Taxonomic discordance of immersive realities in dentistry: A systematic scoping review.

OBJECTIVES: This review aimed to map taxonomy frameworks, descriptions, and applications of immersive technologies in the dental literature. DATA: The Preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) guidelines was followed, and the protocol was registered at open science framework platform (https://doi.org/10.17605/OSF.IO/H6N8M). SOURCES: Systematic search was conducted in MEDLINE (via PubMed), Scopus, and Cochrane Library databases, and complemented by manual search. STUDY SELECTION: A total of 84 articles were included, with 81 % between 2019 and 2023. Most studies were experimental (62 %), including education (25 %), protocol feasibility (20 %), in vitro (11 %), and cadaver (6 %). Other study types included clinical report/technique article (24 %), clinical study (9 %), technical note/tip to reader (4 %), and randomized controlled trial (1 %). Three-quarters of the included studies were published in oral and maxillofacial surgery (38 %), dental education (26 %), and implant (12 %) disciplines. Methods of display included head mounted display device (HMD) (55 %), see through screen (32 %), 2D screen display (11 %), and projector display (2 %). Descriptions of immersive realities were fragmented and inconsistent with lack of clear taxonomy framework for the umbrella and the subset terms including virtual reality (VR), augmented reality (AR), mixed reality (MR), augmented virtuality (AV), extended reality, and X reality. CONCLUSIONS: Immersive reality applications in dentistry are gaining popularity with a notable surge in the number of publications in the last 5 years. Ambiguities are apparent in the descriptions of immersive realities. A taxonomy framework based on method of display (full or partial) and reality class (VR, AR, or MR) is proposed. CLINICAL SIGNIFICANCE: Understanding different reality classes can be perplexing due to their blurred boundaries and conceptual overlapping. Immersive technologies offer novel educational and clinical applications. This domain is fast developing. With the current fragmented and inconsistent terminologies, a comprehensive taxonomy framework is necessary.

White spot lesions, plaque accumulation and salivary caries-associated bacteria in clear aligners compared to fixed orthodontic treatment. A systematic review and meta- analysis.

OBJECTIVE: To analyse the available evidence regarding the incidence and severity of white spot lesions (WSLs), plaque accumulation and salivary caries-associated bacteria(SCB) in clear aligners (CA) verses conventional fixed (CF) orthodontic appliances. METHODS: Electronic searches of MEDLINE, Scopus, Embase, Google Scholar, Clinical trial registry, OpenGrey and ProQuest were done for all relevant studies. Eligibility criteria were; Randomized Controlled Trials and Non-Randomized Studies that compared the incidence and severity of WSLs, plaque accumulation and SCB between CA and CF appliances in patients undergoing orthodontic treatment. The risk of bias(ROB) and certainty of evidence was assessed independently by two reviewers using Cochrane's ROB and GRADEpro, respectively. Standardized mean difference (SMD) was used to estimate the effect size using STATA 17 software. RESULTS: A total of 14 studies met the eligibility criteria, and eight were suitable for meta-analysis. The qualitative results showed lower incidence and severity of WSLs, plaque accumulation, and SCB in CA group compared to CF appliances. The pooled results showed significantly lower plaque accumulation(SMD - 1.58;95%CI:-2.57,0.58;p = 0.002) in CA compared to CF appliances. CONCLUSIONS: A moderate-quality evidence reveals less plaque accumulation and less SCB in CA, which might be related to the reduced incidence and severity of WSLs associated with CA when compared with CF appliances. However, the results of the present study should be interpreted with caution given the high ROB among some of the included studies as well as the marked heterogeneity across the studies. CLINICAL RELEVANCE: For patients who can be treated with either CA or CF appliances, CA may be a better choice concerning oral health. REGISTRATION: Open Science Framework (DOI: https://doi.org/10.17605/osf.io/kcpvb ).

The COVID-19 experience of orthodontists in Jordan.

