bluuebunny/crossref_metadata_2025_split huggingface dataset:
The presence of TNF-α and TNFR1 in aseptic root resorption. A preliminary study
Authors: Curl Linda , Sampson Wayne 
Published: August 2023

Abstract

Background: It is hypothesised that osteoprotegerin (OPG), as an osteoclast antagonist, may offer molecular control over the process of orthodontic root resorption. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts and odontoclasts when given at a recommended dosage of 2.5 mg/kg. It was considered that traumatically-induced PDL inflammation produces mediators and cytokines with the ability to stimulate clast cell differentiation and counter the effects of OPG.

Aims: The present study investigated the presence of Tumour Necrosis Factor Alpha (TNF-α) and its receptor Tumour Necrosis Factor Receptor 1 (TNFR1) in a PDL sterile inflammatory model.

Methods: Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats of which 9 were injected with OPG at a dose of 2.5 mg/kg of body weight at the time of freezing. After 7 days, the rats were sacrificed and each maxilla processed for immunohistochemical identification of TNF-α and TNFR1.

Results: Results showed the presence of root resorption in varying amounts and locations in both experimental and control rats. Reparative processes appeared greater in the OPG-treated rats, often with the presence of an ankylotic union. Immunolabelling showed the presence of TNF-α and TNFR1 in the sterile inflammation located mainly in the interradicular PDL area. More definitive labelling appeared in OPG-treated rats.

Conclusion: The results indicated that TNF-α, and its receptor TNFR1, by their presence, may modify OPG effectiveness by offering an alternative pathway for osteoclast formation, which counters the anti-resorptive effects of OPG.
Comparison of the effects of fixed and removable functional appliances on the skeletal and dentoalveolar structures
Authors: Bilgiç Fundagül , Hamamci Orhan , Başaran Güvenç 
Published: August 2023

Abstract

Objective: To compare and analyse the effects of activator and Forsus FRD EZ appliances in the treatment of skeletal Class II division I malocclusion.

Methods: Lateral cephalograms and hand-wrist radiographs were collected from 24 Class II division I growing patients (14 females, 10 males). The patients were randomly divided into two equal groups and either treated with an activator appliance (Mean age 12.67 ± 1.24 years) or with a Forsus FRD EZ appliance (Mean age 12.31 ± 1.09 years). Pretreatment and post-treatment cephalometric radiographs were obtained, traced, superimposed and data analysed using paired t-tests and the Wilcoxon signed rank test.

Results: The results demonstrated that the Forsus FRD EZ effectively corrected the Class II malocclusion, but the changes were mainly dentoalveolar. The Forsus FRD EZ appliance induced a clockwise rotation of the occlusal plane without significant alteration in the vertical facial dimension. Skeletally, maxillary growth was restricted and pogonion moved forward which improved the profile.

Conclusion: The Forsus FRD EZ appliance may be an effective dentoalveolar treatment method to manage a skeletal imbalance and improve the profile in growing patients.
The effects of lubrication on the static frictional resistance of orthodontic brackets
Authors: Al-Mansouri Noor , Palmer Graham , Moles David R. , Jones Steven P. 
Published: August 2023

Abstract

Background: Difficulties are experienced with the collection and storage of freshly harvested human saliva to use as a lubricant for the laboratory testing of the frictional resistance of orthodontic brackets. In order to overcome these difficulties, researchers have suggested the use of saliva substitutes due to their ease of storage and consistency of properties throughout testing. Others have criticized the use of artificial saliva and prefer the dry state. The present study aimed to compare the effects of human saliva and an artificial saliva (Saliva Orthana®) with the dry state for the static frictional resistance testing of orthodontic brackets.

Methods: The static frictional resistance and the lubrication effect of human saliva, Saliva Orthana® and the dry state were investigated using upper central incisor stainless steel brackets and 0.019 x 0.025 inch stainless steel wires in an Instron® Universal Testing Machine. Static frictional resistance was measured 100 times for each lubrication state. The ‘wettability’ of each lubricant was determined by measuring the contact angle against a stainless steel surface using the CAM 200 Optical Contact Angle Meter. Distilled water acted as a control. The viscosity of each lubricant and their Newtonian or non-Newtonian fluid behaviour under stress was measured using a Brookfield Digital Rheometer Model DV-III+.

