This study aimed to evaluate the potential correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation of the maxillary first molars. Scanned images of 104 cast models were grouped according to the severity of Class II malocclusion as follows: Group 1, 1/4 Class II malocclusion; Group 2, 1/2 Class II malocclusion; Group 3, 3/4 Class II malocclusion; and Group 4, complete Class II malocclusion. The rotation was measured using parameters described by Henry, Friel, and Ricketts, referred to as indicators 1, 2, and 3, respectively. The correlation was evaluated using the Spearman's correlation coefficient. The rotational indicators were compared using one-way analysis of variance. For all statistical analyses used p < 0.05, a positive correlation was observed between the severity of Class II malocclusion and the mesiopalatal rotation of the maxillary first molar. This correlation was statistically significant for indicator 1 between Groups 1 and 3 and for indicator 2 between Groups 1 and 4, which include cases of extreme malocclusion. In conclusion, there is a positive correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation in the maxillary first molars.

Although dental radiology is not directly involved in either invasive procedures or in the use of piercing-cutting material, the high-touch areas of dental x-ray device, including radiographic films, are a potential source of infection. The purpose of this study was to assess the amount of cross infection present in the dental x-ray devices of the School of Dentistry of the Federal University of Maranhão by investigating the presence of pathogenic microorganisms in high-touch areas of dental x-ray devices (tube head, timer button, portable processing box and lead apron). Twenty surfaces of 4 dental radiology clinics were cultured in different media. The results showed that 70 percent of the surfaces had contamination. All the dental x-ray devices assessed were contaminated (tube head, timers or both) as well as all the lead aprons. The portable processing boxes showed 75 percent of contamination. The groups found no statistical significance between the different surfaces assessed and the microorganisms. The highest frequent microorganisms found were from Staphylococcus genus. The authors concluded that because of the high incidence of contamination found, the x-ray devices used in the dental clinics could be at potential risk of cross infection, demonstrating the necessity for applying biosecurity practices when taking radiographic and during radiographic processing.