OBJECTIVES: To understand the impact of the COVID-19 pandemic on orthodontic clinical services in Jordan. MATERIALS AND METHODS: Google Forms electronic questionnaires were distributed between March and June 2021 using the WhatsApp platform of the Jordanian Orthodontic Society and via direct WhatsApp messages. The survey was identical and contemporaneous to that used in the United Kingdom. RESULTS: The survey yielded 127 unique responses, giving a response rate of 53.1%. The factors that had the greatest impact on service delivery were government guidance (78%), patients' fear of attending (70.1%), and increased cross-infection measures (65.4%). The survey revealed that there had been a perceived deterioration in oral hygiene (60.3%) and levels of compliance (61.9%) in patients in active treatment even though patients in treatment were prioritized during the pandemic. Also, 56.8% of respondents felt clinical staff should be vaccinated and undergo regular testing for COVID-19. Orthodontists within Jordan were optimistic regarding the speed at which clinical services would return to pre-pandemic levels of activity with 32.5% anticipating this would take less than 6 months. CONCLUSIONS: Patients in active orthodontic treatment, during COVID-19, have been prioritized but at the expense of new and review patients. Respondents in Jordan felt COVID-19 would have ongoing effects on clinical care, professional practice, and society. Most respondents supported the vaccination of orthodontic staff and were optimistic about the effect of a vaccination program on restoring clinical services.

Leveling the curve of Spee using different sized archwires: a randomized clinical trial of blood flow changes.

OBJECTIVES: To compare blood flow (BF) changes of teeth subjected to orthodontic forces during curve of Spee (COS) leveling using different archwires (AW). MATERIAL AND METHODS: Thirty subjects with COS > 5 mm were randomly assigned (1:1:1) into three groups based on the AW used: group 1: 0.017 × 0.025-inch stainless-steel (SS)AW, group 2: 0.019 × 0.025-inch SSAW, and group 3: 0.021 × 0.025-inch ß-titanium (TMA)AW. In the 3 groups, a 5 mm-depth reverse COS was placed in the AWs. A laser Doppler flowmeter was used to measure BF at different time intervals (T0-T4). RESULTS: In the 3 AWs group, BF of all measured teeth was reduced 20 min after force application. Afterwards, the BF values started to increase until the baseline values were almost restored within 1 week. Differences in BF changes between the extrusion and intrusion subgroups were observed within groups 1 and 3 during the first 20 min of force application (P < 0.05). Similar BF changes were recorded using the 3 different AWs. BF changes were associated with tooth type and the amount of COS depth change. CONCLUSIONS: During CoS leveling, similar BF changes were recorded using the 3 different AWs. Tooth type and the amount of COS depth change were associated with BF changes within the first 20 min of force application. Greater BF reduction was found in premolars compared to incisors during the first 20 min of AW placement. CLINICAL RELEVANCE: It is important to select a type of applied forces that minimally affect the BF. Intrusive forces appeared to have lower negative effects on the BF of teeth during COS leveling. TRIAL REGISTRATION: ClinicalTrial.gov (# NCT04549948).

Effect of piezocision-assisted lower second molar protraction on periodontal tissues, alveolar bone height, and lower second molar root resorption.

OBJECTIVES: To assess the effect of piezocision on periodontal tissues and alveolar bone height and to detect lower second molar root resorption in piezocision-assisted mandibular second molar protraction compared to no-piezocision molar protraction. MATERIALS AND METHODS: Twenty-one subjects (four males, 17 females, aged 22.43 ± 2.83 years) who presented with bilateral extraction of lower first molars were included. The patients were divided into two groups; Group 1: Piezocision-assisted molar protraction (right or left side of subjects) in which piezocision was performed immediately before lower second molar protraction and, Group 2: No-piezocision molar protraction in which lower second molar protraction was not surgically assisted. Plaque index (PI), gingival index (GI), periodontal pocket depth (PPD), width of keratinized gingiva (WKG), gingival recession (GR), lower second molar mesial root resorption, alveolar bone height, and mandibular bone height were recorded at T1 (immediately before molar protraction) and at T2 (after second molar space closure). RESULTS: In the piezocision-assisted molar protraction group, significant changes were detected in the WKG (P < .001), GR (P < .05), and the mandibular bone height (P < .001). Compared to the no-piezocision group, piezocision-assisted molar protraction resulted in an increased WKG (P < .001) and less second molar mesial root resorption (P < .01). CONCLUSIONS: Piezocision does not have any detrimental effect on the periodontium and produces less root resorption.

