A Chinese man in his early twenties presented to our office with his parents for new patient exam and regular cleaning three years ago. A panoramic X-ray was taken for screening purpose (Fig.1). Two weeks later, he returned with severe pain in the left bottom jaw. The panoramic X-ray was reviewed (Fig.1) and blown up at the boxed area of Fig.1. The affected tooth is shown by * in Fig.2. It has an abscess change at the root tip (Fig.3 yellow outline). Below the abscess is a big nerve inside the jawbone (red lines) and one of its branches: nerve loop (pink). Normally there is separation between the abscess and the loop. But in this case, the abscess is so severe that it is continually communicated with the loop (Fig.4 >). This is the reason why this patient had severe toothache. A new small X-ray was taken to confirm the changes (Fig.5,6).
The patient and his family claim that the pain is caused by cleaning. In fact, this patient has a special tooth abnormality by birth. There is a sharp cusp on this type of the tooth. It is easily broken, maybe without notice, when the tooth erupts into the mouth (at about the age of 11-12. Then the nerve inside the tooth is dead and infected. The infection develops slowly toward outside the tooth: the root tip. Everything may happen without notice. Any change in X-ray usually takes a least six month to form. The root tip abscess was present at the time of cleaning (Fig.1-3) and after (Fig.5,6) in this case.
Appearance of severe pain happened after cleaning. Are they related? Most unlikely. Regular cleaning is to remove plaque and tartar from the outside of a tooth. It does not touch the nerve inside the tooth or root tip. There are several factors that can precipitate root tip infection to flare up (causing pain). Therefore, root tip abscess and cleaning are probably coincidence.
Xin Wei, DDS, PhD, MS 1st edition 03/24/2013, last revision 03/24/2013