Mesial Surface

Mesial” refers to the surface of the tooth that is toward the front of the mouth

Overall, there are five surfaces to each tooth:

Occlusal – the chewing or grinding surface of the bicuspid and molar teeth
Mesial – surface toward the front of the mouth
Distal – behind towards the back of the mouth.
Buccal – the tooth surface which is next to your cheeks.
Lingual – the tooth surface next to your tongue