Bite force changes after surgical correction of mandibular prognathism in subjects with increased vertical dimension : A prospective clinical trial.

PURPOSE: Occlusal bite force (OBF) is the most important parameter in assessing biting efficiency. The aim of this study was to record OBF changes after surgical correction of high angle maxillary/mandibular (Max/Mand) class III patients and to compare these with that recorded in class III patients with average Max/Mand angle. MATERIALS AND METHODS: Initially included were 42 patients with severe class III skeletal malocclusion who were scheduled for orthodontic surgery: group 1-22 patients with increased vertical relationship scheduled for bimaxillary surgery; group 2-20 patients with average vertical relationship scheduled for mandibular setback only. OBF measurements before surgery (T0), at debonding (T1) and at least 3 months after debonding (T2) were recorded using a portable occlusal force gauge. The following were also measured: maximum OBF (MOBF) achieved by the subject on each side, averaged OBF on each side (AOBF) and maximum OBF at the incisal region (MIOBF). At T2, only 33 patients (group 1: 17 and group 2: 16) were included in the analysis due to loss to follow-up. RESULTS: MOBF increased significantly in group 1, while no significant changes were detected in group 2. MIOBF increased after surgical correction in both groups. Significant increase in MIOBF was observed at T1 (P < 0.001) followed by an insignificant decrease during the observation period (3-6 months after treatment; P > 0.05). The two groups differed significantly in MOBF at T1 and T2, while no statistically significant differences were detected between the groups for MIOBF changes at the various time intervals (P > 0.05). The number of posterior teeth with occlusal contacts increased in both groups. Relapse was detected in group 1 where the number of posterior teeth in contact decreased during the observation period (T1-T2). CONCLUSION: OBF greatly improved after surgical correction of the vertical morphology. Correction of high angle mandibular prognathism improves oral function in addition to esthetics.

Tooth size discrepancy in orthodontic patients with skeletal anterior open bite.

OBJECTIVE: To find out if there is any relationship between tooth size discrepancy (TSD) and skeletal anterior open bite (AOB) and to assess the correlation between the amount of AOB and TSD. METHOD: A total of 100 Class I subjects were included in this study (average age 15.21 ± 2.84 years). Fifty patients had skeletal AOB (>3 mm) and 50 subjects acted as controls and had a normal overbite. Teeth mesio-distal widths were measured using a digital caliper. Anterior, overall, and posterior TSD ratios were calculated. An independent t-test was employed to assess differences between groups and between genders. Pearson correlation coefficient was used to assess the correlation between the amount of AOB and TSD. RESULTS: Significant differences in anterior (p = .038) and posterior (p = .015) TSD ratios were detected. In the skeletal AOB group, no significant gender differences were detected (p > .05), whereas in the normal bite and total sample group, males had smaller posterior teeth compared to females (p < .05). All the differences were smaller than 1 SD of Bolton's ratios. No significant correlation was found between the amount of AOB and TSD ratios (p > .05). CONCLUSIONS: Skeletal AOB had larger anterior and smaller posterior mandibular teeth, but the differences were less than 1 SD of Bolton's ratios. Males have smaller mandibular posterior teeth than females. The amount of AOB is not correlated with the TSD ratios.

Cranial base measurements in different anteroposterior skeletal relationships using Bjork-Jarabak analysis.

