Tridimensional Changes in Mandibular Arch after Rapid Maxillary Expansion Therapy: A Clinical Study.

Aim: The upper jaw transverse deficit is certainly one of the most common clinical issues in the orthodontic field. It can be due to skeletal or dental factors, and its etiology may be both genetic and environmental. Rapid maxillary expanders (RMEs) are certainly the most effective appliance for upper transverse deficiency correction. The aim of this study was to evaluate the changes that occurred in the mandibular arch during treatment with RMEs in growing subjects by analyzing tridimensional lower digital casts. Materials and Methods: The study group (SG) consisted of 20 subjects (10 M, 10 F; mean age 9.4 ± 2.8 years old) randomly selected at the Department of Orthodontics at the University of Rome, "Tor Vergata". The inclusion criteria were negative posterior transverse interarch discrepancy ≥ 4 mm, mixed dentition phase with first permanent molars erupted, and prepubertal skeletal maturation stage (CS1-2), evaluated on a lateral radiograph through the Cervical Vertebral Maturation method. The SG was compared to an untreated control group (CG) of 20 subjects (10 M, 10 F, mean age 8.7 ± 2.3 years old) enrolled with the same inclusion criteria. The SG was treated by using RMEs. Dental casts of the lower arch were taken at two different times (T0-T1 = 6 months). All the dental casts were scanned with an OrthoXscan (Dentaurum 6mmbh E Co., Ispringen, Germany) and twenty points on the mandibular arch were digitized using Viewbox software. A Student t-test was used to compare the means of the quantitative variables associated with the effect of the device over time T0 and T1. Results: The results show a statistically significant increase (p < 0.05) in the intercanine and the intermolar diameters between the times T0 and T1 when compared to the CG. Conclusions: Rapid maxillary orthopedic expansion may achieve an increase in mandibular intercanine and intermolar diameter.

Upper arch dimensional changes with clear aligners in the early mixed dentition : A prospective study.

BACKGROUND: One goal of orthodontic treatment in mixed dentition is to expand the maxillary arch to allow proper tooth alignment and a correction of sagittal and vertical malocclusions. However, for most treatment protocols, expected outcome is not really clear to allow for a standardization of phase I orthodontic treatments. This lack of information makes it difficult for clinicians to predict tooth movements, including transverse expansion efficacy with Invisalign® (Align Technology, Santa Clara, CA, USA) in children. Therefore, the aim of the present study was to evaluate the transverse maxillary arch development with the Invisalign First System® in growing subjects. METHODS: The study group included 23 subjects (9 females, 14 males, mean age 9.4 ± 1.2 years). Patients were treated nonextraction with Invisalign First System® clear aligners with no auxiliaries other than Invisalign® attachments. Transverse interdental widths were measured only in the upper arch on each model at the start (T1) and at the end (T2) of treatment. A paired t­test was chosen to compare T2-T1 changes. The level of significance was set at 5%. RESULTS: The greatest increase of maxillary width was detected at the level of the upper first deciduous molars (+3.7 ± 1.4 mm; P < 0.001), followed by the level of the second deciduous molars (+3.4 ± 1.6 mm; P < 0.001) and by the deciduous canine (+2.6 ± 2.0 mm; P < 0.001). Upper first molars showed a greater expansion in the intermolar mesial width (+3.2 ± 1.2 mm; P < 0.001) than in the intermolar distal (+1.7 ± 1.2 mm; P < 0.001) and transpalatal width (+1.2 ± 1.2 mm; P < 0.01). CONCLUSIONS: The Invisalign First System® can be considered effective in growing patients who require maxillary arch development. The greatest net increase was detected at the level of upper first deciduous molars, whereas the upper first molars showed a greater expansion in the intermolar mesial width due to a rotation that occurs around its palatal root.

Mandibular morphometric analysis in open bite early treatment relapse subjects: a retrospective observational pilot study.

