Dietary and metabolic effects on the oral status of patients with phenylketonuria: a nation-based cross-sectional study.

OBJECTIVES: The aim of this study was to compare the prevalence of oral diseases (caries, periodontal disease, enamel defects) between patients with phenylketonuria (PKU), their siblings, and a matched control group. MATERIALS AND METHODS: A total of 109 patients with PKU, 14 siblings of PKU patients, and 100 healthy individuals aged 6 to 68 years were recruited. All participants completed a questionnaire based on their health status. The patients' decayed/missing/filled teeth index (dmft/DMFT), gingival bleeding index (GBI), plaque control record (PCR), periodontal screening and recording index (PSR), and developmental enamel defects index (DDE) were recorded. Descriptive statistics and regression modeling were used to examine potential associations between the exposure and the outcomes of interest. RESULTS: Patients with PKU had 1.6 times more caries (95% confidence interval (CI) 1.22 to 2.20; p = 0.001), seven times more enamel defects (95% CI 3.94 to 14.21; p < 0.001), and four times higher PSR values (95% CI 2.26 to 7.15; p < 0.001) than the control group. The siblings had significantly fewer enamel defects but no significant differences in caries and periodontal parameters compared to the PKU patients. CONCLUSIONS: The results showed a higher risk for the development of caries, periodontitis, and enamel defects in PKU patients. CLINICAL RELEVANCE: Implementation of preventive measures and regular dental care is necessary for patients with PKU.

Accuracy of indirect bracket placement with medium-soft, transparent, broad-coverage transfer trays fabricated using computer-aided design and manufacturing: An in-vivo study.

INTRODUCTION: The objective of this study was to test the precision of in-vivo indirect bracket placement via medium-soft, transparent, broad-coverage, computer-aided designed and manufactured transfer trays using an automated digital method. METHODS: Seventeen patients requiring vestibular fixed appliances were consecutively recruited, and bonding accuracy was measured at each bracket, evaluating 3 linear (mesiodistal, buccolingual, and vertical) and 3 angular measurements (torque, tip, and rotation) with an automated method involving digital superimposition of individual teeth. Mean and standard deviation values were calculated for both arches, single arch, and tooth type, and the percentages of single deviations over the thresholds of 0.25 mm and 1° were calculated, as well as maximum and minimum values for each deviation and directional bias. Correlations between each variable (arch, tooth type, and single tooth) and deviations were investigated through classification and regression trees (CART) predictive models. RESULTS: Neither mean nor single linear deviations ever exceeded the set cutoff value of 0.25 mm. Mean angular deviations never exceeded 1°, but some individual angular deviations did, specifically 8.31% of torque, 13.16% of tip, and 7.16% of rotation deviations. The highest percentage of deviation was recorded for rotation of the maxillary incisors (18.11%). No evident trend in directional deviation bias was found. Tooth type appears to influence mesiodistal and torque deviations, whereas the single tooth variable influenced the percentage of rotation deviations exceeding 1° (P <0.05). CONCLUSIONS: This computer-aided designed and manufactured medium-soft, transparent transfer tray provides accurate bracket placement and could be recommended for routine fixed appliance treatment.

Management of white spot lesions induced during orthodontic treatment with multibracket appliance: a national-based survey.

