bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of organizational and technical methods for predicting emergency situations and possible losses as their results
Authors: Ivanets Hryhorii , Horielyshev Stanislav , Sagradian Martin , Ivanets Mykhailo , Boikov Igor , Baulin Dmitro , Kozlov Yurij , Nakonechnyi Aleksandr , Safoshkina Lyudmila
Published: September 2021

Emergency prevention is based on analysis, forecasting and early response to emergencies. A systematic approach to solving the problem of preventing emergencies envisages forecasting emergencies by type, level and possible losses caused as a their results both in the state as a whole and in its regions. To implement a systematic approach based on a formalized mathematical model, an organizational and technical method has been developed for predicting emergencies and possible losses caused as their results.

The method is a combination of a variable order polynomial regression method, a weighted least squares method, and a probabilistic statistical method. This allows to compensate for the shortcomings of some at the expense of others, which will lead to an increase in forecasting accuracy.

A control algorithm has been developed for the implementation of an organizational and technical method for predicting emergency situations and possible losses caused as their results. Its use involves the implementation of a number of interrelated procedures. At the first stage, the collection, processing and analysis of information on emergency situations in the country for a certain period of monitoring is carried out. This is the basis for predicting the processes of emergencies in general, in nature, level and types, as well as losses due to them both in the state and its regions. The information received is taken into account when forming a decision on the actions of civil protection units in order to adequately respond to emergency situations and eliminate their consequences. Based on the analysis of the effectiveness of the actions of the response units, the decisions on the elimination of emergency situations are adjusted.

The developed method makes it possible to reasonably approach the planning and implementation of organizational and technical measures to prevent emergency situations, taking into account the potential threats to the territories and population of the country's regions
A numerical study to improve the position and angle of the producer gas injector inside the intake manifold to minimize emissions and efficiency enhancement of a bi engine
Authors: Mahmood Hussein A. , Al-Sulttani Ali O. , Attia Osam H. , Adam Nor Mariah.
Published: September 2021

To develop a petrol engine so that it works under the bi-engine pattern (producer gas-petrol) without any additional engine modifications, a single-point injection method inside the intake manifold is a simple and inexpensive method. Still, it leads to poor mixing performance between the air and producer gas. This deficiency can cause unsatisfactory engine performance and high exhaust emissions. In order to improve the mixing inside the intake manifold, nine separate cases were modelled to evaluate the impact of the position and angle orientation inside the intake manifold on the uniformity and spread of the mixture under AFR=2.07. A petrol engine (1.6 L), the maximum engine speed (8000 rpm), and bi-engine mode (petrol-producer gas engine). The employ of the numerical simulation software (ANSYS workbench 19), the propagation, flow characteristics, and uniformity of the blend within the nine different cases were evaluated. According to the outcomes of the numerical simulation, it was found that creating vortices and turbulent flow for the producer gas and air inside the intake manifold is the perfect method to obtain a uniformity mixture of air and producer gas inside the intake manifold. In addition, extending the blending duration allows air and producer gas fuel to be mixed efficiently. Furthermore, the greatest uniformity and the maximum spread rate at the outlet of manifold are obtained in cases 1, 4, and 7, when the producer gas injector location is constant (P1, P2 or P3). In addition, the weakest spread of producer gas at the outlet of the manifold is observed in case 9 in comparison with the other cases. Moreover, it is observed that case (1) generated the maximum uniformity index (UI) level
Trends in surgical-orthodontic management of Class III malocclusions in Western Australia
Authors: Sibanda Webson , Goonewardene Mithran , Duigou Christophe , Naoum Steven
Published: September 2021

Aim

The aim of this retrospective cohort study was to identify trends in the surgical-orthodontic management of skeletal Class III malocclusions in Western Australia between 1985 and 2016.

Methods

The records of 225 patients (132 females, 93 males) who received combined surgical-orthodontic correction of their Class III malocclusion between 1985 and 2016 were retrospectively assessed. The subjects were divided into three groups according to surgery type: Group (1) maxillary advancement only; Group (2) mandibular setback only; Group (3) two-jaw surgery.

Results

A trend towards two-jaw surgery for Class III correction was observed. Between 1985 and 2016, 123 patients (55%) were treated via two-jaw surgery; 97 patients (43%) were treated via maxillary advancement alone and five patients (2%) were treated via mandibular setback alone. Between 2011 and 2016, 61% were treated via two-jaw surgery; 37% were treated via maxillary advancement surgery; 2% were treated via mandibular setback surgery. Gender affected surgery type: two-jaw surgery (60% female); maxillary advancement (62% female); mandibular setback (17% female). A greater proportion of females received Class III surgical management in comparison with males (59:41).

Conclusion

Two-jaw surgery is the most common procedure for the surgical correction of skeletal Class III malocclusions in Western Australia. Of the single jaw procedures, isolated maxillary advancement surgery is more common than mandibular setback procedures.
Clinical use of orthodontic mini-implants for intrusion and retraction: a systematic review
Authors: Oswal Sanjam , Agarkar Sanket S. , Jethe Sandeep , Yerawadekar Sujata , Kawale Pradeep , Deshmukh Sonali , Rahalkar Jayesh S.
Published: September 2021

Background

Bimaxillary dental protrusion is common in many ethnic groups and is generally treated by the extraction of all first premolars. However, temporary anchorage devices (TADs) are currently gaining popularity and most studies have focused on anchorage loss, treatment duration, mini-implant success and failure rates, pain, discomfort and root resorption. Few studies have focused on the clinical effectiveness of implants for the intrusion and retraction of anterior teeth.

