To cite thiS 8l1lcle: Clin. Onh. Res. l, t998; 97-tOt Moorncs CFA: Thoughts on th<' <'arly treatmmt of Clas.• II malocduslon CorvrtRht C MunksparJ t998Abstract: The timing of Class II, division 1 malocclusion treat-m~nt is discussed in the context of the development of the dentition within the craniofacial environment. The occlusion of the dentition actually serves as the key that controls and maintains the exact position of the mandible vis-a-vis the maxilla during childhood, pubescence and throughout adulthood. Re-J search and clinical evidence suggest that treatmeQt which 'disturbs' the interdigitation of teeth in the Class II malocclusioncan lead to correction of the distocclusion. This correction can theoretically be undertaken throughout childhood and adolescence, and even thereafter. Treatment at a very young age was thought to normalize the occlusion, and consequently the growth process, leading to more stable results. Re-examination of this concept shows that. for practical purposes, the presence of the first premolars signals an ear1y indication for treatment of Class II, division 1 malocclusion. The mobiHty of the deciduous second mandibular molars provides the last opportunity to prevent, whenever possible, a four premolar extraction approach.