Objectives
To compare and validate two tridimensional diagnostic methods for quantifying and categorizing external root resorption using an artificial intelligence (AI)-aided, automatic, or manual digital segmentation process.
Materials and Methods
40 teeth were segmented from 10 cone beam computed tomography (CBCT) records from five patients. Stereolithographic files were created, and automatic, manual, or AI-aided segmentation of each incisor was performed by two double-blinded operators. Two quantification methods were used and compared by analyzing final segmented regions of the tooth. This study followed QAREL (Quality Appraisal of Diagnostic Reliability) and COSMIN (COnsensus-based Standards for the selection of health Measurement Instruments) guidelines. Reproducibility was assessed using the Dahlberg formula, coefficient of variation, and intraclass correlation coefficient (ICC) (P value < .05).
Results
Intra- and interobserver correlations were high (ICC: > 0.736; P < .01). Statistically significant differences were found between the two measurement methods for high-quality CBCT images of central incisors, mainly at the level of the apical third. Specific differences were found between methods when root resorption was evaluated in the middle and apical thirds using AI segmentation of the central incisor (P = .043). When referring to total volume loss of the lateral incisor, differences (P = .021) were observed between methods when segmented by manual or AI-aided procedures. Highest specificity (100%) was observed for AI-aided segmentation and Method 2 for evaluation of root resorption at the apical third volume.
Conclusions
Assessment of root resorption with CBCT is highly dependent on CBCT definition, type of segmentation, and measurement method. Three-dimensional (3D) measurement method described by three landmark points yielded satisfactory results using any tested segmentations.
ABSTRACT
Objectives
To examine how defects in alveolar bone affect movement of teeth during orthodontic treatment.
Materials and Methods
Pretreatment cone-beam computed tomography images from 26 patients: 15 females and 11 males, with a mean age of 21.5 years (SD ± 3.7 years), were used to evaluate the buccal alveolar bone on the maxillary canine. Maxillary canines (n = 52) were subsequently categorized into three groups: control or no bone defects (n = 17), fenestration (n = 20), and quasidefect (n = 15). Each canine was displaced distally for 16 weeks using nickel-titanium closed coil springs (50 g) and segmental archwire mechanics. The rate and amount of tooth movement were evaluated using superimposition of lateral cephalograms and three-dimensional digital dental models between before and after canine retraction. Rate of tooth movement was evaluated among different bone defect groups.
Results
Rate of movement was significantly decreased in the fenestration (0.87 ± 0.23 mm/mo) and quasidefect groups (0.62 ± 0.14 mm/mo) compared to the control group (1.17 ± 0.40 mm/mo). Also, 85% of all subjects exhibited an evident asymmetric pattern of tooth movement, and 77% of these subjects presented with unilateral bone defects.
Conclusions
The type and existence of alveolar bone defects have a substantial effect on rate of tooth movement. Therefore, when conducting orthodontic tooth movement investigations and planning orthodontic treatment, it is important to consider the existence of alveolar bone defects.
ABSTRACT
Objectives
To analyze and summarize the current scientific evidence regarding the clinical predictability of mesiodistal movements of upper and lower molars in patients treated with clear aligners without auxiliary aid.
Materials and Methods
This review followed PRISMA guidelines and was registered in PROSPERO (CRD42022357639). Databases were searched up to September 2024. Data extraction was performed independently by two reviewers, risk of bias was assessed using the ROBINS-I tool, and certainty of evidence was evaluated qualitatively using the GRADE tool.
Results
919 articles were identified, and six prospective and retrospective studies met the inclusion criteria, predominantly using the Invisalign system. Upper molar predictability was 61.1 ± 9.1% for movements ranging from 0.45 to 3.2 mm. Lower molar distalization showed lower predictability and molar mesial movement had median predictability rates of 85.6 ± 1.1%. Moderate to serious risk of bias and very low quality of evidence was found.
Conclusions
Upper molar distalization using clear aligners appears to be predictable for distalization from 1.5 to 3.2 mm. Anchorage reinforcement or overcorrection should be considered when planning mesiodistal movements. Standardization of the measurement method is necessary to improve efficacy of these systems.
