Variability of the dental surface: effects on orthodontic treatment.

OBJECTIVES

The Author studied the variability of the vestibular surfaces of tooth usually involved in orthodontic treatment.

MATERIALS AND METHODS

200 model casts of Italian subject with complete permanent dentition have been analyzed studying the clinical crown dimension and the angulations of tangents drawn at 3 and 4 mm.

RESULTS

The authors found differences in the vestibular surfaces curvature in the last teeth of each series, more accemptuated in the lower than in the upper arch.

CONCLUSION

The conclusions of this study are related to the use of orthodontic straight wire appliances. The use of standard values with a complete torque, independently from the individuals, is based on the hypothesis of equal positioning on the tooth surface and related to the teeth axis. A variation in the torque of the upper central incisor for different kinds of straight wire appliance related to extreme variation of vestibular curvature is hypothesised.