An investigation of inter-examiner reproducibility in recording malocclusion parameters during orthodontic epidemiologic studies

This study assesses inter-examiner reproducibility in recording various malocclusion parameters and Index of Orthodontic Treatment Need (IOTN) grade during patient examination by utilising the kappa statistic. Five previously calibrated orthodontists clinically examined 233 non-orthodontically treated schoolchildren aged 14-17 years for recording various malocclusion parameters. The examination was repeated twice, thirty days apart and precluded the use of study-models or radiographs. Although good inter-examiner reproducibility was observed in recording incisor class, IOTN dental health grade, type of posterior crossbite, and excellent for parameters with absolute criteria like erupted supernumeraries, etc, substantial examiner variation resulted in only fair reproducibility for recording IOTN esthetic category, canine class, overbite category, traumatic overbite and upper centre-line shift of two millimetres or more from the facial midline. Reproducibility for detecting occlusal displacement in the presence of crossbite was poor, and kappa statistic was incalculable for recording openbite and number of upper incisors rotated 30° or more. Kappa was also incalculable for recording IOTN dental health subcategory due to the creation of asymmetric tables caused by rarely chosen subcategory options. Despite prior agreement between previously calibrated examiners on evaluation criteria, detection of certain malocclusion parameters during an epidemiological examination can prove to be challenging. Epidemiological studies that report on prevalence of malocclusion in the population should always report on the kappa reproducibility, especially if the study is carried out by multiple examiners.

Fixed appliance orthodontic treatment duration in Brunei Darussalam

Introduction: Fixed appliance orthodontic treatment (braces) is routinely used to address mal-positions of teeth and create esthetic smiles. Although it is desirable that treatment not exceed two years but, in practice, duration of up to two-and-a-half years is deemed acceptable. This review was undertaken to determine treatment duration for routine state-funded fixed appliance treatment in Brunei Darussalam and identify possible influencing factors. Materials and Methods: 100 consecutive cases (Malocclusion class I [29%], II [51%] and III [20%]) of completed routine, single-phase fixed appliance treatment treated at the National Dental Centre, Bandar Seri Begawan, selected retrospectively from 31st December 2008 were reviewed for treatment duration including possible factors affecting this parameter. Results: Only 19% had desirable treatment duration (≤2 years) and 41% had acceptable treatment duration (2.01 to 2.5 years). Forty percent had treatment duration in excess of 2.5 years. Excess time due to accumulative non-optimal visit intervals, and number of adjustment visits showed significant high correlation coefficient values to treatment duration (p<0.01). Extractions showed low but significant correlation to treatment duration while age revealed low negative correlation to treatment duration (p<0.05). The lowest incidence of repairs occurred in those whose treatment did not exceed two years whilst the highest incidence of broken appointments was observed in those who had treatment duration in excess of three years. Conclusions: This retrospective review indicates that treatment duration for most of our sample is longer than desirable. The accumulative effect of non-optimal visit intervals, increased number of adjustment visits, age at start of treatment, high proportion of extraction cases, increased incidence of repairs and broken appointments may be contributory. Further investigations including prospective studies are required.