Curve of Spee was measured on study models in millimeters using divider by placing a scale on mandibular occlusal plane touching the incisor and last molar (fig-2).
Results have established a positive effect between Curve of Spee and maxillo-mandibular discrepancy.
Whereas curve of Spee in this group had mean 2.23 millimeters with (SD +- 1.78) (table).
Curve of Spee in class I group had mean value of 1.90 millimeters with (SD +- 0.85).
Measuring the depth of the Curve of Spee is considered to be a critical point for treatment protocols.
199916 used study models for measuring curve of Spee. This study also used study models because of more reliability and less chances of error.
Orthodontic correction of overbite often involves leveling the curve of Spee by anterior intrusion, posterior extrusion, or a combination of these actions.
However, there is a little consensus in literature concerning the measurement of curve of Spee. Baldridge6 used the perpendicular distance on both sides.
The purpose of the study was to evaluate and compare the depth of curve of Spee in class I, class II div1, class II div 2, class II subdivision and class III malocclusion in individuals between 12-29 years age.
We also divided the depth of curve of Spee in three groups:
with a Vernier Caliper as the perpendicular distance between the deepest cusp tip and a flat plane, that was laid on top of the mandibular dental cast touching the incisal edges of the central incisors and the distal cusp tips of the most posterior teeth in the lower arch as done by Braun et al5 and Braun and Schmidt.16 The measurement was made on the right and left side of the dental arch and the mean value of these two measurements were used as depth of curve of Spee.
Our result showed that 52 patients had a normal curve of Spee, 33 had a deep curve and 15 had a flat curve of Spee.