BACKGROUND: The purpose of this retrospective study was to evaluate the mandibular shape differences between a group of success and a group of failure Anterior Open Bite (AOB) malocclusion early orthodontic treatment in growing subjects, in order to identify mandibular features of relapse. METHODS: Twenty three patients (7 males, 16 females, 9.3 years ±1,5 years) were enrolled from the Department of Orthodontics at the University of Rome Tor Vergata. Inclusion criteria were: white ancestry, overbite < 0 mm, mixed dentition phase, end-to-end or Class I molar relationship, first skeletal class assessed on lateral cephalograms (0° < ANB < 4°), cervical skeletal maturation CS1-CS2, no previous orthodontic treatment, no congenital diseases. Pre-treatment (T1) lateral cephalograms were acquired. Each patient underwent early orthodontic treatment with Rapid Maxillary Expander (RME) and Bite Block (BB) or Quad-Helix Crib (QHC) until open bite correction. Radiographic records were recollected at T2 (permanent dentition, skeletal cervical maturation CS3-CS4). Mean interval time T2-T1 was 4.2 years ±6 months. According to treatment stability, a Relapse Group (RG 11 patients, 3 M, 8F; 13.7 years ±8 months, 7 subjects treated with RME/BB, 4 with QH/C) and a Success Group (SG, 12 patients, 4 M, 8F; 13.4 ± 10 months, 7 subjects treated with QH/C, 5 with RME/BB) were identified. On the lateral radiographs the mandibular length (Co-Gn), the inferior gonial angle (NGo^GoMe) and the antegonial notch depth (AND) were analyzed. Then the mandibular Geometric Morphometric analysis (GMM) was applied. Intergroup statistically significant differences were found using student's t-tests. Procrustes analysis and principal component analysis (PCA) were performed for the GMM. RESULTS: At T1 no statistically significant differences were found between RG and SG, however higher values of antegonial notch depth were found in RG. T2-T1 comparison showed in RG statistically significant increases in Co-Gn (p = 0.04), NGo^GoMe angle (p = 0.01) and antegonial notch depth (p = 0,04). PC1 confirmed the increase in the antegonial notch depth in RG when compared to SG at T2. CONCLUSIONS: The increased antegonial notch depth associated with the increased mandibular length and the increased gonial angle could be responsible of relapse of early orthodontic treatment in open bite growing subjects.

Analysis of Maxillary First Molar Derotation with Invisalign Clear Aligners in Permanent Dentition.

The objective of this study was to examine the distal rotation of mesial rotated maxillary first permanent molars in a sample of Class II dental malocclusion adult patients treated with Invisalign Clear Aligners (CA). Forty patients (20 males, 20 females, 22.4 ± 3.9 years) were included in the study sample (Department of Orthodontics of University of Rome "Tor Vergata"). Inclusion criteria were: Caucasian ancestry, complete permanent dentition with fully erupted upper second molars, Class II molar relationship, absence of tooth or craniofacial anomalies or caries and periodontal diseases. Pre-treatment (T1), post-treatment (T2) digital casts, and final ClinCheck simulation models (T2CC) were analysed. To measure the rotation of maxillary first molars, Henry's angle (H°) was evaluated. Maxillary first molars with an H° > 11° were considered mesio-rotated (in total 59 teeth). The treatment CA protocol included disto-rotation without distalization movements. At T1, T2 and T2CC five measurements on the collected dental casts were analysed: Henry's angle (H°); mesial buccal expansion (ME); distal buccal expansion (DE); mesial buccal sagittal (MS); and distal buccal sagittal (DS). A comparison between the results of T2-T1 and T2CC-T2 was performed using a paired t-test. The differences between T2-T1 highlighted a significant distal rotation of the maxillary first molars (−7.4°) and an expansion movement of 2.20 mm for ME and 1.50 mm for DE. In the post-treatment, the mesial buccal cusps shifted of 1.0 mm, while the distal buccal cusps showed a distal movement of 0.9 mm. Analysing the H° comparison between T2CC-T2, the difference was −1.1°. The T2CC-T2 comparison in the sagittal plane showed a difference of 0.9 mm for the MS and 0.7 mm for the DS. The accuracy was 82% for molar derotation movement. In conclusion, CA provides the upper arch expansion associated with the upper first molars' distal rotation. These movements provide 2 mm of improvement in arch perimeter and molar intercuspation.

