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This case report describes a successful orthodontic therapy of an adult female treated by mandibular central incisor extraction and vestibular fixed appliances. The patient presented a skeletal Class I with normodivergent facial pattern, Class II subdivision dental relationship, extremely deep Curve of Spee and severe overbite. Moreover, during the treatment, the upper left first molar does not respond to orthodontic forces due to tooth ankylosis, augmenting the difficulty of this case. Despite this, a good occlusal relationship on both sites and an optimal extraoral outcome have been achieved after a 26-months therapy. To our knowledge no case report with such entity of Curve of Spee with contemporary tooth ankylosis has been presented.

This case report describes orthodontic treatment including both skeletal maxillary expansion and unilateral distalization by means of a single bone-borne appliance followed by clear aligner therapy in a young adult patient. A surgical guide was digitally designed and three-dimensionally printed to facilitate the placement of four miniscrews in the palatal vault. The miniscrews were fitted and the bone-borne appliance was delivered in a single clinical appointment. The postexpansion photographic records and models demonstrate the opening of the palatal median suture, the pure skeletal expansion, and the resolution of the left crossbite after 40 activations. Specifically, left molar Class I was obtained in about 5 months without any loss of anterior anchorage, and the subsequent aligner phase achieved all of the objectives established in the treatment plan. This case report shows clearly how careful digital planning of miniscrew insertion and the delivery of a pure bone-borne appliance in a single sitting enabled good clinical outcomes to be achieved in an acceptable timeframe, without side effects, even in a young adult patient.

Summary Background Class III patients are characterized by a deficiency of the maxilla and/or a prognathism of the mandible and require early treatment. Diagnosis This case report describes the treatment of a 5-year-old patient with a skeletal class III relationship, a significant mandibular symphysis deviation towards the right side and a different height of the mandibular angles. Management and outcome The patient was treated with rapid maxillary expander combined with miniscrew, facemask and aligners. A functional and aesthetic occlusion in an improved facial profile was established at the end of the orthodontic treatment. Pre-treatment, post-treatment and one year retention records for the patient are presented. Discussion Class III patients require early treatment in order to optimize the traditional expander effects; subsequently hybrid anchorage allowed to maximize skeletal advancement. In addition, loss of space for the erupting teeth and dento-alveolar tipping were avoided. The good results of the phase I treatment and of the active retainer meant that a complex case would become relatively simple at the phase II treatment.

Descrizione della relazione tra classificazione NOHL definita durante la drug-induced sleep endoscopy e AHI iniziale in pazienti con OSAS da moderato a grave, e valutazione dei risultati ottenuti con dispositivi orali.La drug-induced sleep endoscopy (DISE) è ampiamente riconosciuta come un valido strumento per la diagnosi e la pianificazione del trattamento della sindrome delle apnee ostruttive (OSAS), in quanto consente una visualizzazione diretta dei siti e pattern di collasso delle vie aeree superiori (VAS). In letteratura sono state proposte molteplici classificazioni per descrivere gli eventi osservati duranti la DISE, fra cui la NOHL (Nasopharynx cavity and walls, Oropharynx, Hypopharynx, Larynx) classification (Vicini 2012). Lo studio si prefigge gli obiettivi di identificare quali strutture anatomiche, definite secondo la classificazione NOHL, sono più rappresentate nel collasso delle VAS in pazienti con OSAS da moderato (15 ≤ AHI ≤ 30) a grave (AHI30), e valutare il risultato del trattamento con dispositivi orali (OA), in termini di riduzione dell’AHI. Il gruppo studio è composto da 35 pazienti (29 M, 6 F, età media 50,6, BMI medio 26) con diagnosi polisonnografica di OSAS da moderato a severo, sottoposti a DISE e classificati secondo la classificazione NOHL per individuare le sedi anatomiche e i pattern di collasso più frequentemente riportati. I pazienti sono stati successivamente indirizzati a terapia con Mandibular Advancing Devices (MAD), ed è stato valutato il risultato del trattamento in termini di riduzione dell’AHI. Nel campione esaminato, le strutture anatomiche più frequentemente coinvolte nel collasso delle VAS risultano essere il nasofaringe (N) e la base lingua (H), con indice di correlazione 0,35 (p0,04), mentre non è stata evidenziata significatività per l’area retropalatale (O) e la laringe (L). L’analisi descrittiva ha evidenziato inoltre un collasso multisede in tutti i pazienti, con coinvolgimento di più strutture nella meccanica ostruttiva. In tutti i pazienti è stata osservata una riduzione dell’AHI dopo terapia con MAD (p0,00), sebbene in alcuni casi non completamente risolutiva della patologia.Nowadays, drug-induced sleep endoscopy is widely recognised as a valid tool for diagnosis and treatment planning of obstructive sleep apnoea syndrome (OSAS), as it allows a direct visualisation of sites and patterns of collapse of the upper airways (UA). Various classifications have been proposed in the literature to describe the events observed during DISE, including the NOHL (Nasopharynx cavity and walls, Oropharynx, Hypopharynx, Larynx) classification. This study was aimed at assessing which anatomical structures, according to the NOHL Classification, were most frequently involved in UA collapse in patients with moderate to severe OSAS, and evaluating treatment results with oral appliances (OA), in terms of AHI reduction. The study group consisted of 35 patients (29 M, 6 F, mean age 50.6, average BMI 26) with polysomnographic diagnosis of moderate to severe OSAS, subjected to DISE and classified according to the NOHL classification to identify the anatomical sites and patterns of UA collapse most frequently reported. Patients were subsequently addressed to mandibular advancing device (MAD) therapy and treatment results in terms of AHI reduction were evaluated. In the sample examined, the anatomical structures most frequently involved in the collapse of the UA were the nasopharynx cavity and walls and tongue base, with a correlation index of 0.35 (p0.04), while no significance was found for the retro-palatal area or larynx. Descriptive analysis revealed multilevel collapse in all patients, involving multiple anatomical structures in obstructive mechanics. In all patients, AHI reduction was observed after treatment with MAD (p0.00).

