Accuracy of lingual straight-wire orthodontic treatment with passive self-ligating brackets and square slot: a retrospective study.

OBJECTIVES: To investigate the accuracy of torque, tip and rotation and linear intra-arch movements yielded by passive self-ligating lingual straight-wire appliances with brackets featuring square slots. MATERIALS AND METHODS: Twenty-five adult Caucasian patients (16 females and 9 males; mean age 26.5 ± 4.3 years) with Class I or mild Class II head-to-head malocclusion were orthodontically treated via passive lingual self-ligating straight-wire appliances (ALIAS, Ormco, Orange, CA) with no extraction. Records were retrospectively analysed, and digital models of pre-treatment (T0), planned (T1) and achieved (T2) phase were acquired for both arches in each patient via an intraoral scanner (Medit I500 (iScan Medit, Seoul, Korea). VAM software (Vectra, Canfield Scientific, Fairfield, NJ, USA) was used to measure both angular values (torque, tip and rotation) and linear intra-arch widths (between canines, first and second premolars and first and second molars). Measurements were obtained for all the movements investigated for each tooth group (incisors, canines, premolars and molars), by arch (maxillary and mandibular) and for both arches at T0, T1 and T2. The accuracy of angular values was compared using Student's t-test against a hypothetical 100%, and among the various tooth groups by post-hoc tests. Transverse linear measurements were investigated by means of the non-parametric Friedman test. The significance threshold was set at 0.05. RESULTS: The mean accuracy of angular values was 77.25 ± 7.71% for torque, 78.41 ± 6.17% for tip and 77.99 ± 6.58% for rotation. In all cases, however, there was a significant difference between planned and achieved movements, and accuracy was significantly lower than the hypothetical 100% for all tooth groups, individual arches and dentition (p < 0.001). For intra-arch diameters, the greatest accuracy values were found for the anterior sectors (83.54 ± 5.19% for the maxillary inter-canine distance) and the lowest for the posterior sectors (67.28% for the maxillary inter-second molar distance). CONCLUSION: Straight-wire lingual treatment with passive self-ligating appliances featuring with square slot displayed excellent clinical accuracy, albeit with statistical accuracy decreasing antero-posteriorly.

Is a non-radiological-assisted method valid for establishing crown-root relationships in an orthodontic set-up incorporating the roots? A retrospective study.

INTRODUCTION: This study aimed to obtain information on the relationship between crown and root in terms of morphology - dimensions and crown-root angles -to be used for orthodontic set-ups without the use of radiological examinations. MATERIAL AND METHODS: All the good quality CBCTs of patients obeying the eligibility criteria, from 2000 to 2015, were analysed. All teeth were analysed except for third molars. Six variables were evaluated: crown (CL) and root length (RL), crown width (CW), root width (RW), crown-root angles in both the frontal (CR-frontal) and sagittal plane (CR-sagittal). All teeth were divided into 3 groups according to number of root (single, two, three-rooted). The measurements were assessed with the Invivo professional software and then, subjected to correlation matrices and linear regression statistical analysis in order to find any significant correlations between crown and root measurements (α≤0.05). RESULTS: Seventy-three out of 247 good quality CBCTs were assessed. Correlation matrices statistical analysis showed linear correlations for some variables investigated, especially for CW/RW pairing in all subgroups (r=0.81, r=0.70 and r=0.58 respectively for single-, two- and three-rooted) and CL/RL in the single-rooted subgroup (r=0.29). Subsequent linear regression analysis allowed to obtain information about roots starting from crown measurements by means of equations [RW=0.76+(0.73×CW) and RL=10.94+(0.25×CL) for single-rooted teeth; RL=1.11+(0.73×CW) and RW=0.99+(0.76×CW), respectively for single- and two-rooted teeth]. No linear correlation was found between crown measurements and C-R angular values. CONCLUSION: It is possible to obtain root information starting from some crown measurements but these do not fulfil the need of minimal information to guarantee a perfect root position starting from that of crown.

Sella turcica dimensions and maxillary growth in patients with unilateral cleft lip and palate.