Evaluation of the Upper Arch Morphological Changes after Two Different Protocols of Expansion in Early Mixed Dentition: Rapid Maxillary Expansion and Invisalign® First System.

Background: The objective of this retrospective study was to analyze the morphological changes of the upper arch after two protocols of expansion, the Invisalign® First system and rapid maxillary expansion (RME), in mixed dentition by means of geometric morphometric analysis (GMM). Methods: Digital dental casts of 32 children treated either with RME (RME group: 17 subjects; mean age 8.1 years) or the First system (First group: subjects; mean age 8.4 years) were collected. For both the RG and FG, pre-(T1) and post-treatment(T2) digital models were created. A total of 14 landmarks were digitized and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. Results: The PC1 resulting from the T2-T1 comparison in the RG g showed statistically significant morphological changes in the posterior region of the upper arch shape, without significant variations in the anterior region. The comparison of the T2-T1 changes in the FG showed an increase in the transverse dimension at the level of the canine and the first deciduous molar widths, with morphological variation in the anterior region due to frontal teeth alignment. Conclusions: The First system induced shape modifications of the upper arch during expansion in contrast to RME. The FG presented an improvement in the maxillary arch shape, while the RG maintained the initial triangular shape.

Comparison of the dento-skeletal effects produced by Leaf expander versus rapid maxillary expander in prepubertal patients: a two-center randomized controlled trial.

OBJECTIVE: This study aimed to compare the skeletal and dentoalveolar effects produced by slow maxillary expansion (SME) with the Leaf expander versus the conventional rapid maxillary expansion (RME) on digital dental casts, lateral and postero-anterior cephalometric radiographs. TRIAL DESIGN: This is a superiority, two-center, two arms parallel balanced randomization trial. METHODS: Patients in the mixed dentition were included with a transverse interarch discrepancy of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group) was compared to a conventional RME screw (RME group). The primary response variable was the difference in maxillary intermolar width (U6-U6) measured at baseline (T0) and one-year follow-up (T1) on the digital dental casts. Other dento-skeletal variables were also measured on digital dental casts and cephalograms. Computer-generated block randomization was used with allocation concealed in sequentially numbered opaque sealed envelopes. The examiner was blinded on the type of expander used. Linear models were used for statistical analysis. RESULTS: Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. U6-U6 did not show a statistically significant difference between the two groups (-0.4 mm in favor of the RME group, 95% CI from -1.2 to 0.5, P = 0.365). As for the other secondary variables no statistically significant differences were found between the two groups except maxillary intercanine width (U3-U3, -0.9 mm in favor of the RME group, 95%CI from -1.5 to -0.3, P = 0.005) and maxillary skeletal width (Mx-Mx, -1.4 mm in favor of the RME group, 95%CI from -2.4 to -0.3, P = 0.013). CONCLUSIONS: No significant differences between the RME and Leaf groups were detected for any of the analyzed dento-skeletal variables except the T1-T0 differences in U3-U3 and Mx-Mx that were significantly greater in the RME group. REGISTRATION: The study was registered in the ISRCTN register on 08/11/2016 with the number ISRCTN18263886. FUNDING: No funding or conflict of interest to be declared.

Palatal vault morphometric analysis of the effects of two early orthodontic treatments in anterior open bite growing subjects: a controlled clinical study.

BACKGROUND: The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM). METHODS: AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. RESULTS: At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs. CG demonstrated a slight transversal maxillary expansion. CONCLUSIONS: RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Maxillary arch development with Invisalign system.

