When posterior teeth such as the molars fracture, there is usually a correlation with anterior teeth wear and fracture as well. In the ideal bite, the anterior teeth length, contour, and position help guide the joints to move properly. This front teeth feature called "anterior guidance" also helps prevent the back teeth from contacting when the patient grinds on the teeth from side to side. When the anterior teeth are misaligned and/or have been ground down by the bite force, the posterior teeth can begin to come into contact during the grinding movements. The excess bite force on the back teeth can then create fracture lines on the teeth over time, and eventually can cause the tooth to fracture.
In the case below, a patient presents with a fractured molar. A close up look at the anterior teeth reveals multiple wear facets and fracture lines on the front teeth as well. The bite force has taken a told on this patient's dentition, and fractures on the teeth and his restorations are inevitable.
In another case below the patient's bite simply split the molar into two halves:
In a different case below, the patient also presents with molars ground down significantly. The old porcelain crowns also have been ground down to expose the metal core inside. A close up look of the anterior teeth profile allows us to match the shape of wear facets of upper and lower teeth together like pieces of a jig saw puzzle.
Uncontrolled bite force is one of many causes for the destruction of people's teeth throughout their life time. If the above cases remain untreated, the teeth can eventually wear themselves down to little nubs over time. If the cases are treated, they must be recognized as scenarios which require careful monitoring and adjustments during the patient's regular check-up appointments. Moreover, additional preventive measures such as night guards are crucial in helping the teeth from being destroyed when the patients grind uncontrollably in their sleep.
It is important to understand that bite related cases require a life time of maintenance and handling by the right clinician. The over all picture of the bite must be evaluated and treated comprehensively rather than simple tooth by tooth treatment.