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

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.

Second mesiobuccal canal segmentation with YOLOv5 architecture using cone beam computed tomography images

The objective of this study is to use a deep-learning model based on CNN architecture to detect the second mesiobuccal (MB2) canals, which are seen as a variation in maxillary molars root canals. In the current study, 922 axial sections from 153 patients' cone beam computed tomography (CBCT) images were used. The segmentation method was employed to identify the MB2 canals in maxillary molars that had not previously had endodontic treatment. Labeled images were divided into training (80%), validation (10%) and testing (10%) groups. The artificial intelligence (AI) model was trained using the You Only Look Once v5 (YOLOv5x) architecture with 500 epochs and a learning rate of 0.01. Confusion matrix and receiver-operating characteristic (ROC) analysis were used in the statistical evaluation of the results. The sensitivity of the MB2 canal segmentation model was 0.92, the precision was 0.83, and the F1 score value was 0.87. The area under the curve (AUC) in the ROC graph of the model was 0.84. The mAP value at 0.5 inter-over union (IoU) was found as 0.88. The deep-learning algorithm used showed a high success in the detection of the MB2 canal. The success of the endodontic treatment can be increased and clinicians' time can be preserved using the newly created artificial intelligence-based models to identify variations in root canal anatomy before the treatment.

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 ).

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 β-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).

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.

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.

Evaluation of maxillary sinus dimensions and volume using cone beam computed tomography in patients with unilaterally displaced palatal and buccal maxillary canines

OBJECTIVES

To evaluate and compare the maxillary sinus (MS) dimensions and volume in unilaterally displaced palatal and buccal maxillary canines.

METHODS

CBCT images for 133 patients were included in the study. Maxillary canines were unilaterally displaced palatally in 83 patients (PDCs) and buccally in 50 patients(BDCs). The following variables were measured: canine position in relation to MS walls, MS pneumatization and MS dimensions and volume.

RESULTS

MS was extended to the incisor region in 10% and 13% and to the canine region in 48% and 23% in BDCs and PDCs subjects, respectively. In BDC subjects, maxillary canine crown tip was more laterally (24.23 mm compared to 22.93 mm (p < 0.05)) and closer vertically (5.82 mm compared to 9.58 mm (p < 0.001)) to the MS, maxillary canine root tip was closer to the MS anterior (0 mm compared to 1.64 mm (p < 0.05)) and lateral (19.70 mm compared to 22.02 mm (p < 0.001)) walls and the MS volume (11.57mm³ compared to 9.09 mm³ (p < 0.001)) was increased in the displaced side compared to the non-displaced side. In PDC subjects, a significant difference between the displaced and non-displaced sides was detected in the vertical (3.28 mm compared to 5.89 mm (p < 0.001)) and lateral (21.63 mm compared to 24.25 mm (p < 0.001)) position of maxillary canine to the MS wall, the anterior (- 0.84 mm compared to 1.13 mm (p < 0.05)) and lateral (20.48 mm compared to 22.44 mm (p < 0.001)) position of canine root tip to the MS and the MS volume (7.71mm³ compared to 9.14mm³ (p < 0.001)). PDC sides differed from BDC sides in the lateral and vertical position of canine crown tip to MS and in MS volume. PDC showed negative association with MS volume and anteroposterior skeletal relationship and a positive association with MS height.

CONCLUSIONS

PDCs subjects have a reduced MS volume and BDCs subjects have an increased MS volume. PDCs are associated with reduced MS volume, increased MS height and Class III skeletal relationship.

Comparison of second molar protraction using different timing for piezocision application: A randomized clinical trial

OBJECTIVE

To compare second molar protraction between early, late and no piezocision groups.

MATERIAL AND METHODS

Forty subjects with bilaterally extracted mandibular first molars were selected to participate in the study. Subjects were subdivided into two groups: piezocision and no piezocision. The piezocision group was further subdivided into two subgroups: early piezocision (piezocision performed immediately before second molar protraction) and late piezocision (piezocision performed three months after starting molar protraction). In the no piezocision group, molar protraction was done without surgery. The intervention (piezocision group and timing of piezocision/side within group) was randomly allocated using the permuted random block size of 2, with 1:1 allocation ratio. The amount of second molar protraction, duration of space closure and anterior anchorage loss were measured. A repeated measures analysis of variance was conducted to define the differences between the measured variables at the different time intervals. Differences between groups were assessed using ANOVA test.