ABSTRACT
In this case report, we present the treatment of a 28-year-old patient with lip incompetence and vertical maxillary excess (VME), using a combination of a midpalatal miniscrew-anchored cantilever clip appliance and submerged buccal shelf miniscrews. The patient exhibited a convex profile, long face, gummy smile, and protrusion, with a Class II skeletal relationship and mentalis strain. The patient declined conventional orthognathic surgery, leading to an orthodontic camouflage treatment plan involving extraction of four first premolars, maximum retraction, and active vertical control with skeletal anchorage devices. Treatment included the use of infrazygomatic crest miniscrews, anterior subapical miniscrews, and a cantilever clip appliance for molar intrusion, resulting in significant improvement in facial profile, reduction of gummy smile, resolution of lip incompetence, and alleviation of mentalis strain. This case demonstrates the effectiveness of a nonsurgical orthodontic intervention in managing a complex case of VME and lip incompetence.
ABSTRACT
Objectives
To evaluate changes in glenoid fossa morphology before, during, and after orthodontic treatment with extractions.
Materials and Methods
Eighty-four cone-beam computed tomograms from 28 adult female patients with Angle Class II, division 1 malocclusion, who underwent orthodontic treatment involving premolar extraction and mini-implant insertion, were collected at three time points: before treatment (T0), during treatment (just before extraction space closure, T1), and after treatment (T2). Changes in the morphology of the glenoid fossa and the relationship of the anterior teeth among T0, T1, and T2 were recorded.
Results
Inclination of the articular eminence (AEI-BFL and AEI-TRL) increased from T1 to T2 and from T0 to T2, whereas the width of the glenoid fossa (GFW) decreased from T1 to T2 and from T0 to T2. Changes in depth of the glenoid fossa (GFD) and the ratio of GFW to GFD were observed only in T0–T2. The height of the articular eminence (AEH) showed no significant differences among the three time points. Except for incisor overbite, which decreased from T0 to T1 and then to T2, all other dental parameters showed differences only in T1–T2 and T0–T2.
Conclusions
Orthodontic treatment with extractions can induce adaptive morphological changes in the glenoid fossa, primarily during the stage of extraction space closure. These changes are mainly characterized by a steeper AEI and a reduction in GFW.
ABSTRACT
Objectives
To compare orthodontic treatment cooperation between Generation Y and Generation Z teenagers and evaluate influence of age on compliance.
Materials and Methods
This was a retrospective cohort study analyzing records of 124 patients (62 from each generation) treated at Tel Aviv University Dental School between 2007 and 2021. Patient cooperation was assessed through weighted noncompliance scores incorporating elastic or headgear wear, oral hygiene, appointment attendance, appliance breakage, and new caries development. Each noncompliance incident was weighted (1.0 point for major incidents, 0.5 for minor) and standardized by treatment duration. Multiple regression analysis accounted for age differences.
Results
Mean age differed significantly between Generation Y (15.5 ± 1.7 years) and Generation Z (13.1 ± 1.6 years; P < .001). Initial noncooperation scores were similar (Generation Y: 36.8% ± 16.4%; Generation Z: 35.8% ± 15.8%; P = .732). After age adjustment, regression analysis revealed significantly higher noncooperation in Generation Y (B = 8.29; P = .014). Age independently influenced cooperation, with each year increase associated with a 3% decrease in noncooperation scores (B = −3.04; P < .001).
Conclusions
Generation Z teenagers exhibited better orthodontic treatment cooperation than Generation Y after age adjustment. Age independently predicted cooperation, with older teenagers showing better compliance regardless of generation. Treatment planning should consider both generational differences and individual patient factors when selecting compliance-dependent treatment options.
ABSTRACT
Objectives
To compare a slow, rapid activation protocol for miniscrew-assisted maxillary expansion in adults.
Materials and Methods
Fifteen consecutive adult patients underwent miniscrew-assisted slow palatal expansion (MASPE) using a bone borne device. A control group treated with miniscrew-assisted rapid palatal expansion (MARPE) was matched for initial demographic data and expansion need.
Results
No statistically significant differences in bispinal expansion were observed between the MASPE and MARPE groups at the anterior, middle, or posterior levels.
Conclusions
MASPE successfully achieved skeletal expansion of the maxilla in 86.7% of adult patients treated. The expansion pattern and results were comparable to MARPE.
ABSTRACT
Objectives
To evaluate the influence of personalized aligner replacement, with or without physical methods of acceleration using low-frequency vibration combined with a low-level laser, on the tooth movement rate and accuracy of clear aligners.
Materials and Methods
Forty participants were randomly allocated to three groups. Fourteen participants used the standard replacement protocol in Group A, Group B included 14 participants using a personalized replacement protocol, and 12 participants in Group C followed the personalized replacement protocol and used a physical device that combined low-frequency vibration and low-level laser. Aligner replacement cycles of the first 12 steps were recorded, and GOM inspect suite software 2022 (GOM; Braunschweig, Germany) was used to evaluate maxillary molar movement accuracy using digital models collected before treatment and at the end of the 12th step.
