Root resorption in relation to a modified piezocision technique

ABSTRACT Objectives To evaluate root resorption of lower incisors and canines quantitatively in a group of patients who underwent orthodontic treatment with piezocision and/or a collagen reinforcement technique with a fully resorbable three-dimensional (3D) collagen xenograft matrix compared with a control group. Materials and Methods The study sample of this secondary analysis consisted of 32 periodontally healthy patients with angle Class I malocclusion or mild Class II or III malocclusion and moderate irregularity index scores who underwent orthodontic treatment and had before (T0) and after treatment (T1) cone-beam computed tomography scans. Root resorption of lower incisors and canines was assessed quantitatively in the following four groups: the control group received orthodontic treatment without piezocision, experimental group 1 received orthodontic treatment with piezocision, experimental group 2 received orthodontic treatment with piezocision and a 3D collagen matrix, and experimental group 3 received orthodontic treatment with a 3D collagen matrix. Results An overall statistically significant decrease in root length from T0 to T1 for all groups was observed (P < .05). However, there was no significant difference among the groups in the amount of root length decrease from T0 to T1. Conclusions Orthodontic treatment combined with piezocision does not increase the risk of root resorption of lower incisors and canines when compared with orthodontic treatment without acceleration techniques. More studies with larger samples should be undertaken to confirm these results.

A comparison between stereophotogrammetry and smartphone structured light technology for three-dimensional face scanning

ABSTRACT Objectives To compare three-dimensional facial scans obtained by stereophotogrammetry with two different applications for smartphone supporting the TrueDepth system, a structured light technology. Materials and Methods Facial scans of 40 different subjects were acquired with three different systems. The 3dMDtrio Stereophotogrammetry System (3dMD, Atlanta, Ga) was compared with a smartphone (iPhone Xs; Apple, Cupertino, Calif) equipped with the Bellus3D Face Application (version 1.6.11; Bellus3D Inc, Campbell, Calif) or Capture (version 1.2.5; Standard Cyborg Inc, San Francisco, Calif). Times of image acquisition and elaboration were recorded. The surface-to-surface deviation and the distance between 18 landmarks from 3dMD reference images to those acquired with Bellus3D or Capture were measured. Results Capturing and processing times with the smartphone applications were considerably longer than with the 3dMD system. The surface-to-surface deviation analysis between the Bellus3D and 3dMD showed an overlap percentage of 80.01% ± 5.92% and 56.62% ± 7.65% within the ranges of 1 mm and 0.5 mm discrepancy, respectively. Images from Capture showed an overlap percentage of 81.40% ± 9.59% and 56.45% ± 11.62% within the ranges of 1 mm and 0.5 mm, respectively. Conclusions The face image acquisition with the 3dMD device is fast and accurate, but bulky and expensive. The new smartphone applications combined with the TrueDepth sensors show promising results. They need more accuracy from the operator and more compliance from the patient because of the increased acquisition time. Their greatest advantages are related to cost and portability.

Transfer accuracy of 3D-printed trays for indirect bonding of orthodontic brackets:

ABSTRACT Objectives To evaluate the transfer accuracy of 3D-printed indirect bonding trays constructed using a fully digital workflow in vivo. Materials and Methods Twenty-three consecutive patients had their incisors, canines, and premolars bonded using fully digitally designed and 3D-printed transfer trays. Intraoral scans were taken to capture final bracket positioning on teeth after bonding. Digital models of postbonding scans were superimposed on those of corresponding virtual bracket setups, and bracket positioning differences were quantified. A total of 363 brackets were evaluated. One-tailed t-tests were used to determine whether bracket positioning differences were within the limit of 0.5 mm in mesiodistal, buccolingual, and occlusogingival dimensions, and within 2° for torque, tip, and rotation. Results Mean bracket positioning differences were 0.10 mm, 0.10 mm, and 0.18 mm for mesiodistal, buccolingual, and occlusogingival measurements, respectively, with frequencies of bracket positioning within the 0.5-mm limit ranging from 96.4% to 100%. Mean differences were significantly within the acceptable limit for all linear dimensions. Mean differences were 2.55°, 2.01°, and 2.47° for torque, tip, and rotation, respectively, with frequencies within the 2°-limit ranging from 46.0% to 57.0%. Mean differences for all angular dimensions were outside the acceptable limit; however, this may have been due to limitations of scan data. Conclusions Indirect bonding using 3D-printed trays transfers planned bracket position from the digital setup to the patient's dentition with a high positional accuracy in mesiodistal, buccolingual, and occlusogingival dimensions. Questions remain regarding the transfer accuracy for torque, tip, and rotation.

Combined orthodontic and surgical open bite correction:

This paper is divided into Part 1, the study findings, and Part 2, a detailed explanation of orthodontic and surgical methods used in the study. In this Part 1, treatment protocols will be mentioned, but explained in Part 2.