OBJECTIVES: The study aimed to survey current strategies against enamel demineralization during multibracket therapy (MBT) and guide a prevention concept based on existing scientific evidence. MATERIALS AND METHODS: The survey comprised questions on the prevention and management of white spot lesions (WSL). The questionnaire was sent via email to orthodontists working in practices and universities throughout Germany. The analysis involved descriptive statistics using the chi-square test (p < 0.05). RESULTS: A prevention protocol was used before MBT by 80.6% of the participants. Less than a quarter of the participants regularly applied topical fluoride (gel or varnish) during MBT. According to the respondents' assessment, the prevalence of WSL during MBT is 11.6%, mainly observed in 12- to 15-year-old male patients. Orthodontists graduating after 2000 tended to recommend and apply fluoride-containing materials more often than their senior colleagues (p = 0.039). Participants from private practices applied fluoride varnish or gel more frequently than those from university clinics (p = 0.013). Fluoridation was the most common (70.7%) treatment for WSL after MBT, followed by resin infiltration (21.2%). The majority (80.9%) of the participants favor a guideline for preventing WSL. CONCLUSIONS: WSL prevention during MBT is challenging. Males in puberty are predominantly affected. Younger orthodontists are more concerned about the prevention of WSL during MBT. CLINICAL RELEVANCE: The non-negligible prevalence of individuals with WSL emphasizes the need for dental education and health care reform. This would help to implement standardized procedures and establish innovative applications.

Accuracy of indirect bonding trays - a measurement algorithm.

AIM: To present an image-processing measurement algorithm to evaluate the transfer accuracy of indirect bonding (IDB) trays, exemplified by a CAD/CAM-based IDB tray integrated into a digital orthodontic workflow. MATERIALS AND METHODS: Plaster casts of 24 patients with full dentition and different malocclusions were scanned with an intraoral scanner (Trios; 3Shape, Copenhagen, Denmark) to obtain digital models, which served for the virtual placement of orthodontic brackets in simulation software (OnyxCeph; Image Instruments, Chemnitz, Germany). The resulting STL files were sent to a dental laboratory (CA Digital; Hilden, Germany) for the production of INDIVIDUA IDB trays. These trays were used to transfer the brackets to the respective plaster casts. Finally, a second scan was performed to record the actual bracket positions. The transfer accuracy was then analyzed by a measurement algorithm scripted to automation, which calculated the deviations of the planned and real bracket positions with a local best-fit alignment, resulting in three linear and three angular measurements for each bracket. RESULTS: In total, 622 brackets and tubes were transferred successfully. The presented algorithm analyzed the transfer accuracy and demonstrated that the linear measurements were 98.3% within the range of the American Board of Orthodontics standard. The angular measurements were 86.7% within this range when the INDIVIDUA IDB tray was used. CONCLUSION: Scripted measurement algorithms facilitated the evaluation of present and future materials and designs for IDB trays to obtain an efficient solution for orthodontic practice. The INDIVIDUA IDB tray is a digital alternative to conventional IDB trays (Int J Comput Dent 2022;25(3):295-302; doi: 10.3290/j.ijcd.b2599775).

Selective vs stepwise removal of deep carious lesions in primary molars: 24 months follow-up from a randomized controlled trial.

OBJECTIVES: For well-defined deep (> 2/3 dentin extension) carious lesions, selective (SE) or stepwise (SW) carious tissue removals have been recommended, while there is limited comparative evidence for both. We compared SE and SW over 24 months in a randomized controlled trial. METHODS: A two-arm superiority trial was conducted comparing SW/SE in primary molars without pulpal symptoms but well-defined deep lesions. Seventy-four children (1 molar/child) aged 3-9 years were recruited. In a first step, peripheral carious tissue was removed until hard dentin remained, while in proximity to the pulp, leathery dentin was left. An adhesive compomer restoration was placed and restorations re-examined after 6 months. In SW, re-entry and removal to firm dentin was conducted pulpo-proximally, followed by re-restoration. Molars were re-evaluated for a total of 24 months. Our primary outcome was success (absence of restorative/endodontic complications or pulp exposures). Secondary outcomes included total treatment and opportunity costs and restoration quality, assessed using modified USPHS criteria. RESULTS: After 24 months, 63 molars (31 SE, 32 SW) were re-assessed. Four failures occurred (2 exposures in SW; 2 pulpal complications in SE, 1 of them leading to extraction, p > 0.05). Restoration integrity was satisfying in both groups (USPHS A/B/C in 21/8/0 SE and 23/7/0 SW, p > 0.05). Treatment and opportunity costs were significantly higher in SW than SE (mean 171 ± 51 vs. 106 ± 90; p < 0.001). CONCLUSIONS: After 2 years, SE and SW showed similar efficacy for managing deep carious lesions in primary molars. The higher costs for SW should be considered during decision-making. CLINICAL SIGNIFICANCE: In primary molars with well-defined deep carious lesions SE was less costly and similarly efficacious like SW. From a cost and applicability perspective, SW may need to be indicated restrictively, e.g., for very deep (> 3/4 dentin extension) lesions only. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02232828.

