Introducing Scenario Based Learning interactive to postgraduates in UQ Orthodontic Program.

INTRODUCTION: E-learning has gained momentum in health sciences and seems to have great potential in specialist dental education. Higher acceptability by learners is particularly associated with the surge of smart devices. Currently, there are limited number of e-learning modules available for dental education, particularly in Orthodontics. MATERIAL AND METHODS: Scenario Based Learning interactive (SBLi(®)) software was used for the first time in Orthodontics Postgraduate training at the University of Queensland. Nine interactive modules were created embedded with clinical procedure videos, web-links, evidence-based literature, along with opportunity for self-assessment and evaluation. Qualitative data were collected before and after the administration of the SBLi(®) for Orthodontics. The purpose of this data was to investigate learning styles and the acceptance of e-modules as part of postgraduate training. RESULTS: Advantages of the package included high acceptance rate, greater confidence in the application of clinical skills covered in the modules and reduced contact time particularly with limited academic staff. E-modules demonstrated high compatibility with the learning styles of the participants and were considered engaging. CONCLUSIONS: It seems apparent that e-learning is most effective in a blended learning environment, supplemented with the traditional classroom approach, rather than as a sole mechanism for postgraduate training.

Evaluation of a novel approach in the prevention of white spot lesions around orthodontic brackets.

BACKGROUND: The purpose of this study was to evaluate and compare the relative efficacy of a resin fissure sealant, nano-filled self-adhesive protective coating, resin infiltrant, glass ionomer cement (GIC), and GIC containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in preventing the formation of subsurface lesions of enamel (SLE) adjacent to orthodontic brackets by acting as an enamel surface sealant (ESS). METHODS: Eighty-five enamel specimens with molar tubes bonded at their centre were randomly divided into five groups, each treated with a different material at the bracket's periphery. Specimens were stored in an acetate demineralization solution at pH 4.5 for 7 days at 37 °C then imaged using quantitative light-induced fluorescence (QLF) to determine the difference in fluorescence (∆F) between sound- and acid-exposed enamel. Lesion cross-sections were then examined using backscattered scanning electron microscopy (SEM) to measure lesion depth. RESULTS: The use of GIC alone or incorporating CPP-ACP significantly reduced ∆F compared with other materials. Backscattered SEM images showed no measurable demineralization for enamel treated with either GIC material in contrast with other groups, which showed statistically significant demineralization levels. CONCLUSIONS: The fluoride-releasing effects and CPP-ACP benefits of the GIC materials show promise as an effective ESS in inhibiting enamel demineralization adjacent to orthodontic brackets.

Age-related changes in maxillary and mandibular cortical bone thickness in relation to temporary anchorage device placement.

BACKGROUND: The aim of this study was to investigate the correlation between alveolar bone cortical thickness (ABCT) and age in the maxillae and mandible in humans. This information could then be translated into clinical application with temporary anchorage devices (TADs) in orthdontics. METHODS: Samples comprised 82 post-mortem CT datasets (41 males and 41 females) aged between 11 to 50 years, and were divided into five different age groups and gender. Alveolar ABCT was measured in the labial/buccal and palatal/lingual sides of the incisor, canine, premolar, molar and tuberosity/retromolar regions of the maxillae and mandible. Correlations between ABCT and age and gender were analysed with linear regression analysis. RESULTS: Strong correlation between ABCT and age was found for the maxilla on the labial side of the maxillary incisor region (p < 0.001). On the palatal aspect, significant correlations between ABCT and age were found in the maxillary incisor and maxillary premolar regions (p = 0.01 and p = 0.047 respectively). Significant correlation between ABCT and gender was found only at the buccal aspect of the maxillary molar region (p = 0.022). In the mandible, a statistically significant correlation between ABCT and age was found in the cortical bone of the labial side of the mandibular incisor region (p = 0.017). However, statistically significant negative correlation between ABCT and age was found in the mandibular canine region (p = 0.033). The only site to demonstrate a significant difference in change in ABCT with age between males and females was the lingual side of the retromolar region, in which female ABCT increased more than in males (slope = 0.015). CONCLUSIONS: There is minimal clinically significant correlation between ABCT and age at the alveolar bone level. Although investigations show statistically significant correlations, these may not be clinically significant as those regions are not ideal for anchorage reinforcement with TADs in orthodontic practice.