The aim of this study was to determine and compare the play and torque expression of self-ligating and conventionally ligated lingual brackets, with square and rectangular slots, when engaged with archwires of different size, cross section and material.Passive play and torque expression of 3 types of archwires and 5 types of brackets from four different manufacturers were measured and compared using a dynamometer. Each archwire was tested five times in each bracket; passive play was compared to ideal values, while torque expression was tested at 5, 10 and 20 Nmm as clinically efficacious values.Regarding full thickness stainless steel archwires, the lowest passive play was found in STb brackets (2.66 ± 0.89°, Ormco, Glendora, CA, USA), which was statistically significantly lower than for ALIAS brackets (4.44 ± 0.75°, Ormco), In-Ovation L brackets (6.14 ± 3.22°, Dentsply GAC, Bohemia, NY, USA), Harmony brackets (7.76 ± 2.94°, American Orthodontics, Sheboygan, WI, USA) and eBrace brackets (9.46 ± 3.94°, Riton Biomaterial, Guangzhou, China). Increasing the torsional load to the greatest torsional load clinically applicable, there were no statistically significant differences between STb, ALIAS, In-Ovation L and Harmony brackets.STb and ALIAS brackets generated the lowest passive play; STb and In-Ovation L brackets showed the lowest angle of play at the greatest torque expression. These measurements allow to understand the accuracy of lingual systems and at the same time the amount of overcorrections to be applied in the setup in order to obtain high quality orthodontic treatments.EINFüHRUNG: Ziel dieser Studie war es, das Spiel und die Torqueexpression von selbstligierenden und konventionell ligierten lingualen Brackets mit quadratischen und rechteckigen Slots zu bestimmen und beim Einsatz mit Drahtbögen unterschiedlicher Größe sowie unterschiedlichen Querschnitts und Materials zu vergleichen.Das Torquespiel und die Torqueexpression von 3 Arten von Drahtbögen und 5 Brackettypen von 4 Herstellern wurden gemessen und unter Verwendung eines Dynamometers miteinander verglichen. Jeder Drahtbogen wurde 5‑mal in jedem Bracket untersucht. Das Torquespiel wurde mit idealen Werten verglichen, während die Torqueexpression bei den klinisch wirksamen Werten 5, 10 und 20 Nmm getestet wurde.Bei den Edelstahlbögen in voller Stärke wurde das geringste Torquespiel bei STb-Brackets (2,66 ± 0,89°, Ormco, Glendora, CA, USA) festgestellt, es war statistisch signifikant niedriger als bei ALIAS- (4,44 ± 0.75°, Ormco), In-Ovation-L- (6,14 ± 3,22°, Dentsply GAC, Bohemia, NY, USA), Harmonie- (7,76 ± 2,94°, American Orthodontics, Sheboygan, WI, USA) und eBrace-Brackets (9,46 ± 3,94°, Riton Biomaterial, Guangzhou, China). Bei Erhöhung der Torsionsbelastung auf die maximale klinisch anwendbare Torsionsbelastung gab es keine statistisch signifikanten Unterschiede zwischen STb‑, ALIAS-, In-Ovation-L- und Harmony-Brackets.STb- und ALIAS-Brackets verursachten das geringste Torquespiel; STb- und In-Ovation-L-Brackets zeigten den geringsten Spielwinkel bei der größten Torqueexpression. Diese Messungen ermöglichen es, die Genauigkeit der lingualen Systeme zu verstehen und damit auch das Ausmaß der im Setup anzuwendenden Überkorrekturen, um qualitativ hochwertige kieferorthopädische Behandlungen zu erhalten.

Objectives: This study aimed to assess frequency and multiple-night variability of sleep bruxism (SB) as well as sleep-time masticatory muscle activities (sMMA) in the home environment in healthy young adults using a portable device that provides electrocardiographic (ECG) and surface electromyographic (EMG) recordings from the masticatory muscles. Methods: The study was performed on 27 subjects (11 males, 16 females, mean age 28.3 &plusmn, 1.7 years) selected from a sample of healthy young students. Evaluation was carried out for four nights to record data on masticatory muscle activities using a compact portable device that previously showed an excellent agreement with polysomnography (PSG) for the detection of SB events. The number of SB episodes per sleep hour (bruxism index), and the number of tonic, phasic and mixed sMMA events per hour were assessed. A descriptive evaluation of the frequency of each condition was performed on all individuals, and gender comparison was investigated. Results: Mean sleep duration over the four recording nights was 7 &plusmn, 1.3 h. The average SB index was 3.6 &plusmn, 1.2. Most of the sMMA were tonic (49.9%) and phasic (44.1%). An ANOVA test showed the absence of significant differences between the four nights. No significant gender differences were detected for the SB index, phasic or tonic contractions, conversely, gender differences were detected for mixed sMMA events (p &lt, 0.05). Conclusion: This investigation supports the concept that sMMA events are quite frequent in healthy adults. Differences over the four-night recording span were not significant. These data could be compared to subjects with underlying conditions that may lead to an additive bruxism activity and possible clinical consequences.

A smartphone-based ecological momentary assessment (EMA) strategy to collect real time data on awake bruxism (AB) has been recently introduced. The aim of this study was to assess the compliance with its use over 1 week in a sample of healthy young adults. Sixty (N = 60) healthy young adults (mean age 24.2 ± 4.1 years) used a dedicated smartphone application that sent 20 alerts at random times throughout the day. Upon alert receipt, the subjects had to report in real time their condition among five possible options: relaxed jaw muscles, teeth contact, teeth clenching, teeth grinding, and mandible bracing. Compliance rate with the app was assessed at the individual and group level in terms of percentage of answered alerts as well as number of days that were needed to reach the targeted observation period of 7 days with a compliance of at least 60%. The mean compliance recorded with the smartphone application was 67.8% of the total alerts. On average, 9.8 ± 3.2 days (range 7–19) have been necessary to achieve the targeted goal of 7 days with a minimum of 60% alerts/day. No gender differences were detected in any compliance data. Response rate was not different during weekdays or weekends. This investigation is the first attempt to assess individual compliance with EMA for reporting awake bruxism. Results suggest that a smartphone-based strategy can have interesting potential. The compliance rate reported in this study will serve as a comparison standpoint for future investigations. Based on the recent multidisciplinary focus on the study of awake bruxism, EMA has emerged as a potential approach for use in the clinical and research settings. This investigation suggests that compliance with such strategy is good, thus making it worthy of adoption for the assessment of AB and its clinical implications.

Objective: To assess the association between self-reported awake bruxism (AB) and the chronotype profile among Brazilian, Portuguese, and Italian dental students.Methods: A cross-sectional ...

Mechanical properties along the length of latest generation “multi-force” archwires were measured and compare with commercially available thermally activated and non-thermally activated nickel-titanium (NiTi) archwires. A modified deflection test was used to produce load/deflection curves for different positions along the lengths of a sample of 114 NiTi archwires composed by thermal NiTi, non-thermal NiTi, two types of multi-force NiTi and one type of multi-force copper archwires of various cross-sections (0.016 × 0.016 inch, 0.016 × 0.022 inch, 0.018 × 0.025 inch and 0.019 × 0.025 inch). The length, slope and mean force expressed were calculated from the resulting unloading plateaus, enabling comparison between types of archwire at different points along their lengths. Among conventional thermal, conventional nonthermal and multiforce archwires, all parameters investigated were statistically different, whereby the performance of the latter was superior. Multi-force archwires displayed 27% and 31% lighter mean forces in the upper and lower arches, respectively, in addition to 62% and 40% reductions in unloading plateau slope and length, respectively, as compared to conventional CuNiTi wires. Comparison of the different types of multi-force wires tested revealed statistically significant differences in the three parameters, depending on the testing position but irrespective of their cross-section. Although conventional archwires display identical behaviour along their lengths, as advertised the multi-force archwires do indeed exert a progressive force which differs between anterior, medial and posterior sections. The multi-force wires provide lighter, more prolonged and constant forces than conventional wires without cross-section-dependent variation.

