I found that last six months my smile has changed. I believe it's from hormones cause in that period a stated getting boobs.
I do not like the look of my smile. I think I got more fat change or something. It looks like I cannot smile I just stretching my face....
before:
https://picasaweb.google.com/mantonisphotos/September22011#5647500945650100818
https://picasaweb.google.com/mantonisphotos/September22011#5647500957962426354

After:
https://picasaweb.google.com/mantonisphotos/September22011#5647500948307342466
https://picasaweb.google.com/mantonisphotos/September22011#5647500946147691234

I have to say, the only really big difference in your smile to me between the before and after photos is that in the before photos, you were showing your teeth more, and in the after photos, it looks like you're more self-conscious of them and not smiling so widely. Maybe you need someone to make you laugh a lot before getting photographed x

I would say it has changed your smile (even though your smile before looked great, now it just looks more feminine)... I think the biggest change is your lower jaw.  Though I know that HRT does not change bone structure, the obvious redistribution of facial gynoid fat and muscle has made your mandible appear smaller.  Actually, with your jaw appearing smaller, your cheeks most definitely look more pronounced.  Personally, I think you look more vibrant and it makes me jealous

I think they definitely change after fat redistributes!  Looking at before and after pictures lately, it seems the fat has migrated substantially from my jaw area to the area beneath my eyes.  The entire center of my face has changed.

Of course, my smiles are now more genuine since I transitioned, so that creates change too.

I definitely see a difference but I don't see it in just the mouth. I see it in the eyes. Your eyes in the first two pictures didn't look as happy...in the second two there was like a sparkle to them..Like you were more comfortable with yourself. Very beautiful smile by the way =)

I hope I'll get fuller lips!

Yup hormone changes how you look when smiling. One MAJOR thing I noticed is fatter cheeks (so they bunch up and make that line from the nose a lot easier / more like female).