RESULTS

No difference was detected between early and late piezocision groups in the amount of molar protraction at the end of space closure. Duration of complete space closure was 9 and 10 months in the piezocision and no piezocision groups. Anchorage loss was similar between the three studied groups.

CONCLUSIONS

Early and late piezocision have similar effect and both increased the amount of second molar protraction temporarily in the first 2-3 months after surgery. Duration of mandibular first molar space closure was reduced by one month when piezocision was applied. Anchorage loss was similar in the three groups.

Efficacy of lower arch leveling, lower incisors' root resorption, and pain associated with the correction of curve of Spee using different orthodontic archwires: a randomized clinical trial

Objectives

To compare between 3 archwires (AWs) for leveling curve of Spee (COS) in terms of efficacy of reduction, external apical root resorption (EARR), pain experienced, and the lower arch dimensional changes during COS leveling.

Trial design

Randomized clinical trial.

Setting

Jordan University of Science and Technology Postgraduate dental clinics.

Material and methods

Fifty-three subjects with COS > 5 mm were included in this study. The subjects were randomly divided 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 SS AW; and group 3, 0.021 × 0.025-inch β-titanium (TMA) AW. The intervention was randomly allocated using the permuted random block size of 3 with a 1:1:1 allocation ratio. In the three groups, a 5-mm depth reverse COS was placed in the AWs. The following time points were defined for COS assessment: T1, before interventional leveling AW placement; and T2–T7, 1–6 months after interventional leveling AW placement. Records consisted of dental study models and periapical (PA) radiographs. Pain scores were recorded using visual analogue scale. Patients were followed up on a monthly basis until COS < 1.5 mm.

Main outcome measures

COS depth reduction, lower incisors’ EARR, pain scores, and arch dimensional changes.

Results

An overall reduction of 3.82 mm, 4.47 mm, and 3.85 mm of the depth of COS was achieved in groups 1, 2, and 3, respectively. The mean differences of 0.65 mm between groups 1 and 2 and 0.62 mm between groups 2 and 3 were significant at P < 0.05. Lower incisors’ EARR during leveling COS ranged from 0.68 to 0.72 mm, from 0.63 to 0.82 mm, and from 0.53 to 0.88 mm in groups 1, 2, and 3, respectively (P > 0.05). Higher pain scores were reported by group 2 subjects during the first 24 h. Arch length and width increased significantly in groups 2 and 3 (P < 0.05). In all groups, COS leveling was achieved by lower incisor intrusion and proclination and lower molar extrusion.

Conclusions

All investigated AWs were effective in leveling COS with minimal lower incisors’ EARR (< 1 mm). COS was leveled by lower incisors’ intrusion and proclination and lower molar extrusion. Pain scores were the highest in group 2 during the first 24 h.

Clinical relevance

The 3 investigated leveling AWs were effective for the leveling COS and at the same time safe on the roots of the lower anterior teeth.

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.

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.

Smile microesthetics as perceived by dental professionals and laypersons

OBJECTIVES

To evaluate and compare the perception of different dental professionals and laypersons toward altered gingival characteristics (microesthetics) and to identify those characteristics that are most negatively and positively rated.

MATERIALS AND METHODS

A smiling photograph of a female dental student was selected and digitally manipulated to create changes in different microesthetic parameters. These altered images were rated by the following five groups: 120 orthodontists, 45 periodontists, 49 prosthodontists, 130 general dentists, and 172 laypersons. Smile esthetics scores were calculated, and comparisons between groups were performed using the univariate general linear model.

RESULTS

The presence of black triangles between the upper incisors was the most negatively rated, and the ideal smile was the most positively rated. Significant differences were detected in the rating scores among the different study groups (P < .05). Orthodontists, prosthodontists, and general dentists scored the presence of a black triangle in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons.