OBJECTIVES: We aimed to investigate associations between sella turcica dimensions and maxillary growth in children with unilateral cleft lip and palate (UCLP). METHODS: Forty-nine patients with non-syndromic UCLP, prior to secondary alveolar bone-grafting, were included. The outcomes measured were sella turcica and maxillary cephalometric measurements, and scores representing dental arch relationships derived from dental casts. On lateral cephalograms, sella width, height, and area were measured, as well as maxillary length, height, protrusion, and inclination. Dental arch relationships were measured using the modified Huddart/Bodenham (MHB) scoring system, and translated GOSLON yardstick score. Multiple linear regression was used to assess associations between sella turcica measurements and either cephalometric parameters or MHB/GOSLON scores, including age and sex as covariables. RESULTS: No significant associations were found between sella turcica dimensions and dental arch relationships. For cephalometric measurements, sella height and area were associated with basal maxillary length, alveolar maxillary length, and anterior maxillary height. CONCLUSIONS: Sella height and area seem to be predictors for both maxillary length and height as assessed cephalometrically, in a sample of patients with non-syndromic UCLP.

Evaluation of Tooth Movement Accuracy with Aligners: A Prospective Study.

Background. Clear aligners treatment (CAT) is a common solution in orthodontics to treat both simple and complex malocclusions. This study aimed to evaluate the predictability of CAT, comparing the virtually planned and the achieved tooth movement at the end of stage 15, which is often the time of first refinement. Methods. Seventeen patients (mean age: 28.3 years) were enrolled in the study. Torque, tip and rotation were analyzed in 238 maxillary teeth on digital models at Pre-treatment (T0), at the end of stage 15 (T15) and at virtually planned stage 15 (T15i). Prescription, Achieved movement and performance values were calculated to compare the virtually planned and the clinical tooth position. Data were analyzed by means of Student's t test with a level of significance set at p < 0.05. Results. The largest iper-performance was the torque correction of the second molars (+2.3° ± 3.1°), the greatest under-performance was the tip correction of the first molars (−2.3° ± 3.3°), while rotation corrections of all the teeth showed more accurate performance. No significant differences were found between mean Prescription and mean Achieved movement for all the assessed movements (p < 0.05). Conclusions. An accurate evaluation of CAT after the 15th aligner is fundamental in order to individuate the movements that are not matching the digital set-up.

Palatal changes in crossbite patients treated with rapid maxillary expansion vs untreated ones: A geometric morphometric study.

OBJECTIVE: The present study aimed to analyse palatal changes due to rapid maxillary expansion (RME) by using modern geometric morphometric analysis (GMA) on 3D models. SETTINGS AND SAMPLE POPULATION: Forty children with posterior crossbite and maxillary deficiency were selected for this study. Twenty children were treated with RME (mean age 7.4 ± 0.8 years), whereas 20 children were not treated (mean age 7.2 ± 1.1 years). MATERIALS AND METHODS: In the treated group, RME screw was activated until overcorrection was achieved and the RME appliance remained in place for 11 months. Digital dental casts were recorded before treatment and 1 year after the end of active treatment. GMA was performed to compare shape and dimensional variations among groups (between-group principal component analysis). RESULTS: All children in the treated group achieved crossbite correction. None of the control group children achieved crossbite self-correction. No significant shape and dimensional changes were noted in the control group after 1 year. On the other hand, significant shape and dimensional changes were noted in the treated group after 1 year (P < .05). Most of the shape changes in the treated group were similar but more pronounced compared to those observed in the control group. All major changes in palatal morphology occurred on the lateral sides of the palatal vault (widening) and at the height (shortening). Some shape changes were observed in the treated group alone. CONCLUSIONS: Application of GMA to evaluate the effects of RME in crossbite patients revealed significant changes in palatal morphology compared with the absence of changes in the control group.

Sella turcica morphometrics in children with unilateral cleft lip and palate.

OBJECTIVE: To use morphometric methods to investigate the size and shape of the sella turcica in children with unilateral cleft lip and palate (UCLP). SETTING AND SAMPLE POPULATION: Fifty-six healthy children with non-syndromic UCLP, from a major paediatric teaching hospital, with lateral cephalograms taken prior to alveolar bone grafting, were compared with an age- and sex-matched control group of healthy children without orofacial clefts, with lateral cephalograms taken prior to orthodontic treatment. MATERIALS AND METHODS: In this cross-sectional study, conventional measurements were performed on the sella turcica to measure width, height and area on lateral cephalograms. Sella shape was also analysed using 11 points defining the sella turcica contours, using geometric morphometrics. Procrustes superimposition was used to register all sella contour tracings to calculate average sella shape. Principal component analysis was applied to the residuals of the point coordinates, and principal components (PCs) of shape were extracted. RESULTS: Statistically significant differences between the UCLP and control groups were found for sella posterior height, midpoint height, maximum height and area, where all of these were smaller in children with UCLP. Principal component analysis revealed that the first two PCs accounted for 84.7% of total shape variance. There was a statistically significant difference in sella shape between children with UCLP and control children. CONCLUSIONS: In children with UCLP, the sella turcica is shorter and with a smaller surface area when compared to matched non-cleft children. Moreover, sella turcica shape, when disregarding size, seems to differ to that of non-cleft children.

