Journal of Orthodontic Science最新文献

Aim: To evaluate the shear strength of Orthocem and BracePaste polymerizable cement light-cured with light-emitting diode (LED) units with different wavelengths (Bluephase N) with their high power, low power, and soft start programs in the bonding of metal brackets.

Materials and methods: In vitro experimental research was performed. Mini Roth 0.022 metal brackets (Roth Orthometric brackets) were used. The adhesives were placed on the metal brackets with Orthocem and BracePaste resin cement. To compare the average strengths, the analysis of variance (ANOVA) test was used (P < 0.05).

Results: The average shear strength was better with Bracepaste polymerizable cement compared to Orthocem cement in all its high power, low power, and soft star programs; the highest was Bracepaste with soft start of 26.52 MPa, and the lowest was Orthocem with soft start of 13.92 MPa. When evaluating the differences, it was found that these were statistically significant in all groups (P < 0.05).

Conclusions: Differences were found in the shear strength of light-curing Orthocem and Bracepaste light-curing cement cured with LED units with different wavelengths in bonding metal brackets to the tooth in vitro.

Objectives: The study aimed to compare the effects of quadhelix and nickel-titanium (NiTi) expander appliances on lower facial height, to quantify, and evaluate dentoalveolar and orthopedic changes in transverse plane, respectively, to estimate the difference in changes between these two appliances.

Materials and methods: Twenty patients, ten for the quadhelix and NiTi expander in the two-appliance group, respectively, participated in this study. A total of 8 readings, 1 for clinical facial height, 2 for model analysis, and 5 for posteroanterior cephalometric analysis were recorded. The statistical tests used were, Student's unpaired and paired t-tests.

Results: Both appliances individually, produced statistically highly significant (p < 0.01) expansion every month in both premolar and molar areas with more uniform expansion for quadhelix and less expansion in NiTi palatal expander in the premolar region initially. The skeletal to dental change ratio showed that there was more dental change than skeletal with no inter-appliance differences statistically while assessing the PA cephalometric readings.

Conclusions: This study infers that both appliances are equally efficacious maxillary expanders, which are primarily dentoalveolar and not skeletal (p < 0.05).

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.

Objective: The Brodie bite (BRB) is a rare posterior crossbite affecting the transverse occlusal relationship with the palatal cusps of the upper molars, biting into the vestibule and outside the buccal cusps of the lower molar teeth. The BRB is a highly challenging orthodontic problem and is an extreme form of scissors bite. Patients with this problem present with facial deformity and inability to chew on the affected side. The problem is usually not identified until it becomes severe. This study aimed to identify the prevalence of BRB among untreated orthodontic patients in two geo-political zones in Nigeria.

Methods: A total of 1,041 untreated orthodontic patients who presented to two different orthodontic centres located in two geo-political zones (South/South-Benin City and North Central-Abuja, Nigeria) over a 3-year period were evaluated for the presence of BRB. The transverse dimension of the occlusion was examined for the presence of a crossbite or scissors bite. The molar teeth were used as the reference point for occlusion with Angle's classification of malocclusion. Four groups were identified, namely, teeth in occlusion (TIO) (Angle's Classes I, II or III malocclusion served as the control group), scissors or lingual crossbite (LCB), buccal crossbite (BCB) and BRB. A posterior crossbite was confirmed when the upper molar teeth were biting outside the buccal groove of the lower molar teeth either lingually or buccally. A BRB was identified when the palatal cusps of the upper molars were biting into the buccal vestibule of the lower jaw, with the deviation of the face to that side. Statistical analyses were performed using SPSS version 21; frequencies were determined for the variables, and cross-tabulations between the variables were established. P values < 0.05 were considered significant.

Results: The overall prevalence of BRB in this study was 0.6% (six patients). The values in the South/South (Benin City) were 997 untreated orthodontic patients, with a prevalence of 0.5% (five patients). The North Central (Abuja) zone had a total of 44 untreated orthodontic patients, with a prevalence of 2.3% (one patient). Unilateral BRB was seen in five patients (80%), and bilateral BRB was seen in one patient (20%). The condition was more prevalent among women (four patients, 80%) and on the right side (three patients, 60%). Angle's relationship in Classes I, II and III (TIO or control group) was seen in 911 patients (87.5%). The LCB and BCB groups comprised 39 (3.8%) and 85 patients (8.1%), respectively. Posterior crossbite was seen in 130 patients (12.5%).

Conclusion: The prevalence of BRB in this study was found to be 0.6%, with the condition being more prevalent in women and on the right side.

Objective: To determine the prevalence of dilaceration in a sample of patients presenting for initial orthodontic care.

