The Use of CAD/CAM Technology in Mandibular Canine Disimpaction: A Case Report.

This case report of an 11-year-old subject shows the digital workflow for the management of an impacted mandibular canine using Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) technology along with Temporary Anchorage Devices (TADs). The miniscrew insertion site was planned using software, and a surgical guide was digitally designed and 3D printed. Orthodontic traction was performed using a 3D-designed and -printed device. In a single sitting, the miniscrew was inserted and the disimpaction device was also delivered. The primary objective of recovery and the repositioning of the impacted mandibular canine in the axis with its eruptive path was achieved. The space available and the subject's early stage of mixed dentition was considered favourable to a spontaneous eruption. This case report shows how CAD/CAM digital technology, combined with 3D printing, enables the creation of a surgical guide to position the miniscrew and the customized devices used for mandibular canine disimpaction. CAD/CAM surgical guides can help clinicians to position TADs with more accuracy and predictability, ensuring high quality bone support offering primary stability. Although orthodontic traction is the most complex therapeutic choice to implement, with the aid of CAD/CAM technology it is possible to proceed with accurate and minimally invasive orthodontic traction in order to recover a mandibular canine.

Local factors relating to mandibular canine impaction: A retrospective study.

INTRODUCTION: This study aimed to investigate the characteristics of impacted and transmigrated mandibular canines and the association existing between them and some local factors, such as degrees of axial inclination of mandibular incisors, skeletal Class, and mandibular symphysis width. METHODS: A retrospective observational study was performed on the medical records and radiographic examination (panoramic radiographs and lateral cephalograms) of 102 orthodontic patients divided into a study group, with at least 1 impacted mandibular canine (51 subjects) and a control group, without mandibular impaction (51 subjects). A chi-square test, t test, and analysis of variance test analysis were used to analyze the data. RESULTS: Unilateral and buccal impaction and the presence of the deciduous canine were the more prevalent characteristics of impacted canines, whereas 39.2% presented transmigration. Furthermore, the persistence of the deciduous canine on the impaction side (P <0.0001) and the mesial axial inclination of the impacted canine (P <0.0001) were found to be statistically significant characteristics. A statistically significant association was found between the impaction of the mandibular canine and mandibular incisor to the mandibular plane angle (IMPA) (IMPA, 95.8°; P = 0.009). An additional statistically significant association was found with transmigrated canines (IMPA, 96.8°; P = 0.024). CONCLUSIONS: The mesialization of the canine cusp and the persistence of the mandibular deciduous canine are characteristics frequently found in the impaction of the mandibular canine. An accentuated vestibular inclination of the mandibular incisors is significantly associated with mandibular canine impaction.

Accuracy Of Imaging Software for 3d Rendering of Tooth Structures, Usable in Clinical Settings.

AIM: The aim of this study was to evaluate the segmentation accuracy of dentition testing four free-source semi-automatic software. MATERIALS AND METHODS: A total of 20 cone-beam computed tomography (CBCT) were selected to perform semi-automatic segmentation of maxillary and mandibular dentition. The software tested were Invesalius, ITK-Snap, 3D Slicer and Seg3D. Each tooth model was also manually segmented (Mimics software) and set as the gold standard (GS) reference of the investigation. A specific 3D imaging technology was used to perform the superimposition between the teeth models obtained with semi-automatic software and the GS model, and to perform the surface-to-surface matching analysis. The accuracy of semi-automatic segmentation was evaluated calculating the volumetric mean differences (mean bias and limits of agreement) and the percentage of matching of the tooth models compared to the manual segmentation (GS). Qualitative assessments were performed using color-coded maps. All data were statistically analysed to perform software comparisons. RESULT: Statistically significant differences were found in the volumetric and matching percentage data (p < 0,05). Invesalius was the most accurate software for 3D rendering of the dentition with a volumetric bias (Mimics) ranging from 4,59 mm3 to 85,79 mm3; instead, ITK-SNAP showed the higher volumetric bias, ranging from 30,22 mm3 to 319,83 mm3. The dis-matched area was mainly located at the radicular region of the teeth. Volumetric data showed excellent inter-software reliability with coefficient values ranging from 0,951 to 0,997. CONCLUSIO: Different semi-automatic software algorithms could generate different patterns of inaccuracy error in the segmentation of teeth.

Can computer-guided surgery help orthodontics in miniscrew insertion and corticotomies? A narrative review.

