Broken Root Tips
Mrs. Jin (in her forties) has gum disease. To control the latter, two bottom wisdom teeth need to be extracted. One of them is shown in Fig1 as 3 on the bottom. The top wisdom tooth is already gone. So the bottom wisdom tooth is useless. X-ray in Fig1 is called bitewing. It does not show the roots of back teeth (1,2 stand for 1st and 2nd molars). Before wisdom tooth extraction, we should take panoramic or periapical (PA in short) film. Mrs. Jin brings us an old PA, which does not show the shape of the root(s) of the wisdom tooth (Fig.2: *) and refuses to take a new one.
Anyway, we go ahead to remove the wisdom tooth. During the procedure, a clicking sound is heard. One of root tips is broken (Fig.3: arrowhead). This wisdom tooth has 2 roots (M, D).
Turn this tooth 90 degrees (Fig.4). It appears that Root D is more skinny than the other one (M), which apparently has 2 roots fused together (1,2). The Root M is not straight!
The broken root tip in fact is extremely difficult to be taken out, because of bleeding and poor visibility in the back of the mouth. More importantly, the root tip (Fig.5: D) is very close to a big nerve in the lower jaw (N). Finally we decide not to bother taking it out, since the tooth has no root infection. Actually Mrs. Jin is doing very well after extraction with no sign of infection or pain. Broken root tip is usually due to its being not so straight, which is confirmed by computer tracing (from Fig.2 to Fig.5 black outline). Let's trace the broken root tip in the extracted tooth (Fig.6 white outline) and assume that the bottom wisdom tooth on the other side has also curvy roots.
But old X-ray does not show exactly how bad the situation is (Fig.7: M, D). It does show that D root tip is pretty close to the nerve (N). The patient refuses to take new X-ray again. She is afraid of extra radiation.
With great pre-caution, the tooth is extracted smoothly. The distal (Fig.8,9 D) root tip cracks (<), but comes out with the tooth. Both roots are not straight.
In all, let the doctor take good X-ray before any extraction.
Xin Wei, DDS, PhD, MS 1st edition 11/03/2011, last revision 11/13/2011