Functional factors associated with continuous eruption of maxillary incisors in adulthood: A 10-year prospective cohort study.

PURPOSE: To investigate whether functional factors estimated by the masseter muscle thickness (MMT) and the maximum occlusal force (MOF), were associated with the amount of continuous eruption of maxillary incisors in adults. MATERIALS AND METHODS: Dental casts were taken twice in 24 adult female patients during a 10-year prospective cohort study. At the first appointment, ultrasonographic measures of the MMT and MOF were recorded. The casts were scanned into a digital model and measurements of the eruption and clinical crown lengthening (CL) of the maxillary incisors were calculated after superimpositions on the palatal region. Univariate and multivariate mixed effect regression models were used to assess the single and joint role of functional factors, with presence or absence of occlusal contacts and CL on incisor eruption. RESULTS: By using the linear mixed effects regression model, we observed that both the MMT and MOF were correlated with the maxillary incisor eruption. In particular, the thicker the masseter or the stronger the occlusal force, the lower the amount of eruption. Using a backward multivariable mixed effects model, the incisor eruption was correlated with the MMT combined with presence or absence of contacts and clinical CL. The amount of tooth eruption (0.32 mm on average) was positively associated with CL (0.29 mm on average); therefore, the greater the CL (gingival recession), the greater the amount of tooth eruption. The presence of occlusion contact between the maxillary incisors and their mandibular antagonists was found as an inhibitor of eruption in the multivariate model. CONCLUSIONS: The functional capacity of masticatory muscles, as estimated by the MMT, plays a role in the amount of maxillary incisor eruption. The stronger the masticatory muscles, the lower the amount of eruption.

Headgear compliance as assessed by a temperature-sensitive recording device: a prospective clinical study.

OBJECTIVE: To accurately describe compliance in headgear wearing time by using a temperature- and force-sensitive device over an 8 month period of use in a prospective clinical manner. MATERIALS AND METHODS: Twenty children with Class II malocclusion aged 8-12 years were randomly selected for treatment with cervical headgear. The headgears were equipped with an electronic module, which measured temperature and force, and patients were instructed to wear the headgear 12 hours daily. The recorded values were analysed to determine the number of days the headgear was used, the number of hours per day it was worn, and the percentage of compliance (100 per cent corresponding to 12 hours daily). RESULTS: The average treatment period was 8.4 months with 5.8 months of effective use. When effectively used, headgear was worn 8.7 hours a day (compliance of 73 per cent). Including days where it was not worn, compliance was 6.4 hours (54 per cent). The appliance was used on average 0.5 hours during the day (8 am-8 pm) and 5.9 hours during the night (8 pm-8 am). Very low compliance was recorded during July and August. CONCLUSION: The average compliance with cervical headgear use was 54 per cent of the 12 hour prescription. The headgear was effectively used only 5.8 months over the study period, with roughly 30 per cent of no use. Headgear was used almost exclusively during evening and night-time. During the summer period, compliance was particularly poor.

Does low-frequency vibration have an effect on aligner treatment? A single-centre, randomized controlled trial.