CONCLUSIONS

The ideal smile and that with black triangles between the upper incisors were rated as the most and the least attractive smiles, respectively. Orthodontists, prosthodontists, and general dentists scored the presence of black triangles in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive smiles, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons.

The effect of intraoral aging of the working stainless steel archwire on the rate of premolar extraction space closure: a randomized clinical trial

OBJECTIVES

The aims of this study were to investigate the effect of the working archwire intra-aging on the rate of upper first premolar space closure and to measure frictional resistance during space closure.

METHODS

A total of 28 subjects participated in this study. All patients were treated by upper first premolar extraction. Subjects were subdivided into 2 groups: non-replacement side: consisted of the right or left sides of the upper arch where space closure was done using the same 0.019 × 0.025-inch SS; replacement side: comprised the other side of the subjects where the working archwire was replaced with a new one each visit. The working archwire in the upper arch was split into 2 halves (new archwire on one side and old one on the other side); each one-half was connected to the other in the midline by a joining shim. Elastomeric chain was used to close extraction spaces. The amount of space closure (mm) was recorded each visit for 3 months.

RESULTS

In the non-replacement side, the rate of upper space closure was 0.80 mm/month coronally and 0.75 mm/month gingivally. In the replacement side, it was 0.69 mm/month coronally and 0.67 mm/month gingivally (p > 0.05). Mean frictional force for the non-replacement side was 3.58 ± 1.20 N, and it was 2.43 ± 1.21 N for the replacement side (p < 0.01).

CONCLUSIONS

Intraoral archwire aging has no effect on the rate of upper premolar space closure/month although frictional resistance of the aged archwire was higher than of the new one. Clinical relevance No need to replace 0.019 × 0.025-inch SS every visit during space closure to overcome corrosion and frictional resistance.

Pulpal blood flow changes and pain scores related to using Superelastic 0.018-inch Nickel Titanium as the first orthodontic alignment archwire: a prospective clinical trial

Background

Optimal orthodontic force results in maximum rate of tooth movement without tissue damage. Even though starting orthodontic treatment with a thicker archwire may shorten treatment duration, the evidence on the effect of using 0.018-inch NiTi as the first alignment archwire on pulpal blood flow (PBF) status is still scarce.

Objectives

to record PBF changes and pain scores associated with using 0.018-inch NiTi as the first alignment archwire during fixed orthodontic treatment.

Methodology

Patients were selected from subjects attending postgraduate orthodontic teaching clinics at Jordan University of Science and Technology. In total, forty healthy patients who exhibited mild lower arch crowding were included. A split-mouth trial design was used. Each patient received two archwire sizes at one time joined in the midline by crimpable hook and applied in the lower arch. Patients were assigned into one of two groups based on archwire sizes used. Group 1: 0.014-inch and 0.018-inch NiTi (Six males, 14 females aged 19.4±1.33 years) and Group 2: 0.016-inch and 0.018-inch NiTi (Seven males, 13 females aged 19.6±1.45 years). The archwire size group was randomly allocated with a 1:1 allocation ratio. A Laser Doppler Flowmeter was used to measure PBF at different time intervals (T0-T5). Pain scores were recorded using a visual analogue scale (VAS). A repeated measures ANOVA and a post-hoc Bonferroni comparison tests were conducted to examine differences at the different time points before and during orthodontic alignment.

Results

For all studied archwire sizes, PBF decreased 20 minutes after their placement. Most PBF changes occurred within 24hours and continued to decrease until 72 hours after archwire placement where the maximum reduction was reached. Eventually, normal values were reverted within 1 month. PBF changes were similar between all alignment – groups.

Conclusions

Initial orthodontic alignment with 0.018-inch NiTi does not cause irreversible changes to pulpal vasculature or produces higher pain scores.

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.

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.

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-β (IL-1β) 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-1β 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.

Periodontal health knowledge and awareness among subjects with fixed orthodontic appliance

OBJECTIVE

To report on periodontal health knowledge and awareness among orthodontic patients and to investigate the effect of age, attitude and duration of orthodontic treatment on periodontal health awareness among orthodontic patients.

