By the age of 18, the average adult has 32 teeth: 16 on the top and 16 on the bottom.
The average jaw however, can usually only hold 28 teeth. The wisdom teeth are the last teeth to erupt so when they try to fit, there is often not enough space in the mouth for this to happen without experiencing complications.
Wisdom teeth do not need to be removed if they are aligned properly and the gum is healthy around them, however this is often not the case. They may grow sideways, partially emerge from the gum and even remain trapped beneath the gum and bone. These then become impacted teeth. Impacted teeth can take many positions in the bone as they attempt to find a pathway that will allow them to emerge successfully; and hence cause many problems.
If partially emerged, the opening around the tooth allows bacteria to grow and eventually causes infection. The result: swelling, stiffness, pain and possibly illness. The pressure from the emerging wisdom tooth may move other teeth and disrupt the orthodontic or natural alignment. The most serious problem that can occur is a tumour or cyst forming around the impacted wisdom tooth, resulting in the destruction of the jawbone and healthy teeth. Studies have shown that early evaluation and treatment of the offending impacted tooth or teeth can avoid these issues and result in a superior outcome for the patient.