OBJECTIVES: To evaluate tooth movements during maxillary arch expansion with clear aligner treatment. MATERIALS AND METHODS: The study group included 28 subjects (16 females, 12 males, mean age 31.9 ± 5.4 years) collected prospectively from January 2018 to May 2019. Inclusion criteria were European ancestry, posterior transverse discrepancy of 3-6 mm, permanent dentition stage, presence of second permanent molars, mild or moderate crowding, and good compliance with aligners. Treatment protocol included nonextraction strategies, application of Invisalign clear aligner system, and no auxiliaries other than Invisalign attachments. Linear and angular measurements were performed before treatment (T1), at the end of treatment (T2), and on final virtual models (T2 ClinCheck). A paired t-test was used to compare T2-T1 and T2-T2 ClinCheck changes. The level of significance was set at 5%. RESULTS: Statistically significant differences were found for all measurements, except for ones at the upper second molars. The greatest increase in maxillary width was detected at the upper first and second premolars: +3.5 mm for the first premolar and +3.8 mm for the second premolar at T2. Comparison of T2-T1 angular outcomes showed statistically significant changes in the inclinations of all teeth except for the second permanent molars. T2-T2 ClinCheck showed significant differences for both linear and angular measurements for maxillary canines, resulting in poor predictability. CONCLUSIONS: Maxillary arch development revealed a progressive reduction of the expansion rate and buccal tipping in the anterior, lateral, and posterior regions, with the greatest net increase at the first and second premolars. Clinical attention should be paid to maxillary canine movements, and overcorrection should be planned for them during dentoalveolar expansion.

Comparison between two screws for maxillary expansion: a multicenter randomized controlled trial on patient's reported outcome measures.

OBJECTIVE: The objective of this study was to compare an expansion screw of the maxilla that generates moderate and continuous forces versus a conventional screw for rapid maxillary expansion (RME) on patient-reported outcome measure during the first 12 weeks of treatment. TRIAL DESIGN: This is a superiority, multicenter, two-arm parallel balanced randomization trial. METHODS: Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group, treated with an expansion screw with Ni-Ti springs) was compared to a conventional RME screw that generates intermittent heavy forces (RME group). The primary response variable was the visual analogue scale (VAS) on pain calculated in the first 12 weeks of therapy. The VAS on difficulty on speaking and oral hygiene, patient satisfaction, and complications were also evaluated. A computer-generated block randomization was used with allocation concealed in sequentially numbered opaque-sealed envelopes. Blinding was not applicable. Linear models were used for statistical analysis. RESULTS: Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. The mean of the VAS for pain was 0.3 ± 0.4 in the Leaf group and 0.6 ± 0.5 in the RME group. The difference was -0.3 (95 per cent CI from -0.5 to -0.0; P = 0.017) in favour of the Leaf group. The difference in pain was marked in the first week (Leaf group 2.2 ± 2.3; RME group 3.7 ± 2.6; difference -1.5; 95 per cent CI from -2.7 to -0.3; P = 0.019). CONCLUSIONS: Patients in the Leaf group experienced a lower degree of pain, especially during the first week following the application of the expander. For the other variables, no significant differences were reported between the two treatments. REGISTRATION: The study was registered in the ISRCTN register on 8 November 2016 with the number ISRCTN18263886.

Changes in mandibular shape after early treatment in subjects with open bite: a geometric morphometric analysis.

OBJECTIVES: To evaluate the mandibular modifications in anterior open bite (OB) growing subjects treated with Rapid Maxillary Expansion and bite block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Method (GMM) and conventional cephalometric. MATERIALS: The OB group comprised 34 subjects (26 girls, 8 boys) with dentoskeletal OB and a mean age of 8.0 ± 1.0 years. OB group was divided in two subgroups: RME/BB group comprised 17 subjects (13 girls, 4 boys), while QH/C group included 17 subjects (13 girls, 4 boys). The two subgroups were compared with a CG of 17 subjects (13 girls, 4 boys) matched for sex, age, vertical pattern, and observation periods. Two consecutives lateral cephalograms were available: the first one was taken before treatment (T1), and the second one was acquired at a follow-up observation at least 4 years after the completion of treatment (T2). Landmarks and semilandmarks were digitized on lateral cephalograms and GMM was applied. Procrustes analysis and principal component analysis were performed. Analysis of variance (ANOVA) with Tukey post hoc tests was used to compare the T2-T1 cephalometric changes between the RME/BB, QH/C, and CG. RESULTS: In the long term, RME/BB showed a significantly greater decrease of the Condylar axis to mandibular plane angle when compared to CG and QH/C. GMM showed an increased in height of the mandibular ramus in RME/BB group with tendency to counterclockwise rotation of the mandible when compared with QH/C and CG groups. CONCLUSIONS: RME/BB subjects showed significant changes in the shape of the mandibular ramus with a counterclockwise rotation tendency when compared with QH/C and CG subjects.