Orthodontics has considerably increased the use of technology combined with surgery as a tool to improve dental movements in terms of predictability, acceleration of movement, and fewer side effects. To achieve these goals miniscrews and corticotomy were introduced. The digital workflow permits an increase in the accuracy of surgical and orthodontic setups. The tool that transfers the information is the CAD/CAM (Computer-Aided Design/ Computer-Aided Manufacturing) template. The aim of this review is to illustrate the use of computer-guided surgery in orthodontics regarding miniscrews and piezocision. The search strategy was a combination of Medical Subject Headings (Mesh) and free text words for PubMed. A total of 27 articles were included in this review: 16 concerned miniscrews and 11 concerned corticotomy. The current need for faster treatments, the improved systems of anchorage, and the evolution of imaging technologies require operators to be knowledgeable of the digital workflow. CAD/CAM templates allow greater precision and predictability of miniscrew insertion even if in the hands of less experienced clinicians and permit a better orientation and depth of the cortical incision. In conclusion, digital planning makes surgery faster and easier and allows for the identification and correction of any potential problem before the procedure.

Efficacy and Accuracy of Maxillary Arch Expansion with Clear Aligner Treatment.

The aim of this work was to evaluate the efficacy and accuracy of maxillary arch transverse expansion using the Invisalign® clear aligner system without auxiliaries other than Invisalign attachments. Knowing the accuracy of a movement through a clear aligner system allows the clinician to plan the treatment with greater precision and to achieve the expected result faster. The study group included 28 patients with a mean age of 17 ± 3.2 years. The treatment protocol for all the selected patients included the application of the Invisalign® clear aligner system without auxiliaries, except for the Invisalign® attachments; in no case were tooth extraction or interproximal enamel reduction (IPR) performed. Linear measurements of the expansion were assessed before treatment (T0), at the end of treatment (T1), and on final virtual models by ClinCheck® (TC). A paired t-test was used to compare T0-T1 and T1-TC differences. A paired t-test was applied, and one normality was validated with the Shapiro-Wilks test. If normality was not met, the nonparametric test (Mann-Whitney U test) was applied. The level of significance was set at 5%. Statistically significant differences were found for all measurements at T0-T1. The results showed an average accuracy of efficacy of 70.88%. The differences in predictability between the various vestibular measurements (intercanine, inter-premolar, and intermolar) were not statistically significant, while they were for gingival measurements. The overall accuracy of the expansion treatment was 70%, regardless of tooth type.

Enamel Analysis by 3D Scanning after Three Orthodontic Clean-Up Procedures: An In-Vitro Test of a New Piezoelectric Tool.

(1) Background: To assess the clinical safety and efficacy of a new piezoelectric instrument for orthodontic clean-up; (2) Methods: An in-vitro comparative study on 75 teeth extracted for orthodontic reasons compared the tested method (Treatment 1) with two other procedures: One step finisher and polisher (Inverted cone One gloss Shofu Dental, Kyoto, Japan) (Treatment 2) and twelve-fluted tungsten carbide bur (123-603-00, Dentaurum, Pforzheim, Germany) and Sof-Lex discs Pop-On XT Kit (3M ESPE) (Treatment 3), with n:25 samples in each group. Clinical safety (enamel volume loss) and effectiveness (residual adhesive volume) were assessed using the structured light 3D scanner Atos Compact Scan (GOM GmbH) together with the support of Atos Professional software. The surfaces were scanned three times to assess: (i) the volume of the residual adhesive (RAV) after bracket removal; (ii) the volume of the relative residual adhesive (dAV) after the clean-up procedure; (iii) volume of the enamel loss (EVL); (3) Results: The mean RAV (mm3) was 0.239 ± 0.337; 0.069 ± 0.124, 0.120 ± 0.193 and the mean EVL (mm3) was 0.1870 ± 0.177, 0.187 ± 0.299 and 0.290 ± 0.205, for treatment 1, 2 and 3, respectively. The distribution was asymmetrical between groups in both cases; (4) Conclusions: The tested instrument proved to be effective and safe for post-orthodontic clean-up. With the increasing use of invisible aligners, the possibility of using an ergonomic and fast instrument is of benefit to both patient and practitioner.

Dental and skeletal features in subjects with missing maxillary lateral incisors: a case control retrospective study.

