The force module for the bending art system. Preliminary results.

The force module for the bending art system (BAS) is used to calculate the initial forces and moments expected to act on a tooth after changing arch wires. The present study analyses the accuracy of the force module on the basis of 10 patients treated with the BAS (with an average observation period of 10 months). An average of 6 arch wires (0.16" x 0.016" steel) were used on each jaw. The approximate pressure in the periodontium was determined and statistically evaluated from the force module readings. The resulting average pressure values for the molars ranged between 0.26 N/cm2 and 0.54 N/cm2. The value in the area of the incisors, cuspids and bicuspids ranged between 1.03 N/cm2 and 2.83 N/cm2. Maximum pressure was 8.02 N/cm2. The results are discussed from a clinical point of view on a case-to-case basis. They are plausible in and for themselves. The more severe the initial state of misalignment, the higher the pressure values. These forces can be reduced by increasing the number of arch wires or by altering the form of the archwire correspondingly. The computer-generated values should be confirmed by taking a direct measurement on the tooth. The force module is just the first step in providing a reproducible estimation of the forces acting on a tooth. Even if the calculated absolute values should still be judged with reservation, they are nevertheless suitable for providing a comparative evaluation of various treatment concepts with reference to the forces acting on the periodontium and can serve clinicians as a rapidly available decision-making aid.