Ouch! My Tooth Hurts!

By Dr. Boris Zusin · Published September 2, 2021

“Ouch! my tooth hurts!”, said one of my patients the other day during a routine examination. “Especially when I chew on my left side. Is it a cavity?” Sometimes it is a cavity that causes a tooth to hurt. A lot of times it is not. A lot of times pain sensation, especially on chewing, is caused by micro-fractures in the tooth. During chewing, forces of mastication flex the tooth along those fracture lines and cause pain sensation. In this patient’s x-rays and photos, fracture lines were clearly visible in several areas of the tooth. As time progresses, pain may become more pronounced. Quite often, this is followed by a separation of a portion of the tooth along those fracture lines (the tooth breaks). Quite often you get relief of pain after that. Some other times, you lose the tooth.

There might be many reasons why teeth develop fracture lines: para-functional activities like grinding or clenching, anterior open bite (only back teeth touching when fully closed), lack of anterior guidance (only front teeth touching during sideways or forward movement of the lower jaw), and excessive stresses applied to back teeth during those movements.

Whatever causes these fractures, once a tooth becomes symptomatic on chewing, you need to reinforce it before it breaks. That is usually achieved with onlays or crowns — as in this case, where a fracture line in the upper left first molar was caught and reinforced before it progressed further.