Background The aim of this study is to compare the biomechanical effects of the conventional 0.019 × 0.025-in stainless steel archwire with the dual-section archwire when en-masse retraction is performed with sliding mechanics and skeletal anchorage. Methods Models of maxillary dentition equipped with the 0.019 × 0.025-in archwire and the dual-section archwire, whose anterior portion is 0.021 × 0.025-in and posterior portion is 0.018 × 0.025-in were constructed. Then, long-term tooth movement during en-masse retraction was simulated using the finite element method. Power arms of 8, 10, 12 and 14 mm length were employed to control anterior torque, and retraction forces of 2 N were applied with a direct skeletal anchorage. Results For achieving bodily movement of the incisors, power arms longer than 14 mm were required for the 0.019 × 0.025-in archwire, while between 8 and 10 mm for the dual-section archwire. The longer the power arms, the greater the counter-clockwise rotation of the occlusal plane was produced. Frictional resistance generated between the archwire and brackets and tubes on the posterior teeth was smaller than 5% of the retraction force of 2 N. Conclusions The use of dual-section archwire might bring some biomechanical advantages as it allows to apply retraction force at a considerable lower height, and with a reduced occlusal plane rotation, compared to the conventional archwire. Clinical studies are needed to confirm the present results.

Objective: To evaluate the subgingival microbiological changes during the first six months of therapy with clear aligners (CAs) and fixed appliances (FAs). The null hypothesis was that there would be no microbiological differences between the two. Setting/Sample: Two groups of patients to be treated, respectively, with CAs (14 patients; 9 females and 5 males; mean age 21years±0.25) and FAs (13 patients; 8 females and 5 males; mean 14years±0.75) were consecutively recruited. Materials and Methods: Subgingival microbiological samples were obtained at the right upper central incisor and right first molar at four different time points: before appliance fitting (T0), and at 1month (T1), 3months (T3) and 6months (T6) thereafter. Total bacterial load (TBL) and counts of the bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Campylobacter rectus, Treponema denticola and Tannerella forsythia were determined using real-time PCR. Results: Total bacterial load did not vary in the CA group, while a significant increase was detected after 3 and 6months of treatment in the FA group. Unlike red complex species, Crectus and Fnucleatum were often detected: levels remained stable in the CA group but increased progressively in the FA group. Conclusion: The type of orthodontic appliance influences the subgingival microbiota. TBL increased in the FA group but not in the CA group, although the levels of the individual periodontal pathogenic bacteria species did not significantly increase during the observation period.

Objective The twofold aim of the present investigation was to: 1. evaluate the degree of mid-palatal suture (MPS) maturation via CBCT in relation to patient age, and 2. to determine whether there was a correlation between quantitative (i.e., suture density) and qualitative (i.e., suture morphology) analysis. Materials and methods The stage of mid-palatal suture maturation and suture density ratio were assessed for 160 subjects on CBCTs using five qualitative stages proposed by Angelieri with the addition of three additional stages (i.e., B/C, C/D and D/E) and quantitative grey density scores of Grunheid MPS1,2,3,4 with the addition of parasutural bone and soft palate. The repeatability of both methods was evaluated using Cohen's K.The relationship between midpalatal suture maturation and age was assessed using ANOVA and Classification and Regression Trees (CART) analysis and tabulation and a χ2 test for quantitative and qualitative analysis respectively. Statistical significance was assessed using a 5% threshold. Results The final sample included 160 CBCTs (80 male,80 female; mean age 23.2±13.5). Both methods were found to be correlated and highly repeatable. In addiction they showed an age-related correlation in MPS morphology. Conclusion The mid-palatal suture density ratio and the stage of mid-palatal suture maturation has the potential to become useful in clinical practice. In fact, despite the correlation between MPS maturation stage and age, the latter parameter cannot be used as a clinical discriminator due to the great variability between subjects. It is therefore advisable to assess each patient individually on CBCT scans in order to determine treatment choices.

Summary Objective The purpose of this study was to evaluate the biomechanical properties of miniscrews of 5 different lengths, 2 different diameters, and different combinations of insertion used for palatal skeletal anchorage. Materials and methods Twenty-four different combinations of a total of 120 miniscrews of two different diameters (2.0 mm and 2.3 mm) and five different lengths (9 mm, 11 mm, 13 mm and 15 mm) were tested at different angles of insertion (90° and 45°) and distances from a synthetic bone block (3 mm, 5 mm, 7 mm). Samples were fixed in an Instron Universal Testing Machine and a load was applied in single cantilever mode to the neck of each miniscrew. The stiffness and maximum load before permanent deformation were recorded. Model-based recursive partitioning testing (CART) was used to evaluate differences between groups. Results Significantly higher forces were necessary to deform miniscrews of diameter 2.3 mm than those of 2.0 mm, those inserted at an angle of 45° with respect to 90°, and at smaller distances between the miniscrew neck and block; in addition, the maximum load and stiffness increased with increasing screw length. Conclusion This in vitro experimental study showed strong correlations between deformation load and miniscrew geometry, insertion angle and distance from the synthetic block, results that should be considered when planning miniscrew insertion in order to reduce the risk of unwanted fracture.

Objective This report describes the fluorescence-aided composite removal during lingual bracket debonding with an ultraviolet light emitting diode flashlight. The purpose of this technique is to help clinicians in composite removal without enamel surface damage. Clinical considerations The bracket debonding requires clinical attention in order to remove all composites and resins without enamel surface damage. Different protocols can be used in order to minimize the enamel damages and the excess bonding remnants. The fluorescence-aided composite removal permits to have an immediate visualization of the composites and adhesives, especially for the uneven lingual surfaces, of which the interindividual morphological variability is greater than the buccal surfaces. Conclusions The fluorescence-aided composite removal during lingual brackets debonding minimizes the risks described in literature and it is an easier, more accurate, reliable, noninvasive, inexpensive, and time-saving method. Clinical significance The application of this technique allows, with inexpensive flashlights, to remove all the composite on the lingual surfaces during debonding, without damaging the tooth and saving time.

The Extreme Energy Events (EEE) Project employs Multi-gap Resistive Plate Chamber (MRPC) for studying the secondary cosmic ray muons in Extensive Air Showers. The array consists of about 60 tracking detectors, sparse on Italian territory and at CERN. The MRPCs are flowed with a gas mixture based on $C_2H_2F_4$ and $SF_6$, both of which are fluorinated greenhouse gases with a high environmental impact on the atmosphere. Due to the restrictions imposed by the European Union, these gases are being phased out of production and their cost is largely increasing. The EEE Collaboration started a campaign to reduce the gas emission from its array with the aim of containing costs and decreasing the experiment global warming impact. One method is to reduce the gas rate in each EEE detector. Another is to develop a gas recirculation system, whose a first prototype has been installed at one of the EEE stations located at CERN. Jointly a parallel strategy is focused on searching for environmental friendly gas mixtures which are able to substitute the standard mixture without affecting the MRPC performance. An overview and first results are presented here., Comment: 11 pages, 9 figures

This case shows that using a rapid palatal expander (RPE) and then a pendulum appliance anchored to palatal miniscrews is an option for improving treatment management in a noncompliant patient requiring maxillary expansion and molar distalization in the late mixed dentition. First, an RPE was used to expand the maxillary arch. Then, a modified pendulum appliance was used to distalize the maxillary first permanent molars. Optimal positioning of two palatal miniscrews enabled both appliances to be supported by skeletal anchorage. Treatment was finished using multibracket fixed appliances, and after 2 years, skeletal Class I as well as dental Class I canine and molar relationships were achieved.

