A comparative assessment of changes in dental arches associated with different activation protocols of rapid maxillary expansion.

AIM: The aim of this study is to compare dental arch changes associated with different activation protocols of maxillary expander. MATERIALS AND METHODS: A sample of 101 subjects with constricted maxillary arches (49 males and 52 females; mean age 10.96 ± 1.91 years) was enrolled in the study. All subjects underwent RME with a stainless steel banded expander cemented to the maxillary first molars and the expansion screw was randomly activated with two different rapid maxillary expansion protocols (one- quarter per day or two quarters per day). The study also involved a control group of 22 subjects (10 females and 12 males, mean age 10.39 ± 1.32 years) who underwent no treatment. A statistical comparison between the dental arch measures obtained before and after treatment in the two groups was performed. RESULTS: The Wilcoxon rank-sum test shows statistically significant differences of the measurement increases between the two activation protocols (at least p=0.01). Statistically significant differences were also reported in comparison with the control group. CONCLUSIONS: A faster activation protocol could be able to determine a greater anterior opening of the mid-palatal suture. Moreover, it seems to yield a higher width increase in the molar area.

Sagittal dentoskeletal modifications associated with different activation protocols of rapid maxillary expansion.

AIM: The aim of this study is to compare the sagittal dentoskeletal changes associated with different activation protocols of maxillary expander. MATERIALS AND METHODS: A total of 101 subjects with constricted maxillary arches (49 males and 52 females; mean age 10.08 ± 1.57 years) were enrolled in the study. The study comprised also a control group of 20 subjects (11 females and 9 males, mean age 10.27 ± 1.24 years) who were not treated during the observation period. All the subjects underwent rapid maxillary expansion with a stainless steel banded expander cemented to the maxillary first molars. The expansion screw was randomly activated with two different rapid maxillary expansion protocols (one-quarter per day or two-quarters per day). A statistical comparison between the sagittal cephalometric variations obtained in the two expansion groups was made, and compared with the untreated control group. Data were then stratified for skeletal maturation of each subject. RESULTS: The Wilcoxon rank-sum test shows statistically significant differences between the two RME activation protocols only for overjet. Statistically significant differences were reported in comparison with the control group. CONCLUSIONS: This study suggests that the increase in overjet after RME could be associated with faster activation protocols especially in subjects with lower skeletal maturation.

Analysis of rapid maxillary expansion effects on nasal soft tissues widths.

AIM: The aim of this study was to analyze the variations in nasal dimensions in prepubertal patients associated with RME therapy compared with an untreated age matched control group. METHODS: A group of 61 subjects (26 F, 35 M; mean age 10.5±1.8 years) was enrolled in the study to undergo a rapid maxillary expansion therapy; 41 subjects (26 F, 15 M; mean age 10.7±2.2 years) were enrolled as a control group. Both groups underwent nasal soft tissues width measurements using a caliper at three separate time points: T0 - prior to the placement of RME; T1 - after completion of active expansion phase; T2 - at the removal of the expander (nearly 6 months after T1). RESULTS: The ANOVA showed statistically significant increments (P<0.0001) of the greater alar cartilage (GAC) measurement (0.8±0.2 mm) in the study group, differences for the AB measurements were not statistically significant (P=0.0784). CONCLUSION: The treatment of rapid maxillary expansion can induce an increase in GAC soft tissues width of about 1 mm in prepubertal patients. This increase could not be considered of clinical impact. The alar base width increase less than GAC, this increase is without statistical significance.