Effects of nasoalveolar molding on maxillary arch dimensions and malocclusion characteristics in primary dentition patients with cleft lip and palate.

BACKGROUND: Nasoalveolar molding (NAM) is a presurgical orthopedic technique used in the management of cleft lip and palate deformities. Despite the widespread use of NAM therapy, there is a need for further investigation to assess its specific effects on arch dimensions and malocclusion characteristics. AIM: To evaluate the effects of NAM therapy on maxillary arch dimensions and malocclusion characteristics in patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP). DESIGN: Patients in primary dentition were referred to the Institutional Department of Orthodontics. The NAM group consisted of 21 patients with UCLP (mean age 4.7 ± 0.7 years) and 12 patients with BCLP (mean age 4.8 ± 0.7 years). Sixteen patients with UCLP (mean age 4.9 ± 0.9 years) and five patients with BCLP (mean age 5.4 ± 1.1 years) were included in the non-NAM group. The plaster models of all patients were digitized. Dental arch dimensions and malocclusion characteristics were analyzed via digital software. One-way ANOVA with Bonferroni correction was used for statistical analysis. RESULTS: Intercanine and intermolar widths showed statistically significant differences according to the cleft type (p < .01). There was no statistically significant effect of NAM therapy on maxillary arch parameters and malocclusion characteristics (p > .05). The prevalence of anterior crossbite was 12.1% in the NAM group and 23.8% in the non-NAM group. CONCLUSION: NAM therapy did not affect the maxillary arch dimensions and malocclusion characteristics in patients with UCLP and BCLP. The cleft type was the main factor, leading to a significant difference in maxillary widths.

Evaluation of the effect of different attachment configurations on molar teeth in maxillary expansion with clear aligners - a finite element analysis.

OBJECTIVE: To evaluate the effects of different attachment configurations with and without buccal root torque on expansion movements achieved with aligners through finite element analysis (FEA). METHODS: FEA modelling was done with 0.25 mm buccal expansion force application to the maxillary molars with different attachment configurations: Eight models were tested (1) no attachment (NA), (2) horizontal attachment (HA), (3) gingivally beveled horizontal attachment (GHA), and (4) occlusally beveled horizontal attachment (OHA), as well as models with 6obuccal root torque, (5) no attachment (TNA), (6) horizontal attachment (THA), (7) gingivally beveled horizontal attachment (TGHA), and (8) occlusally beveled horizontal attachment (TOHA). RESULTS: The first and second molars exhibited buccal tipping in all models. The highest amount of buccal tipping for the molars was observed in the NA (6CMB, 0.232 mm; 6CMP, 0.246 mm; 7CMB, 0.281 mm; 7CMP, 0.312 mm) and GHA (6CMB, 0.230; 6CMP, 0.245; 7CMB, 0.279 mm; 7CMP, 0.311 mm) models, respectively, while the least tipping was observed in the TOHA model (6CMB, 0.155 mm; 6CMP, 0.168 mm; 7CMB, 0.216 mm; 7CMP, 0.240 mm). In all groups, the buccal tipping of the second molars was higher than that of the first molars. CONCLUSION: This FEA study showed that expansion with aligners tip maxillary molars buccally and the use of occlusally beveled attachments and addition of buccal root torque reduces uncontrolled buccal tipping.

Relationship between vertical facial morphology and dental arch measurements in class II malocclusion: a retrospective study.