Objective: To investigate the association between volumetric measurements of craniofacial morphology and temporomandibular disorders (TMDs). Methods: Computerized tomography (CT) scans of 20 individuals aged 18 to 40 with (TMD group) or without TMJ pain (control group) were gathered based on a case-control design. Three-dimensional reconstructions were performed to evaluate the gonial angle, condylar volume, and the distance between the posterior edge of the condyle and the sigmoid notch. Results: The gonial angle was significantly larger (8% difference) in the TMD group with respect to controls, whereas the condylar volume was significantly higher in the control group (15.2% difference). No significant difference was found in the linear distance. Conclusion: There is an association between the presence of TMJ pain and some features of craniofacial morphology. Individuals with TMJ pain have a lower condylar volume and a tendency towards hyperdivergent growth.

This case report describes the use of a miniscrew-assisted rapid palatal expander and aligners to correct bilateral cross-bite and crowding in an adult patient with a Class III skeletal pattern. A digitally designed surgical guide was three-dimensionally printed and used to accurately insert four miniscrews into the palate; these were employed to anchor a novel miniscrew-assisted rapid palatal expander appliance without any dental anchorage. Cone-beam computed tomograms before and after miniscrew-assisted rapid palatal expander treatment demonstrated the orthopedic expansion of the maxilla without dental tipping. The patient was then fitted with aligners to correct crowding and malocclusion. This case report demonstrates the successful treatment of an adult patient with a narrow maxilla and bilateral cross-bite using a nonsurgical, conservative treatment.

Introduction The purpose of this study was to describe the skeletal and dentoalveolar changes in a group of growing skeletal Class III patients treated with hybrid rapid palatal expansion and facemask. Methods Twenty-eight growing patients with skeletal Class III malocclusion were treated using a rapid maxillary expander with hybrid anchorage according to the ALT-Ramec protocol (SKAR III; E.P.), followed by 4 months of facemask therapy. Palatal miniscrew placement was accomplished via digital planning and the construction of a high-precision, individualized surgical guide. Pretreatment and posttreatment cephalometric tracings were analyzed, comparing dental and skeletal measurements. Results Point A advanced by a mean of 3.4 mm with respect to the reference plane Vert-T. The mandibular plane rotated clockwise, improving the ANB (+3.41°) and the Wits appraisal (+4.92 mm). The maxillary molar had slight extrusion (0.42 mm) and mesialization (0.87 mm). Conclusions The use of a hybrid-anchorage expander followed by 4 months of facemask treatment improves the skeletal Class III relationship with minimal dental effects, even in older patients (mean age, 11 years 4 months, ± 2.5 years).

To answer a clinical research question: 'is there any association between features of dental occlusion and temporomandibular disorders (TMD)?' A systematic literature review was performed. Inclusion was based on: (i) the type of study, viz., clinical studies on adults assessing the association between TMD (e.g., signs, symptoms, specific diagnoses) and features of dental occlusion by means of single or multiple variable analysis, and (ii) their internal validity, viz., use of clinical assessment approaches to TMD diagnosis. The search accounted for 25 papers included in the review, 10 of which with multiple variable analysis. Quality assessment showed some possible shortcomings, mainly related with the unspecified representativeness of study populations. Seventeen (N = 17) articles compared TMD patients with non-TMD individuals, whilst eight papers compared the features of dental occlusion in individuals with TMD signs/symptoms and healthy subjects in non-patient populations. Findings are quite consistent towards a lack of clinically relevant association between TMD and dental occlusion. Only two (i.e., centric relation [CR]-maximum intercuspation [MI] slide and mediotrusive interferences) of the almost forty occlusion features evaluated in the various studies were associated with TMD in the majority (e.g., at least 50%) of single variable analyses in patient populations. Only mediotrusive interferences are associated with TMD in the majority of multiple variable analyses. Such association does not imply a causal relationship and may even have opposite implications than commonly believed (i.e., interferences being the result, and not the cause, of TMD). Findings support the absence of a disease-specific association. Based on that, there seems to lack ground to further hypothesise a role for dental occlusion in the pathophysiology of TMD. Clinicians are encouraged to abandon the old gnathological paradigm in TMD practice.

Introduction This case demonstrates that hybrid application of clear aligners can be a rational and efficient approach for treating malocclusions, as compared with a clear aligner therapy alone option in which the magnitude of some movements would require a higher number of aligners and likely further refinement. Treatment plan and progress After a first successful orthopedic phase face mask + rapid maxillary expansion (FM + RME), a diagnostic digital setup of the second orthodontic treatment phase was performed, opting for an esthetic approach to make the treatment as fast and efficient as possible. After positioning lingual tubes on both arches, digital models were obtained and lingual archwires, passing through the previously positioned tubes, were simulated digitally. Then, a virtual setup comprising 10 steps for both arches was planned. Aligners enveloped fixed partial lingual appliances, improving patient comfort and efficiency of overall treatment. Aligners were changed every 7 days and the second phase of treatment was finished in 10 weeks with good occlusion and alignment in both arches. The entire treatment of the Class III patient was completed in 13 months of active therapy. Conclusion Combining clear aligner therapy and fixed lingual appliance is an esthetic means of treating malocclusions in a shorter treatment time with low costs and high efficiency.

Objectives The aim of this study is to investigate and compare the characteristics of as received and retrieved NiTi archwires at a constant temperature by plotting their load/deflection graphs and quantifying three parameters describing the discharge plateau phase. Materials and methods Two hundred four NiTi archwires, traditional and heat-activated, of various cross sections, were obtained from 5 different manufacturers. Specimens prepared from the selected wires were subjected to a three-point bending test where 92 were retrieved through an in vivo retrieval protocol (crowding group C1 and group C2), 56 went through an in vitro retrieval protocol, and 56 were as received. The in vitro retrieval protocol was performed by a gear motor connected to a stainless steel support that performed fatigue cycles to the bent wires in artificial saliva. The load/deflection graphs of as received and retrieved wires were described through three parameters and the results were analyzed with classification and regression trees (CART) and analysis of variance (ANOVA). Results Statistically significant differences between as received and retrieved wires were found only for the parameter plateau slope which represents the constancy of force expressed by the wire. Conclusions The aging of NiTi archwires influences the force constancy expressed. The behavior of the wires changes depending on the size, brand, and type of retrieval protocol. In terms of performance, the poorest is represented by all wires retrieved in vitro and in vivo group C2 (moderate to severe crowding).

Atmospheric particulate is one of the main responsible for the environmental pollution of highly populated cities. The particulate matter can be considered an aerosol of many particles, with different shapes, morphologies and sizes down to few micrometers. These small particles are responsible for climate changes and, when inhaled, can reach the lungs causing respiratory and cardiovascular diseases. Usually commercial sensors are based on passive filters and are designed to measure only particles whose size is below a certain value. Therefore, a measuring system capable of assessing the quality of air and evaluating not only the amount of particles, but also the size distribution of the particulate matter in urban atmospheres could be extremely helpful. This paper describes a simple and cheap optical solution, which is able to detect the total amount of solid pollution particles and classify them according to their average size, giving a fast response to the users.

Objectives: A cross-sectional study was performed to assess the association between possible sleep bruxism (SB) and awake bruxism (AB) with sleep characteristics and chronotype (i.e. circadian cycle preference). Methods: One-hundred-nineteen young adults filled out a self-reported questionnaire to assess SB and AB, a questionnaire about daily life aspects, as well as the Morningness-Eveningness Questionnaire (MEQ) to profile chronotype. Results: The frequency of self-reported SB and AB was 25.2% and 37.0%, respectively. Both SB and AB were significantly more frequent in females than males. Most participants had an intermediate chronotype profile (n = 85; 71.4%). Neither SB (p = 0.556) nor AB (p = 0.334) were associated with chronotype. Nightmares were more prevalent among individuals with possible SB (38.3%). Difficulty concentrating in daily activities was more frequently reported among individuals with AB (51.9%). Conclusion: There was no association between possible SB and AB or the chronotype profiles among Italian dental students.

