The phrase "smaller jaws" refers to having a less prominent or less prominent jawline. It means that the lower part of someone's face is not as large or prominent as others'. Full definition
Special «small - bite» kibble is the perfect size for smaller jaws and is shaped to help promote tartar removal. (bluebuffalo.com)
Instead of the wood nymph, rainbow farting unicorns breastfeeding experience, you've got a surprisingly powerful yet small jaw with or without teeth gripping your nipple, a sick feeling in your stomach, and a barely stifled screech of pain. (theleakyboob.com)
The Dr. who did procedure would tell me after procedure that she didn't think tie was serious enough to warrant the frenectomy and that the real issue was an anatomically small jaw that would simply have to grow. (fedisbest.org)