BACKGROUND: The aim of this study was to investigate the relationship between missing maxillary lateral incisors and the mesio-distal (MD) diameters of the teeth. Occlusal and skeletal characteristics of the patients have been analyzed. METHODS: Seventy-nine patients were included in the study (permanent dentition, mean age: 13.7): 30 subjects with uni- or bilateral maxillary lateral incisors agenesis (study group, SG) and 49 patients with no maxillary lateral incisors agenesis (control group, CG). Orthopanoramics, plaster models and cephalometric analysis were used to perform the evaluations. RESULTS: Compared to the CG, in the SG, most of the teeth had smaller MD diameter. In the bilateral agenesis subgroup, the average differences between teeth diameters were lower than those found by comparing them to the unilateral agenesis subgroup and to the SG. Overjet was reduced on average in the SG. In the SG were found less cases of cross-bite and scissor-bite, less frequency of impaction of at least one tooth and agenesis of other teeth, crowding only in the lower arch, square or ovoid arch shape in the upper arch and square in the lower arch, increased interincisal angle and decreased SN^GoMe. CONCLUSIONS: Upper lateral incisors agenesis, especially in cases of unilateral agenesis, is associated with MD teeth reduction. The agenesis of the upper lateral incisors is associated with a greater probability of agenesis affecting other teeth, molar and canine class II, reduced overjet and overbite, square or ovoid upper arch shapes, increased interincisal angle and reduced total divergence.

Evaluation of nasal airway resistance in a cohort of children with primary snoring and maxillary deficiency.

BACKGROUND: The aim of this study was to test whether rapid palatal expansion is effective to improve nasal airway patency in a sample of pediatric patients with primary snoring. METHODS: A group of 21 subjects, 11 girls (52%) and 10 boys (48%), with a mean age of 7.1 years (SD=1.3; range 4-9 years) were treated with a rapid maxillary expansion (RME) device. Nasal airway resistance was assessed via rhinomanometric exam before (pre-) and 6 months after (post-) the rapid palatal expansion treatment. RESULTS: Data analysis showed a statistically significant increase in the mean scores of the results of the rhinomanometric exam between the pre- and post-measurements with a significant reduction in total inspiratory and expiratory air resistance values after rapid palatal expansion. CONCLUSIONS: Our results show that RME treatment is associated with an improvement in nasal airway resistance due to a substantial reduction in nasal resistance associated with the orthopedic action of the orthodontic device.

Factors affecting duration of post-surgical orthodontics in the Surgery First/Early Approach: A retrospective study.

BACKGROUND: Surgery First Approach (SFA) and Surgery Early (SE) are considered promising alternatives, compared to the conventional three-stages orthodontic-surgical approach, for treatment of dento-maxillofacial deformities. However, many features need further study, like the role of the orthodontist. Aim of the study was to analyse the clinical characteristics of patients who underwent SFA and SE, and if differences in duration of orthodontics could be influenced by clinical features. METHODS: A retrospective research was performed on patients who met the inclusion criteria for SFA (31) and SE (12), of the total of patients affected by dento-facial deformities in our Unit (191) in the period 2012-2017. After collection of clinical data, duration of orthodontics, age, pre-treatment PAR Index, ANB angle, amount of the curve of Spee were compared. A regression analysis evaluated if these clinical parameters, together with type of bracket and type of intervention, could influence the duration of post-surgical orthodontics. RESULTS: All patients who performed the SFA/SE were affected by class III, II and active Unilateral Condylar Hyperplasia (22% of total population). Pre-treatment mean differences of age (p = 0.0518), PAR Index (p = 0.0916), curve of Spee (p = 0.1006) between groups were not statistically significant. A statically significant difference was found for the overall duration of therapy, for the significant shorter duration of pre-surgical orthodontics, while the difference of post-surgical orthodontics duration was not significant (p = 0.4753). Type of bracket (rho=-0.19039, p = 0.266) and intervention performed (rho=-0.11522, p = 0.5034) were not correlated with duration of post-surgical orthodontics, as well as pre-treatment PAR Index, ANB angle and depth of the curve of Spee. CONCLUSIONS: Surgery First/Early Approach is a therapeutic choice that could be performed only in patients affected by specific malocclusions and who exactly meet indications. Protocol and post-surgical occlusal stability are factors that should influence the duration of therapy more than clinical characteristics.

