正牙学 zhèngyáxué orthodontics; odontoplasty Definitions Defs Origin Strokes Stroke Words Sentences Sents 正 zhèng verb to correct to rectify; to put right; to adjust a position to be straight; to correct an error牙 yá noun tooth tooth; teeth学 學 xué nounaffix branch of learning (bound form) a subject or branch of study; often used as a suffix for -logy, -ics, or -science