Objectives

To assess the clinical use of orthodontic mini-implants for the intrusion and retraction of anterior teeth.

Methods

A systematic review of articles selected from PUBMED and Google Scholar was carried out to determine the clinical use of orthodontic mini-implants for anterior tooth intrusion and retraction. Additional studies were hand searched to identify and include clinical trials, prospective and retrospective studies, while excluding finite element method (FEM) studies and case reports. A total of 598 articles were identified, of which 37 papers met the inclusion criteria and, following the elimination of duplicates, 20 articles were selected.

Results

Orthodontic mini-implants are more efficient for intrusion and retraction when compared to conventional intraoral and extra-oral anchorage devices. A greater amount of intrusion and retraction is achieved when mini-implants are placed between the first and second premolars without using any specific intrusive mechanics.

Conclusion

The present review highlights the clinical effectiveness of orthodontic mini-implants for anterior tooth intrusion and retraction and the results suggest that orthodontic mini-implants are more effective than other conventional methods of anchorage reinforcement.
Detection methods of orthodontically induced inflammatory root resorption (OIIRR): a review
Authors: Yazid Farinawati , Teh Yongxian , Ashari Asma , Ariffin Shahrul Hisham Zainal , Wahab Rohaya Megat Abdul
Published: September 2021

Background

Orthodontically induced inflammatory root resorption (OIIRR) is unwelcome iatrogenic damage associated with orthodontic treatment. Patients with a high risk of developing OIIRR are commonly monitored using radiographic techniques. Alternative, more sensitive methods using biological markers facilitate the early detection of OIIRR, which can minimise root surface damage and allow the timely cessation of orthodontic treatment in order to facilitate a reparative process.

Aim

The present review examines the current use of 2D and 3D radiographic techniques to detect and quantify OIIRR and, further, evaluates the latest literature on alternative detection methods of OIIRR.

Method

Published studies were searched electronically throughout PubMed, Scopus and ScienceDirect using keywords including ‘root resorption’, ‘OIIRR’, ‘radiograph’ and ‘biological markers’.

Results

The detection methods for OIIRR were divided into radiographic and biological marker methods. Orthopantomogram (OPG) and periapical radiography are currently the most widely used radiographic methods to detect and monitor OIIRR as they are readily available in most dental clinics, cost effective and have a relatively low radiation dose. However, the radiographic methods are not only subject to standardisation and magnification issues, but also require repeated radiation exposure to patients. Therefore, published research into the potential for biological markers as a safer and more sensitive alternative for the early detection of OIIRR was reviewed.

Conclusion

The result of the review highlights the potential for the use of biological markers in the early detection of OIIRR as a relatively safer and more sensitive alternative to conventional radiographic methods.
The incidence and severity of root resorption following orthodontic treatment using clear aligners
Authors: Costello Christopher James , Kerr Brett , Weir Tony , Freer Elissa
Published: September 2021

Introduction

The aim of this study was to assess the incidence and severity of root resorption in patients who were orthodontically treated by clear aligner therapy.

Methods

Linear tooth lengths of maxillary and mandibular teeth from the second molar to second molar were measured from pre- and post-treatment cone beam computed tomography examinations of 25 patients who were treated by a clear aligner system.

Results

Mean reductions in tooth length varied according to tooth type, with maxillary central and lateral incisors experiencing the most resorption, of 0.5 ± 0.41 mm and 0.4 ± 0.56 mm respectively. All tooth types had most resorption fall within the <0.25 mm range, with 7% of central and lateral incisors accounting for resorption >1.5 mm. Although the level of resorption identified in this study was less than that reported for fixed appliances, overall, the trends were similar.

Conclusions

Orthodontic treatment carried out with clear aligners resulted in root resorption that was largely clinically insignificant. There was a general trend towards more resorption affecting anterior teeth in both the maxilla and mandible. Original tooth length was found to be a predictor of the amount of resorption.
Assessment of microdamage caused by orthodontic miniscrew pilot holes
Authors: Jensen Sven W. , Jensen Emilija D. , Sampson Wayne J. , Dreyer Craig W.
Published: September 2021

Introduction

The clinical success of orthodontic miniscrew implants may be improved after pre-drilling a pilot hole. However, the amount of microdamage to the bone surface produced by the pilot hole is largely unknown. The present study aimed to quantify the damage to cortical bone after the creation of a pilot hole.

Materials and methods

Porcine tibia bone was prepared into 30 rectangular bone block specimens with widths of 1.5, 2.0 or 2.5 mm. A pilot hole (0.9 mm diameter) was drilled into each bone specimen. Sequential staining allowed the microdamage on the entry and exit surfaces to be imaged by a confocal laser scanning microscope. Image analysis software was used to measure histomorphometric parameters.