OBJECTIVES: To assess the linear and angular cranial base measurements (Bjork polygon) in different anteroposterior (AP) skeletal relationships using Bjork-Jarabak analysis. MATERIALS AND METHODS: Pretreatment lateral cephalograms of 288 (146 women, 142 men, mean ages 21.24 ± 2.72 years and 22.94 ± 3.28 years, respectively) adult patients were divided into Class I, II, and III skeletal relationships according to their ANB angle. Linear and angular measurements of Bjork polygon were measured and compared among different skeletal relationships. Analysis of variance was performed to detect the differences among groups. Independent-sample t-test was used to detect differences between men and women. RESULTS: The Class II skeletal relationship has a significantly larger saddle angle than Class III does (P < .05), whereas Class III has a significantly larger gonial angle than Class II does (P < .05). The articular angle and sum of Bjork polygon angles were not significantly different among groups (P > .05). Anterior (N-S) and posterior (S-Ar) cranial base lengths were similar in the different AP skeletal relationships (P > .05). The ramal height and body of the mandible length were significantly larger in Class III compared with Class I and II (P < .05). Women had a significantly larger articular angle than men did (P < .05), although men had significantly larger linear measurements of Bjork polygon than women did (P < .05). CONCLUSIONS: The Class III skeletal relationship has a smaller saddle angle and larger mandibular length and gonial angle. Men have a larger cranial base and mandibular linear measurements and a smaller articular angle compared with women.

Evaluation of maxillary canine root and maxillary bone thickness and density in patients with displaced maxillary canines: A cone-beam tomography study.

INTRODUCTION: This study investigated lateral incisor and canine morphology and dimensions, maxillary bone density, and volume in subjects with displaced maxillary canines. METHODS: Cone-beam computed tomography images for 134 palatally displaced canines (PDCs), 57 buccally displaced canines (BDCs), and 87 nondisplaced canines (NDCs) were analyzed. Canine and lateral incisor dimensions, alveolar bone dimensions, and maxillary bone volume and density were measured. RESULTS: The root length of BDCs was short compared with NDC and PDC groups. The lateral incisor was short in the PDC group compared with NDC and BDC groups. In the BDC group, maxillary bone volume was reduced compared with NDCs and PDCs. Significant differences were detected between BDC and PDC groups in bone density buccal to canines and between BDC and NDC groups in bone density distal to canines. The density of maxillary bone was the highest in the PDC group and the lowest in the BDC group compared with the NDC group. Eight variables were associated with the site of maxillary canine displacement: lateral incisor tip, alveolar bone density, alveolar bone width, bone density buccal to canine, canine width labiopalatally, maxillary bone volume, and canine midsagittal width. CONCLUSIONS: In PDCs, the maxillary lateral incisor was short, the canine root had a larger crown/root ratio, and maxillary bone volume was increased compared with NDCs. In BDCs, the canine root was shorter than NDCs and PDCs, maxillary bone volume was reduced compared with NDCs, and bone density at the buccal side was reduced compared with the PDC group.

A comparative assessment of the amount and rate of orthodontic space closure toward a healed vs recent lower premolar extraction site.

OBJECTIVES: To investigate and compare the amount and rate of space closure and tooth tipping during orthodontic space closure toward a recent vs healed first premolar extraction site. MATERIALS AND METHODS: The mandibular arches of 23 patients were included. Treatment plans included lower first premolar extractions. After reaching 0.019 × 0.025-inch stainless-steel archwires (SSAW), patients were subdivided into two groups (Group 1: space closure was carried out toward a healed first premolar extraction space and Group 2: space closure was carried out immediately after first premolar extraction). Elastomeric power chain from second molar to second molar was used to close lower extraction spaces. The following time points were defined: T1: just before space closure; T2-T4: 1-3 months after initial space closure. Records consisted of dental study models. The amount and rate of extraction space closure were evaluated at each time point. RESULTS: In Group 1 (healed socket), a total amount of 1.98 mm (coronally) and 1.75 mm (gingivally) of space closure was achieved. The rate of space closure was 0.66 mm/month coronally and 0.58 mm/month gingivally. In Group 2 (recent socket), the total amount of space closure was 3.02 mm coronally and 2.68 mm gingivally. The rate of space closure was 1.01 mm/month coronally and 0.89 mm/month gingivally. Differences between the two groups were significant (P < .01). Tipping of adjacent teeth during space closure was similar in both groups (P > .05). CONCLUSIONS: In the lower arch, the amount and rate of space closure toward a recent extraction site were higher than that toward a healed extraction socket with similar tipping of teeth in both groups.

The COVID-19 experience of orthodontists in the UK.