3D evaluation of maxillary morphology in Marfan growing subjects: a controlled clinical study.

BACKGROUND: Marfan syndrome is a rare autosomal dominant inherited disease of the connective tissue associated with various craniofacial abnormalities. Aim of the present study was to assess the variability of palatal shape in a sample of 31 Marfan patients compared to a control group of no syndromic subjects, in two stages of dentition, by using 3D geometric morphometric analysis. METHODS: Thirty one growing subjects with Marfan syndrome were selected and divided into two subgroups: MG1 with mixed dentition (10 M, 6F, mean age 7+/- 0.7 years), MG2 with permanent dentition (8 M, 7F, mean age 13+/- 0,5 years). Each subgroup was compared to a control group (CG1 mixed dentition, 9 M, 7F, mean age 7.6+/- 0.5 years; CG2 permanent dentition, 9 M, 6F, mean age 12.8+/- 0.7 years) matched on age, sex distribution, stage of dentition and skeletal maturation. Then the two subgroups were compared one to each other. For each patient maxillary dental casts were taken, scanned and digitized. 3D geometric morphometric methods were applied. Procrustes analysis was used and principal component analysis was performed to reveal the main patterns of palatal shape variation. RESULTS: Both Marfan subgroups showed important reductions in the transversal plane associated with a deep palatal vault when compared to the control groups (MG1 vs CG1 P = 0,003; MG2 vs CG2 P = 0,07). Moreover a statistically significant difference between the palatal shape of MG1 and MG2 was found (P = 0.017) showing a significant worsening of palatal depth and constriction from mixed to permanent dentition in Marfan subjects. CONCLUSION: Marfan subjects showed a specific palatal morphology with maxillary constriction and deeper palatal vault when compared to a control group of healthy subjects. The constriction and the depth of the palatal vault in Marfan patients worsen from mixed dentition to permanent dentition more then in no syndromic subjects.

Geometric morphometric analysis of the palatal morphology in growing subjects with skeletal open bite.

OBJECTIVES: To assess the morphological shape variations of the palatal vault in Open Bite (OB) growing subjects when compared with a Control Group (CG) by means of Geometric Morphometric Method (GMM). MATERIALS AND METHODS: The OB Group (OBG) consisted of 75 subjects (39 females, 36 males; mean age: 8.5 ± 0.8 years) who were collected retrospectively with the following inclusion criteria: European ancestry, overbite less than 0 mm, mixed dentition stage, prepubertal skeletal maturation (CS1-CS2), hyperdivergent skeletal pattern (SN^GoGn > 37°). The OBG was compared with a CG of 46 prepubertal subjects presenting normal occlusion (24 females, 22 males; mean age of 8.3 ± 1.7 years). For each subject, lateral cephalograms and maxillary dental casts were available. Landmarks and semilandmarks were digitized on digital dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. OBG was divided in two subgroups: Sucking Habits Group (SHG) (39 subjects) and Non-Sucking Habits Group (NSHG) (36 subjects). RESULTS: PC1 showed significant morphological changes in transverse and vertical dimensions with OBG palates higher and narrower when compared with CG. When comparing the two subgroups no statistically significant differences were found. NSHG demonstrated a slight reduction of the transverse dimension and a deeper palatal vault respect to SHG. LIMITATIONS: The limitations of this study were the division of OBG in two subgroups based on referral of thumb sucking habits without assessing the duration and the intensity of thumb sucking. CONCLUSIONS: OB subjects presented with a significant constriction of the maxillary arch when compared with CG. The morphological palatal shape variations in OBG were not influenced by the presence or absence of non-nutritive sucking habits.

