歯し周しゅう治ち療りょう学がくMeaningsNoun1. periodonticsKanji used歯tooth周circumference治rein in療therapy学studyComposed of歯しtooth; age; yearsNoun周しゅうcounter for laps or circuits; perimeterCounter治ち療りょう(medical) treatment; care; therapy; cure; remedyNoun学がくlearning; scholarship; study; erudition; knowledge; education; study of ...; -ology; -icsNoun