It is common to have dental problems associated with pregnancy. Pregnancy can cause tooth decay to speed up and some women will experience problems with their gums (hyper plastic gingivitis). Pregnancy gingivitis is probably most common and the gums become inflamed and swollen. They can also bleed easily and become very sore or sensitive. This occurs due to an increased level of circulating progesterone and estrogens. Studies have also shown that there is an alteration in the bacterial levels surrounding the gum tissue, and that the immune system responds differently to plaque during pregnancy.
It is difficult to comment on your wife’s condition without examining her or seeing the X-ray. Perhaps you could take another opinion.