Smile esthetic: comparison of perception amongst orthodontists, dental students, orthodontic patients and surgical orthodontic patients

Most patients require orthodontic treatment to improve the esthetics of their smile. Orthodontists must consider how some parameters of mini-esthetics can influence the patient's esthetic perception. Methods: A photograph of the smile of a young female was taken and some modifications were made to the buccal corridor, gingival exposure, smile arc and midline position to assess the influence of these variables on smile attractiveness. Two hundred examiners were selected from four groups: orthodontists (O), dental students (DS), orthodontic patients (OP) and surgical-orthodontic patients (SOP). Each examiner was asked to complete the questionnaire with an approval rating from 1 to 10. Significant level was set at P ≤ 0.05. Results: Only orthodontists considered buccal corridors of 4mm and midline deviation of 1mm as non-esthetic; all other examiners considered gingival exposures ≥3 mm and midline angulation as non-esthetic. All examiners assigned higher satisfaction values to the photo with the concordant smile arc and defined as non-esthetic the covered smile and the reverse smile arc. Patients perceived as non-esthetic only midline deviations of 4mm. The surgical orthodontic patients assigned lower values to the photos and showed greater attention to evaluating the esthetics of the smile than the orthodontic patients. Conclusion: Smile arc, gingival exposure and midline angulation influence smile esthetics; the role of buccal corridors and midline deviation is dependent on the type of examiner

External root resorption (ERR) and rapid maxillary expansion (RME) at post-retention stage: a comparison between tooth-borne and bone-borne RME.

BACKGROUND: The study aimed to compare external root resorption (ERR) three-dimensionally in subjects treated with tooth-borne (TB) versus bone-borne (BB) rapid maxillary expansion (RME). Forty subjects who received tooth-borne RME (TB group, average age 13.3 years ± 1.10 years) or bone-borne RME (BB group, average age 14.7 ± 1.15 years) were assessed using CBCT imaging before treatment (T0) and after a 6-month retention period (T1). 3D reconstructions of the radicular anatomy of maxillary first molars (M1), first and second premolars (P1 and P2) were generated to calculate volumetric (mean and percentage values) and shape changes (deviation analysis of the radicular models) obtained at each time point. 2D assessment of radicular length changes was also performed for each tooth. Data were statistically analyzed to perform intra-group (different teeth) and inter-group comparisons. RESULTS: In both groups, all the investigated teeth showed a significant reduction in radicular volume and length (p < 0.05), with the first molars being the teeth most affected by the resorption process (volume and palatal root length). When volumetric radicular changes were calculated as a percentage of the pre-treatment volumes, no differences were found among the investigated teeth (p > 0.05). Based on the deviation analysis from radicular models superimposition, the areas most affected by shape change were the apex and bucco-medial root surface. Overall, the amount of ERR was significantly greater in the TB group (mm3: M1 = 17.03, P1 = 6.42, P2 = 5.26) compared to the BB group (mm3: M1 = 3.11, P1 = 1.04, P2 = 1.24). CONCLUSIONS: Despite the statistical significance, the difference in the amount of ERR of the posterior maxillary dentition between TB-RME and BB-RME remains clinically questionable.

Predictive Analysis of Maxillary Canine Impaction through Sella Turcica Bridging, Ponticulus Posticus Calcification, and Lateral Incisor Anomalies: A Retrospective Observational Study.

Maxillary canine impaction is an increasing dental anomaly and is often related to other dento-skeletal anomalies. The aim of this work is to support the clinician in evaluating the relationship between a displaced maxillary canine and clinical (the features of lateral incisors)/skeletal (ponticulus posticus and sella turcica bridging) anomalies through orthopanoramic radiographs, lateral cephalograms, and plaster casts to identify the parameters that best predict maxillary canine impaction. A retrospective observational study was carried out on the analysis of the medical records, radiographic findings (panoramic radiographs and lateral cephalograms), and plaster casts of 203 orthodontic patients divided into a case group, with at least one impacted maxillary canine, and a control group, without an impaction. A chi-square test and logistic regression analysis were used to analyze the data. A statistically significant association was found between the impaction of the maxillary canine and the female sex, the bridging of the sella turcica, the ponticulus posticus calcification, and the anomaly of the lateral incisor; a logistic regression revealed that these significant variables were found to be positive predictors of impacted maxillary canines, particularly in reference to the impaction in the palatal area. Finding one of these clinical and radiographic elements can represent a predictive sign of the possible impaction of the maxillary canine.

Accuracy of orthodontic models prototyped for clear aligners therapy: A 3D imaging analysis comparing different market segments 3D printing protocols.