OBJECTIVE: To understand and compare the perceived impact and ongoing effects of the COVID-19 pandemic on orthodontic clinical services in the UK. DESIGN: Descriptive cross-sectional survey. SETTING: Online electronic questionnaire. PARTICIPANTS: Members of the British Orthodontic Society (BOS). METHODS: Electronic questionnaires were circulated between March and June 2021. The UK survey was distributed via emails from the BOS, Orthodontic Managed Clinical Networks and WhatsApp groups. RESULTS: A total of 560 unique responses were received. There were more respondents who were aged over 50 years (52%) then respondents who were aged below 50 years (48%) with the median age range being 50-54 years (20%). The main causes of disruption to clinical practice were felt to be national restrictions (85%), increased cross-infection measures (84%), social distancing (80%) and professional guidance (80%). Respondents felt more negatively in their opinions regarding dentistry's preparedness for the pandemic (5%) and how dentistry coped in the crisis (35%), when compared to orthodontic services specifically (8% and 58%, respectively). The respondents were not confident about the potential beneficial effects of a vaccination programme on orthodontic clinical service provision (21%). Telephone consultations (84%) and video consultations (61%) were the main adaptations used by the respondents during the pandemic. CONCLUSIONS: Respondents felt that COVID-19 will have long-term societal, clinical and professional implications. The majority of our respondents supported the vaccination and weekly testing of the orthodontic team. Respondents felt that during the pandemic there had been a deterioration in care provision and were not optimistic about a vaccination programme restoring services to pre-pandemic levels of activity. During the pandemic, patients in active orthodontic treatment have been prioritised but at the expense of new and review patients, and as services recover respondents were concerned about the difficulty of arranging dental extractions.

A comparative study of initial changes in pulpal blood flow between conventional and self-ligating fixed orthodontic brackets during leveling and alignment stage.

OBJECTIVES: To evaluate and compare the initial changes in pulpal blood flow (PBF) between conventional and self-ligating fixed orthodontic brackets during leveling and alignment stage using 0.016 × 0.022 NiTi as alignment archwire. MATERIALS AND METHODS: Twenty-two patients (16 females and 6 males) aged 19.00 ± 2.53 years who presented with mild lower arch crowding were selected to participate in the study. A split mouth study design was applied for each patient. The intervention (self-ligating brackets) was randomly allocated to the right or left side of the patient using the permuted random block size of 2 with 1:1 allocation ratio. Two different fixed appliance brackets were used in the lower arch (self-ligating brackets on one side and conventional brackets on the other side of the same patients. Two alignment archwires; 0.016″ NiTi and 0.016 × 0.022″ NiTi were used in this study. PBF was measured for the lower right and left sides using laser Doppler flowmetry at different time intervals (20 min, 24 h, 72 h, 1 week, and 1 month) RESULTS: PBF started to decrease 20 min after insertion of both archwires using both types of brackets. Maximum decrease was reached after 72 h of archwire insertion. After 1 week of force application, PBF started to increase to restore its original values after 1 month. Differences between the 2 groups were not significant (P > 0.05). CONCLUSIONS: In both treatment groups, PBF reduced within 48 h. PBF started to increase after 1 week until it reached its original values after 1 month. Changes in PBF at the measured time intervals in the two groups were similar. CLINICAL RELEVANCE: The use of 0.016 × 0.022″ NiTi immediately after 0.016″ NiTi for alignment does not produce any damaging effect on the teeth.

Vertical gingival display changes associated with upper premolars extraction orthodontic treatment: A prospective clinical trial.