Summary Background Low-frequency vibrations have been proposed as a means of accelerating tooth movement and reducing orthodontic treatment times. Objective To determine any differences in the accuracy of dental movement in patients treated with a low-frequency vibration aligner protocol and/or by reducing the aligner replacement interval with respect to a conventional protocol. Design This trial was designed as a single-centre, randomized controlled clinical trial. Methods Participants: Patients (aged 27.1 ± 9.0 years) who required orthodontic treatment with aligners. Randomization: Patients were randomly allocated to three arms as determined by a computer-randomization scheme. Group A were assigned a conventional protocol (aligners replaced every 14 days); group B also used a low-frequency vibration device for 20 minutes per day; group C followed the same vibration protocol but replaced their aligners every 7 days. Blinding: The operator who performed the set-up and the one who analysed the data were blinded to the group of the patients. Outcome: Pre- and post-treatment digital models were analysed using VAM software to identify the accuracy/imprecision of dental movements. One-way analysis of variance (P < 0.05) and the Bonferroni post hoc test were used to identify any statistically significant differences between the three arms in terms of the accuracy of tooth movement versus the prescription. Results Numbers analysed: A total of 45 patients (15 for group) were analysed (i.e. 2286 dental movements). Outcome: No statistically significant differences emerged between groups A and C in the upper arch, or among groups A, B, and C in the lower. Group B displayed significantly greater accuracy with respect to group A in upper incisor rotation (P = 0.016), and to group C in vestibulolingual (P = 0.007) and mesiodistal tipping (P = 0.029) of the upper canines, and vestibulolingual tipping of the upper molars (P = 0.0001). Harms: No adverse events or side-effects were registered. Conclusions Considering all tooth and movement types of the 45 participants, the mean total imprecision was 2.1 ± 0.9 degrees, with respect to a mean prescription of 5.7 ± 2.2 degrees. There was no difference in accuracy between replacing the aligners accompanied by low-frequency vibration every 7 days and replacing them every 14 days without vibration. Moreover, low-frequency vibration seemed to improve the accuracy of a conventional protocol in terms of upper incisor rotation. Trial registration The German Clinical Trials Register (DRK00015613).

The analysis of forces, moments and pressure points has long been of great interest in orthodontics. Hence, we set out to define a method for measuring the pressure exerted by aligners on the teeth, and specifically to identify the precise points of pressure exertion. Intraoral scans were performed on a patient with optimal alignment and levelling before and after 2&ordm, vestibularisation of the upper central incisor. Pressure sensor film was placed in a dedicated housing between the aligner and teeth in order to record the pressure exerted after 15 s of aligner application. The images captured by the film were scanned, digitised, and subsequently analysed. Areas and amounts of pressure generated by the aligners were evaluated, and the net force of each was calculated, adjusted to take into consideration passive values. The method revealed the areas of contact by which the aligner transmits force on the teeth, and the pressures at which it does so. The pressure exerted by an aligner is not evenly distributed across the entire surface of the tooth during lingual tipping of an upper incisor. The areas of force concentration were not identical, as these are influenced by factors resulting from the manufacturing and casting processes.

This case report discussed a combined surgical-orthodontic rescue of two impacted teeth in a large dentigerous cyst by the means of fixed orthodontic appliances. After careful evaluation of the 3D radiographic exams, extraction of the deciduous elements was carried out, followed by marsupialization and orthodontic traction of the impacted teeth. Surgical procedures, pre- and posttreatment records and orthodontic biomechanical evaluations are discussed.

Aims To assess the correlation between tooth wear and sleep-time masseter muscle activity (sMMA) in a group of healthy young adults who underwent home electromyographic/electrocardiographic (EMG/ECG) recordings with a portable device. Methods A total of 41 healthy volunteers (23 women, 18 men; mean age 28.8 years, range 25 to 40) with good natural dentition underwent a 2-night in-home evaluation with a portable device that allowed a simultaneous sleep-time recording of EMG signals from both masseter muscles and heart rate. The number of sleep bruxism (SB) episodes per sleep hour (SB index), the number of phasic, tonic, and mixed sMMA events per hour, and the total number of sMMA events per night were calculated. All individuals also underwent an assessment of tooth wear on digital casts with the adoption of a six-degree rating scale. Correlations between sMMA variables and tooth wear were assessed using Pearson test. The null hypothesis was that correlation between the two conditions would not be significant. Results On average, the SB index was 4.5 ± 2.6, while the total number of sleep-time masseter contractions was 97.2 ± 55.2. Of those contractions, almost 60% were phasic. Average tooth wear was 1.5 ± 0.7, with the canines and mandibular incisors showing the highest wear scores. For all pairwise analyses, correlation values were not significant (P values .11 to .69), with r values ranging from 0.064 to 0.253. Conclusion The null hypothesis of an absence of correlation between tooth wear and sMMA could not be rejected, implying that tooth wear cannot be used as an indicator of ongoing SB or sMMA. Future studies taking into account the multifaceted nature of tooth wear and the complex natural course of sleep phenomena are encouraged to investigate the issue further, at the individual level.

Background Contemporary orthodontics involves many potentially hazardous factors, including psychological stress with proven undesirable sequelae. The purpose of this study was to gain more insight into cardiocirculatory dynamics in orthodontists during work time and specifically to investigate the potential hazard of a series of orthodontic-related stressors. Material and methods The study population consisted of 10 orthodontists (five men and five women, aged 32–65; mean 57 ± 12). A 24-hour automatic device was fitted to each orthodontist to monitor blood pressure and heart rate. The parameter used for statistical analysis was myocardial oxygen consumption (MVO2) as the product of heart rate and systolic blood pressure (double product). Results The mean MVO2 percent increase in the entire population of orthodontists during the working day was 25.5 ± 14.1 with a range of 0% to 73%. The mean MVO2 percent increase during operative performances was 29.0 ± 14.1 versus 21.2 ± 13.3 during nonoperative performances; the difference was statistically significant (F = 11.7; P < 0.01). The mean MVO2 percent increase in the presence of parents was 28.5 ± 15.2 versus 22.6 ± 12.4 in the absence of parents; the difference was statistically significant (F = 5.4; P < 0.05). A statistically significant relationship was found between single values of MVO2 percent increases during performances and the degree of patient cooperation (F = 9.4; r = 0.27; P < 0.01). No statistically significant relationship (F = 1.9) was found between single values of MVO2 percent increases during performances and single values of subjective stress experienced by each orthodontist during each performance. Conclusions Routine practice affects the cardiovascular system of orthodontists during the working day. Lack of patient cooperation and psychological pressure from parents in the dental office may have a negative impact on the degree of circulatory dynamics

Background The aim of this study is to evaluate the mechanical properties of the screws used for rapid expansion of the upper jaw. Methods Ten types of expansion screw were assessed, seven with four arms: Lancer Philosophy 1, Dentaurum Hyrax Click Medium, Forestadent Anatomic Expander type “S”, Forestadent Anatomic Expander type “S” for narrow palates, Forestadent Memory, Leone A 2620-10 with telescopic guide, and Leone A 0630-10 with orthogonal arms; and three with two arms: Dentaurum Variety S.P., Target Baby REP Veltri, and Leone A 362113. A test expander with the mean dimensions taken from measurements on a sample of 100 expanders was constructed for each screw. The test expanders were connected to the supports of an Instron 4467 (Instron Corp., USA) mechanical testing machine equipped with a 500 N load cell, and the compression force exerted after each activation was measured. The mean forces expressed by the two- and four-arm expanders were then compared. Results After five activations, the forces expressed by the two-arm devices were double than those expressed by the four-arm devices on average (224 ± 59.9 N vs. 103 ± 32.9 N), and such values remained high after subsequent activations. Conclusions The expanders tested demonstrated stiffness characteristics compatible with opening of the palatine sutures in pre-adolescent patients. The stiffness of such devices can be further increased during the construction phase.

