諂笑: ingratiating smile; fawning smile, flattery smile
真笑: True smile, genuine smile
假笑: feign smile, fake smile
佯笑:feign smile,fake smile
齲齒笑 flattery smile as if teeth pain. (笑起來好像牙齒疼、滿臉不高興的樣子。)語本後漢書.卷三十四.梁統傳:「壽色美而善為妖態,作愁眉,嗁妝,墮馬髻,折腰步,齲齒笑,以為媚惑。」
各位大神請拍磚!