Results
No significant difference was found in the accuracy of maxillary molar movement between Groups A and B, but the tooth movement rate in Group B was significantly greater. The accuracy of maxillary molar movement was similar in Groups B and C, and the tooth movement rate in Group C was significantly increased.
Conclusions
The personalized replacement protocol decreased the number of aligner replacement cycles without impacting the accuracy of tooth movement. With personalized replacement, a physical method of acceleration combining low-level laser and low-frequency vibration significantly accelerated orthodontic tooth movement and had little influence on the accuracy of tooth movement.
ABSTRACT
Objectives
To compare mandibular incisor root length (RL) and root volume (RV) changes after 6 months of wearing either a removable anterior bite plane (RABP) during meals (F + M) or not during meals (F − M). Additionally, changes in incisal maximum bite force (IMBF) and their correlation with RL and RV changes were assessed.
Materials and Methods
Thirty-six children with deep bite using RABPs full time were randomly assigned in equal numbers to either the F + M group or F − M group. Cone-beam computed tomographic radiographs and IMBF were recorded at baseline (CT0) and after 6 months (CT1). Within and between group comparisons of RL and RV were performed (P = .05) with Bonferroni correction applied for segmental RV differences (P = .008). Relationships between IMBF changes and RL and RV changes were analyzed (P = .05).
Results
Both groups showed significant reductions in RL and RV. RL decrease in the F + M group (0.25 ± 0.14 mm) was significantly greater than in the F − M group (0.21 ± 0.14 mm). Reduction in RV was not significantly different between the groups, but IMBF significantly increased in both groups. Significant correlations were observed between IMBF changes and RL (r = 0.56) and RV (r = 0.86) changes.
Conclusions
Deep bite correction using RABPs for 6 months with F + M protocol resulted in a greater decrease in mandibular incisor RL compared to the F − M protocol. However, RV changes were comparable between protocols. IMBF may influence the degree of RL and RV changes.
ABSTRACT
Objectives
To assess case outcomes using the American Board of Orthodontics (ABO) Objective Grading System (OGS) in patients treated with lower incisor extraction.
Materials and Methods
Discrepancy indices (DI) were used to stratify patients into mild, moderate, and complex categories and overjet, overbite, and buccal occlusion were examined. Nineteen subjects were included in the study, among which 52.6% were females.
Results
The average (SD) age was 28.5 (15.1) years, and the average (SD) DI was 15.2 (8.6) with an even distribution of mild, moderate, and complex cases. The mean post-treatment OGS was 31, with 52.6% of the patients achieving passing ABO clinical scores. 31.6% achieved normal post-treatment overjet. A total of 52.6% achieved normal post-treatment overbite, and 84.2% achieved normal post-treatment buccal occlusion.
Conclusions
An increase in overbite and overjet, and a decrease in buccal occlusion measurement, were found after lower incisor extraction treatment. The ABO-OGS scores obtained were high, indicating that they may not pass the ABO criteria established.
ABSTRACT
Objectives
To evaluate root development after forced eruption of impacted maxillary canines before or after complete root development of the contralateral canine.
Materials and Methods
A total of 50 patients (21 male, 29 female; mean age: 12.4 years) with unilateral impaction of maxillary canines were classified to “Immature group” with incomplete root development of the contralateral canine or “Mature group” with complete root development of the contralateral canine. Volume, total length, crown length, root length, and root/crown ratio (R/C) of the impacted canine and the contralateral canine were measured in the posttreatment cone-beam computed tomography images.
Results
In the immature group, total length and root length of impacted canines were 0.68 mm and 0.51 mm shorter than contralateral canines, respectively (P < .05). In the mature group, volume, total length, root length, and R/C of impacted canines were 37.90 mm3, 2.43 mm, 2.53 mm, and 0.26 smaller, respectively, than contralateral canines (P < .001). Crown length also showed a statistically significant difference between impacted canines and contralateral canines (P < .05). When differences between impacted canines and contralateral canines were compared between the immature and mature groups, all variables showed statistically significant differences, with the mean difference in total length and root length being 1.75 mm and 2.02 mm larger, respectively, in the mature group, (P < .001).