Introduction The aims of this study were to confirm the efficacy of the Bolton index in a group of natural Class I white Italian patients with complete dentition, minimal crowding, and no previous orthodontic treatment, and to evaluate the mesiodistal tooth dimensions with multivariate cluster analysis. Methods Tooth measurements were obtained from a sample of 56 patients with normal occlusion, with a normal Bolton index (22 men, 34 women; mean age, 27.8 years), without previous orthodontic treatment or prosthetic or Class II restorations. Maxillary and mandibular measurements were analyzed separately in the sexes. Clustering was performed using the partitioning around medoid algorithm and principal component analysis-based transformed data. Statistical analysis was conducted. Results The multivariate analysis showed 3 distinct clusters of both maxillary and mandibular tooth measurements in the male and female subjects. Statistically significant differences were found between the sexes in terms of average tooth measurements, and there was significant proportionality between the maxillary and mandibular arch clusters. Conclusion Although the Bolton index is useful for identifying dentodental discrepancies in most patients, cluster analysis enabled the mandibular and maxillary tooth dimensions of the male and female subjects to be divided into 3 general classes (clusters) and the precise location of the discrepancies to be pinpointed.

Introduction Patients with missing upper lateral incisors are challenging to treat and an ideal result does not exist, although there is evidence that good results may be achieved with both canine mesialization and space opening. The aim of this retrospective study was to evaluate if the closure of the spaces in bilateral agenesis of the upper lateral incisors may affect the final upper arch form. Methods The initial and final dental casts of 26 adult patients (20 women and 6 men) with bilaterally missing lateral incisors treated with space closure (study group) were collected by the archives of four different orthodontists and were chosen based on the high-quality final results. Results were compared with those achieved by the same orthodontists on the initial and final casts of 26 adult patients with full dentition (20 men and 6 women) treated without extractions (control group). All upper dental casts were scanned to retrieve arch-forms, determine spatial coordinates, and perform quantitative measurements to interpolate the curves representing the form of the arches. Results Closure space treatment induces great changes in the arch length, no changes in intercanine width, and a little reduction of intermolar distance. When compared with those found in the control group, the final upper arches of the experimental group were flattened in the anterior zone and reduced in the anteroposterior dimension. This result was independent from the technique (type of brackets, prescriptions in the brackets, archwire sequence, archform) used by the four orthodontists who had treated the cases. Conclusions When spaces were closed in cases with bilaterally missing lateral incisors, the anteroposterior dimension suffered the most important modifications.

Resume Objectifs Determiner et comparer la rigidite relative d’un large eventail de fils orthodontiques frequemment utilises. Les fils testes etaient carres et rectangulaires de sections variees en acier, acier supertrempe, NiTi et TMA. Notre objectif etait de fournir aux cliniciens un guide utile et facile a consulter sur le choix des sequences d’arcs. Materiels et methodes Vingt-quatre fils de forme, de section et de materiau differents ont ete selectionnes. Chaque type de fil a ete soumis a un test de pliage a trois points realise 3 fois en utilisant un dynamometre Instron 4467. Chaque echantillon a ete deforme de 1 mm et la charge correspondante a ete enregistree. La rigidite relative de chaque fil echantillon a ete calculee et les echantillons ont ete compares en fonction de leur materiau et de leur section. Resultats Nous avons observe des differences importantes de resistance a la flexion entre tous les arcs testes. Comme prevu, la resistance a la flexion de fils ayant la meme section augmentait avec l’augmentation de la rigidite du materiau dont ils etaient fabriques. Plus precisement, les fils en acier peuvent avoir une rigidite 8 fois plus grande que celle des arcs en NiTi de meme forme et section, et les fils en acier supertrempe sont invariablement plus rigides que les fils en acier traditionnel. Des differences prononcees de resistance a la flexion ont ete relevees aussi entre les arcs en NiTi fabriques avec le meme materiau mais presentant des caracteristiques de forme differentes. Conclusions Pour les fils de meme section, l’acier possede toujours une rigidite plus grande que le TMA ou le NiTi, et l’acier supertrempe est toujours plus rigide que les aciers conventionnels. Quant au fil de meme materiau, la rigidite augmente en fonction de la section, et en particulier de sa hauteur.

Introduction Our objective was to evaluate the efficacy of a fluoridated varnish in preventing white spot lesions in patients with fixed appliances. A laser-induced fluorescence device was used to determine any correlations between the degree of demineralization and the length of the observation period, the arch sector, the frequency of varnish application, and the specific tooth site. Methods A split-mouth study design was used for 24 orthodontic patients, allocated randomly to 2 subgroups with differing frequencies of Duraphat varnish (Colgate-Palmolive, New York, NY) application. Repeated measures of the degree of demineralization were taken on the vestibular surfaces of 12 teeth (6 varnished and 6 unvarnished controls). Measurements were taken at 4 sites using a DIAGNOdent Pen 2190 laser (KaVo, Biberach an der Riss, Germany) and then subjected to statistical analysis. Results Generalized linear model and coefficient model analysis showed differences in the degrees of demineralization between treated and untreated teeth, but this was not statistically significant in terms of time point, frequency of application, or specific tooth site. However, when we analyzed the position of the teeth, the varnished anterior teeth showed a statistically significant reduction in demineralization compared with their unvarnished counterparts. Conclusions Periodic application of fluoride varnish can offer some protection against white spots, but not to a statistically significant degree if the patients have excellent oral hygiene.

Aims: To determine whether there is a correlation between any psychological features and sleep bruxism (SB). Methods: A total of 36 healthy volunteers underwent an in-home evaluation with a portable device combining electromyographic (EMG) and electrocardiographic (ECG) recordings for the diagnosis of SB. They were administered questionnaires that assessed state and trait anxiety levels and coping strategies. The study hypothesis was that the SB index was significantly correlated with an individual's anxiety and coping. Correlation between SB index and psychological features was assessed and a comparison between SB prevalences in subjects with different psychological scores was carried out. Results: Correlation analysis showed that the SB index was not correlated with any of the psychological scales; however, there were some significant correlations (r values range from 0.393 to 0.458) between the SB index and specific items from the trait anxiety and coping scales. Crosstabulations of subjects with SB and with high (overmedian) or low (undermedian) scores for the various psychological measures revealed significant correlations between the prevalence of SB in higher-scoring subjects for state anxiety scores (Phi coefficient = .456; P = .006), trait anxiety scores (Phi = 0.369; P = .027), and social support coping strategy (Phi = 0.387; P = .020). Conclusion: These findings support the study hypothesis only in part and confirm the absence of a clear-cut relationship between SB and psychological features.