BACKGROUND: Extraction of upper bicuspids have been anecdotally blamed to increase the vertical gingival display (VGD) anteriorly. However, the extraction may be needed in some cases in order to correct the underlying orthodontic problem. Objectives: To investigate and compare vertical gingival display (VGD) changes associated with upper (first vs second) premolars extraction during orthodontic treatment. MATERIAL AND METHODS: Design: A prospective clinical trial. Setting: Postgraduate dental teaching clinics at Jordan University of Science and Technology (JUST). Sample population: Sixty orthodontic patients were included in the study. They were treated with upper first or second premolars extraction according to the underlying problem and the individualized treatment plan of each patient. Records (radiographs, study casts and clinical photographs) were taken for all subjects pre- and post- orthodontic treatment. Outcome measures: Pre- and post-treatment VGD, lip length in static and dynamic positions and the amount of upper teeth retractions were recorded. The paired and the independent t- test were used to detect differences within/between groups. Factors affecting VGD were investigated using backward stepwise linear regression analysis. RESULTS: In both static and dynamic captures, VGD increased after orthodontic treatment in both premolars extraction groups. Pre- and post-treatment variables differed significantly in groups 1 and 2. VGD changes were similar in both treatment groups. A significant association was found between VGD change during orthodontic treatment and upper canine retraction (P<0.001), pre-treatment ANB angle (P<0.01) and upper incisor retraction(P<0.05). CONCLUSIONS: The amount of anterior VGD increases after upper premolars extraction. The increase in VGD after first and second premolars extractions was comparable. The increase in VGD after orthodontic treatment is associated with the amount of canine retraction, pre-treatment ANB and the amount of incisor retraction. Key words:Vertical gingival display, tooth extraction, dental esthetics.

Effect of piezocision on mandibular second molar protraction.

OBJECTIVES: To assess the effects of piezocision on the rate of mandibular second molar protraction. MATERIALS AND METHODS: Thirty-one subjects (average age: 22.26 ± 5.63 years) who presented with at least one extracted mandibular first molar were selected to participate in the study. The subjects were subdivided into one of two groups, 22 molars each: group 1, where piezocision was performed immediately before molar protraction and group 2, where molar protraction was performed with no piezocision. Piezocision was performed by making two vertical incisions mesial and distal to the extraction space, and bone cuts were done with a length up to the mucogingival line at a depth of 3 mm. The rate of second molar protraction, duration of space closure, and level of interleukin-1-ß (IL-1ß) in gingival crevicular fluid (GCF) during the first month of space closure were recorded. RESULTS: During the first 2 months after surgery, the rates of second molar protraction were 1.26 ± 0.12 mm/month and 0.68 ± 0.19 mm/month in the piezocision and no piezocision groups, respectively (P < .001). Duration of lower first molar space closure was 9.61 ± 0.98 months in the piezocision group and 10.87 ± 1.52 months in the no piezocision group (P < .01). The level of IL-1ß in GCF was higher in the piezocision group compared to the no piezocision group, up to 1 week after surgery (P = .02). CONCLUSIONS: Although piezocision doubled the rate of second molar protraction during the first 2 months after surgery, overall second molar protraction was increased by only 1 month.

Enamel demineralization during clear aligner orthodontic treatment compared with fixed appliance therapy, evaluated with quantitative light-induced fluorescence: A randomized clinical trial.