Methods: Examining radiographs from a random sample of orthopantomogram images was used to acquire the data. In all, 2,801 dental records were evaluated at Oman Dental College (ODC), Oman. A dental X-ray processing software was utilized to view the images. A tooth was classified as having a mesial/distal dilaceration if its long axis exhibited an angle of 90 degrees or greater. Dilacerated roots in the buccal/lingual direction were diagnosed by observing the appearance of a spherical opaque area with a dark shadow in its central region, projected by the apical foramen, which gave the root canal a "bull's-eye" appearance.

Results: Dilacerations were found in 17.32% of the records examined. The maxillary second molars (22.71%) were the most commonly affected, followed by the mandibular third molars and mandibular lateral incisors (21.90% and 17.23%, respectively). The central incisors and canines were the least affected, with dilaceration affecting less than 0.2% of the teeth. The mandible was found to have more dilacerations than the maxilla (53.78% and 46.22%, respectively). 61.03% of dilacerations occurred in molars, 43.12% of which occurred in third molars.

Conclusion: Dilaceration is a notable dental anomaly that can affect any tooth, with some teeth being more affected than others. Dilaceration in maxillary second molars and mandibular lateral incisors is more common in the population of this study than in other populations reported in the literature. Recognizing the condition will allow for more effective orthodontic treatment.

Objective: A novel technique, named the MH setup (MH is an abbreviation for the author's name), was developed to provide an accurate yet simplified method to produce custom-made brackets without bonding errors. This setup aimed to simplify the treatment and eliminate the finishing phase, so that the orthodontist was able to provide better care with less time and lower costs.

Materials and methods: The setup was performed in two major steps: direct bonding on the cast followed by cutting and setting the teeth into precise positions using brackets. The first set of brackets, bonded directly onto casts, oriented the teeth by setting them ideally into wax rims with full control over first-, second-, and third-order bends. The fully engaged archwire used allowed for precise control over the arch symmetry and form. Setting teeth in wax allowed the clinician to refine the occlusion and correct any minor errors that arose during the initial bonding. The second set of brackets, mounted on the fully engaged archwire, featured custom-made composite bases. The transfer tray combined the benefits of its soft inner and hard outer layers, providing control over bonding and later ease of peeling from the brackets.

Results: The patient was satisfied with a full bonding procedure lasting 15 min that remained simple without unnecessary stress. The clinician was confident that the procedure allowed the precise positioning of brackets and simple bonding for all teeth in the arch, combined with the elimination of the finishing phase.

Conclusion: The MH technique offered a simple, precise, and inexpensive improvement to the Kesling wax setup. The process allowed for precise bonding without errors or expensive armamentarium. The brackets were transformed into custom-made prescriptions and could be used with labial or lingual techniques. The method allowed for teeth addition, trimming, or overcorrection according to the clinician's preferences. The MH setup facilitated visualization of the treatment objectives with precise locations and the opportunity to revise the treatment plan or to discuss further options with the patient.

Objectives: The study aims to measure the mandibular condylar height (CH), ramus height (RH), total height (CH+RH), asymmetry index, and condylar volume (Cvol) in individuals with different anteroposterior and vertical skeletal discrepancies.

Materials and methods: The study sample consisted of 131 subjects (60 females and 71 males) with a mean age of 35.06 ± 12.79 years. Pre-existing CBCT images were divided into groups according to the anteroposterior and vertical skeletal discrepancies. The investigator analyzed the data using t-tests to assess the mandibular bilateral sides of the individuals and gender differences. The mean difference between groups was determined using a one-way analysis of variance (ANOVA). The Chi-square test was used to study the association between the asymmetry index and groups.

Results: Each individual's bilateral sides exhibited statistically significant differences in CH, RH, and Cvol (P = 0.033, P = 0.039, P = 0.005, respectively), but not in CH+RH (P = 0.458). There were, however, statistically significant gender differences in CH+RH (P < 0.001). Skeletal Class III and hypodivergent groups revealed the highest linear and volumetric values compared to other groups. The asymmetry index was increased in CH (P = 0.006) and Cvol (P = 0.002) in skeletal Class II subjects.

Conclusions: Significant differences in CH, RH, and Cvol were found on the right and left sides of the same individual. This study found increased linear and volumetric values in males, skeletal Class III, and hypodivergent subjects. Class II individuals had an increased CH and Cvol asymmetry index. This study highlights in-depth knowledge of mandibular asymmetry, which is extremely important to achieve an accurate diagnosis and provide the best treatment outcome.

Objectives: The purpose of the study is as follows: To evaluate the dental and skeletal changes of the AdvanSync 2 appliance.To evaluate the soft tissue changes of the AdvanSync 2 appliance using photometric analysis.

