Weaker jaw muscles means that it's more likely that the actual jaw is not as closed as it should be at rest. This leads to the teeth not being together and the jaw hanging down and back. Over time this lack of support leads to the jaw and chin recessing via facial melting. It's also been shown that having stronger/larger jaw muscles leads to the actual total size of the jaw bone becoming bigger;

/community/community/main-forum/masseter-affects-length-not-just-width/

The jaw and the tongue (in terms of facial support) are not completely separate functions and by counteracting each other, lead to proper facial development. If the jaw is too weak and doesn't stay closed this means that it's very hard to get the tongue on the palate as its base is further away from the roof of the mouth and it also easily pushes itself away from the palate due to the weakness of the jaw. This means that if you have weak jaw muscles you are also compromising your tongue posture. The opposite situation is not as bad but still has issues: Strong jaw and weak tongue means that the teeth could be pressed too tightly together due to not having the counteracting force by the tongue not be sufficiently planted on the palate.

For this reason I think that the diamond shape you mention here is probably possible but more unlikely than someone with a weak jaw and weak maxilla or strong jaw and strong maxilla. I'm not sure about this but I'm under the impression that I''ve barely seen anyone with a strong maxilla and recessed jaw.

Chewing increases bone density and size by up to 22% if I remember correctly. This means the maxilla, mandible and other attached bones which share in the load grow and become stronger. Imo this means a more robust looking face with developed muscles and good alveolar bone support for the teeth.

Not chewing would mean this does not happen, but if you mew, you will still get dental and skeletal correction, which means the jaws realign, face changes. It most likely will not result in a small chin, unless it's a genetic defect. 

In most cases the chinlet issue is not genetic, but due to the relationship between the maxilla and mandible as well as the resulting teeth. If you don't have proper tongue and head posture, the maxilla will drop and not grow forward, the teeth will be crowded and the bite crooked. This pushes the mandible down and back as well resulting in a bigger gonial angle and a melted face with a small weak looking jawline.

Look into the Alexander Technique as well as the chin tuck for posture, chew mastiha gum, but not excessively.

How often is ok to chew masthia gum? Is 1 hour a day (30+30) to much?

Is there a chance the masseters grow to large?

Does chewing affect the bone in the whole jaw, from the back to the tip of the chin? 

I have not taken effort to noticeably change my diet and my jaws have gained width over time with just mewing (Granted, I have always eaten hard foods like baby carrots frequently, even before mewing.)

My approach to mewing stimulates the masseter muscles passively, and I believe that Mew has said that it is this resting muscle tone that results in stronger/wider jaws. I mew relatively hard, and I apply about 50% to 60% of my max tongue strength at all times, and the masseter muscles are the antagonist of the tongue, so they are by default also activated to keep my mouth closed.

You can demonstrate this for yourself, just try mewing and consciously allow your masseters to stay relaxed. Your mouth will just open, as the tongue is just pushing your lower jaw down. When mewing, the masseters are constantly working to keep the mouth closed, and are therefore also always working, so I personally think the importance of diet adjustment is somewhat overstated.

Posted by: Yegor_L

I have not taken effort to noticeably change my diet and my jaws have gained width over time with just mewing (Granted, I have always eaten hard foods like baby carrots frequently, even before mewing.)

My approach to mewing stimulates the masseter muscles passively, and I believe that Mew has said that it is this resting muscle tone that results in stronger/wider jaws. I mew relatively hard, and I apply about 50% to 60% of my max tongue strength at all times, and the masseter muscles are the antagonist of the tongue, so they are by default also activated to keep my mouth closed.

 

You can demonstrate this for yourself, just try mewing and consciously allow your masseters to stay relaxed. Your mouth will just open, as the tongue is just pushing your lower jaw down. When mewing, the masseters are constantly working to keep the mouth closed, and are therefore also always working, so I personally think the importance of diet adjustment is somewhat overstated.

My story is the exact same. Chewing is good of course buy posture really makes the difference in jaw position and angle.