Results

The specimens had a mean total damage area of 0.95 mm2, a maximum damage radius of 0.66 mm and a maximum crack length of 0.18 mm. There were no significant differences between the three bone thicknesses for any of the histomorphometric parameters on the entry and exit surfaces (p > 0.05). The total damage area was significantly greater on the exit surface compared to the entry surface (p < 0.0001).

Conclusions

Microdamage caused by the creation of a pilot hole in the cortical bone was minimal and did not appear to be influenced by bone thickness. Therefore, pilot hole pre-drill protocols may be implemented without introducing significant cortical bone microdamage.
Facebook legal and regulatory advertising compliance by specialist orthodontic practices: a cross-sectional survey
Authors: Meade Maurice J. , Dreyer Craig W.
Published: September 2021

Background

Healthcare providers are increasingly using social media websites such as Facebook to advertise their services. The Australian Health Practitioner Regulation Agency guidance on the advertising of healthcare is based on the National Law in Australia and prohibits advertising that is contrary to the patient’s best interests.

Aim

To determine the legal and regulatory advertising compliance of the Facebook pages of specialist orthodontic practices in Australia.

Methods

The Facebook pages of specialist orthodontic practices were identified following a systematic search strategy. The content uploaded to each ‘eligible’ page between March 2019 and February 2020 was reviewed with regard to five specific domains of prohibited advertising. Cronbach’s Alpha Test was used to determine intra-rater agreement.

Results

The Facebook pages of 147 specialist orthodontist practices in Australia, representing 288 specialist orthodontists, satisfied inclusion criteria. Most Facebook pages (82.3%) breached the Law in one or more domains. The mean number (standard deviation) of domains breached was 1.65 (1.3), range 0–5. Non-compliance regarding ‘the use of testimonials’ (76.9%) and ‘information that was likely to create unrealistic expectations of orthodontic treatment’ (40.8%) were the domains most commonly contravened. All five domains were breached in 5.4% of practice Facebook pages. Intra-rater scores were strong, ranging from 0.84 to 0.94.

Conclusions

Compliance of the Facebook pages of specialist orthodontic practices in Australia with legal and regulatory advertisement requirements is poor. Greater awareness of the relevant obligations by specialist orthodontists responsible for their practice Facebook content is necessary to ensure that their advertising is not liable to charges of legal and/or professional misconduct.
A case of idiopathic condylar resorption
Authors: Collett Tony , Chen Laura , Pritchett Rosie , Poon Christopher
Published: September 2021

Background

Idiopathic condylar resorption (ICR) is a well-documented but poorly understood condition, characterised by the progressive degeneration of the temporomandibular joint without an identifiable cause. ICR most commonly presents as a spontaneous, self-limiting episode of bilateral condylar resorption in the absence of pathology, injury or systemic disease. The condition most commonly affects physically active adolescent females, and has a strong predilection for individuals with a Class II skeletal relationship. Some ICR patients exhibit symptoms such as discomfort and/or functional limitations during the active phase of resorption, though some may be completely asymptomatic.

Aim

This case report describes the ICR management of a 20-year-old female with asymptomatic bilateral condylar resorption, resulting in a rapid development of mandibular retrognathia. The retrognathic appearance was of concern to the patient and treatment was desired for this reason.

Methods and results

Combined orthodontic-orthognathic treatment was undertaken. Pre-surgical orthodontics was completed following ICR stabilisation, and surgical correction consisted of a mandibular advancement plus a genioplasty. The resorbed condyles were accepted given the temporomandibular joints remained asymptomatic and there were no functional limitations. Following treatment, the patient remained asymptomatic, functioning without restrictions, and satisfied with the aesthetic outcome.

Conclusion

The combined orthodontic-orthognathic approach addressed the aesthetic and functional concerns of the patient. The condyles were not reconstructed with prostheses and were left in their resorbed anatomical form and relationship. This illustrates the adaptive capabilities of the mandible and associated musculature, and that more complex condylar restorative procedures are not always required.
Orthodontic, periodontal and prosthodontic treatment for a periodontally compromised patient with a deep overbite
Authors: Ouyang Wanlu , Qian Yufen
Published: September 2021

Background

Periodontitis may result in displacement, overeruption and the tilting of teeth, which can lead to occlusal prematurities and accelerate the loss of periodontal structures. Orthodontic treatment is needed to correct displaced tooth positions, but inappropriate force and tooth movement can lead to further loss of supporting tissues.

Aim

To describe the treatment of a deep overbite in a 32-year-old male with a history of periodontitis, gingival recession and missing premolars.

Methods

After evaluation, fixed appliances applying light forces were chosen as the appropriate treatment approach. A segmental arch and a utility arch technique were applied. Periodontal therapy was conducted before and throughout orthodontic care.

Results

After 28 months of treatment, a normal overbite and overjet were restored. A displaced premolar was repositioned. Space needed for the prosthetic replacement of the missing teeth was obtained and dental implants were planned after orthodontic treatment. The height of the alveolar bone increased in some areas. After 18 months of retention, the attachment level of the upper left incisor increased approximately 1 mm.