Deep learning for cephalometric landmark detection: systematic review and meta-analysis.

OBJECTIVES: Deep learning (DL) has been increasingly employed for automated landmark detection, e.g., for cephalometric purposes. We performed a systematic review and meta-analysis to assess the accuracy and underlying evidence for DL for cephalometric landmark detection on 2-D and 3-D radiographs. METHODS: Diagnostic accuracy studies published in 2015-2020 in Medline/Embase/IEEE/arXiv and employing DL for cephalometric landmark detection were identified and extracted by two independent reviewers. Random-effects meta-analysis, subgroup, and meta-regression were performed, and study quality was assessed using QUADAS-2. The review was registered (PROSPERO no. 227498). DATA: From 321 identified records, 19 studies (published 2017-2020), all employing convolutional neural networks, mainly on 2-D lateral radiographs (n=15), using data from publicly available datasets (n=12) and testing the detection of a mean of 30 (SD: 25; range.: 7-93) landmarks, were included. The reference test was established by two experts (n=11), 1 expert (n=4), 3 experts (n=3), and a set of annotators (n=1). Risk of bias was high, and applicability concerns were detected for most studies, mainly regarding the data selection and reference test conduct. Landmark prediction error centered around a 2-mm error threshold (mean; 95% confidence interval: (-0.581; 95 CI: -1.264 to 0.102 mm)). The proportion of landmarks detected within this 2-mm threshold was 0.799 (0.770 to 0.824). CONCLUSIONS: DL shows relatively high accuracy for detecting landmarks on cephalometric imagery. The overall body of evidence is consistent but suffers from high risk of bias. Demonstrating robustness and generalizability of DL for landmark detection is needed. CLINICAL SIGNIFICANCE: Existing DL models show consistent and largely high accuracy for automated detection of cephalometric landmarks. The majority of studies so far focused on 2-D imagery; data on 3-D imagery are sparse, but promising. Future studies should focus on demonstrating generalizability, robustness, and clinical usefulness of DL for this objective.

Knowledge, attitudes, and beliefs regarding molar incisor hypomineralization (MIH) amongst German dental students.

BACKGROUND: Knowledge of molar incisor hypomineralization (MIH) has relevance for paediatric dentists. AIM: To assess final-year German dental students' knowledge, attitudes, and beliefs regarding MIH. MATERIALS AND METHODS: A previously validated questionnaire was posted to the 31 German dental schools. Demographic covariates as well as knowledge regarding diagnosis and prevalence, and attitudes and beliefs around aetiology and management were collected. RESULTS: Twenty-two (71%) dental schools responded and a total of 877 students participated. Most (97%) were familiar with MIH and 88% were aware of the diagnostic criteria for MIH; however, only 42% knew how to implement them. One-third were able to identify MIH and 16% reported diagnostic confidence when doing so; 90% assumed the MIH prevalence to be <10%. Two-thirds of the respondents implicated genetic components as the main aetiological factor of MIH. Resin composite (60%) and preformed metal crowns (46%) were the dental materials most often suggested for restorative management. Almost all (98%) respondents were interested in receiving more clinical training. CONCLUSION: German students were familiar with MIH; however, they reported low levels of knowledge and confidence regarding its prevalence and diagnosis. Standardized nationwide, up-to-date curricula should be implemented to educate future dentists in Germany.

