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

Outcome and comparator choice in molar incisor hypomineralisation (MIH) intervention studies: a systematic review and social network analysis

OBJECTIVES: Outcome and comparator choice strongly determine the validity and implementation of clinical trial results. We aimed to assess outcome and comparator choice in intervention studies on molar incisor hypomineralisation (MIH) using systematic review and social network analysis (SNA). DESIGN AND DATA SOURCES: Medline, Embase, Cochrane Central, Google Scholar, opengrey.eu as well as DRKS.de and Clinicaltrials.gov were searched for MIH intervention studies. The search covered the period from 1980 to 2019. ELIGIBILITY CRITERIA: Clinical single-arm/multiarm, controlled/uncontrolled studies reporting on the management of MIH were included. Reported outcomes and comparators were extracted and categorised. SNA was used to evaluate comparator choice and the resulting trial networks. DATA EXTRACTION: Of the 7979 identified records, 100 were evaluated in full text and 35 studies (17 randomised controlled trials, 14 prospective and 4 retrospective cohort studies) were included. RESULTS: In total, 2124 patients with a mean age of 11 years (min/max 6/70 years) were included. Outcomes fell in one of 11 different outcome categories: restoration success, aesthetic improvement, pain/hypersensitivity/discomfort, mineral gain, space management, anaesthesia effectiveness, preventive success, efficiency, quality of life, gingival and periodontal health and patient satisfaction. Comparators were mainly restorative interventions (17 studies), remineralisation (3), treatment of hypersensitivity (10), aesthetic interventions (5) and orthodontic interventions (3). Two highly clustered comparator networks emerged; many interventions were not robustly linked to these networks. CONCLUSIONS: MIH intervention studies recorded both clinically centred and patient-centred outcomes. Core outcome set development should consider these and supplement them with outcomes on, for example, applicability. The high number of compared interventions tested in only few studies and our SNA results implicate that the current evidence may not be robust

A Comparative Study of Shock Absorption Capacities of Custom Fabricated Mouthguards using a Triangulation Sensor

This in-vitro study compares the shock absorption qualities of five mouthguard designs measured with a triangulation laser sensor during small hard object collisions. The aim was to investigate the impact of different labial designs on mouthguard performance. METHODS: Five different custom-fabricated ethylene vinyl acetate (EVA) types of mouthguards with varying thickness and different labial inserts (polyethylene terephthalate glycol-modified (PETG), nylon mesh, air space) were tested with a triangulation laser sensor during different energy blows, generated with a pendulum testing device. The pendulum hits were applied to the center of a pivoted tooth crown in a custom-built upper jaw model. Measurements were executed with the mouthguards on the model and with no mouthguard as a negative control. RESULTS: Tooth deflection was reduced with all mouthguards in comparison to no mouthguard. Increasing mouthguard thickness improved the mouthguards' shock absorption capacities. Also, adding labial inserts increased their preventive qualities in ascending order: Mouthguard with a soft insert (nylon mesh), a hard insert (PETG), air space plus a hard insert (PETG). CONCLUSION: Increasing EVA foil thickness of a mouthguard, increasing labial thickness, and adding labial inserts (soft, stiff and air space) improve mouthguard shock absorption capabilities during small hard object collisions, thereby improving dental trauma prevention

Elution study of acrylic monomers from orthodontic materials using high performance liquid chromatography (HPLC)

Purpose: Main goal of the study was the identification and quantitative analysis of monomer elution from materials commonly used in fixed orthodontic therapy. Studies have shown severe health effects of monomers including cytotoxic, allergenic or mutagenic potential and endocrine changes. This in vitro study focusses primarily on five resins which are usually processed intraorally and remain in the oral cavity long-term. Methods: We tested the elution of monomers from specimens (7.5 mm x 1.5 mm) immersed in artificial saliva at body temperature (37 degrees C) for 30 min to 5 weeks. The used method is in accordance with DIN EN ISO 10993-13. The five tested materials were BrackFix (R) (Voco GmbH, Cuxhaven, Germany), Triad (R) Gel (DeguDent GmbH, Hanau, Germany), and Transbond (TM) XT, LR and Plus (3M Unitek, Monrovia, CA, USA). All aliquots were analyzed using high performance liquid chromatography (HPLC). Data were statistically analyzed. Results: All five analyzed materials eluted substances over a period of 5 weeks. Identified substances included bisphenol A (BPA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). BPA eluted from Transbond (TM) Plus, XT, LR and BrackFix (R). The cumulated mean values after 35 days ranged from 16.04 to 64.83 ppm, depending on the material. TEGDMA eluted with a mean of 688.61 ppm from Transbond (TM) LR. UDMA with a mean of 1682.00 ppm from Triad (R) Gel. For each material the highest concentrations of all these substances were found in the first elution period. Other substances that were not equivocally identified or of low concentration also eluted. Conclusion: Using the described method, it is possible to qualitatively and quantitatively determine the in vitro elution of monomers from orthodontic materials. The concentrations of the substances identified were below the current maximum recommended intake. However, a cumulative effect and low-dose effects should be considered for both patients and dental professionals, especially for young patients. Measures to reduce exposure patients and practitioners are suggested

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 degrees. 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

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

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

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

Unveiling the Role of Metal Ion Concentration versus Immune Sensitization in Orthodontic Patients-A Long-Term Prospective Evaluation.

Background: This longitudinal prospective study aimed to assess orthodontic patients' immune system response to metal ion release in saliva. Methods: Thirty adult patients (18-35 years) were equally divided into three groups: groups at the end (G1) and beginning (G2) of multibracket appliances (MBA) treatment and a non-treated control group (G3). Participants were evaluated at four timepoints within 21 days, with saliva samples being analyzed for metal ion concentrations and blood for the lymphocyte transformation test (LTT). Results: There were no significant differences between groups or timepoints for saliva. LTT analyses revealed hypersensitivity in one-third of all patients and 50% of G2 for nickel, with three developing sensitizations after MBA insertion. All nickel-sensitized patients exhibited varying elevated saliva nickel concentrations. The most nickel-sensitized patients had low ion saliva loads. In borderline nickel-sensitization cases, saliva ion concentrations were up to 20 times higher than the reference. Hypersensitivity to palladium, gold, and mercury was also observed. Conclusions: These findings indicate that increased MBA ion release was not inherently linked to the immune response (Type-IV sensitization), as reactions occurred even with ion levels below thresholds. This underlines the need for a comprehensive evaluation of the immune response to metal ion release in orthodontic patients

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