Clear aligners' effects on aesthetics: evaluation of facial wrinkles.

BACKGROUND: To evaluate the facial aesthetic effects of orthodontic treatment performed with clear aligners and to compare it to an untreated control group, on lower third facial ageing in adult patients through the use of the Wrinkle Severity Rating Scale (WSRS) at the beginning (T0) and at the end (T1) of the study period. MATERIAL AND METHODS: A clear aligners treated group (TG) of 68 patients was compared to a control group of 33 untreated patients (UG). Each group was divided in 2 subgroups according to age: subgroup 1 if under 40 years of age and subgroup 2 if over. Facial aesthetics of the lower third was evaluated at T0 and T1 by a panel of five aesthetic experts with WSRS. RESULTS: Statistically significant changes were found in all subgroups comparing WSRS scores at T0 and T1. The between group comparisons revealed that wearing clear aligners produces a statistically relevant improvement in lower third facial aesthetics both in younger (p< 0.05) and older (p< 0.001) patients. CONCLUSIONS: The present retrospective cohort study has successfully shown that malocclusion therapy conducted through the use of clear aligners in a population of adults affected by dental crowding has beneficial effects on lower third facial ageing. Key words:Orthodontics, clear aligners, facial aesthetics, facial wrinkles, compliance.

Movement of anterior teeth using clear aligners: a three-dimensional, retrospective evaluation.

BACKGROUND: Clear aligner treatment offers several advantages, but the available literature shows that some kind of tooth movements are unpredictable. In addition, the majority of the studies are focused on one clear aligner system, while different characteristics of various systems can provide different treatment outcomes. The aim of the present retrospective cohort study was to evaluate the predictability of Nuvola® aligner system in achieving torque movements of anterior teeth. METHODS: Thirty-nine adult patients, who were consecutively treated with clear aligners, were retrospectively selected, and digital models pre-treatment (T0), post-treatment (T1) and the digital setup models (TS) were collected. Only the first phase of treatment made of 12 aligners was considered for the present study. Torque of anterior teeth was measured as labiolingual inclination on digital models at T0, T1, and TS using VAM software. Any difference between the predicted and achieved torque movements was evaluated using Wilcoxon signed-rank test or paired sample t test. First-type error was set as p < 0.008. RESULTS: No statistically significant difference was found for all the anterior teeth between predicted and achieved torque movements. CONCLUSIONS: The studied clear aligner system was able to produce clinical outcomes comparable to the planning of the digital setup relative to torque movements of the anterior teeth.

Morphometric covariation between palatal shape and skeletal pattern in Class II growing subjects.

OBJECTIVES: To evaluate the patterns of covariation between palatal and craniofacial morphology in Class II subjects in the early mixed dentition by means of geometric morphometrics. METHODS: A cross-sectional sample of 85 Class II subjects (44 females, 41 males; mean age 8.7 years ± 0.8) was collected retrospectively according to the following inclusion criteria: European ancestry (white), Class II skeletal relationship, Class II division 1 dental relationship, early mixed dentition, and prepubertal skeletal maturation. Pre-treatment digital 3D maxillary dental casts and lateral cephalograms were available. Landmarks and semilandmarks were digitized (239 on the palate and 121 on the cephalogram) and geometric morphometric methods (GMM) were applied. Procrustes analysis and principal component analysis (PCA) were performed to reveal the main patterns of palatal shape and craniofacial skeletal shape variation. Two-block partial least squares analysis (PLS) assessed patterns of covariation between palatal morphology and craniofacial morphology. RESULTS: For the morphology of the palate, the first principal component (PC1) described variation in all three dimensions. For the morphology of the craniofacial complex, PC1 showed shape variation mainly in the vertical direction. Palatal shape and craniofacial shape covaried significantly (RV coefficient: 0.199). PLS1 accounted for more than 64 per cent of total covariation and related divergence of the craniofacial complex to palatal height and width. The more a Class II subject tended towards high-angle divergence, the narrower and higher was the palate. CONCLUSIONS: Class II high-angle patients tended to have narrower and higher palates, while Class II low-angle patients were related to wider and more shallow palates.