BACKGROUND: Low-frequency vibrations have been proposed as a means of accelerating tooth movement and reducing orthodontic treatment times. OBJECTIVE: To determine any differences in the accuracy of dental movement in patients treated with a low-frequency vibration aligner protocol and/or by reducing the aligner replacement interval with respect to a conventional protocol. DESIGN: This trial was designed as a single-centre, randomized controlled clinical trial. METHODS: Participants: Patients (aged 27.1 ± 9.0 years) who required orthodontic treatment with aligners. Randomization: Patients were randomly allocated to three arms as determined by a computer-randomization scheme. Group A were assigned a conventional protocol (aligners replaced every 14 days); group B also used a low-frequency vibration device for 20 minutes per day; group C followed the same vibration protocol but replaced their aligners every 7 days. Blinding: The operator who performed the set-up and the one who analysed the data were blinded to the group of the patients. Outcome: Pre- and post-treatment digital models were analysed using VAM software to identify the accuracy/imprecision of dental movements. One-way analysis of variance (P < 0.05) and the Bonferroni post hoc test were used to identify any statistically significant differences between the three arms in terms of the accuracy of tooth movement versus the prescription. RESULTS: Numbers analysed: A total of 45 patients (15 for group) were analysed (i.e. 2286 dental movements). Outcome: No statistically significant differences emerged between groups A and C in the upper arch, or among groups A, B, and C in the lower. Group B displayed significantly greater accuracy with respect to group A in upper incisor rotation (P = 0.016), and to group C in vestibulolingual (P = 0.007) and mesiodistal tipping (P = 0.029) of the upper canines, and vestibulolingual tipping of the upper molars (P = 0.0001). Harms: No adverse events or side-effects were registered. CONCLUSIONS: Considering all tooth and movement types of the 45 participants, the mean total imprecision was 2.1 ± 0.9 degrees, with respect to a mean prescription of 5.7 ± 2.2 degrees. There was no difference in accuracy between replacing the aligners accompanied by low-frequency vibration every 7 days and replacing them every 14 days without vibration. Moreover, low-frequency vibration seemed to improve the accuracy of a conventional protocol in terms of upper incisor rotation. TRIAL REGISTRATION: The German Clinical Trials Register (DRK00015613).

Measuring 3D shape in orthodontics through geometric morphometrics.

BACKGROUND: Geometric morphometrics (GMM) has been traditionally applied to the field of biology to study developmental differentiations between species. Orthodontics deals with the shape and size of the face and its components. While several tools have been used to measure size, proportions, and relations between anatomical components, shape has been mainly described by esthetic criteria. The purpose of this paper is to present methods to measure shape of 3D orthodontic data, beyond the conventional tools that have been traditionally used in cephalometrics and in facial and dental cast analysis. FINDINGS: The authors showcase an example of applying geometric morphometrics to measure palates from scanned dental casts. GMM can be used as a useful tool to describe the three-dimensional shape of surfaces of orthodontic interest. A general introduction to the theoretical principles of how to apply GMM is provided. CONCLUSIONS: Variability can be measured through the Principal Component Analysis (PCA) and can lead to the identification of shape patterns and sources of variability of the shape, independently from changes in size.

Predictability of orthodontic movement with orthodontic aligners: a retrospective study.

BACKGROUND: The aim of this study was to evaluate the predictability of F22 aligners (Sweden & Martina, Due Carrare, Italy) in guiding teeth into the positions planned using digital orthodontic setup. METHODS: Sixteen adult patients (6 males and 10 females, mean age 28 years 7 months) were selected, and a total of 345 teeth were analysed. Pre-treatment, ideal post-treatment-as planned on digital setup-and real post-treatment models were analysed using VAM software (Vectra, Canfield Scientific, Fairfield, NJ, USA). Prescribed and real rotation, mesiodistal tip and vestibulolingual tip were calculated for each tooth and, subsequently, analysed by tooth type (right and left upper and lower incisors, canines, premolars and molars) to identify the mean error and accuracy of each type of movement achieved with the aligner with respect to those planned using the setup. RESULTS: The mean predictability of movements achieved using F22 aligners was 73.6%. Mesiodistal tipping showed the most predictability, at 82.5% with respect to the ideal; this was followed by vestibulolingual tipping (72.9%) and finally rotation (66.8%). In particular, mesiodistal tip on the upper molars and lower premolars were achieved with the most predictability (93.4 and 96.7%, respectively), while rotation on the lower canines was the least efficaciously achieved (54.2%). CONCLUSIONS: Without the use of auxiliaries, orthodontic aligners are unable to achieve programmed movement with 100% predictability. In particular, although tipping movements were efficaciously achieved, especially at the molars and premolars, rotation of the lower canines was an extremely unpredictable movement.

Continuous eruption of maxillary teeth and changes in clinical crown length: A 10-year longitudinal study in adult women.