INTRODUCTION: The objective of this prospective randomized clinical trial was to investigate the relationship between clear aligner (CA) therapy and the development of white spot lesions and compare it with orthodontic fixed appliance (FA) therapy. METHODS: This was a prospective randomized clinical trial. The setting was the postgraduate orthodontic clinic at Jordan University of Science and Technology. A total of 49 patients (39 female, 10 male; mean age ± standard deviation, 21.25 ± 3 years) who required orthodontic treatment with either FAs or CAs were randomly allocated into 1 of 2 study groups. Eligibility criteria included healthy patients of both sexes (age range 17-24 years), Class I malocclusion with mild-to-moderate crowding (≤5 mm), nonextraction treatment plan, and optimum oral hygiene before treatment as determined by clinical examination. The participants were randomly assigned to a study group according to a simple randomization method using a coin toss by the patient; the text or tail side of the coin indicated treatment with CA (group 1), and the head side of the coin indicated orthodontic treatment with FA (group 2). Blinding was applicable for outcome assessment only. CA therapy was performed for group 1 and FA for group 2. Quantitative light-induced fluorescence (QLF) images were taken before treatment (T0) and 3 months later (T1). The QLF images were then analyzed to assess the research outcomes. The main outcome was the mean amount of fluorescence loss (ΔF). Number of newly developed lesions, deepest point in the lesion (ΔFMax), lesion area (pixels), and plaque surface area (ΔR30) were measured as secondary outcomes. Descriptive statistics and comparison within and between groups were calculated. RESULTS: In total, 42 of the 49 participants recruited completed the study (19 in the CA group and 23 in the FA group). The mean amount of fluorescence loss was 0.4% for the CA group (P = 0.283) and 1.2% for the FA group (P = 0.013). The difference between the 2 groups was significant (confidence interval [CI], -1.8 to -0.4; P = 0.002). The mean increase in lesion area was 82.2 pixels for the CA group (P <0.001) and 9.3 pixels for the FA group (P = 0.225). The difference between the 2 groups was significant (CI, -117 to -75.0; P <0.001). ΔR30 was 1.2% for the CA group and 10.9% for the FA group (CI, 6.847-12.479; P <0.001). The number of newly developed lesions in the CA group was 6 lesions/patient and 8.25 in the FA group (P = 0.039). No serious harm on the oral health of the participants in the 2 study groups was observed other than mild gingivitis associated with plaque accumulation. No serious harm was reported by any of the participants. CONCLUSIONS: Orthodontic treatment with CAs and FAs caused enamel demineralization. The CA group developed larger but shallower white spot lesions, whereas the FA group developed more new lesions with greater severity, but they were smaller in area. More plaque accumulation was found in the FA group compared with the CA group. REGISTRATION: NCT04107012. PROTOCOL: The protocol was published after trial commencement.

Incisor root resorption associated with palatally displaced maxillary canines: Analysis and prediction using discriminant function analysis.

INTRODUCTION: Incisor root resorption associated with palatally displaced canine (PDC-IRR) is an important phenomenon that might alter the orthodontic treatment plan. The aims of this study were to investigate the prevalence and characteristics of PDC-IRRs, to compare PDC-IRR and PDC-No-IRR groups, to identify predictors for PDC-IRR, and to produce a valid PDC-IRR prediction model using discriminant function analysis. METHODS: Cone-beam computed tomography images for 107 palatally displaced canines (PDCs) and 51 fully erupted nondisplaced canines (NDC) were analyzed for the presence of incisor root resorption (IRR). The PDCs were divided into 2 groups: PDC-IRR (52 canines) and PDC-No-IRR (55 canines). The 3 groups were compared, and the following variables were measured: canine follicle size, contact with adjacent incisors, associated dental abnormalities, sector analysis, canine vertical relation to adjacent root, lateral incisor angulation and inclination, canine angulation and distance to reference planes (dental midline, midpalatal suture, occlusal plane, pterygoid vertical plane, and lateral incisor), and space available for canine in the dental arch. Discriminant functional analysis was used to produce a discriminant function equation to predict PDC-IRR. RESULTS: Root resorption affected 74% of lateral incisors adjacent to PDCs and 25.5% of lateral incisors adjacent to NDCs. IRR was located lingually in 41% of PDCs and in the mid and apical thirds in 89%. In the PDC-IRR group, 94.2% of canines were in contact with adjacent roots compared with 23.6% in the PDC-No-IRR group (P <0.001). Canine follicle size was >2 mm in 42% of PDC subjects. Overall mean value of follicle width in PDC canines was 1.79 ± 1.06 mm. Peg-shaped lateral incisors were recorded in 19% of PDC subjects compared with 4% in NDCs (P = 0.012). The stepwise analysis using cone-beam computed tomography records produced a discriminant function based on 3 variables. The analysis correctly predicted the outcome in 83% of subjects. The variables contributing to the prediction equation were canine contact with adjacent incisors, size of canine dental follicle, and the presence of peg-shaped lateral incisor. CONCLUSIONS: Canines in contact with adjacent incisor roots was the only risk factor detected for PDC-IRR. Very good predictive discrimination (83%) emerged for PDC-IRR subjects. Predictors of PDC-IRR were canine contact with adjacent incisor, size of canine dental follicle, and presence of peg-shaped lateral incisor.

