Complex sentence: Commonly the origin of the infection is an anterior mandibular tooth with associated periapical abscess which erodes through the buccal cortical plate of the mandibular at a level below the attachment of the mentalis muscle.
Split into simpler sentences: Commonly the origin of the infection is an anterior mandibular tooth. A periapical abscess which erodes through the buccal cortical plate of the mandibular at a level below the attachment of the mentalis muscle.