Amal Bader Farraj

This retrospective study compared Class II orthodontic non-extraction treatment using Carriere Motion Appliance (CMA) and Twin Block (TB) appliances. Methods: The treatment of 38 patients was assessed. Pre- and post-treatment cephalometric radiographs were analyzed to evaluate skeletal, dental, and soft tissue treatment outcomes and efficacy. Results: Both appliances effectively corrected the Class II molar relationship. When measured at the distal aspect of the first molar, TB achieved 4.22 mm, while CMA had a 2.55 mm correction. When measured in the mesial aspect, the CMA achieved a 3.9 mm correction. The changes in SNB and ANB were statistically significant only in the TB group. The CMA appliance demonstrated statistically significantly less protrusion of the mandibular incisors and less upper incisor retrusion without vertical changes compared to the TB appliance. The TB demonstrated statistically significant lower lip protrusion compared to the CMA. Conclusion: The CMA corrects Class II malocclusions only by exerting a dentoalveolar influence and does not demonstrate the added effects associated with TB, such as elongation of lower facial height (LFH) and less loss of lower anchorage. Nonetheless, the correction in the TB group comprised both dentoalveolar and skeletal components. The CMA promotes a multidirectional upper and lower molar movement, and despite our 2D cephalometric analysis, we were able to estimate the extent of upper molar derotation.

Enamel erosion has become a common clinical finding that often impairs dental esthetics and function. In the current study, we aimed to implement the three-dimensional surface texture analysis (3DST) method to explore the protective effect of fluoride on surface texture prior to erosive conditions. For each of the 50 teeth used in this study, the polished buccal enamel surface was divided into three separate areas: the first area was untouched polished enamel, the two other surfaces were immersed in 0.3% citric acid for 30 s. One was treated with high-concentration (19,000 ppm) sodium fluoride (NaF) solution prior to acid attack, and the other had no treatment prior to acid exposure. Enamel surface texture and step height measurements were obtained using a high-resolution disk scanning confocal microscope, and SEM images were also acquired. Surfaces treated with fluoride showed fewer variations in 3-D surface texture parameters than the eroded surface compared to the control group (p = 0.001). This was in accordance with the SEM descriptive images. The findings indicate that pre-fluoridated enamel areas were less affected by the acid and showed similar features to the untouched enamel. Moreover, a protective effect of the fluoride treatment against irreversible enamel damage was noted as the surface loss (step-height) was significantly reduced (p = 0.03). The study showed that 3DST analysis is a valuable methodology for detecting and quantifying subtle differences between the surfaces. When exploring the combination of all surface texture parameters, it was revealed that the pre-fluoridated eroded enamel surfaces showed considerable similarity to the untouched enamel.