Comparison of 1- and 3-piece directly 3-dimensional printed indirect bonding trays: An in vitro study.

INTRODUCTION: This study aimed to compare the transfer accuracy of indirect bonding trays of different thicknesses and numbers of pieces. METHODS: Digital indirect bonding was performed on 56 printed resin models, divided into 4 groups with 14 models in each: 1-mm 1-piece tray (OPT), 2-mm OPT, 1-mm 3-piece tray (TPT), and 2-mm TPT. The trays were designed using Appliance Designer (3Shape A/S, Copenhagen, Denmark). Angular (torque, tip, or angulation) and linear (mesiodistal, buccolingual, occlusogingival, or vertical) differences were compared by using open-source GOM Inspect software (GOM GmbH, Braunschweig, Germany). RESULTS: In the buccolingual direction, the 1-mm TPT (0.180 ± 0.041 mm) was significantly more accurate than the 1-mm OPT (0.240 ± 0.032 mm). In the vertical direction, significant differences were seen between the 1-mm and 2-mm OPTs (1-mm OPT: 0.220 ± 0.043 mm; 2-mm OPT: 0.428 ± 0.143 mm; P = 0.003) and between the 1-mm and 2-mm TPTs (1-mm TPT: 0.210 ± 0.072 mm; 2-mm TPT: 0.340 ± 0.062 mm; P = 0.004) in the total region. In the tip angle, significant differences were seen between the 1-mm and 2-mm OPTs and between the 1-mm OPT and TPT. In the torque angle, a significant difference was seen between the 1-mm TPT (2.815°±0.350°)and 2-mmTPT (2.368° ± 0.245°; P = 0.017). CONCLUSIONS: Both the thickness and the splitting of the trays impacted the bracket bonding accuracy. The 1-mm trays were more accurate than the 2-mm trays. Despite a few statistically significant differences between the 1-mm OPT and TPT, the 1-mm OPT was recommended for clinical use, considering the designing and placing of the trays.

Three-dimensional evaluation of the temporomandibular joints after unilateral surgically assisted rapid maxillary expansion in adults: A preliminary retrospective study.

BACKGROUND: Unilateral surgically assisted rapid maxillary expansion (U-SARME) is a successful method for correction of true unilateral posterior crossbite (TUPC). OBJECTIVES: This retrospective preliminary study aimed to evaluate the position and morphology of condyles in TUPC cases and the effects of U-SARME on condyle with the help of cone beam computed tomography (CBCT). METHODS: Fifteen patients (mean age: 18.69 ± 1.59 years) who were diagnosed as TUPC and undergone U-SARME were selected. Preoperative (T0) and after 6-month retention (T1) DICOM data of CBCT images were evaluated with MIMICs version 19.0 software. Condylar morphology (medio-lateral and antero-posterior dimensions) and position (anterior, posterior, medial and lateral joint spaces, frontal/axial axis angles, the ratio of posterior to anterior joint space and the percentage of posterior to anterior joint space) were evaluated. Student's t-test was used for intergroup (crossbite, normal) comparisons. Paired-samples t-test was used for intra-group comparisons (p = .05). RESULTS: There were no positional or dimensional asymmetry of the condyles between crossbite and normal sides initially and after expansion. Regarding T0-T1 changes, while significant increase was determined in medial (0.3 ± 0.29 mm; p = .001) and superior (0.39 ± 0.7 mm; p = .045) joint spaces on crossbite side, posterior (0.79 ± 0.99 mm; p = .008), superior (0.5 ± 0.79 mm; p = .029) and lateral joint spaces (0.31 ± 0.54 mm; p = .042) presented significant increases on normal side. However, no significant changes were found between crossbite and normal sides at T0 and T1. CONCLUSIONS: Condyles were symmetrical in true unilateral posterior crossbite cases and the symmetry were not disrupted following U-SARME.

A Novel Approach for the Reconstruction of Premaxilla by Archwise Distraction in Bilateral Cleft Lip and Palate.

Interdental distraction osteogenesis has been introduced as a successful treatment protocol for repairing large clefts. In this article, a new method for reconstruction of the premaxilla in 2 bilateral cleft lip and palate patients is introduced. The aim was to distract the lateral segments through the curve of the dental arch, achieve complete closure of the gaps, and use the premaxilla as a bone graft. Patient 1 (20-year-old female) had double jaw surgery before but presented residual alveolar cleft and small premaxilla. Patient 2 (21-year-old male) had anterior and posterior crossbite and caries of teeth on premaxilla. Following the preliminary fixed orthodontic treatment in both patients, archwise distraction protocol was performed. The distraction duration and the achieved amount of new bone per side were 4 weeks/22 mm and 5 weeks/25 mm in Patients 1 and 2, respectively. At the end of a 2-month retention period, docking side surgery was performed and premaxilla was used as the bone graft. The protocol was very effective for not only closure of the large cleft defects but also the reconstruction of the premaxilla. Anteroposterior relationship and the patients' profiles were considerably and positively affected.

Three-dimensional evaluation of surgically assisted asymmetric rapid maxillary expansion.