Conclusions
Regardless of treatment timing, total length and root length of impacted canines were shorter than those of contralateral canines. Forced eruption of the impacted canine undertaken before root development of the contralateral canine showed better root development in both linear and volumetric measurements.
ABSTRACT
Objectives
To investigate the possible association between the presence of extreme premolar rotations (135° to 180° rotated premolars) and other dental anomalies within the dental anomaly pattern (DAP).
Materials and Methods
Thirty-two healthy subjects exhibiting at least one premolar rotated 135° to 180° were identified from the archives of a university orthodontic clinic. Inclusion criteria were: presence of a rotated premolar, availability of panoramic radiographs, dental study casts, and intraoral photographs. The concomitant occurrence of additional dental anomalies was evaluated based on the DAP, including tooth agenesis, infraocclusion of deciduous molars, peg-shaped lateral incisors, palatally-displaced canines and transpositions. Comparisons were made to a randomly selected control group (n = 96) without this anomaly, using chi-square statistics.
Results
The experimental group displayed a higher prevalence of dental anomalies compared to the control group. Forty-seven percent of patients in the experimental group exhibited dental agenesis, whereas only 8% of the control group had dental agenesis (P < .001). Infraocclusion of deciduous molars (22% vs 5%; P = .005) and canine impaction (16% vs 3%; P = .035) were also observed more frequently in patients in the experimental group.
Conclusions
These findings reveal significant associations between the presence of extreme premolar rotations and the occurrence of other dental anomalies, namely dental agenesis, infraocclusion of deciduous molars, and palatally-displaced canines. These observations suggest a shared genetic origin for these anomalies.
ABSTRACT
Objectives
To analyze, appraise, and synthesize papers in which authors have compared the effects of chemotherapeutic toothpaste (CTP) and regular toothpaste (RTP) on plaque scores (PSs), gingival scores (GSs), and bleeding scores (BSs) in orthodontic patients wearing fixed appliances (FAs).
Materials and Methods
PubMed-MEDLINE, Cochrane-CENTRAL, and Embase databases were searched with predefined search terms until April 2024 for controlled or randomized controlled clinical trials aligning with the aim. In the eligible papers, risk of bias was evaluated, data of interest were extracted, and a descriptive analysis was performed. If possible, meta-analyses and subanalyses on specific factors were conducted. The quality of evidence and strength of the recommendation were rated.
Results
In our search and selection, we obtained five papers describing eight comparisons. Potential risk of bias was assessed as some concerns to high, and heterogeneity was considered substantial. Descriptive analysis revealed no significant difference in PS and BS, with an improvement in GS favoring CTP. Meta-analyses of the end scores showed CTP significantly reduced PS (standardized mean difference [SMD] = −0.26; 95% confidence interval [CI] = −0.52, −0.01; P = .04). However, no significant effects were observed on GS and BS. These findings were supported by the subanalyses on CTP with chlorhexidine (CHX; PS: mean difference [MD] = −5.12; 95% CI = −10.08, −0.15; P = .04). The quality of evidence was graded as very low, and strength of the recommendation was judged as very weak.
Conclusions
For orthodontic patients with FAs, very weak certainty exists in recommending CTP (eg, with CHX) over RTP for use with toothbrushing. CTP may have a very small effect on PS and a small effect on GS.
ABSTRACT
Objectives
To identify the rotational fulcrum (RF) and to evaluate the skeletal and dentoalveolar effects after rapid palatal expansion (RPE) with tooth-borne and tooth-bone-borne (MARPE) appliances.
Materials and Methods
31 patients were selected (MARPE group: n = 14, age 16.2 ± 2 years; hyrax group: n = 17, age 14.7 ± 0.8 years) with RPE indication and having cone-beam computed tomography before (T1) and after RPE (T2) and after 6 months of retention (T3).
Results
In the MARPE group, the RF was at or above the frontozygomatic suture (FZS), whereas in the hyrax group, it was at or below the FZS. The skeletal response rates were 70% (2°) and 33% (1.09°); alveolar response rates, 18% (0.52°) and 20% (0.68°); and dental response rates, 12% (0.35°) and 47% (1.54°) in the MARPE and hyrax groups, respectively, with a significant difference between groups in skeletal (P = .005) and dental (P < .001) regions. After retention, no significant difference was found between groups.
Conclusions
Although MARPE resulted in a higher RF in the coronal view, both techniques effectively corrected transverse discrepancies with similar stability. Considering the between-group differences in relation to skeletal and dentoalveolar response, MARPE should be used for cases in which minimal compensatory tooth movement is desired.