Comparison of the shock absorption capacities of different mouthguards.

BACKGROUND/AIMS: In this in vitro study, the protective qualities of different mouthguard types were examined during small hard object collisions. The aim was to investigate inconclusive aspects of hard inserts, nylon nets, and air spaces as reinforcements in the anterior region and the protection qualities of ethylene vinyl acetate (EVA). MATERIALS AND METHODS: Five different mouthguards with a labial thickness between 2 mm and 11 mm made of materials of varying stiffness were investigated. As a negative control, the same experiments were performed without a mouthguard. Different combinations of EVA and labial inserts ((polyethylene terephthalate glycol-modified [PETG]), nylon mesh, air space) were tested. Using a stainless steel pendulum device, blows of different energy (0.07-2.85 joules) were applied to the center of the crown of a pivoted tooth in a custom-built jaw model. A laser Doppler vibrometer measured the tooth deflection, while an acceleration sensor attached to the pendulum measured the braking accelerations. RESULTS: Tooth deflection was reduced up to 99.7% compared to no mouthguard, and the braking acceleration was reduced up to 72.2% by increasing the mouthguards' labial thickness in combination with labial inserts of different stiffness and a built-in air space between the front teeth and the mouthguard. The mouthguards made of soft materials (EVA with nylon mesh) showed slightly better protection qualities than the more rigid mouthguards of similar thickness (PETG; P<.05). However, with increasing impact energy, their protective capacities decreased to a greater extent than the stiffer mouthguards. CONCLUSIONS: The combination of increased labial thickness and labial inserts of varying stiffness and eventually an air space offers the best protection capacities for hard, small object collisions.

Comparison of effects of OSA treatment by MAD and by CPAP on cardiac autonomic function during daytime.

PURPOSE: The present study compared the effects of mandibular advancement therapy (MAD) with continuous positive airway pressure therapy (CPAP) on daytime cardiac autonomic modulation in a wide range of obstructive sleep apnea (OSA) patients under controlled conditions in a randomized, two-period crossover trial. METHODS: Forty OSA patients underwent treatment with MAD and with CPAP for 12 weeks each. At baseline and after each treatment period, patients were assessed by polysomnography as well as by a daytime cardiac autonomic function test that measured heart rate variability (HRV), continuous blood pressure (BP), and baroreceptor sensitivity (BRS) under conditions of spontaneous breathing, with breathing at 6, 12, and 15/min. RESULTS: Both CPAP and MAD therapy substantially eliminated apneas and hypopneas. CPAP had a greater effect. During daytime with all four conditions of controlled breathing, three-minute mean values of continuous diastolic BP were significantly reduced for both MAD and CPAP therapy. At the same time, selective increases due to therapy with MAD were found for HRV high frequency (HF) values. No changes were observed for BRS in either therapy mode. CONCLUSIONS: These findings indicate that both MAD and CPAP result in similar beneficial changes in cardiac autonomic function during daytime, especially in blood pressure. CPAP is more effective than MAD in eliminating respiratory events.

The German 19-item version of the Child Oral Health Impact Profile: translation and psychometric properties.

OBJECTIVES: This study seeks to develop and validate the 19-item German version of the Child Oral Health Impact Profile (COHIP-G19), an instrument to assess the oral health-related quality of life (OHRQoL) in children and adolescents. MATERIALS AND METHODS: The 19 items of the original English-language COHIP were translated into German using an established forward-backward approach. For the assessment of the psychometric properties of the COHIP-G19, children and adolescents aged 7-17 years came from two samples: 112 patients were consecutively recruited at a university-based orthodontic clinic and 313 came from a convenience sample of students in public schools. RESULTS: Internal consistency of the COHIP-G19 was satisfactory in both populations (Cronbach's alpha, 0.78/0.80; average inter-item correlation, 0.16/0.17). The COHIP-G19 summary scores were correlated in the expected direction with a global oral health rating (r = 0.46/0.40) and two measures for perceived general health (EQ-5D-Y: r = 0.26/0.29; KIDSCREEN-27: r = 0.40/0.33). While COHIP-G19 summary scores did not significantly differ with respect to the presence of caries or gingivitis (p > 0.05), malocclusion and insufficient oral hygiene behavior were related to more impaired OHRQoL, represented in significantly lower COHIP-G19 summary scores in students in public schools (p < 0.05), but not in orthodontic patients. CONCLUSIONS: While this study revealed some potential to improve reliability and validity in scores of the German version of the COHIP-19, overall, the study proved the instrument has sufficient psychometric properties and is well comparable to the original English-language version. CLINICAL RELEVANCE: The COHIP-G19 is a valid and reliable instrument to assess OHRQoL in German children and adolescents in clinical and community settings.