Conclusion

For patients with a compromised periodontium, adequate management of the tissues is the basis of orthodontic care. Appropriate orthodontic treatment may be beneficial to periodontal health in the long term.
Valid consent and orthodontic treatment
Authors: Meade Maurice J. , Weston Annalene , Dreyer Craig W.
Published: September 2021

Valid patient consent is a legal and ethical principle that is fundamental to healthcare provision. Oral health practitioners (OHPs) must understand the principles that need to be addressed to ensure that the consent given by a patient is valid. Failure to obtain consent may result in a negligence claim or a complaint of professional misconduct against the OHP. Orthodontic treatment is mostly elective but is not without risk to the patient. Obtaining and maintaining valid consent for orthodontic treatment presents additional challenges in comparison with other dental procedures as the treatment lasts over a longer time and is most commonly performed in adolescents. In addition, prospective patients need to be informed regarding ‘lifelong’ management in the retention phase to minimise the risk of relapse. The present paper outlines the principles of valid consent with particular regard to orthodontic treatment in the adolescent patient. OHPs must ensure that they are satisfied that the competent patient has the capacity to voluntarily consent. Clinicians must also recognise that valid consent is not a one-off ‘tick the box’ procedural exercise but an ongoing process of effective information sharing in light of changing laws and an ever-changing scientific evidence base within a patient-centred model of healthcare.
An Angle Class I malocclusion with a paradental cyst
Authors: Miyamoto Yutaka , Kanzaki Hiroyuki , Amemiya Tsuyoshi , Hamada Yoshiki , Nakamura Yoshiki
Published: September 2021

According to the WHO, a paradental cyst is classified as an odontogenic inflammatory lesion, showing a relative frequency of 0.9–4.7% in the world population. There are no identifiable reports of orthodontic treatment of patients who also present with a paradental cyst. The presenting patient was a Japanese female, aged 16 years and 10 months. The chief complaint was crowding and protrusion of the incisors. The magnitude of the overjet was +4.0 mm, overbite was +3.8 mm, and the intermolar relationship was Angle Class I. Pretreatment computed tomography identified a radiolucency extending from the root furcation to the apex of the mandibular left first molar, which was diagnosed as a paradental cyst. Orthodontic treatment was performed using lingual multi-bracket appliances and miniscrews following the extraction of the affected mandibular first molar, mandibular right first premolar and both maxillary first premolars. The paradental cyst was enucleated, and occlusal cusp-fossa relationships were maintained with complete space closure. This case is the first report of orthodontic treatment in association with the management of a paradental cys.
Effect of combined oral contraceptives on orthodontic tooth movement in a female rat model
Authors: Yu Jinghong , Zhou Yifei , Zhang Tao , Lv Jialing , Firth Fiona , Zhao Xian , Xu Xiaomei , Mei Li
Published: September 2021

Background

To investigate the effect of combined oral contraceptives (COC) on orthodontic tooth movement (OTM) and periodontal remodelling in a female rat model.

Methods

A total of 80 three-month-old female, Sprague-Dawley rats were randomly divided into experimental and control groups. The maxillary first molars were moved mesially using nickel-titanium coil springs (50 g force). The experimental group (N = 40) ingested 1.5 ml COC (Marvelon, 0.12 mg/d, N.V. Organon, Oss, The Netherlands) daily. The control group (N = 40) ingested 1.5 ml saline (0.9% sodium chloride) daily. After 7, 14, 21 and 28 days of force application, 10 rats in each group were euthanased and a vernier calliper was used to measure the orthodontic movement of the first molar. Root resorption at pressure areas was assessed by H and E staining. Micro-CT was used to detect alveolar bone mineral density.

Results and conclusion

The amount of OTM in the experimental group (0.46 ± 0.16 mm) was significantly less than in the control group (0.85 ± 0.25 mm; p = 0.003) during the 28 days of observation. There were significantly smaller (p = 0.002) root resorption lacunae in the experimental group (111710 ± 4037 pixels) compared with the control group (204962 ± 21318 pixels) after 28 days. There was no statistically significant difference in the bone mineral density between the experimental and control groups throughout the study period (p > 0.05 at each time point). The short-term administration of COC may retard tooth movement and reduce the level of root resorption during OTM in female rats.
Interceptive orthodontic practices in general dentistry: a cross-sectional study
Authors: Currell Scott Derek , Vaughan Matthew , Dreyer Craig W.
Published: September 2021

Objectives

To evaluate the current practice of interceptive orthodontics undertaken by general dental practitioners and identify influencing factors.

Materials and methods

Printed questionnaires were provided to 200 registered Australian general dental practitioners. Participants were questioned about their current confidence, attitudes, and practice, related to interceptive orthodontics in general dentistry.

Results

The decision to practise interceptive orthodontics (17.4% of respondents) was strongly dependent on the confidence of the dentist (x2 = 48.693; df = 4; p < 0.001). It was also found that the provision of interceptive orthodontics was prevented by its perceived importance (x2 = 23.559; df = 5; p < 0.001) and benefit in a general dental setting (x2 = 9.411; df = 4; p = 0.035). The provision of more education was not shown to likely increase the number of dentists performing interceptive orthodontics. Low clinician confidence in the provision of interceptive orthodontics was also shown to result in orthodontic consultation prior to performing treatment (x2 = 31.782; df = 16; p = 0.004) or referral to an orthodontist (x2 = 42.465; df = 12; p < 0.001).