BACKGROUND: Continuous physiologic eruption of teeth may become a main aesthetic issue for implants inserted in the maxillary anterior region. PURPOSE: To study maxillary tooth vertical changes during a 10 years period by 3-dimensional superimposition of digital dental casts. MATERIAL AND METHODS: Alginate impressions were taken at both baseline and at the 10-year follow-up in a sample of 24 adult Swedish women (average age of 48 years at T0). The upper arch plaster casts were digitized with a 3-dimensional scanner and then superimposed on the palate and the palatal rugae. Occlusal and gingival anatomic structures were digitized for each upper tooth from first molar to first molar. The vertical changes of these structures gave an indication of tooth extrusion and apical or coronal displacement of the gingival margin. RESULTS: A trend was found for eruption in the anterior region (+0.3 mm on average) while a slight extrusion if not any was found in the first molars and premolars area. Vertical displacement of the gingival margin showed also a positive trend from first molars to incisors. Negative average values, corresponding clinically to gingival recession, were found on first molars (-0.36 mm) and premolars (-0.15 mm), while no displacement was detected in the anteriors. Clinical crown lengths increased in all teeth and it is mainly due to gingival recession for first molars and premolars, while for the incisors the eruption is coupled to a slight equivalent gingival coronal migration. CONCLUSIONS: During a 10-year period, continuous eruption takes place in female adult subjects, especially in the upper incisors area while gingival recession occurred in first molars and premolars area leading to crown length elongation. Implant placement in the anterior area of the maxilla may have an aesthetic impact even in mature adults due to the continuous eruption of the adjacent teeth.

Comparison and reproducibility of 2 regions of reference for maxillary regional registration with cone-beam computed tomography.

INTRODUCTION: The aims of this study were to evaluate the differences between 2 regions of maxillary voxel-based registration and to test the reproducibility of the registration. METHODS: Three-dimensional models were built for before-treatment (T1) and after-treatment (T2) based on cone-beam computed tomography images from 16 growing subjects. Landmarks were labeled in all T2 models of the maxilla, and voxel-based registrations were performed independently by 2 observers at 2 times using 2 reference regions. The first region, the maxillary region, included the maxillary bone clipped inferiorly at the dentoalveolar processes, superiorly at the plane passing through the right and left orbitale points, laterally at the zygomatic processes through the orbitale point, and posteriorly at a plane passing through the distal surface of the second molars. In the second region, the palate and infrazygomatic region had different posterior and anterior limits (at the plane passing through the distal aspects of the first molars and the canines, respectively). The differences between the registration regions were measured by comparing the distances between corresponding landmarks in the T2 registered models and comparing the corresponding x, y, and z coordinates from corresponding landmarks. Statistical analysis of the differences between the T2 surface models was performed by evaluating the means and standard deviations of the distances between landmarks and by testing the agreement between coordinates from corresponding landmarks (intraclass correlation coefficient and Bland-Altman method). RESULTS: The means of the differences between landmarks from the palate and infrazygomatic region to the maxillary region 3-dimensional surface models at T2 for all regions of reference, times of registrations, and observer combinations were smaller than 0.5 mm. The intraclass correlation coefficient and the Bland-Altman plots indicated adequate concordance. CONCLUSIONS: The 2 regions of regional maxillary registration showed similar results and adequate intraobserver and interobserver reproducibility values.

Three-dimensional digital cast analysis of the effects produced by a passive self-ligating system.

AIM: To evaluate maxillary and mandibular dental arch changes induced by a passive self-ligating system by analysing digital dental casts. SUBJECTS AND METHODS: A sample of 25 growing patients (16 females and 9 males, mean age 12.8 years) treated with passive self-ligating brackets was compared to a sample of 25 untreated controls (15 females and 10 males, mean age 13.4 years). Sixty three-dimensional points were digitised on the maxillary and mandibular pre- and post-treatment virtual models to evaluate differences in the transverse and antero-posterior arch dimensions and in the torque values of representative anterior and posterior teeth. Statistical comparisons were performed with independent sample t-tests with Holm-Bonferroni correction for multiple tests. RESULTS: The greatest increments in arch widths were found at the maxillary and mandibular premolar level (ranging from 2.0 to 2.2mm) and they were associated with significant increases in maxillary and mandibular arch perimeters (2.3 and 2.5mm, respectively), and in buccal crown torque of the upper premolars (with adequate torque control of all other teeth). CONCLUSIONS: The passive self-ligating system produced a modest but statistically significant widening of both maxillary and mandibular dental arches that were associated with significant net gains in maxillary and mandibular arch perimeters.

Bonded versus banded rapid palatal expander followed by facial mask therapy: analysis on digital dental casts.

