Effect of multimedia information sequencing on educational outcome in orthodontic training.

The aim of this research was to compare the effectiveness of hierarchical sequencing (HS) versus elaboration sequencing (ES) models in improving educational outcome of clinical knowledge when using instructional multimedia programs in postgraduate orthodontic training. Twenty-four postgraduate and 24 undergraduate dental students participated in this study. The postgraduates were following an orthodontic speciality training programme. The undergraduates were fourth- and fifth-year dental students. Twelve instructional multimedia modules were developed, six logically sequenced (LS) discussing six different orthodontic topics. Another six modules on identical topics were sequenced according to one macro-sequencing (MS) model. The implemented MS model was either HS or ES. The only difference between LS and MS modules was the adopted sequencing model. All participants were assigned into consistent pairs of students and were randomly divided into a test and a control group. In each pair, one student studied the LS module (control group) while the other studied the MS version (test group). Pre- and post-evaluation tests of each pair of participants were performed to measure knowledge, understanding and application of each participant with regard to the discussed topic. A multilevel analysis was conducted to assess the estimated effect of the different sequencing models. The level of significance was set at 0.05. At baseline, no significant differences (P > 0.05) were found in pre-test scores between groups. The HS model showed a significant effect on the scores achieved (P = 0.05). The test group showed a significantly higher estimated probability of correct answers to the questions (P = 0.003) when applying the HS model. The HS model may improve educational outcome when using instructional multimedia programs in postgraduate orthodontic training.

Accuracy and reliability of 2-dimensional photography versus 3-dimensional soft tissue imaging.

PURPOSE: This study was conducted to objectively and subjectively compare the accuracy and reliability of 2-dimensional (2D) photography and 3-dimensional (3D) soft tissue imaging. MATERIALS AND METHODS: Facial images of 50 volunteers (25 males, 25 females) were captured with a Nikon D800 2D camera (Nikon Corporation, Tokyo, Japan), 3D stereophotogrammetry (SPG), and laser scanning (LS). All subjects were imaged in a relaxed, closed-mouth position with a normal smile. The 2D images were then exported to Mirror® Software (Canfield Scientific, Inc, NJ, USA) and the 3D images into Proplan CMF® software (version 2.1, Materialise HQ, Leuven, Belgium) for further evaluation. For an objective evaluation, 2 observers identified soft tissue landmarks and performed linear measurements on subjects' faces (direct measurements) and both linear and angular measurements on all images (indirect measurements). For a qualitative analysis, 10 dental observers and an expert in facial imaging (subjective gold standard) completed a questionnaire regarding facial characteristics. The reliability of the quantitative data was evaluated using intraclass correlation coefficients, whereas the Fleiss kappa was calculated for qualitative data. RESULTS: Linear and angular measurements carried out on 2D and 3D images showed excellent inter-observer and intra-observer reliability. The 2D photographs displayed the highest combined total error for linear measurements. SPG performed better than LS, with borderline significance (P=0.052). The qualitative assessment showed no significant differences among the 2D and 3D imaging modalities. CONCLUSION: SPG was found to a reliable and accurate tool for the morphological evaluation of soft tissue in comparison to 2D imaging and laser scanning.

The application of Kvaal's dental age calculation technique on panoramic dental radiographs.

INTRODUCTION: Literature reports on a method for dental age calculation which is based only on radiological measurements on periapical dental radiographs: the relationship between chronological age and the two-dimensional dental pulpal size was analysed by means of multiple regression analyses. The purpose of the present study was to evaluate whether this approach could be feasible and could lead to statistically sound results with adequate repeatability when applied on panoramic radiographs. MATERIALS AND METHODS: One hundred and ninety seven panoramic radiographs were collected at random from patients of whom the age ranged from 19 to 75 years. According to the reported technique, six teeth were selected on the panoramic radiograph: in the maxilla the central and lateral incisor and second bicuspid, and in the mandibula the lateral incisor, cuspid and first bicuspid. The same exclusion criteria as in the original paper were respected. Statistical analysis was carried out in order to spot significant differences between the chronological age and the calculated age. RESULTS: When the age was calculated based on measurements of all six teeth or of all three mandibular teeth, no significant differences were found between the real age and the calculated one. In all other instances using the individual teeth separately or using all three maxillary teeth statistical analysis revealed significant differences. CONCLUSION: There appears to be no significant difference between applying the original technique on standard long-cone periapical radiographs or on orthopantomograms, especially when carrying out measurements on all six selected teeth.

Treatment protocol for unilateral cleft lip and palate patients: questioned by two case reports.

BACKGROUND: The types and severity of clefts as well as palatal development and growth in children with repaired cleft lip and palate deformities can vary greatly. Independent of the technique used surgery produces scar tissue, which restricts palatal growth so that by the second decade many patients have an underdeveloped maxilla. Experience has shown that the maxillary retrognathism found in many cleft patients is not amenable to nonsurgical correction. Few long-term studies have evaluated the procedures, sequencing and timing of the treatment methods found to give the best results. This lack of reliable information means there is a serious gap in our ability to assess the value of different treatment modalities. AIMS AND METHODS: From the viewpoint of orthodontics, this article describes the treatment protocol used by the cleft lip and palate team at the University Hospitals of the KU Leuven. The present treatment protocol is illustrated and questioned by two cases. The roles of prediction of facial growth and distraction osteogenesis are discussed.

The effect of using CBCT in the diagnosis of canine impaction and its impact on the orthodontic treatment outcome.

AIM: To investigate the added-value of using CBCT in the orthodontic treatment method of maxillary impacted canines and treatment outcome. MATERIALS AND METHODS: The sample consisted of 118 treated patients. The CBCT group (n = 58) (39 females/19 males with the mean age of 14.3 years) included those with conventional treatment records consisting of panoramic and cephalometric radiographs, intra-and extra-oral photographs, and dental casts and complemented with a CBCT scan for additional diagnostic information. The conventional group (n = 60) (31 females/29 males with mean age 13.1 years) included those with similar conventional treatment records but without CBCT imaging. RESULTS: There were significant differences in the canine-related variables between both groups. The CBCT group had the higher level of difficulty and more severely displaced canines when compared with the conventional group. However, no significant difference was found between groups either in the number of treatment methods used or in the use of interceptive methods combined with other treatment modalities or choice of extraction versus non-extraction. In terms of treatment success and interval duration, no significant differences were found. However, treatment duration was significantly (4 months) shorter in the CBCT group compared with the conventional group (P = 0.023). CONCLUSION: CBCT has been used in cases with more severe symptoms of maxillary canine impaction. The use of CBCT improved the diagnostic capabilities and improved the chances of success in the more difficult cases to a level similar to that of simpler cases treated on the basis of 2D information.