orthodontics /ˌoɚθəˈdɑːntɪks/ noun Learner's definition of ORTHODONTICS
[noncount]
: a branch of dentistry that deals with helping teeth to grow straight畸齿矫正学
— orthodontic
/ˌoɚθəˈdɑːntɪk/ adjective — orthodontist
/ˌoɚθəˈdɑːntɪst/ noun, plural orthodontists [count]