Results: The differences in static frictional resistance between the three lubricants when examined as a group did not reach statistical significance (p = 0.059). The difference between human saliva and Saliva Orthana® was considered to be of weak statistical significance and clinical relevance (Means: 0.917 N; 0.819 N: p = 0.053). Human saliva and the dry state revealed very similar mean frictional values (Means: 0.917 N; 0.875 N: p = 0.932). The contact angle tests indicated a statistically significant difference between the lubricants with Saliva Orthana® having the smallest angle and therefore the highest ‘wettability’. Human saliva had the highest initial viscosity and behaved as a non-Newtonian fluid, contrasting with Saliva Orthana® and distilled water, both of which behaved as Newtonian fluids.

Conclusion: The current results indicate that artificial saliva is not an ideal alternative to human saliva for friction testing in the laboratory. The results therefore support the proposal that, when human saliva is not available, it may be preferable to test orthodontic frictional resistance in the dry state.
Bond failure rates of two self-ligating brackets: a randomised clinical trial
Authors: Luke Chapman J. 
Published: August 2023

Abstract

Aims: To evaluate the bond failure rates of two self-ligating appliance systems bonded with a self-etching primer.

Methods: Forty patients were randomly assigned to either Group SC (SmartClip, 3M Unitek, Monrovia, CA, USA) or Group IR (In-Ovation R, GAC International, Bohemia, NY, USA) appliance groups. Seven hundred and sixty six brackets were bonded with Transbond Plus Self-Etching Primer and Transbond Plus Color Change Adhesive according to the manufacturer’s instructions. Over a 12- month period, the survival rates of the brackets were estimated with the Kaplan-Meier analysis. The survival distributions for the appliance systems, dental arch and position in the dental arch were compared with the log-rank test.

Results: The bond failure rate for SC was significantly lower than IR (p = 0.022). There were no differences in failure rates between either the maxillary and mandibular arches or between the anterior and posterior brackets.

Conclusion: SC provided a more reliable bond than IR over the 12-month observation period, however, both brackets had clinically acceptable bond failure rates.
Changes in malocclusion over time in New Zealand adolescents
Authors: Foster Page Lyndie A. , Murray Thomson W. , Quick Andrew N. 
Published: August 2023

Abstract

Background: The Dental Aesthetic Index (DAI) has been used in many cross-sectional studies of population samples, but its use in assessing changes in malocclusion is less common. The aim of the present study was to describe the natural history of malocclusion and investigate the utility of the DAI as a measure for describing changes in malocclusion in a population-based sample of adolescents.

Method: A repeat examination was conducted of a sample of 430 children first assessed in 2003 at age 13 and re-examined at age 16 (255 or 59.3 per cent of the baseline sample) with their DAI and orthodontic history recorded at each age.

Results: Of the adolescents re-assessed, 28 were in active orthodontic treatment, 30 had completed treatment and 197 had not received any treatment. There were substantial changes in the DAI items from age 13 to 16, with the greatest improvement in maxillary anterior irregularity. Overall, almost one-quarter of participants showed an improvement in their DAI treatment need category which was considerably higher among those who had either received treatment or were in treatment.

Conclusion: The DAI is a valid and responsive tool for measuring change in malocclusion over time. Anterior mandibular irregularity shows the greatest change with age, and orthodontic treatment is effective in treating malocclusion, at least in the short term.
Risk factors associated with external apical root resorption of the maxillary incisors: a 15-year retrospective study
Authors: Rakhshan Vahid , Nateghian Nazanin , Ordoubazari Morteza 
Published: August 2023

Abstract

Aim: To determine the possible risk factors for external apical resorption (EARR) of the maxillary incisors.

Methods: Panoramic radiographs of 132 orthodontic patients with a mean age of 16.9 ± 3.6 years were selected from two practice centres in Tehran. The radiographs were taken between 1990 and 2005 and 63.6% of the subjects were female. Mean, standard deviation and distribution of EARR for various variables were assessed. Prevalence significance, as well as differences between frequency distributions of clinical EARR (≥ 1.2 mm) between genders, treatment plans (extraction/ non-extraction), initial overjet and overbite magnitude, and incisor types (centrals/laterals) were evaluated by the chi-squared test. The mean resorption rates on central and lateral incisors were compared using the independent-samples t-test. Associations between EARR with the age, duration of treatment, pretreatment overjet and overbite were assessed by the Pearson’s correlation test. The reliability of the method was determined by remeasuring 117 randomly selected incisors and determining the associations between both sets of measurements with the Pearson’s correlation coefficients.

Results: The prevalence of EARR, and clinical EARR (≥ 1.2 mm) were 91.8% and 44.78% respectively. The average of EARR was 1.377 ± 1.214 mm, or 8.165 ± 8.021% of pretreatment root lengths. The prevalence of clinical EARR was significantly higher in extraction cases, cases with greater initial overjet and on lateral incisors. Using the t-test, significant differences (p < 0.05) were observed between the extent of resorption between genders (higher in females), treatment plans (higher in extraction cases) and incisor types (greater on lateral incisors). Longer treatment times and excessive initial overjet were correlated with higher EARR levels (p < 0.05, r < 0.2).

