Dental Education Lecture: Bone Re-growth after Wisdom Tooth Extraction

As we are older than 25, the ability to re-grow bone is reduced after wisdom tooth extraction.  But this is not always true.

Mr. Zhao is 42 years old when he develops severe infection between 2nd (2) and 3rd (3, wisdom tooth) molars (Fig.1).  There is no bone above arrowheads.  The 2nd molar has a deep filling (F). 

The wisdom tooth needs to be taken out, while the 2nd molar has root canal (R in Fig.2) and build-up (B: a type of filling after root canal).  There is loss of bone between 2nd and 3rd molar (above arrowheads).

One year after extraction and root canal, bone re-grows behind the 2nd molar (Fig.4 black arrowheads, as compared to white arrowheads in Fig.2).  After another year, bone does not grow any further (taller, Fig.3, as compared to Fig.4), but bone density behind the 2nd molar increases, making this tooth more stable (Fig.3 as compared to Fig.1).

Xin Wei, DDS, PhD, MS 1st edition 03/14/2011, last revision 03/14/2011