Replacing large chin implant with a smaller implant - Are titanium screws the only option to keep it in place?

I am 54 male with a large Implatech face lengthening implant . I have had it for 8 years . I have never liked it. It’s still tight and too square. A surgeon I visited said he can removed it and replace it with a smaller button type implant. My concern was that the small implant will move around inside the large pocket . He said he uses stitches to secure it to the internal tissue to hold it in place . I have never heard of this . Can this work or are titanium screw the only option ?