INTRODUCTION: Unilateral posterior crossbite is classified as true unilateral posterior crossbite (TUPC) or functional posterior crossbite (FPC). The differential diagnosis between TUPC and FPC is of utmost importance for the decision of expansion protocol because conventional expansion methods have some shortcomings for TUPC. The aim of this retrospective study was to 3-dimensionally evaluate the effects of asymmetric rapid maxillary expansion combined with unilateral osteotomy. METHODS: This study sample comprised 16 patients (mean age 18.38 ± 1.45) with TUPC. A Hyrax acrylic cap included the maxillary premolars and molars on the constricted side, and all teeth up to the central incisor were included on the other side to increase anchorage. Unilateral surgically assisted rapid maxillary expansion was performed and included anterior (aperture piriformis), lateral (zygomatic buttress), and posterior (pterygomaxillary junction) osteotomies on the constricted side and separation of the midpalatal suture. Cone-beam computed tomographic scans taken just before the operation and after 6 months of retention were used to assess skeletal, dental, and periodontal changes. RESULTS: Expansion was seen on both sides; however, the amount of expansion and tipping was higher on the osteotomy+ side. Because the canines were not included in the acrylic cap on the osteotomy+ side, they did not present the same amount of tipping as the ipsilateral posterior teeth. More teeth were affected periodontally on the osteotomy- side; however, there were no clinically significant differences between the osteotomy+ and osteotomy- sides (mean differences range +0.54 to -0.57 mm). The aperture piriformis width increased significantly on the osteotomy+ side. CONCLUSIONS: The treatment mechanics had no clinically detrimental effects on the supporting alveolar bone of the maxilla on either side, and it was thought to be effective in cases with TUPC; however, case selection is crucial.

3D printed indirect bonding trays: transfer accuracy of bar vs shell design in a prospective, randomized clinical trial.

OBJECTIVES: To compare the transfer accuracy of two different indirect bonding (IDB) trays. MATERIALS AND METHODS: Digital IDB was performed on a total of 30 patients using one of two designs: shell and bar trays, with 15 patients in each group. Trays were designed with the Appliance Designer software (3Shape A/S, Copenhagen, Denmark). Angular (torque, tip, angulation) and linear (mesiodistal, buccolingual, occlusogingival) differences were compared between the bonded intraoral scans taken immediately after IDB and the virtually bracketed model prepared in Ortho Analyzer software (3Shape A/S) using open source GOM inspect software (GOM GmbH, Braunschweig, Germany). RESULTS: There were no significant differences found between the bar and shell groups. Within the groups, significant tip differences were found between the incisors, canines, and premolars in both groups (P = .0001). Additionally, a statistically significant torque difference was found in the canines and incisors in the shell group. The percentage of values that deviated from the clinical acceptance limit was relatively higher in the bar group. CONCLUSIONS: Although there was no statistical difference between groups, the shell tray showed better results according to clinical acceptability limits. This study is important as it is the first clinical study to compare directly printed transfer trays with different designs.

Does unilateral surgically assisted rapid maxillary expansion (SARME) lead to perinasal asymmetry?

OBJECTIVE: True unilateral posterior crossbite (TUPC) requires unilateral expansion to prevent nonocclusion at the noncrossbite (NC) side. The recommended osteotomies for TUPC after sutural closure are anterior, lateral, and posterior osteotomies only on the crossbite (C) side and median osteotomy of the midpalatal suture, i.e., unilateral surgically assisted rapid maxillary expansion (SARME). The goal was to assess airway and perinasal soft tissue outcomes after SARME. METHODS: Data from 16 patients (8 males, 8 females; mean age 18.38 ± 1.45 years) were retrospectively assessed after unilateral SARME. The expansion (twice daily: 0.5 mm/day) and retention periods comprised 3 weeks and 6 months, respectively. Stereophotogrammetric images were used for soft tissue assessment; cone beam computed tomography (CBCT) was used to evaluate the anterior nasal airway. Statistical analyses were performed. RESULTS: Using linear measurements, soft tissue distances of the alar base and alare to midsagittal plane (MSP) were significantly increased on the C side. A significant decrease was observed for the distance from the lower nostril point to the MSP on the NC side compared to a significant increase on the C side. Comparing the C and NC sides, the changes were significantly higher on the C side for all parameters except the upper nostril point to the MSP distance. Cheek volume was significantly higher on the C side. Volume changes of the anterior nasal airway (ANA) were significantly increased on the C side, but volume changes between NC and C were not significantly different. CONCLUSIONS: Unilateral SARME led to significant expansion of ANA on the C side, but did not lead to asymmetry in the nasal region or have adverse effects on the airway or perinasal soft tissues. Thus, this novel treatment method may be useful in the treatment of patients with TUPC.

Assessment of the Diagnostic Skills of General Dentists in Different Types of Orthodontic Malocclusions.

OBJECTIVE: One of the biggest problems in publicly funded dental clinics is the patient waiting list. The appropriate referral plays a key role in avoiding an increase in the number of patients on this waiting list. This study aimed to assess general dentists' diagnostic skills and approaches for different malocclusions. METHODS: A questionnaire was prepared using photos of 8 patients previously treated for different malocclusions. One hundred twenty general dentists (83 female, mean age: 24 ± 1.18 years; 37 male, mean age: 24 ± 1.95 years) participated in the survey and were asked to decide whether the patient needed orthodontic treatment or orthognathic surgery, and to provide the reason for surgery (irregular teeth, or both unesthetic profile and irregular teeth), and the cause of the unesthetic profile (mandibular protrusion, mandibular retrusion, maxillary protrusion, maxillary retrusion). RESULTS: The answers suggesting the need for orthodontic treatment were significantly higher for all malocclusions except for the Class II camouflage case. Of the Class III cases, the general dentists chose orthognathic surgery for both surgery and facemask cases (93.1%, 66.4% respectively). For the severe open bite case, orthognathic surgery was chosen with a ratio of 81.2%, and orthognathic surgery was decided as not necessary for the mild open bite case (74.8%). Among the surgery cases, mandibular retrusion for the Class II case (94.6%), mandibular protrusion for Class III case (95.4%), and maxillary retrusion for the severe open bite case (44.6%) were the maximum reported reasons. CONCLUSION: The distinction between camouflage and surgical treatment was better made by dentists in Class II and open bite cases than in Class III cases.