The aim of this presentation is to demonstrate the recent innovations in stereophotogrammetry for accurate three-dimensional analysis of the face. The capture time for the face is 3ms, it does not expose the patients to harmful radiation. A personal computer will require less than five minutes to build the 3D model of the face. A user interface has been developed which allows the operator to localise anatomical landmarks and analyse the craniofacial morphology in three dimensions.

Introduction: Cleft lip with or without cleft palate (CLP/CL), is a relatively common condition affecting about 1 in 650 live births in the UK. CLP/CL infants undergo corrective surgeries and are left with residual scars on the lip. This study presents the use of 'Consensus Coding' as a novel method to evaluate scarring after cleft lip repair.

Background and Objectives: The main objective of cleft surgery is to minimise the stigmata associated with cleft lip and palate and related psychological morbidity. The aim of this study was to assess residual soft tissue abnormality following surgical repair of unilateral cleft lip and palate (UCLP) and relate this to psychological adjustment.

This study compared the morbidity associated with transconjunctival and transcutaneous approaches for orbital floor exploration with respect to the position of the lower eyelid following surgery. Two groups of 32 volunteers and 32 patients (12 transconjunctival and 20 transcutaneous) were recruited and three-dimensional (3D) imaging was carried out at 6 months following surgery. In the transcutaneous group, there were significant variations in the shape of the lower eyelid, with more medial displacement of the exocanthion. No significant differences were detected in the transconjunctival group compared to controls. The use of a 3D imaging system provided an objective method of assessing this aspect of morbidity associated with the use of lower eyelid incisions.

Objective: To assess the accuracy and reproducibility of a high-resolution three-dimensional imaging system (WD).Design: The three-dimensional imaging system was validated in vitro using 12 adult facial plaster casts, which had landmarks marked, and the positions of the landmarks on the three-dimensional images captured by WD were compared with those obtained by a coordinate measuring machine (CMM).Methods: Operator error was measured by repeatedly locating landmarks on the three-dimensional image. Reproducibility error of the images was calculated by capturing three-dimensional images of the facial casts on two separate occasions; the Euclidean distance between the two matched sets of coordinates was then calculated. The WD system error was assessed by calculating the three-dimensional global positions of landmarks on the three-dimensional images and comparing them with those obtained by CMM (gold standard).Results: The operator error in placement of landmarks on the three-dimensional model was 0.07 mm, range 0.02-0.11 mm . The reproducibility of the WD capture was 0.13 mm, range 0.11-0.14 mm. The mean distance between the CMM and Di3D landmarks, which constitutes the WD system error, was an average of 0.21 mm, range 0.14-0.32 mm.Conclusions: The WD system error was within 0.2 mm , which is clinically acceptable, and offers considerable improvement in stereophotogrammetry for facial capture and analysis. (c) 2007 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

OBJECTIVE:The use of stone and plaster study models is an integral part of any dental practice and is required for research. Storage of study models is problematic in terms of space and cost. Ayoub et al.(1) introduced a new technique based on the recent advances in stereophotogrammetry for archiving dental study models in a digital format. However, assessment of the accuracy of the generated three-dimensional (3D) models has not been carried out yet. It was the aim of this study to evaluate the accuracy of this technique.DESIGN:A comparative assessment between direct measurements of dental study models and measurements of computer generated 3D images of the same study models was performed.MATERIALS AND METHODS:Twenty-two dental study models stored at Glasgow Dental Hospital and School for the purposes of research were used in the study. The models were captured in three dimensions using a photostereometric technique and stored in digital format.MAIN OUTCOME MEASURES:Measurements were conducted directly on dental study models and on the computer generated 3D images using Euclidean Distance Matrix Analysis.(2) The difference between the two sets of measurements was statistically analysed using a two-sample t-test.RESULTS:The average difference between measurements of dental casts and 3D images was 0.27 mm. This difference was within the range of operator errors (0.10-0.48 mm) and was not statistically significant (P < 0.05).CONCLUSION:This study shows that it is possible to use 3D imaging to store dental study models for treatment monitoring and research with a satisfactory degree of accuracy.