Effect of methotrexate upon antigen-induced arthritis of the rabbit temporomandibular joint.

BACKGROUND: Juvenile idiopathic arthritis (JIA) of the temporomandibular joint (TMJ) can cause severe growth disturbances of the craniomandibular system. Antigen-induced arthritis (AIA) of the rabbit TMJ is simulating the inflammatory process of the TMJ in JIA. The aim of this study was to investigate the effect of a systemic administration of methotrexate (MTX) on AIA in rabbits by means of three different histological staining methods. METHODS: After sensitization, a bilateral arthritis of the TMJ was induced by an intra-articular administration of ovalbumin in 12 New Zealand white rabbits aged 10 weeks. From the 13th week of age, six of the 12 rabbits received weekly intramuscular injections of MTX, and the other six animals remained without therapy. Another six animals served as controls, receiving no treatment or intra-articular injections at all. After euthanasia at the age of 22 weeks, all TMJs were retrieved en bloc. Sagittal sections were cut and stained with haematoxylin-eosin (H-E), Safranin-O for the evaluation of the Mankin score and tartrate-resistant acid phosphatase (TRAP). RESULTS: In the arthritis group, a chronic inflammation with degeneration of the articular cartilage was visible. In the MTX group, the signs of cartilage degeneration were significantly reduced compared with the arthritis group. In contrast, the joints in the control group were inconspicuous. A correlation between the Mankin score and TRAP-positive cells could be found. CONCLUSIONS: Systemic administration of MTX seems to have a positive effect upon the inflammatory process in the rabbit TMJ but fails to eliminate the sign of arthritis completely.

Effect of methotrexate on the mandibular development of arthritic rabbits.

INTRODUCTION: Juvenile idiopathic arthritis affecting the temporomandibular joint (TMJ) can cause severe disturbances of the mandibular development. Methotrexate (MTX) is often administered as a common used remission-inducing agent to treat this disease. The aim of this study was to investigate the effect of low dose MTX on the mandibular growth in arthritic rabbits. SUBJECTS AND METHODS: Eighteen 10-week-old female New Zealand white rabbits were randomly assigned to three groups with six animals in each group. After being sensitized to ovalbumin (OA), the first and the second group received intra-articular injections with OA. The first group remained untreated, the second was treated by weekly injections of MTX. Cephalograms were taken from each animal at 10, 13, 16, 19, and 22 weeks of age and six mandibular distances measured. RESULTS: All distances showed an increase between 10 and 20 per cent, whereas growth was more accentuated in the sagittal dimension. Significant differences in the overall growth could be observed between the arthritic and the control animals and less accentuated between the arthritic and the MTX animals. In contrast, existing differences between the groups were not significant during the intervals, but time had the greatest influence on mandibular growth. CONCLUSIONS: MTX seems to have a positive impact on growth in rabbits suffering from experimental arthritis of the TMJ.

Quality of orthodontic care-A multicenter cohort study in a German convenience sample : Part 2: Cross-sectional patient-reported outcomes after orthodontic treatment.