ABSTRACT
Objectives
To evaluate the accuracy and reliability of an automated landmark identification (ALI) system and the impact of ALI errors on cephalometric measurements on cone-beam computed tomography (CBCT) images.
Materials and Methods
Thirty-one landmarks were identified on 76 CBCT images using Invivo7 software (Anatomage, San Jose, Calif). Ground truth was established by averaging landmark coordinates from two calibrated human examiners. The accuracy of the ALI system was assessed by the mean absolute error (MAE, mm) across coordinate axes, the mean error distance (mm), and the successful detection rate (SDR) for each landmark. Interexaminer reliability between the ALI and manual landmark location was evaluated. Eighteen cephalometric measurements were computed from 25 landmarks. Accuracy of measurements from the ALI system was assessed with the MAE and successful measurement rates (SMR).
Results
The ALI system closely matched human examiners in landmark identification, with an average MAE of 0.94 ± 0.99 mm. Across all three coordinate axes, 87% of the landmarks had <2 mm MAE. ALI average MAE for conventional linear and angular cephalometric measurements were 1.35 ± 1.33 mm and 0.89 ± 0.89 degrees, respectively. Only one measurement, Intercondylar Width, showed MAE >3 mm.
Conclusions
The ALI system showed clinically acceptable accuracy and reliability for the majority of cephalometric landmarks and measurements. Clinicians are advised to critically evaluate ALI landmarks with substantial errors, to fully utilize the capabilities of commercial software effectively.
ABSTRACT
Objectives
To describe parent perspectives on effective patient-provider communication (PPC) during orthodontic consultations for their children.
Materials and Methods
Qualitative description guided the study design. Parents of children who recently underwent an orthodontic consultation and were fluent in English were purposefully selected. Interviews continued until data saturation was achieved. Data were analyzed using inductive, manifest thematic analysis.
Results
Fifteen parents, including 10 females and five males, participated. Four themes were inductively developed. Parents attributed several characteristics to effective PPC, including inclusivity, clarity, honesty, and comprehensiveness’s. Specifically, they emphasized the importance of involving children and staff members in the consultation process, delivering honest and justifiable diagnoses and treatment plans, and adopting a holistic approach that considered all phases of the therapeutic process and various dimensions such as tasks, finances, and relationships between patients and care providers.
Conclusions
The findings underscore the significance of care provider-related factors in PPC. These findings also emphasize the need for a collaborative and inclusive approach between orthodontic patients and care providers to foster effective PPC. Subsequent researchers should delve into the perspectives of pediatric patients, particularly adolescents, and care providers regarding effective PPC.
ABSTRACT
Objectives
To investigate the influence of attachment position and torque overcorrection on stress distribution and tooth displacement trends during arch expansion in clear aligner therapy (CAT).
Materials and Methods
Dental and skeletal models were obtained from an adult volunteer with angle Class I and mild crowding. Attachments were designed on the buccal, lingual, and buccolingual surfaces of the first molar. Different overcorrection torques were designed on the first molar. The displacement and stress of the whole arch were analyzed using a three-dimensional finite element analysis model.
Results
Crown buccal tipping was observed during arch expansion, while the lingual attachment showed more buccal crown and lingual root movement. Based on the trend of displacement, 1.5° of buccal root torque overcorrection without attachments could lead to bodily movement, 1.8° with a lingual attachment, 0.5° with a buccal attachment, and 0.9° with a buccolingual attachment.
Conclusions
Arch expansion is primarily achieved by teeth tipping despite attachments placed on the buccal or lingual side of teeth in CAT. Appropriate overcorrection of buccal root torque could contribute to the achievement of bodily movement.
ABSTRACT
Objectives
To evaluate the reliability and accuracy of Keynote for tracing and analyzing cephalograms in comparison to Quick Ceph Studio.
Materials and Methods
This was a cross-sectional study, which utilized the lateral cephalometric digital images (radiographs) from 49 patients. The study site was the Dental Radiology unit in the School of Dentistry of the Muhimbili University of Health and Allied Sciences (MUHAS), in Dar es Salaam, Tanzania. Cephalograms were imported to Quick Ceph Studio and then to Keynote for analysis. Minimum, maximum, mean, standard deviation, and mean difference were used to describe the data. Agreement between the two techniques was assessed by the Bland-Altman plot, linear regression, and interexaminer reliability tests. A level of significance was considered at P < .05, and a 95% CI was estimated for the outcomes in the study groups.
