Journal of Orthodontics

A calibrated loop-forming jig is described, which can be used to bend standard sized loops and stops at known intervals along an archwire. A variety of loops may be constructed, using rectangular or round wire.

A technique of transplanting canines using orthodontic bracket fixation is described. The extracted tooth has its root suspended in the patient's own blood whilst the dried isolated crown is freely accessible for the direct bonding of an edgewise bracket at a predetermined position. A special bottle with rubber and clamp in the lid is needed for this procedure and is described.

Advantages of the technique include the following: Ideal positioning of the canine under direct vision; the possibility of forming a canine eminence and the easy assessment at intervals, of the firmness of the transplant. Therefore, the fixation may be removed, in many cases, before the usual 6 week period.

Facial growth has an important bearing on orthodontic treatment and on its stability. However, despite much research in this field, the prediction of facial growth is subject to considerable inaccuracies. The best that can be done is to base treatment on the existing facial pattern with an allowance for average growth according to age and sex. In view of the uncertainty of prediction, treatment planning should be based on facial and dental relationships that change least with growth.

The lateral cephalograms of 20 hypopituitary patients were analysed. The cases were untreated at the time, and covered an age range of 6–15 years. The linear and angular measurements were compared with those of growth study controls, and were tested for significance. The results confirm the facial immaturity of Patients with a deficiency of growth hormone and indicate that, whilst all linear parameters are reduced, maxillary length is less retarded than the others. There were differences amongst the angular comparisons, the gonial angle being particularly increased.

A method of mounting an Adams Cephalostat on a vertical Potter-Bucky frame is described and its performance investigated.

The investigation is a continued examination of the dental and skeletal changes accompanying rapid maxillary expansion on 23 patient. It also examines the stability of these changes 5 years post retention The results show that the final increase in width between the upper first molars recorded 5 years post retention Was 45 percent of that initially achieved by rapid maxillary expansion. The mean final increase in the inter canine width was only 23 percent of the expansion achieved initially. The results do not support the common belief that rapid maxillary expansion increases the overjet and reduces the overbite. No unfavourable skeletal and dental side effects of rapid maxillary expansion could be found.

A quad helix expansion device is described and modifications shown which increase its range of action.

The long term result of orthodontic extractions of mandibular second premolars and permanent first molars was investigated by measuring the degree of tooth tipping mesial and distal to the extraction sites in cases with complete and incomplete closure of extraction spaces after treatment and/or at follow-up examination. Tooth inclination was determined from photographs taken of dental casts made after treatment and follow-up examination. The inclination of the teeth was measured in relation to each other and in relation to the occlusal line. The results of the investigation revealed that teeth which were tipped mesial and/or distal to the extraction sites after orthodontic treatment had a tendency to upright in relation to each other and in relation to the occlusal line. Uprighting was pronounced in cases which had extraction spaces remaining after treatment, but which were closed at the time of follow-up examination, and in cases with closed extraction spaces after treatment. However, minimal changes in inclination of the teeth adjacent to the extraction sites were found in cases with incomplete space closure after treatment and at follow-up.

Extra-oral anchorage is often needed during treatment with removable appliances. A technique Using high pull headgear with J-hooks is described and some advantages outlined.

A method for the assessment and treatment of late incisor crowding is described. An index for the crowding is determined and from this the lack of space is calculated in millimetres. If the discrepancy is less than 4 mm, treatment by removal of approximal enamel may be recommended. An index for lower incisor tooth shape is also discussed. A case history demonstrates alignment of upper and lower labial segments by interdental stripping and the use of simple appliances.

The clinical and technical procedures involved in the fabrication of the Face Mask reverse headgear are detailed and illustrated. It is hoped this will lead to its wider use in appropriate clinical situations.