[Biomechanical aspects of the space gaining therapy according to Cetlin]

The non extraction technique according to N. Cetlin for the treatment of crowded and protrusive dentitions in class I and class II malocclusions is assessed. The intent of this article is to outline the approach to non extraction treatment with the following major clinical objectives: 1) space gaining in both maxillary and mandibular arches; 2) anchorage preservation throughout treatment and 3) intrusion of the maxillary incisors.