This paper is the first of a series on the comprehensive management of young people with hypodontia. The paper looks at the background to the condition, the possible aetiological factors, the prevalence of hypodontia and other related conditions. Lastly there is consideration of the role of the paediatric dentist in interdisciplinary management of the affected child and adolescent patient.

Computer-based digital orthodontic models have been developed that have the potential to replace dental casts. The aim of this study was to examine the accuracy and reproducibility of measurements made on digital models. Ten sets of orthodontic study models were scanned using the Arius3D Foundation System and three-dimensional (3D) images were produced by computer software. Two examiners individually measured 11 parameters on the conventional casts and the digital models on two occasions. The parameters included mesio-distal crown diameter, intercanine and intermolar width, arch length, overjet, and incisor crown height. The measurement techniques were compared using paired t-tests, the coefficient of reliability, and by calculating mean values and the difference between methods. When comparing measurements made on digital models with those on dental casts, systematic errors were detected for five of the 11 parameters at the 10 per cent level. Random errors were a cause of concern for measurements of three parameters. The most accurate and reproducible measurements were lower intercanine width (mean difference between measurements 0.05 +/- 0.32 mm) and overjet (mean difference 0.07 +/- 0.33 mm). Most parameters on the digital models can be reliably measured, and digital models can potentially eliminate the requirement for the production and storage of dental casts, but this will depend on cost.

This paper considers the role of restorative dentistry in the management of hypodontia. The paper describes the general restorative considerations common to patients with hypodontia and illustrates the variety of restorative techniques available in the restorative management of hypodontia and oligodontia.

Orthodontic treatment can greatly facilitate any restorative treatment or sometimes even eliminate the need for it. There are several issues that commonly arise in the orthodontic management of patients with hypodontia. These include: space management; uprighting and aligning teeth; and management of deep overbite and retention and stability. The following paper discusses these aspects of orthodontic management.

Reliability of scoring dental arch relationships using intraoral 3D scans was superior to indirect digital and to plaster models; Subjects with UCLP preferred intra-oral 3D scanning to dental impressions, mirrored by parents/carers; This study supports the replacement of conventional impressions with intra-oral 3D scans in longitudinal evaluations of the outcomes of cleft care.