Conclusions: Factors related to premolar extraction, initial ovejet size, treatment time and being female may be correlated with higher EARR. Clinically significant resorption did not occur more in females.
An investigation of cephalometric and morphological predictors of successful Twin Block therapy
Authors: Fleming Padhraig S. , Qureshi Usman , Pandis Nikolaos , DiBiase Andrew , Lee Robert T. 
Published: August 2023

Abstract

Objective: To identify predictors of overjet reduction, changes in mandibular length (Co-Me) and antero-posterior changes in mandibular position (Pog-Vert) during Twin Block therapy.

Methods: Pre- and post-treatment cephalograms of 131 participants were analysed (Mean age 12.73 years ± 1) following Twin Block therapy.

Results: Mean annualised overjet reduction was 7.29 mm (± 2.99) with chin projection improving by 2.66 mm (± 5.37). The magnitude of the initial overjet was a strong predictor (95% CI: 0.30, 0.77, p < 0.01) of overjet reduction and change in chin position (95% CI: 0.08, 0.77, p = 0.02). Greater forward movement of Pogonion occurred if there was greater retrusion of Pogonion at the outset (95% CI: 0.15, 0.45, p < 0.01). No prognostic relationship was noted for other potential cephalometric predictors including pretreatment mandibular lower border morphology and Co-Go-Me angle.

Conclusion: No relationship between mandibular morphology, vertical skeletal pattern and favourable dentoalveolar and skeletal responses to Twin Block therapy could be found. These results require confirmation on an external sample.
Occlusal bite force changes during 6 months of orthodontic treatment with fixed appliances
Authors: Alomari Sawsan A. , Abu Alhaija Elham S. 
Published: August 2023

Abstract

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.
Subjective symptoms of RME patients treated with three different screw activation protocols: a randomised clinical trial
Authors: Halıcıoğlu Koray , Kiki Ali , Yavuz İbrahim 
Published: August 2023

Abstract

Aims: The purpose of the present study was to evaluate the subjective symptoms of patients during the active phase of rapid maxillary expansion (RME) treatment, and further, to assess the differences between three different RME activation protocols.

Materials and methods: The clinical sample consisted of 60 patients (mean age 13.5 years) with maxillary transverse deficiency requiring expansion. The subjects were randomly divided into three groups on which different expansion protocols were performed. An evaluation of the subjective symptoms was carried out by a Numerical Rating Scale (NRS). The patients completed questionnaires after the first, fifth, tenth, twentieth and final activations. A Shapiro-Wilk test was applied to evaluate homogenity; a Kruskall Wallis test was performed for gender-related differences and to compare the different activation schedules. The Wilcoxon test was used to compare the activations at the various time intervals.

Results: No gender-related differences were found. Ninety-eight percent of the patients reported pain during RME. There were no specific differences between groups except for the pain perceived at the twentieth activation. In all groups, pain, the sensation of pressure and its duration were highest at the fifth activation. Subjective symptoms tended to decrease after the fifth and tenth activations. Headache and dizziness were minimal.

Conclusion: Different activation protocols did not appear to alter subjective symptoms encountered during RME. The majority of the patients undergoing RME suffered pain and pressure sensations especially after the fifth activation.
Measurements from conventional, digital and CT-derived cephalograms: a comparative study
Authors: Ghoneima Ahmed , Albarakati Sahar , Baysal Asli , Uysal Tancan , Kula Katherine 
Published: August 2023

Abstract

Objective: The purpose of this retrospective radiographic study was to determine the reliability and reproducibility of skeletal and dental measurements of lateral cephalograms created from a computerised tomography (CT) scan compared with conventional and digital lateral cephalograms.

Methods: CT and conventional lateral cephalograms of the same patients were obtained from university archives. The lateral cephalometric radiographs of 30 patients were manually traced. The radiographs were subsequently scanned and traced using Dolphin Imaging software version 11 (Dolphin Imaging, Chatsworth, CA, USA). The CT-created lateral cephalograms were also traced using the same software. Sixteen (10 angular and 6 linear) measurements were performed. Cephalometric measurements obtained from conventional, digital and CT-created cephalograms were statistically compared using repeated measures analysis of variance (ANOVA). Statistical significance was set at the p < 0.05 level of confidence.