METHODS

A total of 297 orthodontics patient (90 males, 207 females) with mean age of 17.7 ± 5.0 years (older then 18 years = 119, 18 years or younger = 178) were included in this study. Subjects were currently wearing upper and lower fixed orthodontic appliances for an mean period of 12.55 ± 10.86 months (less than or equal to 18 months = 231, more than 18 months = 66). Data was collected through a self-administered questionnaire (demographic characteristics, subjects' awareness toward their periodontal health, periodontal knowledge among orthodontic patient and patients' attitude toward orthodontic treatment regarding periodontal health) and clinical periodontal examination.

RESULTS

Periodontal knowledge was poor among orthodontic patients in relation to dental plaque. Only 24 subjects (8%) correctly answered knowledge-related questions. Adult orthodontic patients reported negative attitude toward fixed orthodontic treatment in respect to periodontal health (p<0.001). Duration of orthodontic treatment negatively affected subjects' attitude toward fixed orthodontic treatment (p<0.01). The majority of subjects were in the high level of awareness group (64%). Orthodontic patients' awareness toward their periodontal health during fixed orthodontic treatment was affected by attitude scores (p=0.005), number of teeth with gingival recession (p=0.041), Gingival Index (p=0.000), duration of treatment (p=0.047) and age (p=0.008).

CONCLUSIONS

Periodontal health knowledge among orthodontic patients was poor. Orthodontic patients' awareness of their periodontal health was moderate and was affected by age, attitude and duration of orthodontic treatment.

Third molar tooth agenesis and pattern of impaction in patients with palatally displaced canines

OBJECTIVES

To investigate the association between third molar agenesis and pattern of impaction, missing teeth, and peg-shaped lateral incisor with palatal canine displacement (PDC).

MATERIALS AND METHODS

The pretreatment orthodontic orthopantomograms of 438 patients (122 males and 316 females) diagnosed with PDC were included. A total of 338 patients with normally erupted canines who had a preexisting radiograph as part of their orthodontic treatment (125 males and 313 females) served as controls. Orthopantomograms were evaluated for missing third molars, third molar eruption status, and type of impaction, third molar spaces, third molar width, and angulation.

RESULTS

In the PDC group, at least one third molar was missing in 48% and 19% in the upper and lower arches, respectively. Also, 38% and 67% of PDC patients had at least one third molar impaction in the upper and lower arches, respectively. The difference between the PDC and control groups was significant for both missing and impacted third molars ( P < .001 for each). The most common type of third molar impaction in the upper arch was vertical and distoangular in the PDC and control groups, respectively. Upper and lower third molar width and spaces were reduced in PDC patients when compared with the control group ( P < .001). In PDC patients, missing teeth and peg-shaped lateral incisors were recorded in 5.6% and 9.1%, respectively.

CONCLUSIONS

PDC patients showed a high prevalence of third molar agenesis and impaction. Upper and lower third molar width and space were reduced in the PDC patients. There were no significant associations between tooth agenesis (other than third molars) and the PDC anomaly.

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.

The effect of different bracket base cleaning method on shear bond strength of rebonded brackets

AIM

To assess the effect of different bracket base conditioning method on shear bond strength (SBS) of rebonded brackets.

MATERIALS AND METHODS

Eighty brackets were bonded to freshly extracted premolar teeth using light cured composite adhesive. SBS was measured for 20 random samples as control group (G1). After debonding, 60 debonded brackets were allocated randomly into three groups of bracket base conditioning methods to remove the remaining adhesives. G2: bracket base cleaned with slow speed round carbide bur (CB), G3: cleaned with ultrasonic scaler (US), G4: cleaned with sandblasting (SB). After that, brackets were rebonded in the same manner as frst bonding and SBS was measured. Modifed adhesive remnant index (ARI) was recorded for all groups.

RESULTS

SBS for new brackets was 11.95 MPa followed by 11.65 MPa for G2, 11.56 MPa for G4 and 11.04 MPa for G3 group. There were no statistically signifcant differences between all groups (p = 0.946). In all groups, failure mode showed that the majority of adhesive composite remained on the bracket base with ARI of 4. There was no statistically signifcant difference between all groups in ARI (p = 0.584).

