Dental Education Lecture: Overloading

We have totally 8 molars, but Mr. Lee has lost 4 of them (the teeth #3,18,30 and 31 in Fig.1,2).  The implant tooth is the only functioning molar (I in Fig.2).  It has provided service for ten years.  One day, Mr. Lee chews something hard and hears cracking sound.  After that, he cannot chew anymore with that implant.  The implant is usually very sturdy, but it may separate from the bone or its parts will break if overloaded.

We need to do some repair for the implant tooth.  For long term, the four missing teeth should be restored with implants to share chewing force.

First of all, let us do design in dental models.  Fig.3 shows one side of back teeth (compare to Fig.1).  The tooth #2 is the only remaining molar on that side.  To replace 3 missing teeth (#3, 30, and 31) in ideal position, the tooth #2 needs to be pushed and tilted backward first (compare black line(s) indicated by arrowheads in Fig.3,4).  A mini-implant is to be used for this purpose. With good planning, final results should be fine.

Xin Wei, DDS, PhD, MS 1st edition 05/12/2011, last revision 09/28/2012