Background: To evaluate the relationship between dental arch measurements and the vertical facial pattern determined in skeletal Class II untreated patients. Methods: Lateral cephalograms and plaster models were obtained from 124 untreated female adults (average age: 17.6 ± 3.8 years). Class I (CI), Class II Division 1 (CII/1) and Class II Division 2 (CII/2) malocclusions were divided into three subgroups according to their vertical morphology as hypodivergent, normodivergent and hyperdivergent. The multivariate variance analysis (MANOVA) method was used in the comparison of measurement values according to vertical and sagittal morphology. The relationship between both A point-Nasion-B point (ANB) and Frankfurt-mandibular plane (FMA) angles and dental arch measurements was examined by Pearson correlation analysis. The significance level was received as p < 0.05. Results: While vertical morphology has a statistically significant effect on mandibular arch length, sagittal morphology affects maxillary arch depth. The parameters influenced by both morphologies are maxillary and mandibular arch length, as well as maxillary intermolar width. The mandibular arch length was significantly shorter in hyperdivergent-CII-2 malocclusion (50.5 ± 7.4 mm). Larger values were obtained in both mandibular arch length and maxillary arch depth measurements in CII-1 malocclusion compared to CII-2 malocclusion. The maxillary intermolar width was significantly shorter in hypodivergent-CII-1 malocclusion (46.8 ± 3.4 mm), while it was higher in hypodivergent-CI malocclusion (51.1 ± 3.4 mm). The maxillary arch length was the lowest in hyperdivergent-CI malocclusion (63.1 ± 13.3 mm) and the highest in hypodivergent-CI malocclusion (72.8 ± 7.6 mm). Additionally, a positive but weak correlation was found between ANB and FMA angles. Conclusion: Dental arch measurements have been found to be affected by both vertical facial morphology and skeletal sagittal relationship. A positive correlation was found between ANB and FMA angles.

Patient perceptions and attitudes regarding post-orthodontic treatment changes.

OBJECTIVES: To determine patient perceptions and attitudes regarding posttreatment changes at least 2 years after completion of orthodontic treatment. MATERIALS AND METHODS: A total of 125 patients (75 females, 50 males, aged 22.93 ± 2.98 years) were enrolled at least 2 years after debonding. Participants had either vacuum-formed retainers (VFRs) or bonded retainers (BRs). Posttreatment changes were evaluated digitally by comparing tooth positions at debonding and at least 2 years after debonding. A questionnaire was used to assess patient attitudes. Retainer usage, awareness of relapse, satisfaction with their current occlusion, and whether posttreatment changes were severe enough for them to consider retreatment were investigated. RESULTS: All patients showed some posttreatment changes in irregularity. Only 74% of patients wearing VFRs and 47.1% of patients wearing BRs were aware of posttreatment changes. Patients were more likely to notice posttreatment changes if there was an increase in mandibular irregularity of 1-3 mm. Awareness of posttreatment changes in the upper arch was higher in both groups. The majority of participants were satisfied with the results even if they noticed some minor posttreatment changes (VFR, 69.4%; BR, 76.5%). Dissatisfaction with posttreatment changes did not necessarily mean that a patient wanted retreatment. CONCLUSIONS: A total of 26% of patients wearing VFRs and 52.9% of patients wearing BRs were unaware of posttreatment changes. Approximately half of the patients who noticed posttreatment changes were still satisfied with the result 2 years after debonding. Even patients dissatisfied with the effect of posttreatment changes do not necessarily want retreatment.

Changes in Orbicularis Oris Superior and Masseter Muscle Activities After Upper Incisor Protrusion in Class II Division 2 Malocclusion: An Electromyographic Study.

OBJECTIVE: This prospective study aimed to evaluate the orbicularis oris superior and masseter muscle activity changes after upper incisor protrusion in CII/2 malocclusion. METHODS: A total of 20 patients (mean age 10.29 ± 0.90 years) with CII/2 malocclusion were selected for the study group. A total of 15 patients (mean age 10.56 ± 1.06 years) with Angle Class I malocclusion were recruited as control. Upper incisors were protruded with utility arch in the study group. Muscle activities were evaluated with Biopac MP150 surface electromyography device before and after upper incisor proclination and at the 6-month retention. Orbicularis oris superior and left-right masseter muscles were recorded during rest electromyography and maximum contraction electromyography. Repeated measures and two-way repeated-measures analysis of variance with Bonferroni correction were used for statistical analysis. RESULTS: A significant change occurred over time in orbicularis oris superior (P < 0.001), left masseter (P < 0.01) and right masseter (P < 0.05) maximum contraction electromyography in the CII/2 group. However, a significant difference was not found between groups P > 0.05. In the CII/2 group, orbicularis oris superior maximum contraction electromyography value was increased after upper incisor protrusion and this increase remained stable. Left masseter and right masseter maximum contraction electromyography measurements were decreased after protrusion and then increased after retention significantly. Rest electromyography values for all muscles were not statistically significant. No significant differences with the control group were found. CONCLUSION: Upper incisor protrusion increased orbicularis oris superior activity and the increase remained stable after retention. Masseter activities decreased after protrusion and then increased to the initial values. These changes did not show significant differences with the control group.