OBJECTIVES: In light of the growing interest in orthodontic care and its effectiveness in Germany, part 2 of this multicenter cohort study evaluated patient-reported outcomes such as oral health-related quality of life (OHRQoL), oral hygiene habits, oral health beliefs, and potential influencing factors. METHODS: Of 586 patients screened from seven German study centers, data from 343 patients were analyzed for this part of the study. At the end of their orthodontic treatment, study participants filled out a questionnaire of either the German long version of the Oral Health Impact Profile (OHIP-G 49) or the German short version of the Child Oral Health Impact Profile (COHIP-19), depending on their age, as well as questions about their oral hygiene behavior and beliefs. Patient-, treatment- and occlusion-related factors were analyzed to account for potential influencing factors with regard to patients' OHRQoL after orthodontic treatment. RESULTS: In all, 222 study participants filled out the OHIP-based and 121 the COHIP-based questionnaire. The mean OHIP-G 49 score was 12.68 and the mean OHIP-G 14 score was 3.09; the mean COHIP-19 score was 6.52 (inverted score 69.48). For OHIP-G 49 scores, a nonsignificant trend towards a higher score for male patients (14.45 vs 11.54; p = 0.061) was detected, while this trend was inverse for the COHIP-19 scores, i.e., female patients reported more impairment (total score 6.99 vs. 5.84; p = 0.099). Analyses suggested a trend towards better OHRQoL for patients who classified for the Peer Assessment Rating (PAR) Index improvement rate group 'greatly improved' as well as for nonsmokers. Oral hygiene habits and beliefs after orthodontic treatment were estimated to be good. CONCLUSION: In this German cohort, OHRQoL proved to be good and was rather unimpaired after orthodontic treatment. Furthermore, self-reported oral hygiene behavior and oral health beliefs represented good health awareness.

Scanning electron microscopy evaluation of enamel surfaces using different air-polishing powders in the orthodontic setting: an in vitro study.

PURPOSE: The aim of this in vitro study was to quantify and compare changes of the enamel surface caused by periodical use of different air-polishing powders during multibracket therapy. METHODS: Bovine high-gloss polished enamel specimens were air-polished using an AIR-FLOW® Master Piezon with maximum powder and water settings. Each specimen was blasted with sodium bicarbonate (AIR-FLOW® Powder Classic, Electro Medical Systems, Munich, Germany) and erythritol (AIR-FLOW® Powder Plus, Electro Medical Systems). Blasting duration was adapted to the powders' cleaning efficacy and corresponded to 25 air-polishing treatments in a patient with braces. A spindle apparatus ensured uniform guidance at a distance of 4 mm and a 90° angle. Qualitative and quantitative assessments were performed with the use of low vacuum scanning electron microscopy. Following external filtering and image processing, arithmetical square height (Sa) and root mean square height (Sq) were determined. RESULTS: Both prophy powders caused a significant increase in enamel roughness. Surfaces blasted with sodium bicarbonate (Sa = 64.35 ± 36.65 nm; Sq = 80.14 ± 44.80 nm) showed significantly (p < 0.001) higher roughness than samples treated with erythritol (Sa = 24.40 ± 7.42 nm; Sq = 30.86 ± 9.30 nm). The observed defects in enamel structure caused by sodium bicarbonate extended across prism boundaries. Prism structure remained intact after air-polishing with erythritol. CONCLUSION: Both applied air-polishing powders led to surface alterations. Despite shorter treatment times, sodium bicarbonate was significantly more abrasive than erythritol. Clinicians must compromise between saving time and abrasively removing healthy enamel.

Eruption Pattern of Third Molars in Orthodontic Patients Treated with First Permanent Molar Extraction: A Longitudinal Retrospective Evaluation.

