Impacted wisdom teeth without a communication to the mouth, that have no pathology associated with the tooth, and have not caused tooth resorption on the blocking tooth, rarely have symptoms.[9] The chances of developing pathology on an impacted wisdom tooth that is not communicating with the mouth is approximately 12%.[9] However, when impacted wisdom teeth communicate with the mouth, food and bacteria penetrate to the space around the tooth and cause symptoms such as localized pain, swelling and bleeding of the tissue overlying the tooth. The tissue overlying the tooth is called the operculum, and the disorder is called pericoronitis which means inflammation around the crown of the tooth.[2]:141 Low grade chronic periodontitis commonly occurs on either the wisdom tooth or the second molar, causing less obvious symptoms such as bad breath and bleeding from the gums. The teeth can also remain asymptomatic (pain free), even with disease.[3]