Journal of Orthodontics

An assessment of the long-term results of a series of first and second premolar extractions. First premolar extractions produced a higher proportion of satisfactory upper contacts and buccal occlusions, but second premolar extractions, were more often associated with space closure. Approximately 40 per cent of lower contacts were unsatisfactory. There was little difference between the premolars in this or with regard to residual lower incisor crowding. No association between the presence of third molars and space closure was found.

The principles of prefabricating round and edgewise archwires using a wax bite technique and their specific application to prescriptions for upper and lower archwire designs are described. The technique has proved particularly useful both in teaching beginners the elements of fixed appliance therapy and in reducing the length of patient appointments.

A case is described in which an overjet reduced spontaneously from 9 mm to 5 mm without orthodontic treatment.

The Harvold activator is described and its effects are explained.

A survey of 612 kibbutz children from 7 to 12 years of age indicated a very high prevalence and prolonged persistence of the thumb sucking habit. Several psychological and social factors related to community living were investigated and are discussed as possible aetiological factors.

Some cases are presented in which improvement in the position of unerupted impacted teeth took place following simple treatment. Some suggestions are made to account for the phenomena.

A survey was carried out on 60 patients for whom lower second molar removal had been recommended at least 5 years previously, no other treatment being indicated in the lower arch. Of the 114 teeth recommended for removal, only 84 were extracted. Eighty four per cent of third molars erupted satisfactorily, where second molars had been extracted, while only 36 per cent of third molars erupted into good occlusion where the recommended extractions had not been carried out. In the extraction group, factors associated with a poor result were lack of third molar root formation at the time of removal of the second molar and space between the third molar crypt and the lamina dura of the second molar.