OBJECTIVES: This study aimed to evaluate the accuracy of orthodontic models for the production of clear aligners generated with four 3D printers featuring different technologies and belonging to different market segments. MATERIALS AND METHODS: Eighty identical dental models were generated from two master digital files (.stl), respectively with aligned (AM group) and crowded dentition (CM group), and prototyped via four different 3D printers, i.e., Asiga Pro 4K65 (DLP technology, high-professional segment), Elegoo Mars Pro (LCD technology, entry-level segment), Form 3B (SLA technology, medium-professional segment) and Vector 3SP (SLA technology, industrial segment). Each 3D printed model was scanned and superimposed with the master file, and deviation analysis was used to evaluate trueness and precision (root mean square values). All data were statistically analyzed (p < 0.05). RESULTS: The trueness error was lower in models prototyped with SLA printers compared to the LCD/DLP printers (p < 0.001); models prototyped with Elegoo Mars Pro-showed higher precision error compared to the other printers (P < 0.001). The models in the CM group showed higher trueness error compared to AM group when prototyped with LCD/DLP printers (p < 0.001). Accuracy error values were within the accepted clinical error for producing clear aligners (< 0.25 mm), with the entry-level 3D printer almost reaching this value. CONCLUSION: The accuracy of orthodontic models generated for clear aligners can be influenced by different technologies/market segments of the 3D printers used. CLINICAL RELEVANCE: Caution should be taken with entry-level 3D printers for producing clear aligners.

Temporomandibular disorders in Venezuelan and Italian adolescents.

OBJECTIVE: The aim of this research was to compare the prevalence of temporomandibular disorders (TMDs) among Venezuelan and Italian adolescents. METHODS: One hundred-seventeen Venezuelan and 138 Italian adolescents aged 11-18 years were examined according to the Diagnostic Criteria for TMDs (DC/TMD). Signs and symptoms were registered. RESULTS: TMD prevalence among Venezuelan adolescents (17.9%) was lower than that among Italian adolescents (29.7%) and was higher in females and in the 15-18 age group. Intra-articular disorders were the most frequent in Venezuelan (8.5%) and Italian adolescents (13.0%). Pain-associated disorders were more frequent in the 11-14 age group, while intra-articular disorders were more frequent in the 15-18 age group in both samples. Italian adolescents presented greater muscle pain and joint noise than Venezuelan adolescents. CONCLUSION: TMD prevalence in Venezuelan adolescents was lower than that in Italian adolescents. This suggests the involvement of cultural and/or genetic factors in the etiology of these disorders.

Assessment of maxillary canting on cone beam computed tomography and digital models: A retrospective study and proposal of a method.

OBJECTIVES: The mounting of the plaster casts on articulator procedure is routinely performed in orthognathic surgery to assess canting of the maxillary occlusal plane, but the currently used protocols and reference plane could be source of errors which affect reliability. Nowadays the assessment of canting of the maxillary occlusal plane could be also performed with an entirely digital protocol. Aim of the study was to propose a method to evaluate canting in patients affected by Unilateral Condylar Hyperplasia, comparing the measurements performed on digital models matched on CBCT with those made on traditional articulator. MATERIALS AND METHODS: A retrospective cross-sectional study was designed on 20 patients affected by vertical Unilateral Condylar Hyperplasia treated in the Units of Orthodontics and Maxillo-Facial Surgery. The canting of the maxillary occlusal plane was measured on plaster casts mounted on the conventional articulator and the measures were compared with those made on digital models matched on CBCT, according the protocol developed in our Unit. Molar, canine and basal difference were measured. To compare the two protocols and to test the agreement, we performed descriptive statistics, comparison between means and Bland Altman analysis. P value was set at 0.05. RESULTS: Statistic comparison demonstrated agreement between measurements performed with the digital protocol and conventional physical method. CONCLUSION: Measurements of canting with digital protocol are comparable to the physical standard method. A total digital protocol allows faster availability and storage of patient's data and better communication between orthodontist and maxillo-facial surgeon, especially in patients affected by three-dimensional malocclusions.

Periodontal results of different therapeutic approaches (open vs. closed technique) and timing evaluation (< 2 year vs. > 2 year) of palatal impacted canines: a systematic review.