CONCLUSION

In-offce methods; slow speed CB and US are effective, quick and cheap methods for bracket base cleaning for rebonding.

Mandibular symphysis morphology and dimensions in different anteroposterior jaw relationships

OBJECTIVE

To assess the morphology and dimensions of mandibular symphysis (MS) in different anteroposterior jaw relationships and to investigate whether craniofacial parameters have any correlation with its shape and/or dimensions.

MATERIALS AND METHODS

Lateral cephalograms of subjects with Class I, Class II, and Class III skeletal relationships were traced. Several craniofacial and MS parameters were measured. MS parameters were compared between the three groups using analysis of variance and were correlated with the craniofacial parameters using the Pearson correlation coefficient.

RESULTS

Larger angle of concavity of the chin, more inclination of the alveolar bone toward the mandibular plane, and larger MS dimensions and area (P < .001) were found with a Class III skeletal relationship compared to Class I and Class II relationships. The Pearson correlation coefficient between Id-Me and AFH was r  =  0.83 and between Id-Me and LAFH it was r  =  0.81.

CONCLUSIONS

The dimensions and configuration of MS in the Class III relationship were different than those in Class I and Class II relationships; the alveolar part of MS compensated for the skeletal relationship in the Class III pattern. MS dimensions were strongly correlated to anterior facial dimensions.

Dental arch parameters of the displacement and nondisplacement sides in subjects with unilateral palatal canine ectopia

OBJECTIVE

To compare arch perimeter and teeth size, number, and shape between the two sides of the dental arch-the canine displacement side (DS) and the nondisplacement side (NDS)-in subjects with unilateral palatally displaced canine (PDC).

MATERIALS AND METHODS

Orthopantomograms (OPTs) of 240 subjects with unilateral PDC and 240 OPT matching controls were used. Additionally, study casts of 100 study subjects and 100 controls were used. The age of subjects ranged between 14 and 25 years. Dental casts were digitized and several parameters were recorded.

RESULTS

The transverse width from midpalatal line to the buccal segment and the palatal area on the DS was larger than that in the NDS (P < .05 to .001), with no difference in tooth size between both sides. Maxillary second premolars, canines, and lateral incisors in the PDC group were smaller than those in control group. Peg-shaped lateral incisors were significantly more frequent in the study group (P < .001).

CONCLUSIONS

The transverse width of the DS was larger than that of the NDS. Both sides were generally smaller than those of the control group. Tooth size in the DS was comparable to that in the NDS but smaller than those of the control group. A missing or peg-shaped lateral incisor was the most common reported anomaly.

Occlusal bite force changes during 6 months of orthodontic treatment with fixed appliances

BACKGROUND

Occlusal bite force (OBF) is reported to change during fixed appliance orthodontic treatment.

AIMS

The aim of the present study was to determine bite force changes during the first 6 months of fixed appliance orthodontic treatment and to investigate the relationship between patients' subjective pain levels and recorded changes in OBF.

METHODS

Forty-seven subjects (34 females, 13 males) were recruited from the Dental Teaching Centre at the Jordan University of Science and Technology. The subject's ages ranged between 18 and 26 years (average 19.0 +/- 3.36 years). Bite force was measured using a portable OBF gauge at nine time intervals (T0 - T8). At each OBF recording, subjects were asked to describe their subjective pain level using a visual analogue scale (VAS). A repeated-measures analysis of variance and a Bonferroni post-hoc comparison test were applied to determine differences at the various time intervals.

RESULTS

Bite force significantly reduced during the first month of orthodontic treatment and approximately 50% of pretreatment OBF was lost by the end of the first week. However, bite force recovered to pretreatment levels by the end of the sixth month. Visual analogue pain scores were higher during the first 2 weeks of treatment and were positively correlated with the OBF loss.

CONCLUSION

OBF reduced during the first month of orthodontic treatment but, with time, recovered to pretreatment levels.