Results
The majority of the mean values obtained from Quick Ceph were greater (P < .05) than those obtained from Keynote. According to Bland-Altman plots, all measurements were within the limit of agreement except for only five linear variables. The interexaminer reliability test showed no agreement between the two instruments for all linear parameters except for the LAFH: TAFH, whereas all angular measurements revealed good to excellent agreement (ICC: 0.75 to 0.97) between the methods.
Conclusions
The measurements obtained with the Keynote software were found to be clinically reliable since the limits did not exceed the maximum acceptable difference between the methods. The two software instruments were considered to be in agreement and can be used interchangeably.
ABSTRACT
Objectives
To evaluate the accuracy of Invisalign ClinCheck in predicting open gingival embrasures (OGEs) and to identify predictors of OGEs in adult extraction cases.
Materials and Methods
Fifty-seven adult patients treated with Invisalign and four first premolar extractions were included in this retrospective study. OGEs were measured in maxillary and mandibular anterior regions using posttreatment intraoral photographs (actual OGEs) and the final step from the first treatment plan in ClinCheck (predicted OGEs). Prediction performance indicators including precision, sensitivity, specificity, false positive rate, false negative rate, and accuracy were evaluated at each tooth site. Predictors of OGEs (age, crowding, crown morphology, tooth movement, tooth site, treatment duration, and attachment design) were analyzed using binary logistic regression.
Results
Incidence of actual OGEs was like that of the ClinCheck predicted OGEs in the maxillary and mandibular anterior regions. The predictability of ClinCheck was satisfactory in both the maxilla and mandible, with accuracy rates of 94.0% and 86.0%, respectively. The most accurate prediction was for the maxillary central incisors, achieving a precision of 100% and an accuracy of 96.6%. The most significant predictors of OGEs included patient age at initial consultation, anterior crowding, tooth crown morphology, and type of tooth movement.
Conclusions
Invisalign ClinCheck predicted OGEs in adult patients treated with four premolar extractions. The accuracy of the prediction was satisfactory, 94% in the maxilla and 86% in the mandible, demonstrating great potential for clinical application.
Objectives
To report the prevalence of pulp stones (PSs) in molars of orthodontically treated patients, investigate the impact of orthodontic treatment (ORT) using clear aligners (CAs) and fixed appliances (FAs) on the development of PSs in molars, and investigate the association between the incidence of PSs during ORT and the studied variables.
Materials and Methods
Pretreatment orthopantomograms (OPGs) of 600 patients were assessed. Of those, posttreatment OPGs of 272 patients were available. Molars were subdivided into four subgroups based on type of appliance and force application: group 1, first molars included in FA (n = 707); group 2, first molars included in CA (n = 157); group 3, second molars included in CA (n = 189); group 4, second molars not included in FA during treatment (n = 880). PSs were diagnosed when radiopaque bodies were detected in the coronal and/or radicular pulp space. PS changes after treatment were recorded and analyzed using SPSS.
Results
The prevalence of PSs was 16.6%. The overall incidence of PSs increased by 5.9% and 4.5% in groups 1 and 2, and by 3.7% and 5.3% in groups 3 and 4, respectively (P ≤ .05). No significant differences were found between appliance type groups (1 and 2) and force application groups (3 and 4). The association between PS development and the type of appliance or treatment duration was not significant.
Conclusions
The incidence of PSs increased during ORT, which was more pronounced in maxillary molars. PS development during ORT was not associated with orthodontic appliance type, force application, and duration of ORT.
ABSTRACT
Objectives
To determine effects of printing layer thickness and build orientation on mechanical properties and color stability of direct 3D-printed clear aligner resin.
Materials and Methods
Specimens were printed using 3D printed clear aligner resin with two printing layer thicknesses (50 µm, 100 µm) and three build orientations (90°, 60°, and 45°). Mechanical properties (tensile stress, tensile strain, and elastic modulus), color stability in coffee and artificial saliva, and roughness were then evaluated.
Results
Specimens printed with a 50 µm layer thickness and orientation at 90° demonstrated superior color stability in artificial saliva. However, all specimens showed high susceptibility to coffee staining regardless of layer thickness or orientation. Mechanical properties were improved in the order of 90° < 60° < 45° build orientation, showing statistically significant differences (P < .05). Surface roughness was increased in the order of 90° < 60° < 45° build orientation, showing statistically significant differences (P < .05).
Conclusions
Printing layer thickness and orientation exerted significant effects on mechanical properties, color stability, and surface roughness of 3D-printed clear aligner resin.