OBJECTIVES: To compare the dental effects produced by a bonded versus a banded expander combined with facial mask (FM) in patients with Class III malocclusion by means of digital dental casts. MATERIALS AND METHODS: Two groups of patients with Class III malocclusion and maxillary transverse deficiency in the deciduous or early mixed dentition were selected. The first group consisted of 25 subjects (12 females; 13 males) with a mean age of 7.4 years (SD 1.2 years) treated with a bonded expander and FM. The second group consisted of 25 subjects (13 females; 12 males) with a mean age of 8.1 years (SD 1.3 years) treated with a banded expander and FM. For each subject of the two groups, initial (pre-treatment, T1) and final (post-treatment, T2) dental casts were taken and scanned. Maxillary digital models of T1 and T2 were superimposed on the palatal rugae in order to analyse the maxillary anchorage loss. Significant between-group differences were tested with independent sample t-test (P < 0.05). RESULTS: No statistical differences were found for any of the variables observed. CONCLUSION: Orthopaedic treatment of Class III malocclusion with either a bonded or a banded expander and FM during the deciduous or early mixed dentition induced a significant expansion of the maxillary arch and a slight mesialization of the posterior anchoring teeth with no difference between the two intraoral appliance designs.

Palatal surface and volume in mouth-breathing subjects evaluated with three-dimensional analysis of digital dental casts-a controlled study.

OBJECTIVE: To compare the anatomical characteristics of the maxillary arch, identified as palatal surface area and volume, between mouth-breathing and nose-breathing subjects using a three-dimensional (3D) analysis of digital dental casts. METHODS: Twenty-one Caucasian subjects (14 females and 7 males) with a mean age of 8.5 years [standard deviation (SD) 1.6 years] were selected according to the following criteria: mouth-breathing pattern due to allergic rhinitis, early mixed dentition, skeletal Class I relationship, and pre-pubertal stage of cervical vertebral maturation. This study group (SG) was compared with a control group (CG) of 17 nose-breathing subjects (9 females and 8 males, mean age: 8.5 years; SD: 1.7 years). For each subject, initial dental casts were taken and the upper arch was scanned using a 3D laser scanner. On each digital model, 3D measurements were performed to analyse maxillary arch morphology. Between-group differences were tested with the independent sample Student's t-test (P < 0.05). RESULTS: In mouth-breathing subjects, changes in physiological function of the upper respiratory tract resulted in skeletal adaptations of the maxillary arch. In the SG, both palatal surface area and volume were significantly smaller when compared with values of the CG. In particular, the palatal surface area and palatal volume were, respectively, 13.5 and 27.1 per cent smaller in the SG when compared to the CG. CONCLUSIONS: Subjects with prolonged mouth breathing showed a significant reduction of the palatal surface area and volume leading to a different development of the palatal morphology when compared with subjects with normal breathing pattern.

Evaluation of tip and torque on virtual study models: a validation study.

BACKGROUND: The objectives of this study were to develop and validate a novel analysis protocol to measure linear and angular measurements of tip and torque of each tooth in the dental arches of virtual study models. METHODS: Maxillary and mandibular dental casts of 25 subjects with a full permanent dentition were scanned using a three-dimensional model scanner. Sixty points per arch were digitized on each model, five points on each tooth. A custom analysis to measure linear distances and angles of tip and torque was developed using a new reference plane passing as a best-fit among all of the lingual gingival points, with the intermolar lingual distance set as the reference X-axis. The linear distances measured included buccal, lingual, and centroid transverse widths at the level of canines, premolars, and molars as well as arch depth and arch perimeter. RESULTS: There was no systematic error associated with the methodology used. Intraclass correlation coefficient values were higher than 0.70 on every measure. The average random error in the maxilla was 1.5°±0.4° for torque, 1.8°±0.5° for tip, and 0.4±0.2 mm for linear measurements. The average random error in the mandible was 1.2°±0.3° for torque, 2.0°±0.8° for tip, and 0.1±0.1 mm for the linear measurements. CONCLUSIONS: A custom digital analysis protocol to measure traditional linear measurements as well as tip and torque angulation on virtual dental casts was presented. This validation study demonstrated that the digital analysis used in this study has adequate reproducibility, providing additional information and more accurate intra-arch measurements for clinical diagnosis and dentofacial research.

Upper molar distalization on palatal miniscrews: an easy to manage palatal appliance.

Upper molar distalization supported by miniscrews has become increasingly popular in the last years. A detailed clinical and lab procedure for the realization of a distalization appliance (fast back or distal jet) connected to miniscrews inserted in the anterior region of the palate is presented. A case report illustrates the use of a fast back appliance supported by miniscrews to correct the mesial shift of the molars and of the premolars as a consequence of an early loss of the maxillary deciduous canines.