Results: The intra-rater reliability test for each method showed high values (r > 0.90) except for mandibular length which had a correlation of 0.82 for the CT-created cephalogram. Five measurements (N-A-Pog, N-S, ANS-PNS, Co-ANS and Co-Gn) were found to be significantly different between the CT-created and conventional cephalograms and three measurements (SNB, ANB, and /1-MP) were found to be significantly different between the CT-created and digital cephalograms.

Conclusions: There are statistically-significant differences in measurements produced using a traditional manual analysis, a direct digital analysis or a 3D CT-derived cephalometric analysis of orthodontic patients. These differences are, on average, small but because of individual variation, may be of considerable clinical significance in some patients.
Colour stability of aesthetic brackets: ceramic and plastic
Authors: Filho Hibernon Lopes , Maia Lúcio Henrique , Araújo Marcus V. , Elias Carlos Nelson , Ruellas Antônio Carlos O. 
Published: August 2023

Abstract

Background: The colour stability of aesthetic brackets may differ according to their composition, morphology and surface property, which may consequently influence their aesthetic performance.

Aims: To assess the colour stability of aesthetic brackets (ceramic and plastic) after simulating aging and staining.

Methods: Twelve commercially manufactured ceramic brackets and four different plastic brackets were assessed. To determine possible colour change (ΔE*ab) and the value of the NBS (National Bureau of Standards) unit system, spectrophotometric colour measurements for CIE L*, a* and b* were taken before and after the brackets were aged and stained. Statistical analysis was undertaken using a one-way ANOVA analysis of variance and a Tukey multiple comparison test (α = 0.05).

Results: The colour change between the various (ceramic and plastic) materials was not significant (p > 0.05), but still varied significantly (p < 0.001) between the brackets of the same composition or crystalline structure and among commercial brands.

Conclusion: Colour stability cannot be confirmed simply by knowing the type of material and crystalline composition or structure. (Aust Orthod J 2013; 29: 13-20)
Surgically-assisted rapid maxillary expansion of narrowed maxillae: a case-cohort study
Authors: Gamage Sanjaya N. , Goss Alastair N. 
Published: August 2023

Abstract

Aims: The aim of this study was to investigate a consecutive cohort of surgically-assisted rapid maxillary expansion cases to determine the indications, results and relapse associated with the procedure.

Methods: The records of 21 cases of SARME treated by the Oral and Maxillofacial Surgery and Orthodontic units at the University of Adelaide were examined. Overall expansion and subsequent relapse were compared on study models and postero-anterior cephalometric radiographs against the variables of age, gender, surgeon, surgical technique, final occlusion and the retention period. Statistical analysis was performed on paired variables.

Results: Maximum expansion was gained across the intermolar width and the most relapse identified across the canines. Male patients showed statistically greater stability across the intercanine width. There were otherwise no significant relationships between the treatment variables, stability or relapse.

Conclusions: SARME is a safe surgical technique for narrowed maxillae requiring intermolar expansion of 6 mm or more. Overexpansion of up to 60% is required to compensate for relapse.
The application and correlation of Pont’s Index to the facial framework of three main ethnic groups in Malaysia
Authors: Purmal Kathiravan , Alam Mohammad Khursheed , Moganadass Deeban Das , Zakaria Nur Nadia , Cheong Ngeow Wei 
Published: August 2023

Abstract

Objective: To assess the applicability of Pont’s Index in a Malaysian population by obtaining baseline measurements of dental arch shape based on premolar arch width, molar arch width and the combined width of the maxillary incisors. A secondary aim was to determine whether a correlation exists between arch widths, Pont’s Index and the facial framework.

Methods: Ninety subjects of mixed racial backgrounds had maxillary dental casts made, measured and selected craniofacial anthropometric measurements taken. Arch widths were compared between the measured and the predicted values derived from Pont’s formula. A comparative analysis was performed between interpremolar and intermolar widths and the craniofacial anthropometric measurements. Comparative statistics were applied.

Results: The average interincisal measurement, interpremolar and intermolar widths were 30.31 ± 2.49 mm, 36.67 ± 2.50 mm and 45.21 ± 2.90 mm respectively. No significant differences were detected between the races. The interincisal measurement in males was significantly lower than for females but male intermolar width was significantly higher than for females. The average predicted interpremolar width (37.89 ± 3.11 mm) and intermolar widths (47.36 ± 3.89 mm) were higher than the actual measured means, suggesting that Pont’s Index overestimated interpremolar and intermolar widths in the majority of Malaysians. The premolar index (83.34) and molar index (67.71) of the Malaysians were higher than the original Pont’s Indices. Significant correlations were noted for intermolar width with facial width, mandibular width, mandibular depth and mouth width.

Conclusion: The findings suggest that Pont’s Index should not be applied to the Malaysian population.