ABSTRACT
Objectives
To explore the relationship between changes in Peer Assessment Rating (PAR) score and Oral Health-Related Quality of Life (OHRQoL) following orthodontic treatment and to assess responsiveness of the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) in a cohort of young adults.
Materials and Methods
Participants (n = 162) aged 18–25 years requiring comprehensive fixed orthodontic treatment were recruited. Changes in OHRQoL were measured using the PIDAQ, while malocclusion severity was assessed using the PAR index and Index of Orthodontic Treatment Need. Data were collected before treatment (T0) and 1 month after treatment completion (T1). Responsiveness of the PIDAQ was evaluated using standardized effect size, standardized response mean, and Global Transition Judgment.
Results
A positive, moderate overall correlation (r = 0.417, P < .05) was observed between changes in PAR and PIDAQ scores posttreatment, with significant improvements in OHRQoL reported by 88.1% of participants at T1. Subgroup analysis revealed strong correlations in cases of crowding (r = 0.711) and increased overjet (r = 0.703), while Class III malocclusion showed a weaker correlation (r = 0.263). Multivariate regression analysis revealed that change in PAR score was independently associated (R2 = 0.652) with change in OHRQoL score. The PIDAQ demonstrated responsiveness to treatment-associated changes, with a significant reduction in OHRQoL scores posttreatment.
Conclusions
While a positive correlation between the objective measure of malocclusion severity (PAR) and subjective OHRQoL was identified, the relationship was moderate. The PIDAQ was found to be a responsive scale for assessing OHRQoL in orthodontic patients.
ABSTRACT
Objectives
To assess the perception of smile esthetics, variations in buccolingual crown inclination of the upper anterior teeth were introduced, disrupting the parallelism of these connectors from a frontal view.
Materials and Methods
In this descriptive cross-sectional study, a close-up smile image was modified using Adobe Photoshop to adjust the angulation of connectors, affecting either the six upper anterior teeth (C/C group) or the four upper anterior teeth (LI/LI group). Orthodontists (ORs), general dentists (GDs), and laypersons (LPs) then evaluated the attractiveness of the modified smiles.
Results
A total of 79 LPs, 65 ORs, and 89 GDs participated in the evaluation. LPs gave the highest scores, followed by GDs and ORs, in both the C/C and LI/LI groups. The −6° deviated image was the least favored in the C/C group, while the −9° image received the lowest scores in the LI/LI group.
Conclusions
In this study, we highlight the importance of proper buccolingual crown inclination and parallelism of connectors during treatment. The OR group showed the most critical assessment of smile esthetics related to buccolingual crown inclination variations. Lower scores were noted for greater deformations and negative inclinations in both the LI/LI and C/C groups.
ABSTRACT
Objectives
To test the hypothesis of Burstone and Koenig that a three-bracket geometry can be simplified into two adjacent two-bracket geometries, to evaluate the impact of a third bracket on two-bracket geometries, to identify the force systems of 36 three-bracket geometries using archwires of different materials, and to apply these principles to clinical scenarios.
Materials and Methods
A custom-designed orthodontic force jig supported three force transducers fitted with passive self-ligating brackets (Brackets A, B, and C). In Experiment 1, the force system of a three-bracket geometry was compared with two adjacent two-bracket geometries. In Experiment 2, 36 three-bracket geometries were tested when straight wires of varying materials were engaged.
Results
Experiment 1 results showed that the force system of a three-bracket geometry could be simplified into two adjacent two-bracket geometries. Experiment 2 results showed that the impact of the third bracket (Bracket C) affected the force system of the adjacent bracket only (Bracket B), with Bracket C having no statistically significant effect on the force systems at Bracket A. A distinct pattern of forces and moments was found in each of the 36 three-bracket geometries.
Conclusions
In this study, we experimentally validated the hypothesis of Burstone and Koenig, showing that a three-bracket geometry can be simplified into two adjacent two-bracket geometries. The force system of 36 three-bracket geometries was determined, assisting clinicians with better anticipating previously unpredicted and undesirable movements, thereby improving treatment efficiency.
Objective
A 26-year-old woman came for orthodontic treatment to improve her profile with protrusive lips. Diagnosed as bimaxillary protrusion, extraction followed by anterior retraction was indispensable for the case. However, her left upper lateral incisor was absent, the left upper canine had moved mesially and replaced the adjacent incisor, and the original canine location was restored with a long implant, which was in good condition. Surgical removal of the implant would be tricky and might lead to atrophy of the alveolar bone. In addition, the upper left central incisor had a short, curved root, which could not undergo significant movement.
