Craig,

 

Any oral surgery will affect vocal production. Sometimes it's a good thing. I have a dear friend who had her jaw broken and realigned to fix a bad underbite when we were in high school. After surgery (which was no picnic), it was much easier for her to drop her jaw and she now has a bachelor's and master's in vocal performace and is a successful singer.  For her, surgery was a godsend and helped her vocal production.

 

As for the titanium plate, I would think the big consideration would be how tall (for lack of a better word) the plate is and how much closer  it will bring the palate to the tongue. If it is a significant change, enunciation will certainly be more difficult. If it is a plate that goes in the front half of the roof of the mouth only, I would think that it might be like when an adolescent gets "spacers" put on behind back front teeth with their braces. This definitely creates problems with enunciation with the middle school kids with braces I've been teaching for the last 20 years. I'm no doctor, but putting something int he roof of the mouth seems like it would create problems unless it is is fixing an actual deformity of the palate.  I'll be interested to see what others think!

 

Mary Jane Phillips