BACKGROUND: This review evaluates, as a primary outcome, which surgical technique (open vs. closed) and which type of material used for the auxiliaries (elastic vs. metallic) were preferable in terms of periodontal results during the treatment of palatal-impacted canines. The timing of the evaluation of the results was also assessed as a secondary outcome. METHODS: An electronic search of the literature up to March 2021 was performed on Pubmed, MEDLINE (via Pubmed), EMBASE (via Ovid), Cochrane Reviews and Cochrane Register of Controlled Trials (RCTs) (CENTRAL). The risk of bias evaluation was performed using version 2 of the Cochrane risk of bias tool (RoB 2) for RCTs and the ACROBAT NRSI tool of Cochrane for non-RCTs. RESULTS: 11 articles met the inclusion criteria. Only one RCT was assessed as having a low risk of bias and all the non-RCTs were assessed as having a serious risk of bias. This review revealed better periodontal results for the closed technique and metallic auxiliaries. In addition, it revealed that the timing of the evaluation of the results affects the periodontal results with better results obtained 2 years after the end of treatment. CONCLUSION: In the treatment of a palatal-impacted canine, the closed technique and metallic auxiliaries should be preferred in terms of better periodontal results. The timing of the evaluation of the results affects the periodontal results.

Comparative Evaluation of Esthetic and Structural Aspects in Class II Functional Therapy. A Case-Control Retrospective Study.

Background: To compare the skeletal, dental, and esthetic changes produced by three functional devices, Fränkel-2 appliance (FR-2), Twin Block (TB), and Occlus-o-Guide® (O-o-G®), for the treatment of Class II malocclusion. Methods: Sixty-five patients with Class II Division 1 malocclusion were divided into three groups and were analyzed through cephalometric analysis of skeletal, dental, and esthetic variables before and after treatment. The first group of 23 patients (F: 9; M: 14; mean age: 10.3 ± 1.08 years) was treated with FR-2, the second group of 18 patients (F: 8; M: 10; mean age 10.7 ± 1.05 years) was treated with TB, the third group (F: 11; M: 13; mean age: 9.05 ± 0.39 years) of 24 patients was treated with O-o-G®. The structural effects of the three devices were compared with a control group generated by the growth variations reported in the cephalometric atlas of Bhatia and Leighton. Esthetic analysis was performed comparing the results of the patients treated with a control group of 20 subjects with mandibular retrognathia and Class II Division 1 malocclusion, not subjected to therapy. Results: The three devices resulted in a significant increase in mandibular length, with higher results obtained for FR-2 and TB. A statistically significant increase in the IMPA angle was found for the O-o-G® group, and a notable reduction of both overjet and overbite was detected in all three groups of treated patients. The esthetic evaluation showed overall more significant results in the TB group, especially with regard to the reduction of facial convexity. The retrusion of the upper lip was on average more significant in the O-o-G® group, followed by that in the TB. Conclusions: All three devices have proven to be effective overall in resolving skeletal changes and improving facial esthetics.

Three-dimensional assessment of the spheno-occipital synchondrosis and clivus after tooth-borne and bone-borne rapid maxillary expansion.

OBJECTIVES: To assess changes in spheno-occipital synchondrosis after rapid maxillary expansion (RME) performed with conventional tooth-borne (TB) and bone-borne (BB) appliances. MATERIALS AND METHODS: This study included 40 subjects with transverse maxillary deficiency who received TB RME or BB RME. Cone-beam computed tomography images (CBCT) were taken before treatment (T0), and after a 6-month retention period (T1). Three-dimensional surface models of the spheno-occipital synchondrosis and basilar part of the occipital bone were generated. The CBCTs taken at T0 and T1 were registered at the anterior cranial fossa via voxel-based superimposition. Quantitative evaluation of Basion displacement was performed with linear measurements and Euclidean distances. The volume of the synchndrosis was also calculated for each time point as well as the Nasion-Sella-Basion angle (N-S-Ba°). All data were statistically analyzed to perform inter-timing and intergroup comparisons. RESULTS: In both groups, there was a small increment of the volume of the synchondrosis and of N-S-Ba° (P < .05). Basion showed a posterosuperior pattern of displacement. However, no significant differences (P > .05) were found between the two groups. CONCLUSIONS: Although TB and BB RME seemed to have some effects on the spheno-occipital synchondrosis, differences were very small and clinically negligible.

Clear Aligners: Between Evolution and Efficiency-A Scoping Review.

In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and exclusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the "gingival margin design" feature and "auxiliaries" tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than Invisalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market.