The aim of this study was to evaluate angular and positional changes in the second (M2) and third molars (M3) of orthodontically treated patients undergoing a first molar (M1) extraction. A retrospective longitudinal study with a sample of 152 pre- and post-treatment panoramic radiographs was conducted. Thirty-nine patients (51.3%) were orthodontically treated with M1 extraction and thirty-seven (48.7%) were treated without extraction. Angulations of M2 and M3 relative to the infraorbital (IOP) and the palatal planes (PP) were measured and compared between the groups before orthodontic treatment (T1) and after the completion of orthodontic space closure (T2). The prognosis of M3 eruptions was evaluated by assessing their horizontal and vertical position (inclination) using different classification systems. The angular (p < 0.001) and inclination improvement (p < 0.01) of the maxillary M3 was significant for the M1 extraction group. The mandibular M3 inclination significantly improved (p < 0.01), whereas the groups' angulation and vertical position were not significantly different. These findings suggest that extraction therapy has a favorable effect on the maxillary M2 and M3 angulation, but not on the mandibular. M1 extraction showed a signi- ficant effect on the horizontal position of M3 and thus may improve the eruption space and prognosis.

Accuracy of palatal orthodontic mini-implants placed by conventionally or CAD/CAM-based surgical guides: a comparative in vitro study.

OBJECTIVES: To investigate and compare the transfer accuracy of five different surgical guides (SGs) for the insertion of orthodontic mini-implants (OMIs) in the anterior palate. MATERIALS AND METHODS: Stereolithographic files of 10 maxillary patient models and their corresponding lateral cephalograms were virtually matched and used for planning the position of two parallel OMIs in the paramedian region of the anterior palate. For each patient model, three 3-dimensional (3D)-printed and two conventional SGs were manufactured from different materials, and a total of 96 OMIs were transferred to the anterior palates of the respective 50 molded resin models. The planned (T0) and the actual (T1) OMI positions were analyzed and compared after superimposition of the digitized models. The deviations between the OMI positions in T0 and T1 were described as the distance between the head and the tip, respectively, of each OMI in millimeters and the deviating angle between the OMI axes for each patient and SG. RESULTS: The conventionally manufactured SGs of Pattern Resin LS (GC Europe N.V., Leuven, Belgium) showed the highest linear and angular transfer accuracy for the insertion of OMIs. The highest deviations were found with the SGs made of IMPRIMO LC Splint (3D-printed; Scheu-Dental, Iserlohn, Germany) and Memosil 2 (conventional SG; Kulzer, Hanau, Germany). CONCLUSIONS: The 3D-printed SGs did not reach the accuracy of the conventional SGs made of Pattern Resin but may provide sufficient accuracy for palatal OMI placement.

Longitudinal Three-Dimensional Stereophotogrammetric Growth Analysis in Infants with Unilateral Cleft Lip and Palate from 3 to 12 Months of Age.

This longitudinal study aimed to evaluate facial growth and soft tissue changes in infants with complete unilateral cleft lip, alveolus, and palate (CUCLAP) at ages 3, 9, and 12 months. Using 3D images of 22 CUCLAP infants, average faces and distance maps for the entire face and specific regions were created. Color-coded maps highlighted more significant soft tissue changes from 3 to 9 months than from 9 to 12 months. The first interval showed substantial growth in the entire face, particularly in the forehead, eyes, lower lip, chin, and cheeks (p < 0.001), while the second interval exhibited no significant growth. This study provides insights into facial soft tissue growth in CUCLAP infants during critical developmental stages, emphasizing substantial improvements between 3 and 9 months, mainly in the chin, lower lip, and forehead. However, uneven growth occurred in the upper lip, philtrum, and nostrils throughout both intervals, with an overall decline in growth from 9 to 12 months. These findings underscore the dynamic nature of soft tissue growth in CUCLAP patients, highlighting the need to consider these patterns in treatment planning. Future research should explore the underlying factors and develop customized treatment interventions for enhanced facial aesthetics and function in this population.

Comparison of Two 3D-Printed Indirect Bonding (IDB) Tray Design Versions and Their Influence on the Transfer Accuracy.

