Cracked Tooth Syndrome Cracked tooth syndrome involves fractures that are not obvious and usually too small to be seen on x-rays. When the fracture is below the gum line, it is even more difficult to see. This condition occurs most often in molars, especially the lower, mandibular molars, which tend to absorb most of the force of chewing. Case 1 - Before Case 1 - After Back to Index Cracking the Code