The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through (erupt) is variable, but this generally occurs between late teens and early twenties. Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck (impacted) against other teeth if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is not held anymore as true.

अक़्ल दाढ़ या ज्ञान चौ दाँतों के नाम हैं जो आखिर में निकलते हैं। अधिकतर लोगों को चार अकल दाढ होते हैं - मुँह के हर कोने में एक - ये ज्यादातर जवानी में निकलते हैं।