Conclusions

Interceptive orthodontics was not practised by most dentists. This decision was shown to be influenced by the clinicians’ confidence, further education or training, perceived importance of interceptive orthodontics and the impact that early intervention might have on future orthodontic treatment. Consideration should also be given to clarifying the orthodontic scope of practice for general dentists, in order to reduce the confusion influencing the provision of orthodontic care.
Evaluation of skeletally anchored therapy using miniplates and micro-implants in skeletal Class III treatment
Authors: Esenlik Elçin , Albayrak Gayem Eroğlu , Ağlarcı Cahide , Coşkun Esra Yüksel , Fındık Yavuz , Orhan Hikmet
Published: September 2021

Background/aim

To compare the outcomes of skeletally-anchored (SA) or face mask (FM) therapy in the management of patients presenting with maxillary retrognathia.

Methods

Forty-four consecutively treated maxillary retrognathic patients who underwent SA or FM therapies followed by fixed orthodontics were evaluated. Two micro-implants between the maxillary first molar and the second premolar and two mandibular miniplates were inserted to facilitate the use of Class III elastics in the SA group (23 patients). Facemasks with full occlusal-coverage acrylic appliances were applied in the FM group (21 patients). Lateral cephalometric radiographs obtained before treatment (T0), after orthopaedic treatment (T1), and after fixed orthodontic treatment (T2) were traced and 31 measurements compared.

Results

No statistically significant differences were found between the groups related to treatment duration and gender distribution. The mean age was significantly higher in the SA group (11.70±0.25 years) compared with the FM group (10.57±0.35 years) at T0. The mean ANB angle increased by 3.34° and 3.15° and the mean Wits value reduced by 6.16 mm and 4.13 mm in the FM and SA groups, respectively. Forward movement of the maxilla was similar between the groups. The vertical plane angle increased in both groups following maxillary protraction. However, it decreased in the SA group during fixed orthodontic therapy, which was contrary to what occurred in the FM group. The lower incisors were retracted/retroclined in the FM group and protracted/proclined in the SA group.

Conclusions/implications

Maxillary protraction was achieved in both groups and was maintained during fixed orthodontic therapy. Undesired lower incisor retraction and an increase of the vertical plane angle encountered with FM therapy were minimised by SA therapy.
The association between chronological age, skeletal maturity and dental maturity
Authors: Cutajar Brenda Lee , McDonald Fraser , Roberts Graham , Lucas Victoria , Camilleri Simon
Published: September 2021

Aim

The aim of this study was to analyse the correlation between skeletal and dental maturity.

Materials and methods

The Dental Panoramic Tomogram and Lateral Skull Radiographs of 381 subjects aged between 8.20 years and 17.96 years were examined. Calcification stages of all the teeth on the left hand side and all third molars were determined according to Demirjians 8-stages, whilst the Cervical Vertebral Maturation (CVM) Index was adopted for the assessment of skeletal maturity. Dental age (DA) was determined using the simple weighted average method.

Results

There was no significant difference between DA and chronological age (CA) of the male and female groups. The Spearman rank correlation between CA and CVM was moderate, whilst the correlation between DA and CVM was weak. A moderate correlation was found between the dental calcification stages and CVM for the upper right third molar in males.

Conclusions

The average CA of females at every CVM stage was below that of males, confirming that females undergo earlier skeletal maturation. The similarity between CA and DA confirms that CA can be closely approximated by DA. The low correlations between CA and DA with CVM suggest that these variables should not be used in determining the growth status or potential of the individual.
Clinical evidence in the treatment of white spot lesions following fixed orthodontic therapy: a meta-analysis
Authors: Yeoh Eng Seng , Le Tam , Maravilla Joemer , O’Rourke Vincent , He Yan , Ye Qingsong
Published: September 2021

Objective

This systematic review aims to determine the most effective method of treatment to remineralise post-orthodontic white spot lesions (WSLs).

Method

Six databases were accessed and searched for articles. Screening and selection were conducted according to the PRISMA guidelines using predetermined inclusion and exclusion criteria. Two reviewers independently assessed and extracted identified studies and relevance disagreement was resolved through consensus. Experimental studies were included that involved (i) patients of any age who had WSLs after the removal of fixed appliances, (ii) any treatment to remineralise the WSLs compared with no treatment or a placebo, and (iii) measurement of the changes in enamel mineralisation status after treatment. Eligible articles were assessed for internal bias and underwent narrative synthesis. A meta-analysis using random-effects modelling was performed to calculate a pooled estimate and assess between-study variability using Cochran’s Q and I2.

Results

The nine articles included in this review were found to have a medium or high risk of bias. The qualitative assessment provided contrasting results between studies. The meta-analysis showed both CPP-ACP – pooled d of -0.28 (N = 5 studies; 95% CI = -0.48- -0.07) – and fluoride – pooled d of -0.25 (N = 4 studies; 95% CI = -0.48- -0.02) – to generate improvement in the enamel mineralisation status, with CPP-ACP producing more consistent results compared with fluoride.