Methods: The sample size consisted of 15 patients who reported to the Department of Orthodontics, seeking fixed orthodontic treatment. The effects of the AdvanSync 2 appliance were measured at two intervals.

Results: After the nine months, P values were observed to be less than 0.5, therefore statistically significant for parameters such as Sella-Nasion-Point A (SNA), Condylion-Point A (CO-A), University of Witwatersrand, Condylion-Gnathion (C0-Gn), point A-Nasion-Point B (ANB), Upper incisor-Point A (UI-A) (degree), LI-B (mm), Lower lip to Esthetic plane (LL-E plane), nasolabial angle, mentolabial angle, facial angle, and L lip to the chin. P values were however observed to be greater than 0.5, therefore statistically insignificant for parameters such as sella-Nasion-Point B (SNB), Condylion -gonion (C0-Go), UI A (mm), LI B (mm), UL-EPL, H LINE, Frankfurt mandibular plane (FMA), nose tip angle, nasofrontal angle, nasomental angle, upper lip angle, and U lip to the chin.

Conclusions: AdvanSync 2 appliance brought about a change in Class II malocclusions through Co-Gn, Co-Go, ANB, FMA, UI-A (degree), UI A (linear) LI B (linear), Upper lip to Esthetic plane, LL-E plane, Holdaway LINE, nose tip angle, nasolabial angle, mentolabial angle, nasofrontal angle, nasomental angle, facial angle, upper lip angle, U lip to chin, L lip to the chin after nine months of appliance delivery.

Main points: AdvanSync 2 normalized class II by an increase in the length and body of the mandible.AdvanSync 2 has a restraining effect on the growth of the maxilla.AdvanSync 2 brings about positive soft tissue changes.The major disadvantage is the proclination of the lower incisors.

Objectives: The objective of the study is to test whether the local injection of i-PRF may affect osteoblast, blood vessels and new bone formation in surgically expanded mid palatal suture using maxillary skeletal expander.

Materials and methods: Eighteen adult male local breed dogs were divided randomly into three groups: group I (control), includes the expansion with maxillary skeletal expander that was done without corticotomy and i-PRF. Group II, involves the expansion that was done with mid palatal corticotomy but without i-PRF injection. Group III, has the expansion that was done with mid palatal corticotomy and has injection with 2 ml of i-PRF. Each group consisted of 6 dogs which were subdivided into 3 dogs. Three dogs were sacrificed after 15 days and the other 3 dogs were sacrificed after 45 days. The number of osteoblast, blood vessels and new bone formation percentage were statistically analyzed using Sigma plot platform. Mean and standard error, ANOVA and Duncan were performed among the different groups. Values of P ≤ 0.05 were considered significant.

Results: After expansion, the i-PRF group demonstrated a considerable increase in the amount of new bone in the mid-palatal suture at 15 and 45 days compared with other 2 groups which were indicated by highest percentages of new bone formation (29.30% of 15 days and 76.55% at 45 days) if compared to control group which were (7.72% at 15 days and 22.30% at 45 days). The corticotomy groups were in between, 15.33% and 46.84% respectively. Moreover the number of osteoblasts was higher in corticotomy with i-PRF group on 15 days and decreased on 45 days than the other two groups, while the blood vessels were highest in this group than the other two groups both on 15 and 45 days.

Conclusion: I-PRF enhanced the production of osteoblast, blood vessels, and new bone in the surgically expanded mid palatal suture.

Objectives: To assess the oropharyngeal airway in Iranian female young adults with different skeletal patterns using cone-beam computed tomography (CBCT).

Materials and methods: This descriptive, cross-sectional study evaluated 105 CBCT scans of female patients between 18 and 35 years retrieved from the archives of a radiology clinic. The images were evaluated in axial, sagittal, and frontal sections. In the axial plane, the maximum and minimum cross-sectional area (CSA) of the airways at the oropharynx, minimum width (anteroposteriorly), and minimum depth (laterally) were measured using Mimics Medical software. The oropharyngeal volume was measured by NemoFAB software. The values were compared among the groups with different sagittal, vertical, and transverse patterns. The correlation of indices with airway measurements was analyzed using Monte Carlo Chi-square and Pearson's correlation coefficient.

Results: No significant difference was noted in oropharyngeal airway dimensions and volume among cases with different skeletal sagittal, vertical, and transverse patterns (P > 0.05) except for class III patients with normal transverse pattern in whom maximum CSA in low-angle group was larger than that in normal-angle group (P < 0.05) and class I normal-angle patients in whom maximum CSA in transverse normal group was smaller than that in constriction group (P < 0.05).

Conclusions: Oropharyngeal dimensions were not significantly different in Iranian female young adults with different skeletal patterns.