Effects on lower third molars after extraction of second molars.

The material consisted of 78 cases, 44 males and 34 females of the ages of 10-15 years. The orthodontic treatment followed the diagnosis of Class II malocclusion with crowding in the lower jaw. In addition to extraction of lower second molar the treatment consisted of distal driving of lower first molars in different ways. The treated cases were assessed by use of study models and lateral oblique X-rays. No third molars were treated in any cases. The results showed that in the majority of cases the third molars were adequate substitutes for the extracted second molars.