Conclusions

The meta-analysis found that CPP-ACP and fluoride were effective in reducing post-orthodontic WSLs. Due to the heterogeneity of the included studies with regard to the fluoride concentrations and mode of delivery, the current meta-analysis could not accurately establish which remineralising agent, CPP-APP or fluoride, is more effective. Further high quality studies of long-term duration are required to determine best clinical practice.
Orthodontic treatment in conjunction with distraction osteogenesis and orthognathic surgery for severe facial asymmetry
Authors: Tome Wakako , Aikawa Tomonao , Kitai Noriyuki , Yamashiro Takashi , Kogo Mikihiko
Published: September 2021

The present case report describes the combination of orthodontic treatment and two-stage surgery used to treat a 16-year-old female with a severe maxillary occlusal cant and a mandibular deviation. The patient was diagnosed with right temporomandibular joint ankylosis six months after suffering a facial injury at five years of age. A unilateral condylectomy was performed 12 months later. A hybrid functional appliance was used between nine and 16 years of age to prevent deterioration of the maxillary occlusal cant. At 16 years and six months, it was determined that the patient required a combination of surgical and orthodontic treatment, the pre-surgical orthodontic phase of which was completed at 19 years. The surgery was performed in two stages, which involved a Le-Fort 1 procedure to intrude the maxilla in the left molar region and to extrude in the right molar region. Distraction osteogenesis was performed to achieve a lengthening of the right mandibular ramus. The second operation was a unilateral sagittal split ramus osteotomy to achieve a forward and upward rotation of the left hemimandible. As a result, the patient’s facial asymmetry and occlusion significantly improved. The improvements were well maintained and the patient remained stable after one year of retention.
Comparison of the static frictional resistance and surface topography of ceramic orthodontic brackets: an in vitro study
Authors: AlSubaie Mai , Talic Nabeel
Published: September 2021

Objectives

The aim of this study was to investigate the frictional resistance (FR) and surface topography of newly available polycrystalline alumina (PCA) ceramic brackets characterised by a yttria-stabilised zirconia (YSZ) coating of the slots, compared with monocrystalline alumina (MCA) ceramic brackets and stainless steel (SS) brackets.

Methods

The FR was investigated using a universal testing machine. The test groups included PCA (Clarity Advanced, 3M Unitek, CA, USA) and MCA (Inspire Ice, Ormco, CA, USA). The control group included SS brackets. A sliding test was performed for each bracket type with three bracket-wire angulations (0°, 5°, 10°). A total of 225 sliding tests were performed in a dry environment, and 225 tests were performed in a wet environment of artificial saliva. A scanning electron microscope was used for qualitative assessments. The surface topography of the bracket slots was quantitatively assessed using an optical profilometer.

Results

In the dry environment, the overall FR values were significantly lower for PCA and SS brackets compared with MCA brackets (p < 0.001), but no significant difference was found between PCA and SS brackets. In the wet environment, there were no significant differences between the bracket groups and their overall FR values. There was a significant correlation between the overall FR and the bracket-wire angulation values (p < 0.001). The bracket slot surface topography revealed that the PCA bracket slots had the highest roughness values, followed by SS and MCA brackets (p < 0.001). There was no significant correlation between the roughness values of the bracket slots and the FR in a passive configuration for all bracket types.

Conclusion

A yttria-stabilised zirconium coating of the PCA ceramic bracket slots might be a positive approach to apply for the reduction of FR.
The addition of carbon nanotubes to orthodontic adhesives: an in vitro study
Authors: Marchi Paulo Guilherme Bittencourt , de Brum Ricardi Felipe , Zanini Maurício Matté , Bittencourt Paulo Rodrigo Stival , Busato Mauro Carlos Agner
Published: September 2021

Objective

The evolution of adhesive dentistry and the addition of nanoparticles has heralded an improvement in the mechanical properties of adhesives. Thus, the aim of the present study was to evaluate the effects produced by carbon nanotubes (CN) added to two adhesives used for indirect bonding by an examination of the shear bond strength (SBS) and location of bond failure.

Methods

One hundred and sixty bovine incisors were randomly divided into eight groups (N = 20): (1) indirect bonding with Sondhi adhesive; (2), (3) and (4) indirect bonding with Sondhi adhesive into which CN at 0.5%, 0.25% and 0.05% concentrations were incorporated; (5) indirect bonding with Concise adhesive; (6), (7) and (8) indirect bonding with Concise adhesive into which CN at 0.5%, 0.25% and 0.05% concentrations were incorporated. Following etching with 37% phosphoric acid and the placement of brackets, maximum shear bond strength (SBS) was measured with a mechanical testing machine. The location of bond failure was evaluated using the Adhesive Remnant Index (ARI). The SBS between groups and ARI scores were statistically analysed (p < 0.05).

Results

There was no statistical difference (p > 0.05) in SBS or ARI.

Conclusions

CN addition to Concise and Sondhi adhesives did not influence the SBS and the ARI of the brackets. Therefore, in the conditions of this experiment, there was no benefit in the addition of CN to orthodontic adhesives.
Tooth width measurement using the Lythos digital scanner
Authors: Bowes Michael , Dear William , Close Emily , Freer Terrence J.
Published: September 2021

Introduction

Digital models have become more widely accepted for orthodontic diagnostic purposes. Intraoral scanners have the advantage of eliminating the need for conventional impressions. The aim of the present study was to assess the reliability and reproducibility of the Lythos intraoral scanner and to determine if a significant advantage is delivered over stone model and caliper measurements in tooth width and Bolton ratio accuracy.

