Ds (7) has just started playing the recorder but is having terrible trouble preventing it squeaking. I expect he is blowing too hard but he also has huge tooth gaps (one of which looks permanent - he has one tooth too few near the front) - does anyone know if this might be the problem? Poor thing, he is getting so frustrated!
Would say it is his blowing technique. You make a tight seal with the mouth againt a recorder (unlike flute or brass) so teeth and shape of mouth shouldn't matter. Try exercises like saying 'Sssssss' for as long as possible to help him develop breath control.
Gentle relaxed lip seal on a recorder and breathe into it. Not a tight " blowing birthday candles" and really, teeth shouldn't come into contact with it at all so gappy teeth , buck teeth, braces make no difference (OK braces might affect lip closure.
Cover the holes carefully with relaxed finger pads too. A half open hole will squeak (esp thumb)