Chin dimples only when mouth is closed, will putting Botox in the mentalis muscle make me unable to close my mouth?

In my experience, treatment of the pebble chin in someone with a small chin does not interfere with closing of the lips. The key, however, is to be conservative. More Botox can always be added but once someone is over treated you cannot remove it. Seek a consultation with an expert physician Botox injector - start with a plastic surgeon or dermatologist in your area. I hope this information is helpful for you.Stephen Weber MD, FACSDenver Facial Plastic Surgeon

This area can be treated with conservative amounts of Botox. If it is overtreated, even by a unit or two, it can make it very hard to close the mouth and can even give a "stroke-like" look. Seek an appointment with an expert and be very conservative. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."