Methods

The study comprised 30 typodont models for which conventional alginate impressions and digital scans were obtained to generate stone and digital models, respectively. Mesiodistal tooth width measurements and Bolton ratios were obtained with either calipers and stone models or with Digicast (Ormco Lythos digital model software, Ormco, CA, USA) software using digital models. Pearson’s correlation coefficients tested intra-examiner reliability. Interclass correlation coefficients were used to assess agreement between examiners (reproducibility). The differences in the mean tooth width measurements and Bolton ratios from the typodont values and either the digital or conventional method were used to assess validity by applying two tailed t-tests.

Results

The measurements obtained from the Lythos and stone models had near perfect intra-examiner agreement (Pearson ≥ 0.98). The inter-examiner reproducibility for tooth widths, anterior Bolton and overall Bolton ratio was high and similar for both methods (Lythos scanner Interclass correlation coefficient (ICC) above 0.89, stone models ICC above 0.92). Stone model measurements were statistically twice as accurate as those derived from the digital system (0.032 mm versus 0.074 mm). There were no significant differences in accuracy between the methods for Bolton calculations. Clinically, there was no difference between the methods for tooth width measurements and Bolton calculations.

Conclusions

The Lythos system is as reliable and reproducible as conventional calipers and stone models in tooth width measurements and Bolton calculations. The caliper method presents a statistically more valid tooth width measurement technique but the clinical significance of this is questionable.
Novel aesthetic treatment of bilateral gemination of maxillary central incisors
Authors: Sifakakis Iosif , Chryssafidis Christos , Vastardis Heleni
Published: September 2021

The fusion of adjacent tooth buds and the formation of a single tooth or the gemination of a single tooth are rare and occur less often bilaterally in the permanent dentition.

Following a brief literature review, this case report describes the multidisciplinary treatment of an adolescent patient who presented with the bilateral gemination of the permanent central incisors. It was planned to restore the teeth using porcelain laminated veneers after the completion of orthodontic treatment.

The wide crown of the geminated incisors was restored, to mimic the morphology of two teeth, comprising a wider central and a narrower lateral incisor.

In carefully selected cases, this conservative treatment option preserves the physiologic function of the teeth and the periodontal ligament.
Interproximal reduction in orthodontics: why, where, how much to remove?
Authors: Meredith Lydia , Mei Li , Cannon Richard D. , Farella Mauro
Published: September 2021

Interproximal reduction (IPR) is the deliberate removal of part of the dental enamel from the interproximal contact areas, which decreases the mesiodistal width of a tooth. This enamel may be removed for various reasons, but most commonly to create space during orthodontic treatment or to correct tooth-size discrepancies. Several authors have also encouraged its use as a method by which post-orthodontic stability might be enhanced, particularly in the lower anterior region. With the increased use of removable aligners for orthodontic treatment in which non-extraction therapy is often advocated, the use of IPR becomes a valuable tool to relieve crowding without over-expanding the dental arches.

It is possible that inaccurate IPR could result in the over-reduction of enamel, the creation of ledges and notches in the proximal surfaces, increased tooth sensitivity or damage to the surrounding soft tissues. However, carefully conducted IPR performed within the recommended guidelines may be used as a safe method to gain space for the relief of crowding, to correct tooth-size discrepancies and to improve aesthetics and long-term stability in selected orthodontic patients.
Evaluation of skeletal maturation in individuals with cleft lip and palate
Authors: Uslu-Akcam Ozge
Published: September 2021

Objectives

The assessment of hand-wrist films to identify skeletal maturation stage is a commonly used method for the determination of the status of a growing patient. However, there is limited information available regarding skeletal growth evaluation in subjects with a unilateral cleft lip and palate (UCLP). Therefore, the current study aimed to examine skeletal and chronological ages in subjects with a UCLP for comparison with those of a non-cleft control group to derive clinical guidelines.

Methods

Hand-wrist films of 45 UCLP subjects (24 male, 21 female) and 45 Angle Class I orthodontic patients (17 male, 28 female) were evaluated. Skeletal age was assessed by comparing ossification events with standard radiographs illustrated in the Greulich-Pyle atlas and recording based on the best match of maturity criteria.

Results

A high correlation coefficient was observed between skeletal and chronological ages in the overall study sample (p < 0.01) (N = 90). Skeletal age (11.4 years) was delayed in the UCLP group when compared with chronological age (12.3 years), although the difference between the two was statistically insignificant. Skeletal age (13.6 years) was similar to chronological age in the control group (13.1 years).

Conclusions

The discrepancy between chronological and skeletal age was greater in UCLP subjects compared with controls. Given that the skeletal age of male and female UCLP subjects was delayed in comparison with their chronological ages, it is of particular importance that hand-wrist films should be used instead of chronological age to assess the growth status of UCLP subjects.
Anomalies of permanent tooth number in three Asian ethnicities
Authors: Qian Li , Chew Ming Tak , Yow Mimi , Wong Hung Chew , Kelvin Weng Chiong Foong
Published: September 2021

Objective

The objective of this comparative study was to determine the proportion and distribution of tooth number anomalies in the permanent dentition in a sample of Chinese, Indian and Malay orthodontic patients in Singapore.

