scan area. Tapping mode images and statistical analysis showed that Pro Seal treated samples had the least damaged enamel surface of all groups and the lowest mean of roughness height and total surface area. In conclusion, Pro Seal was the most effective prophylaxis technique in preventing enamel demineralization around orthodontic brackets. labiale inferius; 88% (male) and 92% (female) at mentolabial sulcus; and 93% (male) and 103% (female) at soft tissue pogonion. After surgical setback of mandible, the ratios of soft to hard tissue changes are somewhat different between male and female, especially at labrale inferioris (Li) and soft tissue pogonion (PoG). The ratios of Li:li and PoG:Pog for male were smaller than for female. This suggests that the clinician should pay more attention to the depth of labiomental sulcus and new position of soft tissue pogonion when making surgical predictions for Egyptian adults with mandibular prognathism.