Bracket transfer accuracy with two different three-dimensional printed transfer trays vs silicone transfer trays

ABSTRACT Objectives To compare the transfer accuracy of two different three-dimensional printed trays (Dreve FotoDent ITB [Dreve Dentamid, Unna, Germany] and NextDent Ortho ITB [NextDent, Soesterberg, the Netherlands]) to polyvinyl siloxane (PVS) trays for indirect bonding. Materials and Methods A total of 10 dental models were constructed for each investigated material. Virtual bracket placement was performed on a scanned dental model using OnyxCeph (OnyxCeph 3D Lab, Chemnitz, Germany). Three-dimensional printed transfer trays using a digital light processing system three-dimensional printer and silicone transfer trays were produced. Bracket positions were scanned after the indirect bonding procedure. Linear and angular transfer errors were measured. Significant differences between mean transfer errors and frequency of clinically acceptable errors (<0.25 mm/1°) were analyzed using the Kruskal–Wallis and χ2 tests, respectively. Results All trays showed comparable accuracy of bracket placement. NextDent exhibited a significantly higher frequency of rotational error within the limit of 1° (P = .01) compared with the PVS tray. Although PVS showed significant differences between the tooth groups in all linear dimensions, Dreve exhibited a significant difference in the buccolingual direction only. All groups showed a similar distribution of directional bias. Conclusions Three-dimensional printed trays achieved comparable results with the PVS trays in terms of bracket positioning accuracy. NextDent appears to be inferior compared with PVS regarding the frequency of clinically acceptable errors, whereas Dreve was found to be equal. The influence of tooth groups on the accuracy of bracket positioning may be reduced by using an appropriate three-dimensional printed transfer tray (Dreve).

Detailed three-dimensional orthodontic tooth repositioning to improve restorative outcome:

ABSTRACT The case describes the interdisciplinary treatment of a 23-year-old woman with a Class III malocclusion, missing an upper right lateral incisor, abrasion of the maxillary incisal edges, anterior gingival margin discrepancies, and gingival recession. Initially, the patient was treated with fixed appliances combined with orthognathic surgery. The extraction of the upper left lateral incisor and bilateral canine substitution plan was chosen. At the end of the surgical and orthodontic treatment, the restorative treatment with six veneers was accomplished to improve smile esthetics. Despite the missing lateral incisors, the patient showed a natural, good-looking final result. A symmetric incisal plane was established, a functional occlusion with average vertical and horizontal overlap was set, and the bone scallop and consequently the gingival margins were leveled. The interdisciplinary approach hid all of the initial esthetic defects of the case. The result highlights how to obtain a remarkable improvement of the smile outcome with a well-functioning masticatory system.

Comparison of facemask therapy effects using skeletal and tooth-borne anchorage:

ABSTRACT Objectives To investigate long-term outcomes of dentoskeletal changes induced by facemask therapy using skeletal anchorage in Class III patients and compare them to those of conventional tooth-borne anchorage. Materials and Methods This retrospective study included 20 patients who received facemask (FM) therapy with miniplates as anchorage for maxillary protraction (Miniplate/FM group, 10.6 ± 1.1 years old [mean ± SD]) and 23 patients who were treated with facemask with rapid maxillary expander (RME/FM group, 10.0 ± 1.5 years old [mean ± SD]). Dentoskeletal changes were evaluated using lateral cephalograms at pretreatment (T1), after facemask therapy (T2), and at the post-pubertal stage (T3). Cephalometric changes were compared between groups and clinical success rates at T3 were evaluated. Results SNA and A to N perpendicular to FH increased significantly more in the Miniplate/FM group than in the RME/FM group when comparing short-term effects of facemask therapy (T1–T2). ANB, Wits appraisal, Angle of convexity, mandibular plane angle, and overjet decreased significantly more in the RME/FM group than in the Miniplate/FM group after facemask therapy (T2–T3). A more favorable intermaxillary relationship was observed in the Miniplate/FM group than in the RME/FM group in long-term observations (T1–T3). Clinical success rate at T3 was 95% in the Miniplate/FM group and 85% in the RME/FM group. Conclusions Facemask therapy with skeletal anchorage showed a greater advancement of the maxilla and more favorable stability for correction of Class III malocclusion in the long-term than conventional facemask therapy with tooth-borne anchorage.

Long-term assessment of conventional and mini-screw–assisted rapid palatal expansion on the nasal cavity

ABSTRACT Objectives To evaluate the long-term effects of mini-screw–assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls on the nasal cavity with cone-beam computed tomography (CBCT). Materials and Methods A total of 180 CBCT scans that were part of a previous randomized trial were evaluated retrospectively for 60 patients at pretreatment (T1), postexpansion (T2), and posttreatment (T3). Patients were randomly assigned into 3 groups: MARPE, RPE, and controls (time period T1 to T3; MARPE: 2 years 8 months; RPE: 2 years 9 months; control: 2 years 7 months). Nasal height, nasal length, nasion–ANS height, ANS–PNS length, pyriform height, and nasal septal deviation angle were measured. The changes in alar width, alar base width, anterior nasal cavity width, posterior nasal cavity width, maxillary intermolar width, and maxillary intercanine width were also evaluated. Results The alar base width, posterior nasal cavity width, anterior nasal cavity width, maxillary intercanine width, and maxillary intermolar width significantly increased (P < .05), and the nasal septal deviation angle significantly decreased (P < .05) in both the MARPE and RPE groups as compared with controls in the short term. In the long term, the nasal septal deviation angle was significantly decreased (P < .05) in the MARPE and RPE groups as compared with controls, and the posterior nasal cavity width was significantly increased (P < .05) in the MARPE group compared with the RPE group and controls. Conclusions MARPE and RPE led to a significant increase in the nasal cavity and alar base width compared with controls in the short term. In the long term, a significant increase was observed only in the posterior nasal cavity width with MARPE. Both MARPE and RPE led to a minimal decrease in nasal septal deviation angle in comparison with controls.