Methods

The cross-sectional study was carried out using radiographic and clinical data from the National Dental Centre of Singapore. Panoramic radiographs and clinical records of 1080 (Chinese (N = 415), Indian (N = 317) and Malay (N = 348)) orthodontic patients aged 12 to 16 years were examined for evidence of tooth number anomalies. Fisher’s exact test was applied to compare the occurrence of hypodontia and hyperdontia between the ethnicities and genders.

Results

The prevalence of hypodontia in Chinese, Indian and Malay orthodontic patients was 13.7%, 6.0% and 14.4%, respectively. Chinese patients had a significantly higher prevalence of hypodontia compared with Indian patients (OR 2.50, 95% CI 1.29–4.83, p < 0.001). Malay patients had a significantly higher prevalence of hypodontia compared with Indian patients (OR 2.63, 95% CI 1.34–5.17, p < 0.001). The most commonly missing tooth in the Indian patients was the upper lateral incisor (39.0%), whereas that in the Chinese and Malay patients was the lower second premolar (26.1% and 26.2%, respectively).

The prevalence of hyperdontia in Chinese, Indian and Malay patients was 7.0%, 3.8% and 7.8%, respectively. Male patients had a significantly higher prevalence of hyperdontia compared with female patients (OR 1.87, 95% CI 1.14–3.07, p = 0.015). Supernumerary teeth occurred more frequently in the anterior maxilla (34.1%) than in other regions of the jaws. Supernumerary teeth also occurred more frequently in the maxilla (76.9%) than in the mandible (23.1%).

Conclusion

There are significant differences in the presentation of anomalies in tooth number in the permanent dentition of Chinese, Indian and Malay orthodontic patients in Singapore.
Interdisciplinary management of a patient with advanced dental needs
Authors: Ong Desmond CV , Crasta Kenneth
Published: September 2021

The present case report outlines the interdisciplinary management of an adult patient presenting with advanced generalised periodontal attachment loss, an upper dental midline discrepancy following the previous extraction of the upper left central incisor, and significant lower arch crowding. The endodontic and periodontal condition was stabilised prior to the commencement of fixed appliance orthodontic treatment and subsequent prosthetic replacement of the upper left central incisor. Interdisciplinary management provided a functional occlusion and stability of the periodontal condition along with pleasing facial and smile aesthetics.
Three-dimensional computed tomographic assessment of mandibular muscles in growing subjects with different vertical facial patterns
Authors: Wong Alwyn , Woods Michael G. , Stella Damien
Published: September 2021

Aim

The present study was undertaken to assess the relationship between the mandibular muscles and dentofacial skeletal morphology in children with different underlying vertical facial patterns, using three-dimensional computed tomography (3D-CT).

Method

Thirty children (mean age 12.24 ± 1.57 years) underwent cranial CT examination for diagnostic purposes. 3D-CT images were reconstructed for the evaluation of the cross-sectional size, volume, and spatial orientation of the masseter and medial pterygoid muscles. These muscle parameters were also assessed in relation to the vertical facial pattern, gender and skeleto-dental form.

Results

Significant differences were found in muscular angulation for subjects with different underlying patterns. Greater masseter volumes were associated with increased facial width. Greater intermolar widths were found in brachyfacial subjects, with less acute muscular angulations in relation to horizontal reference lines, compared with dolichofacial subjects. This was also more obvious in the maxillary arch.

Conclusion

Clinicians should note the likely differences in masseter and medial pterygoid orientation and volume in subjects with different underlying vertical facial patterns and that these differences may, in turn, be related to both facial skeletal width and naturally-occurring transverse dental arch dimensions.
Changes in mandibular position in treated Class II division 2 malocclusions in growing and non-growing subjects
Authors: AL-Nimri Kazem , Abo-Zomor Mohamad , Alomari Sawsan
Published: September 2021

Objective

To determine changes in mandibular position after the treatment of patients presenting with Class II division 2 malocclusions and to test the null hypothesis that there is posterior displacement of the mandible in these patients, in comparison with a control group of Class II division 1 subjects.

Materials and methods

The assessed data consisted of pre- and post-treatment cephalometric radiographs of 77 subjects identified with Class II division 1 and Class II division 2 malocclusions matched according to age, gender and treatment duration. All completed fixed appliance orthodontic treatment. The changes in the position of point B, Pogonion and Articulare were determined at the end of treatment by superimposing the cephalometric radiographs on Sella-Nasion line at Sella. Thirteen cephalometric parameters including the distance between Basion and Articular (Ba-Art) were measured at each stage.

Results

In both groups, SNB angle, SNPog angle and Ba-Art distance showed no statistically significant changes. Pogonion was displaced significantly in a forward and downward direction in the growing group, with no significant differences identified between Class II division 1 and Class II division 2 subjects.

Conclusion

The null hypothesis that there is posterior displacement of the mandible in Class II division 2 malocclusion is rejected. The growth pattern of the mandible in both divisions of a Class II malocclusion after orthodontic treatment was found to be similar. (Aust Orthod J 2016; 32: 73–81)