Ultrasonography, lateral cephalometry and 3D imaging of the human masseter muscle.

PURPOSE: To develop prediction equations to assist the clinician to derive cephalometric norms from the non-invasive investigations of ultrasonography (US) and 3D imaging. SETTING AND SAMPLE POPULATION: Adult volunteers from University of Adelaide participated in the study. METHODS: Eleven volunteers (eight women, three men; age range 22-30 years) were recruited for US and standard lateral radiographs measurements along with 3D facial imaging using a structured light technique. The three examinations were performed to assess the vertical and transverse dimensions of the face along with superficial masseter muscle dimensions. In total, 31 variables were statistically analysed for relationship among the three imaging modalities. RESULTS: Pearson's correlation coefficients showed highly significant correlations between lateral cephalometric (Co-Go to R3-R4) and US (volume--thickness) variables (r = 0.92, p < 0.0001; r = 0.95, p < 0.0001, respectively). Strong correlations were also observed with Co-Go and masseter muscle area derived from US r = 0.81 (p = 0.01). Similarly, strong correlations were seen between gonion-menton (Go-me) and facial width from 3D imaging (r = 0.83, p = 0.003). A high statistical significance (p > 0.0001) for curvilinear measurements compared with linear counterparts was revealed with the paired t-test. Factor analyses provided meaningful interrelationships for predictive equations generated for lateral cephalometric variables from 3D image coordinates. CONCLUSIONS: This preliminary investigation suggests that useful clinical information for treatment planning and follow-up can be gathered without repeated exposure to ionizing radiation. For more robust predictive equations, a larger sample would be required to validate such a model.

Ultrasound measurements of the masseter muscle as predictors of cephalometric indices in orthodontics: a pilot study.

This study investigated the potential of ultrasound measurements of the masseter muscle to accurately predict indices normally derived from cephalograms. Masseter muscle measurements on 11 adults (22 to 30 y) were made using lateral cephalometrics and extended field-of-view ultrasound. The ultrasound technique was validated in a simulation pilot study using 12 dry skulls and raw chicken breasts. Twenty cephalometric variables were analyzed against four ultrasound measurements of the masseter muscle. Highly significant correlations (r = 0.81-0.85, p = 0.001-0.002) between ultrasound measurements of the masseter muscle and cephalometric measurements representing the length of the superficial masseter muscle, the length and shape of the mandible and vertical facial proportions were demonstrated. Predictive equations from regression analyses were constructed to deduce ramus length and shape from the ultrasound measurements. The results provide pilot data suggesting that ultrasound is a potential clinical tool for sequential evaluation of masseter muscle length in orthodontics and facial muscle growth studies.

Modulation of masseteric reflexes by simulated mastication.

It is well-known that limb muscle reflexes are modulated during human movements. However, little is known about the existence of equivalent masticatory muscle reflex modulation. We hypothesized that masticatory reflexes would be modulated during chewing so that smooth masticatory movements occur. To examine this hypothesis, we studied the modulation of inhibitory reflexes evoked by periodontal mechanoreceptor activation and of excitatory reflexes evoked by muscle spindle activation during simulated mastication. In 28 participants, 1- and 2-N mechanical taps were delivered to the incisor. Reflex responses to these taps were examined in the average masseteric electromyogram. To differentiate between periodontal mechanoreceptor- and muscle-spindle-mediated reflex components, we performed experiments prior to, and in the presence of, periodontal anesthesia. Both periodontal mechanoreceptor and muscle spindle reflexes were reduced during simulated masticatory movements.