So are there no other points of validation for surgical advancement jaw surgery?
Forgive me, but it appears you speak about validation only in terms of correcting dental overjet (or dental overbite).
Shouldn't the validation (dentally at least) be focused on providing a class I molar occlusion for instance?
Another dental validation may be a little more medical, when we focus on balanced TM joint function. Or what some dentists still seek which is a coincident CO-CR relationship, again in a Class I pattern.
Another set of potential validations are purely medical. Such as prevention of forward jaw posturing, and the prevention of jaw joint dysfunction, or of temporal tension headache from this. Maybe that medical validation could be extended to a consideration of day time airway to improve exercise tolerance, or night time airway to prevent snoring.
Then of course there are the psychological benefits of normalized facial form on the self esteem... Or even more extrapolatively to the socialization consequences or on others perceptions of ugliness vs beauty.
Of course talk of braces and years of "benign" orthodontic treatment, involving dental braces, cat whiskers or dental splints, throughout a child's growing years, ignores completely the development of a normal teenage psyche.
That the orthodontist seeks to validate surgery, or not, in reference to their own orthodontic treatment... Is like asking a chiropractor to validate spinal surgery against their own treatments. Chiropractors often self represent their treatments as "benign", and without adverse consequence, and opportunistic in helping to avoid surgery.
It's a very self serving, self oriented form of clinical practice. And it serves the clinician first and the patient last.