Objective: To investigate the stress release properties of four thermoplastic materials used to make orthodontic aligners when subjected to 24 consecutive hours of deflection. Materials and Methods: Four types of aligner materials (two single and two double layered) were selected. After initial yield strength testing to characterize the materials, each sample was subjected to a constant load for 24 hours in a moist, temperature-regulated environment, and the stress release over time was measured. The test was performed three times on each type of material. Results: All polymers analyzed released a significant amount of stress during the 24-hour period. Stress release was greater during the first 8 hours, reaching a plateau that generally remained constant. The single-layer materials, F22 Aligner polyurethane (Sweden & Martina, Due Carrare, Padova, Italy) and Duran polyethylene terephthalate glycol-modified (SCHEU, Iserlohn, Germany), exhibited the greatest values for both absolute stress and stress decay speed. The double-layer materials, Erkoloc-Pro (Erkodent, Pfalzgrafenweiler, Germany) and Durasoft (SCHEU), exhibited very constant stress release, but at absolute values up to four times lower than the single-layer samples tested. Conclusions: Orthodontic aligner performance is strongly influenced by the material of their construction. Stress release, which may exceed 50% of the initial stress value in the early hours of wear, may cause significant changes in the behavior of the polymers at 24 hours from the application of orthodontic loads, which may influence programmed tooth movement.

Introduction The aim of this study was to investigate the vestibular anatomy of teeth in samples of adult Italian and Mozambican subjects in ideal occlusion and permanent dentition and identify any anatomic characteristics that may influence bonding in the straight-wire technique. Methods Linear measurements and coordinates of each curve representing the clinical crown height and width of each tooth were acquired from digital models of each subject categorized to 1 of 2 groups: Italian (18 males, 22 females; mean age, 29.6 ± 5.7 years) or Mozambican (14 males, 15 females; mean age, 23.4 ± 5.9 years). All subjects had normal dentition and no previous orthodontic treatment, fillings, or prostheses. Method error and systematic error were calculated according to the Dahlberg formula (S2 = ∑ d2/2n) and dependent Student t test (P Results Two clusters were identified for the maxillary second premolars and molars in Italian subjects, whereas in the Mozambican subjects, there were 2 clusters for the maxillary first premolars and lateral incisors and 3 clusters for the maxillary canines and central incisors. The mandibular arch was remarkably homogeneous, with only 1 cluster per tooth in each group. In the mandibular arch, statistical differences were recorded between ethnic groups in crown height at the central incisors and second molars and in crown width in the sector from the second premolar to the second molar. Conclusions There were considerable differences both between and within racial groups in crown height, crown width, and numbers of clusters, which should be taken into account during bonding. Although single-bracket placement guides specific for ethnicity may be feasible for the mandibular arch, the significant diversity in number of clusters in the maxillary arch indicates that more accurate bracket placement guides that take into account such heterogeneity are required.

Background To describe an esthetic orthodontic treatment using aligners in an adult patient with class II subdivision associated with crowding and dental crossbite. An 18-year-old hyperdivergent male patient with skeletal class II from mandibular retrusion presented for an orthodontic treatment. Occlusally, the patient presents class II subdivision, crossbite at tooth 4.4, an upper midline deviated towards the left with respect to the lower and facial midlines, and slight crowding in both arches. The patient refused conventional fixed multibracket treatment in favor of aligners. Pre- and post-treatment records as well as 1-year follow-up records are presented. Findings Treatment objectives were achieved in 12 months, and the patient was satisfied with the functional and esthetic outcomes, which were stable at 1 year. Conclusion Combining aligners with appropriate auxiliaries is an efficacious means of resolving orthodontic issues such as class II, dental crossbite, and crowding in a time-frame comparable to that of conventional fixed orthodontics. Furthermore, this system is associated with optimal oral hygiene and excellent esthetics.

Structured AbstractObjectives To investigate possible changes and/or device-related impairments in phonetic habits produced by rapid maxillary expansion (RME). Materials and Methods Thirty-five patients scheduled for RME were divided into two groups: Group A (banded two-arm Hyrax) and Group B (banded four-arm Hyrax). Speech samples were collected at six time points, before, during and after RME removal. Acoustical analysis was performed using PRAAT and BioVoice analysis tools. Ten volunteers completed a questionnaire on the acceptability of patient's speech. Maxillary dimensions and palatal volume were measured on dental casts before and after expansion using a digital gauge. Results Voice analysis showed an increase in the peak frequency of fricative consonants (/s/,/ʃ/) after expansion, whereas there was no change of formant frequencies of palatal consonants (/ɲ/,/ʎ/). Vowel /i/ displayed a lowering of the first formant frequency, and an increase in the second and third formant frequencies. After bonding, Group B showed both a greater reduction in the peak frequency of fricatives and a greater increase in the formant frequencies of palatal consonants than Group A. Conclusion Rapid maxillary expansion causes a slight phonetic change in the acoustical parameters of both consonants and vowels. The two-arm Hyrax caused less speech impairment than the four-arm Hyrax during the treatment.

Purpose To determine the existence of any correlation between the degree of divergence and apical and coronal arch form using cone-beam computed tomography (CBCT). Materials and methods A total of 176 (88 coronal and 88 apical) CBCT scans pertaining to a sample of 44 subjects (16 males and 28 females), of which 26 were Class I, 14 Class II and 4 Class III, were analysed. A lateral projection of the skull was obtained from each VCT and cephalometric tracing was performed (according to Ricketts) so as to divide the sample into subgroups based on the degree of divergence (11 short-faced, 18 norm-faced and 15 long-faced subjects). Dahlberg's index values were calculated and Student's t-test for paired data was applied. Results On the whole, the hyperbolic cosine curve was found to be the most representative of the arch forms considered. Conclusions A correlation between degree of divergence and the arch form of the apical and, especially, coronal portions of both the upper and lower jaws was revealed.

Objective: To conduct an objective assessment of the level of compliance in young patients prescribed various types of removable appliances and to determine the influence of device type, treatment duration, and patient age, gender, psychological maturity, and awareness of monitoring on compliance. Materials and Methods: A total of 30 patients were fitted with either a class 2 (Frankel or bionator) or a class 3 (face mask) removable appliance, each bearing a compliance indicator chip, and they were instructed to wear them for 13 hours per day. Compliance was monitored by means of the sensor for an average of 8 months. Of the patients, 14 were informed that their appliance was fitted with a monitoring sensor, and 16 were not. The psychological maturity of all patients was assessed on the Nowicki-Strickland Locus of Control Scale, and the effect on compliance of this score as well as the patient- and treatment-related variables considered were determined via statistical analysis Results: The mean compliance recorded by the chips was 8.6 ± 2.9 hours, far lower than the 13 hours prescribed, and younger patients showed significantly greater compliance than adolescents (P < .01). However, no significant differences in compliance were found between intra- and extraoral appliances, and neither gender, psychological scores, treatment duration, nor awareness of being monitored had any significant effect. Conclusions: Compliance is generally very poor in young patients, regardless of their gender and psychological maturity. Although awareness of monitoring does not appear to boost compliance, such systems may be a valuable means of providing a dentist with objective information regarding their patients' compliance.