Materials and Methods
After crucial discussion between orthodontists and implantologists, based on digital setup, an innovative treatment plan was developed. Four incisors were extracted followed by clear aligner therapy for anterior retraction. An individualized zirconia abutment was installed on the upper left implant in a retroclined direction, cemented with a zirconia crown to replace the upper lateral incisor. Minimally invasive veneers were made to reshape the other upper incisors for better esthetics.
Results
Finally, the patient had her profile greatly improved and the teeth well aligned without removal of the implant.
Conclusion
Thus, the seemingly mission impossible was accomplished with a satisfactory outcome, thanks to imaginative treatment planning and delicate interdisciplinary collaboration based on digital simulation.
ABSTRACT
In this case report, we show a strategic approach to prolonging the lifespan of pathologically migrated maxillary canines with a hopeless prognosis in a 57-year-old female patient, highlighting the potential of orthodontic management for middle-aged patients to enhance both occlusion and facial esthetics while minimizing the need for extensive prosthetic treatment. According to the visual treatment objective, the nonextraction treatment plan showed advantages in the type of orthodontic tooth movement and final occlusal relationship. Therefore, considering the favorable periodontal treatment results and single-root teeth, the hopelessly migrated maxillary canines were relocated, eliminating the existing trauma from occlusion. Segmental tooth movement was performed, and orthodontic temporary skeletal anchorage devices were used to support strategic orthodontic tooth movement. After 27 months of treatment, proper occlusion was established with a significant improvement in facial esthetics. The periodontally compromised teeth were preserved with adequate periodontal support. The patient expressed satisfaction with the results, and the 30-month follow-up records confirmed the stability of treatment outcomes.
ABSTRACT
Class III malocclusion due to a retrognathic maxilla is common in patients with cleft lip and palate. Skeletally anchored maxillary protraction using screw-anchored mini-plates combined with intraoral elastics has shown promising results in achieving orthopedic changes and maintaining the outcome until the completion of the growth. This case report presents the course of treatment in a patient with unilateral cleft lip and palate and multiple congenitally missing teeth treated with bone-anchored maxillary protraction until the end of growth. Four mini-plates (Bollard plates) were used during comprehensive fixed orthodontic treatment to protract the dentition and close the space where teeth were missing, extrude the canine, and force eruption of the second premolar using extension arms and cantilevers. A 2-year follow-up at age 17 showed stable occlusion and maintenance of soft tissue results. Bone-anchored maxillary protraction treatment in a patient with cleft lip and palate demonstrates proper orthopedic results and could be a viable alternative to orthognathic surgery.
Class III correction and enhanced periodontal health with aligner treatment in a 53-year-old patient
ABSTRACT
In this case report, we describe the successful camouflage treatment of a 53-year-old female with dental and skeletal Class III malocclusion combined with anterior crossbite, gingival recession, and mobility of the lower incisors, using clear aligners. The treatment involved periodontal debridement followed by orthodontic treatment. The mandibular posterior teeth were distalized to correct the anterior crossbite and to establish Class I molar relationships. During treatment, the mandibular incisors were intruded, and the mandibular occlusal plane underwent a clockwise rotation due to slight extrusion of the maxillary buccal segments and distalization of the mandibular posterior teeth. Following treatment, all objectives were achieved, including resolution of the anterior crossbite, significant reduction of gingival recession and tooth mobility, and improved functional occlusion. The dental and skeletal Class III malocclusion was corrected, and the marginal alveolar bone dehiscence was significantly reduced. The results remained stable over a 3-year retention period, with enhanced molar intercuspation and gingival growth progression. This case adds to the evidence supporting the adaptability and effectiveness of clear aligners in treating orthodontic patients with compromised periodontium. The treatment outcomes support that orthodontic treatment using clear aligners, combined with periodontal monitoring, can assist in managing alveolar bone defects, gingival recession, and tooth mobility.
Validation of an AI-aided 3D method for enhanced volumetric quantification of external root resorption in orthodontics
Alveolar bone defects influence rate of tooth movement
Predictability of mesiodistal movement of upper and lower molars with clear aligners: a systematic review
Lip incompetence resolved by active vertical control in nonsurgical treatment of a protrusion case with vertical maxillary excess
Changes in glenoid fossa of adult female patients with Class II division 1 malocclusion during premolar extraction treatment and mini-implant anchorage: a cone-beam computed tomography study
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