Objective: This study aims to investigate the transfer accuracy of two different design versions for 3D-printed indirect bonding (IDB) trays. Materials and Methods: Digital plaster models of 27 patients virtually received vestibular attachments on every tooth using OnyxCeph³™ (Image Instruments, Chemnitz, Germany). Based on these simulated bracket and tube positions, two versions of transfer trays were designed for each dental arch and patient, which differed in the mechanism of bracket retention: Variant one (V1) had arm-like structures protruding from the tray base and reaching into the horizontal and vertical bracket slots, and variant two (V2) had a pocket-shaped design enclosing the brackets from three sides. Both tray designs were 3D-printed with the same digital light processing (DLP) printer using a flexible resin-based material (IMPRIMO® LC IBT/Asiga MAX™, SCHEU-DENTAL, Iserlohn, Germany). Brackets and tubes (discovery® smart/pearl, Ortho-Cast M-Series, Dentaurum, Ispringen, Germany) were inserted into the respective retention mechanism of the trays and IDB was performed on corresponding plaster models. An intraoral scan (TRIOS® 3W, 3Shape, Copenhagen, Denmark) was performed to capture the actual attachment positions and compared to the virtually planned positions with Geomagic© Control (3D Systems Inc., Rock Hill, SC, USA) using a scripted calculation tool, which superimposed the respective tooth surfaces. The resulting attachment deviations were determined in three linear (mesiodistal, vertical and orovestibular) and three angular (torque, rotation and tip) directions and analyzed with a descriptive statistical analysis. A comparison between the two IDB tray designs was conducted using a mixed model analysis (IBM, SPSS® Statistics 27, Armonk, NY, USA). Results: Both design versions of the 3D-printed IDB trays did not differ significantly in their transfer accuracy (p > 0.05). In total, 98% (V1) and 98.5% (V2) of the linear deviations were within the clinically acceptable range of ±0.2 mm. For the angular deviations, 84.9% (V1) and 86.8% (V2) were within the range of ±1°. With V1, most deviations occurred in the mesiodistal direction (3.3%) and in rotation (18%). With V2, most deviations occurred in the vertical direction (3.8%) and in palatinal and lingual crown torque (16.3%). Conclusions: The transfer accuracies of the investigated design versions for 3D-printed IDB trays show good and comparable results albeit their different retention mechanisms for the attachments and are, therefore, both suitable for clinical practice.

Indirect bonding: an in-vitro comparison of a Polyjet printed versus a conventional silicone transfer tray.

OBJECTIVES: To investigate and compare transfer accuracy between a Polyjet printed indirect bonding (IDB) tray (SureSmile, Dentsply Sirona, Richardson, TX, USA) and a conventional two-layered silicone tray. MATERIALS AND METHODS: Plaster models of 24 patients were digitized with an intraoral scanner, and brackets and tubes were positioned virtually on the provider's homepage. IDB trays were designed over the planned attachments and Polyjet 3D-printed. For the conventional tray, brackets and tubes were bonded in their ideal positions manually before fabricating a two-layered silicone tray. For both trays, attachments were transferred indirectly to corresponding models. A second scan was performed of each bonded model to capture actual attachment positions, which were then compared to initial bracket positions using Geomagic Control (3D Systems Inc., Rock Hill, SC, USA). Linear and angular deviations were evaluated for each attachment within a clinically acceptable range of ≤0.2 mm and 1°. A descriptive statistical analysis and a mixed model were executed. RESULTS: Both trays showed highest accuracy in the orobuccal direction (99.5% for the 3D-printed tray and 100% for the conventional tray). For the 3D-printed tray, most frequent deviations were found for torque (15.4%) and, for the silicone tray, for rotation (1.9%). A significant difference was observed for angular measurements (P = .004) between the trays. CONCLUSIONS: Transfer accuracy of Polyjet printed IDB tray is not as high as transfer accuracy of the conventional silicone tray, though both trays show good results and are suitable for clinical application.