A comparative study of initial changes in pulpal blood flow between clear aligners and fixed orthodontic appliances.

INTRODUCTION: The objective of this study is to evaluate and compare the initial changes of pulpal blood flow (PBF) using clear aligner and fixed orthodontic treatment. METHODS: A total of 45 subjects were subdivided into 2 groups: group 1; 25 subjects treated with preadjusted edgewise fixed appliance with 0.014″ nickel titanium as the alignment archwire and group 2; 20 subjects treated using clear aligner. In both groups, PBF was measured for the maxillary right and mandibular left teeth using Laser Doppler flowmetry at different time intervals (20 minutes, 48 hours, 72 hours, and 1 month) after the fitting of the nickel titanium archwire in group 1 and after the delivery of the second aligner in group 2. A repeated-measures analysis of variance and a Bonferroni post-hoc comparison test were applied to determine differences at the various time intervals. RESULTS: The PBF decreased in both types of appliances after force application. The maximum reduction in PBF was reached after 72 hours. It returned to its normal values within 1 month. The differences in PBF between the 2 groups did not reach any statistical significance. CONCLUSIONS: PBF in orthodontically treated teeth decreased 20 minutes after orthodontic force application in both fixed and clear aligner appliances. In both treatment groups, most changes occurred within 48 hours of force application. PBF returned to its normal values within 1 month. Changes in PBF in both treatment groups were comparable.

Force degradation of orthodontic latex elastics: An in-vivo study.

INTRODUCTION: Our objectives were to assess the force degradation of orthodontic latex elastics over 48 hours in vivo and to study the relationship between the amount of mouth opening and the degree of force decay. METHODS: Fifty-two orthodontic patients wearing fixed appliances using Class II elastics were asked to wear premeasured-force 3/16-in heavy and medium intermaxillary elastics. The force amounts were measured and compared at different time intervals. RESULTS: Fifty percent of the force was lost after 3.9 hours for the medium elastics and after 4.9 hours for the heavy elastics. A continuous significant force drop in all elastics was seen at all time intervals (P <0.05, P <0.001). There was greater force loss in the heavy elastics compared with the medium elastics in vivo at all time intervals (P <0.001); the rates of force loss, however, were similar. CONCLUSIONS: Fifty percent of force degradation occurred in the first 4 to 5 hours. Because of breakage and for oral hygiene purposes, orthodontic elastics should be changed daily; otherwise, elastics can be used for 48 hours. Force decay of the elastics was correlated to the lateral distance between the maxillary canine and the mandibular first molar in occlusion.

Comparison of personality traits, attitude toward orthodontic treatment, and pain perception and experience before and after orthodontic treatment.

OBJECTIVE: To compare personality traits, attitude toward orthodontic treatment, and pain perception and experience before and after orthodontic treatment. MATERIALS AND METHODS: One hundred subjects (50 male and 50 female) were included in this study. The mean (SD) age was 17.5 (2.05) years at T1 and 19.15 (2.32) years at T2. The instruments for data collection were questionnaires that included assessment of patients' personality traits, attitudes toward orthodontic treatment, and pain perception/experience. Subjects completed the questionnaires at two different times: before orthodontic treatment (T1) and after fixed orthodontic treatment (T2). Subjects were treated by fixed orthodontic appliances for an average (SD) period of 18.64 (0.35) months. Paired sample t-test and chi-square test were used to detect any differences. RESULTS: Significant changes in personality traits were detected after orthodontic treatment irrespective of gender. Neuroticism, openness, agreeableness, and conscientiousness scores were improved (P < .001). A positive attitude toward orthodontic treatment was reported at T1 (4.31 [±1.26]) and improved at T2 (3.98 [±1.16]) irrespective of gender (P < .05). The average (SD) expected pain score (T1) was 4.73 (1.88) and the average (SD) experienced pain score (T2) was 4.63 (1.58). Significant difference in the expected and experienced pain scores was not detected (P  =  .11). CONCLUSIONS: Personality traits and attitude toward orthodontic treatment improved after orthodontic treatment. Reported actual pain experience during orthodontic treatment was similar to that expected before treatment.