Journal of Orthodontics

The opening of a new Orthodontic Department at Kingston Hospital in September 1972 gave the opportunity of trying to develop orthodontic appliance systems which would cope with the high percentage of severe malocclusion that is referred. The edgewise appliance has played a central part in many treatments. This particular variant of the appliance has evolved largely from the teaching of the Tweed Foundation, but has been refined and simplified as the result of experience. The first part of the paper demonstrates the separate mechanical parts of the system. The second part contains a discussion of treatment aims and shows two cases to briefly illustrate how the separate parts may be integrated together. An attempt is made to show that the edgewise appliance is a straightforward flexible and evolving technique which can, if necessary, be blended with other appliance systems and changing diagnostic concepts.

A case is described in which a lack of incisor overbite has been corrected by the addition of a filled composite resin. This orthodontic use of the acid-etch technique has proved satisfactory for 2 years.

A report is presented on eleven Class II cases which had been treated by the Begg technique. The cases were analysed from 1 to 3·5 years following retention, with particular emphasis being placed on changes to the lower labial segment. Where relevant, comparisons are made with growth study standards. The use of the lower incisor—Mandibular planes angle (IMPA) is described and criticized and an alternative linear measurement is used to describe changes in the sagittal position of the lower incisors. The results indicate that despite widely held views, it is possible to obtain stable results, following radical alteration to the lower incisor position. There was a trend towards an overall lingual movement of lower incisor apices.

A case report is presented to show treatment of an instanding lateral incisor avoiding extractions and complicated orthodontic treatment.

In this study 1,976 bands were cemented onto the teeth of 102 patients. The mean duration of active treatment for a case was 702 (± 182) days, during which time 419 bands, i.e. 21·2 per cent were recemented. Bands which required most frequent recementing were those affixed to the upper central incisor teeth. Of the 102 bands cemented on the upper central incisors 28·4 per cent remained intact, while 71·6 per cent required recementing. The possible causes for the high incidence of recementation of the incisor bands are discussed. The performance of the direct attachment technique in relation to the conventional orthodontic band is reviewed in the light of the data presented in this survey.

Conventional methods of rapid maxillary expansion using rigid mechanisms are not appropriate to patients with cleft lip and palate in whom there has been severe growth deficiency in the lateral dimension. In such patients, much more expansion is usually needed in the canine regions than in the molar regions. A method is described for producing differential rapid maxillary expansion in such patients.

A lower fixed ‘tongue crib’ was used diagnostically in a case of bimaxillary protrusion. The anterior open bite and lower incisor spacing resolved under the influence of soft tissue action. Lip exercises were instituted to create a new muscle balance and thus maintain the new incisor positions. The literature is reviewed in relation to tongue cribs, lower incisor position and lip tone. The fundamental interest in the case presented is the support it provides for the ‘balance’ theory of lower incisor position.

A case is reported of a lower canine transposed across the midline and erupted next to the opposite lower canine.