Geometric morphometric analysis of the palatal morphology in children with impacted incisors: A three-dimensional evaluation.

OBJECTIVE: To analyze variations in palatal morphology in subjects presenting unilaterally impacted maxillary permanent central incisors compared with a control group of subjects without eruption anomalies using a three-dimensional (3D) analysis. MATERIALS AND METHODS: Twenty-six white subjects (10 girls and 16 boys; mean age 9.5 ± 1.5 years) with unilaterally impacted maxillary permanent central incisors (impacted incisor group [IIG]) were compared with a control group (CG) of 26 subjects (14 girls and 12 boys, mean age 8.7 ± 1.6 years) presenting no eruption disorders. For each subject, dental casts were taken and the upper arch was scanned using a 3D laser scanner. To study the entirety of the shape of the palate in any point of the surface, 3D geometric morphometrics was applied. RESULTS: Subjects with impacted maxillary incisors showed skeletal adaptations of the maxilla. In the IIG, both the superior palatal region and lateral palatal surface showed significantly different morphology when compared with CG, with a narrower and higher palatal vault. CONCLUSION: The absence of maxillary central incisors over the physiological age of eruption influenced the development of the palatal morphology compared with subjects without eruption anomalies.

Post-traumatic impaction of maxillary incisors: diagnosis and treatment.

AIM: To provide clinicians with useful information for immediate diagnosis and management of impacted maxillary incisors due to trauma. METHODS: We present a case of post-traumatic impaction of a central right maxillary incisor in a young patient. The treatment plan consisted in the interceptive management (surgical and orthodontic), the valuation of the necessary space to move the impacted tooth in the normal position and the biomechanical approach for anchorage, avoiding prosthetic/implants replacement. RESULTS: THE THERAPY OF AN IMPACTED MAXILLARY INCISOR DUE TO TRAUMA REQUIRES A MULTIDISCIPLINARY APPROACH: orthodontic, surgical, endodontic and periodontal considerations are essential for successful treatment. CONCLUSIONS: SURGICAL EXPOSURE AND ORTHODONTIC TRACTION IS THE TREATMENT MOST OFTEN USED IN CASE OF POSTTRAUMATIC IMPACTED INCISOR: this technique in fact can lead to suitable results at the periodontal, occlusal and esthetics levels at an early stage and more definitively than with other treatment options.

Impacted maxillary incisors: diagnosis and predictive measurements.

BACKGROUND: When the incisors do not erupt at the expected time, it is crucial for the clinician to determine the etiology and formulate an appropriate treatment plan. AIM: THE AIM OF THIS REPORT IS TO PROVIDE USEFUL INFORMATION FOR IMMEDIATE DIAGNOSIS AND MANAGEMENT OF IMPACTED MAXILLARY INCISORS USING THE INTERCEPTIVE TREATMENT: removal of obstacles and rapid maxillary expansion (RME). DESIGN: An accurate diagnosis may be obtained with clinical and radiographic exam such as panoramic radiograph, computerized tomography (CT) and cone beam computerized tomography (CBCT). It's important to know the predictive measurements of eruption evaluated on panoramic radiograph: distance from the occlusal plane, maturity, angulation and vertical position of the unerupted incisors. Early diagnosis is important and interceptive orthodontic treatment, such as removal of obstacles and orthopedic rapid maxillary expansion (RME), may correct disturbances during the eruption through recovering space for the incisors and improving the intraosseus position of delayed teeth. RESULTS: RME treatment following the surgical removal of the obstacle to the eruption of maxillary incisors leads to an improvement of the intraosseus position of the tooth. CONCLUSIONS: The angulation and the vertical position of the delayed tooth appear to be important in trying to predict eruption. The improvement of the intraosseus position of the unerupted incisor, obtained by removal of the odontoma and rapid maxillary expansion, permits a conservative surgery and the achievement of an excellent esthetics and periodontal result.