Rapid Shifting after Extraction
As well known, the tooth undergoes shifting after a neighbor is extracted. But we do not know how soon it can happen and who is more easily affected.
Mr. You came to our office 5 years ago at the age of 35. His dental condition is pretty bad. The first molar (Fig.1: 1) has severe gum disease and needs to go. The third molar (3, wisdom tooth) is in bad position, causing caries (arrowhead) in the 2nd molar (with a black line in its axis/midline). The third molar also needs to be taken out. Usually the width of the 1st molar is wider than that of 2nd molar (between red lines). Eleven months after 1st molar removal, the 2nd molar tilts and shifts forward (to our right handed side, Fig.2). It gets worse in another 9 months (Fig.3). X-ray in Fig.4 is taken almost five years after extraction. Tilting and shifting of the 2nd molar is so severe that the tooth has to be extracted a few months later.
After extraction of the neighboring teeth, the 2nd molar stands alone without support from its neighbors. It has also gum disease. It does not have bone support, either. The bone in front of it is soft, looking dark (white * in Fig.2, as compared to black *, which is normal). The bone in the back of the 2nd molar is quite low (black arrowhead), as compared to white arrowhead.
When we bite down, the lower molar exerts force upward and forward as shown by red arrow in Fig.3. The Home-Alone upper 2nd molar is being pushed forward each time we chew (yellow arrow). There must be hundreds and thousands of times we chew per day. Finally the 2nd molar gives up, saying adio to its master, five years after 1st molar extraction.
Shifting and tilting can happen quicker after extraction. Mrs. Yu (36 years old) has the 1st molar extracted 1.5 years earlier. Yesterday she requested extracting the 2nd molar because of gum disease and abscess. Pre-extraction X-ray show severe shifting and tilting (Fig.5).
In summary, shifting and tilting can happen very quick, 1-2 years, when you have gum disease. You should restore the missing tooth as soon as possible. Otherwise, you are going to lose 2nd one soon.
Xin Wei, DDS, PhD, MS 1st edition 06/19/2011, last revision 09/29/2012