Purpose To present the most frequent occult pathologies unexpectedly encountered via cone-beam computed tomography (CBCT), with particular reference to the diagnostic role of the dentist and that of the radiographer, with a view to clarifying where the diagnostic responsibility lies. Material and methods A narrative literature review on the most diffused occult pathologies under CBCT was conducted, with iconographical guide as an example for each category. Results The most frequent forms of unexpected pathologies encountered are: the presence of foreign bodies, airway anomaly, and the presence of radio-opacity or -transparency in the maxillofacial district. Conclusions The orthodontists must know that they are responsible to recognize these frequent, and potentially serious, pathologies of the head and neck. If the dentist feels unable to take on this responsibility, he or she should, however, be sure to have the scans read by a specialist radiologist.

Background The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures. Methods Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale (“Value” variable) were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients. Results A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p

Background The aim of this study is to investigate the relative stiffness of straight and mushroom lingual archwires of different diameters, cross sections and alloys, plotting their load/deflection graphs and using a modified three-point bending test. Methods Fujita’s mushroom archwires and straight lingual archwires of different diameters, cross sections and alloys were derived by a virtual set-up of an equal malocclusion and were cut at their straight distal portion. These distal portions were tested using a modified three-point bending test by an Instron 4467 dynamometer and the forces, were exerted at 1-mm deflection and were compared on each resulting load/deflection curve by means of ANOVA (p

The aim of this study was to determine whether there is an association between the presence of asymmetric molar or canine Angle classes on the two sides and the presence of temporomandibular joint dysfunction (TMD). Participants to the study were divided into two groups: TMD group (90 patients) or a control group (58 patients). In the TMD group, clinical assessment for TMD was performed according to the Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) guidelines by the same two trained examiners. In both groups, all subjects underwent an assessment of dental occlusion, focusing on the assessment of bilateral canine and molar Angle class relationship. The study protocol was reviewed and approved by the Institutional Review Board of the University of Padova, and each participant gave written consent to take part in the investigation. TMJ pain was diagnosed in 58, disk displacement in 96, arthrosis in 17, and muscle pain in 46 individuals. Molar Angle class was symmetrical in 86 individuals and asymmetrical in 62 subjects. Molar Angle class was not correlated with any of the TMD diagnoses. Canine Angle class was correlated with TMJ arthrosis. Correlation values with the other TMD diagnoses were low and were not significant. It can be suggested that an association between dental Angle class asymmetry and TMDs does not exist and that the role of dental asymmetries as a factor correlated with the presence of TMD signs and symptoms is minimal.

Summary Aims In order to compare the premaxilla and symphysis in Class I and Class III individuals, we measured the following parameters on CBCT scans: incisor inclination, symphyseal morphology, upper alveolar process morphology, symphyseal and maxillary leeway space, as well as anterior and posterior maxillary and mandibular bone thickness at various points below the cementoenamel junction. Materials and methods CBCT scans were taken of 62 individuals (41 females and 21 males) of ages ranging between 11 and 53 years (mean 23.26). The dentoskeletal relationship and alveolar process morphology (thickness) were evaluated on axial slices of the upper and lower jaws, and Student's parametric t-test for paired data was used to compare Class I and Class III values within different facial types. Results Many significant differences in measurements between the two facial types were noted in terms of tooth inclination, alveolar thickness, and leeway space. Conclusions Our findings confirm that Class III patients have little periodontal support at the upper and lower incisors, irrespective of the amount of symphyseal leeway space available, and any tooth movement must therefore be carefully planned and monitored.

Summary Aims To determine and compare the relative stiffness of a large selection of commonly-used square and rectangular steel, super-tempered steel, NiTi, and TMA orthodontic archwires of various cross-sections, in order to provide the clinician with a useful, easy-to-consult guide to archwire sequence selection. Materials and methods Twenty-four archwires of different cross-section shape, size and material were selected. Each type was subjected to a modified three-point bending test, performed in triplicate using an Instron 4467 dynamometer. Each sample was deflected by 1 mm, and the corresponding load recorded. The relative stiffness of each archwire sample was calculated, and samples were compared by material and by cross-section. Results A considerable difference in resistance to deflection was revealed between all the tested archwires. As expected, the resistance to deflection of archwires of the same cross-section was found to increase with increasing stiffness of their construction material. Specifically, steel archwires can be as much as 8 times stiffer than NiTi archwires of the same shape and cross-section, and super-tempered steel archwires are invariably stiffer than traditional steel versions. Marked differences in resistance to deflection were also found between NiTi archwires made of the same material but with different shape characteristics. Conclusions In archwires of the same cross-section, steel is always stiffer than TMA and NiTi, and super-tempered steel is always stiffer than conventional steels. In archwires of the same material, the stiffness increases with the cross-section, in particular with its height.

Background The treatment options for the early treatment of anterior open bite are still controversial. The aim of this study was to evaluate the actual available evidence on treatments of anterior open bite in the mixed dentition in order to assess the effectiveness of the early treatment in reducing open bite, the most efficacious treatment strategy and the stability of the results. Materials and methods A literature survey was done on November 15, 2015, by means of appropriate Medical Subject Headings (MeSH) using the following databases: PubMed, EMBASE, Cochrane Library, LILACS, VHL, and WEB OF SCIENCE. Randomized clinical trials and studies with a control group (treated or untreated) were then selected by two authors. Trials including patients with syndromes or in the permanent dentition and studies concerning treatment with extractions, full-fixed appliances, or surgery were not considered. Full articles were retrieved for abstracts or titles that met the initial inclusion criteria or lacked sufficient detail for immediate exclusion. Results Two thousand five hundred sixty-nine studies about open bite were available; the search strategy selected 240 of them. Twenty-four articles have been judged suitably for the final review, and their relevant data were analyzed. Discussion Although this review confirms the effectiveness of early treatment of open bite, particularly when no-compliance strategies are employed, meta-analysis was unfeasible due to lack of standardization, important methodological limitations, and shortcomings of the studies. Conclusions A more robust approach to trial design in terms of methodology and error analysis is needed. Besides, more studies with longer periods of follow-up are required.

Objectives: To assess if subjects with a clinical diagnosis of temporomandibular disorders (TMDs) have a similar prevalence of orthodontic history as a population of TMD-free individuals and to assess if those subjects who have a history of ideal orthodontics have fewer symptoms than those with a history of nonideal orthodontics. Materials and Methods: Two groups of age- and sex-matched individuals belonging to either a study (“TMD”) or a control group were recruited. Subjects who underwent orthodontic treatment were classified as having a history of ideal or nonideal orthodontics based on the current presence of normal values in five reference occlusal features. Results: The correlation with a history of orthodontic treatment was not clinically significant for any of the TMD diagnoses (ie, muscle pain, joint pain, disc displacement, arthrosis), with Phi (Φ) coefficient values within the −0.120 to 0.058 range. Within the subset of patients with a history of orthodontics, the correlation of ideal or nonideal orthodontic treatment with TMD diagnoses was, in general, not clinically relevant or was weakly relevant. Conclusions: Findings confirmed the substantial absence of clinically significant effects of orthodontics as far as TMD is concerned. The very low correlation values of a negative or positive history of ideal or nonideal orthodontics with the different TMD diagnoses suggest that orthodontic treatment could not have a true role for TMD.