end in the growth spurt is why jaw surgeries are not immediately recommended for younger people as their jaws still have so much room for change. So if you wonder whether your jaw will grow more when you are already 18, the answer is not really. The growth in the mandible at that age will be minuscule.
What Can You Do to Grow Your Jaw?
Fortunately, even though jaw growth stops early, some procedures are available to fix most jaw problems. These will not necessarily “grow” your jaw, but they will fix any issues that you might have, cosmetic or not. Most problems with the jaw are not precisely how large it is in itself, but rather how it looks in proportion to the rest of the face.
One of the things that we recommend you try out is mewing. It involves the simple process of laying your tongue on the palate to observe proper oral posture. What this will do is bring the mandible forward and up like in this animation.
In effect, the mandible will assume proper growth in the right direction. Note that this works best on younger people but will also work on adults (to a lesser extent). However, it is best to catch any jaw problems early on where orthodontic intervention can help the bone become more normal while you’re still growing. Orthodontics is more powerful than mewing. Mewing should only be an option when you’re already satisfied with your face.
For a more comprehensive discussion on mewing, check out our ultimate guide.
Many teeth problems are directly related to the jaw. There are types of orthodontic apparel that deal with correcting bites. Braces, for example, are very prevalent. While these, in theory, treat teeth, they also influence overbites, underbites, or crossbites, which also affects the jaw’s look.
Of course, not all orthodontic treatments will do something for your jaw. It depends entirely on the underlying problem.
Jaw surgery has many different types. There is a surgery just for the mandible, one just for the maxilla, and surgery for both. Jaw surgery can correct any problems that might have made your jaw look irregular or odd. Double jaw surgery is the only way to make your jaw more massive and forward grown.