Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
치아의 정중면은 두 개의 치아 사이의 중앙 부분입니다.chia-ui jeongjungmyeon-eun du gae-ui chia sai-ui jungang bubun-imnida.The mesial surface of a tooth is the central part between two teeth.