RESUMO
Objective@#To explore the influence of the SmartClip self-ligating bracket and traditional metal bi-wing brackets on plaque control and to provide a reference for the oral healthcare of orthodontic patients.@*Methods@#The patients were divided into the SmartClip self-ligating bracket group, the metal bi-wing bracket group, and the control group, consisting of untreated volunteers, and the patients were examined before treatment, 1 month after the treatment started, 3 months after the treatment started, and when the treatment ended. The oral hygiene status was recorded at four time points, and the plaque index of the following six teeth was compared among the time points: the upper-right central incisor (UR1), the lower-left central incisor (LL1), the upper-right first molar (UR6), the lower-left first molar (LL6), and the upper left canine (UL3) and the lower-right canine (LR3).@*Results@#Compared with before treatment, after first month, third month and end of treatment the plaque index of LL1, LR3, LL6 and UR6 in both the SmartClip self-ligating bracket group and the traditional metal bi-wing bracket group was increased, and the difference was statistically significant (P < 0.05). There was no significant difference in PLI index between the end of treatment and 3 months after orthodontic treatment (P > 0.05). There was no statistically significant difference in PLI index in the control group at each time period (P > 0.05). After three months of orthodontic treatment, the plaque index of LL1 and LR3 in the SmartClip self-ligating bracket group was higher than that in the traditional metal bi-wing bracket group, and the difference was statistically significant (P < 0.05).@*Conclusion@#Lower anterior and posterior areas are susceptible to plaque accumulation in treatment with fixed orthodontic appliances. The SmartClip self-ligating bracket system has no advantage over the traditional metal bi-wing bracket in terms of oral hygiene.
RESUMO
Objective@#To study the relation between the upper first molar root tips and the maxillary sinus floor in patients with different vertical facial patterns using cone-beam computed tomography (CBCT) and to explore the reference data for safe clinical orthodontic treatments.@*Methods@#Three-dimensional images were reconstructed from CBCT data. The CBCT data from 120 adolescents and adults were divided into three groups (low-angle group, average-angle group, high-angle group) based on vertical facial type. For each subject, the distance from the maxillary sinus floor to the upper first molar root tips was measured, and the types of contacts were classified. ANOVA and LSD t tests were used for statistical comparisons and performed using SPSS 19.0.@*Results@#Of the 120 samples, only 27% of the upper first molar root tips lost their contacts with the maxillary sinus floor, and the other 73% of the root tips contacted the sinus to different extents. Significant differences in the distances from the maxillary sinus floor to the upper first molar root tips were found for different vertical facial types (P < 0.05). The high-angle group had the lowest sinus floor, relative to the root tips, of the three adult groups (P < 0.05). In the adult group with a low angle, the measured value for the palatal root tips was the lowest and was significantly different from those in the other groups (P < 0.05).@*Conclusion@#Seventy-three percent of the upper first molar root tips contacted the maxillary sinus floor. The maxillary sinus floor tended to be lower relative to the first molar root tips in patients with a high-angle facial pattern than in others. The roots protruded into the sinus to a greater extent.