Control of anterior anchorage with miniscrews and sliding mechanics in an adolescent with missing second premolars: A clinical report with biomechanical validation.

Congenital missing second premolars in growing patients should be accurately evaluated in order to establish a suitable treatment plan. Concerning the decision of whether to close or maintain spaces in the dental arches, it shall also be based on biomechanical aspects and the aesthetic traits of individual patients. Accordingly, the option of closing tooth spaces requires an adequate application of biomechanical principles aimed at avoiding detrimental effects on dental arches and facial profile. An effective use of titanium miniscrews for immediate loading, associated with efficient sliding mechanics, can represent an elective way to successfully treat such cases. Herein, the objective is to describe the procedure and underscore the advantages of the mentioned approach by presenting a clinical case along with long-term follow-up.

Fluorinated Agents Effects on Orthodontic Alloys: A Descriptive In Vitro Study.

Fluoride-based mouthwashes and gels are preventive measures in countering demineralization and caries but, modifying environmental acidity, can reduce the wet corrosion resistance of orthodontic alloys. To evaluate chemical stability, in vitro experiments were conducted on stainless steel and nickel-titanium wires, weighed before and after immersion in household fluorinated mouthwashes and gels, measuring weight variations and elution of metal ions from acid corrosion phenomena. Elution samples were analyzed by inductively coupled plasma mass spectrometry, detecting residual ion concentration, while surface changes were analyzed under scanning electron microscopy. Results showed stainless steel wires do not undergo significant erosion when exposed to most fluorinated mouthwashes but, at prolonged exposure, alloys elute gradually greater amounts of metals and Ni-Ti wires become more sensitive to some mouthwashes. Ions' elution varies considerably, especially for Ni-Ti wires, if exposed to household fluorinated gels, for which significant negative values were obtained. Changes, affecting wires' outer layer, negatively act on shiny appearance and luster, reducing corrosion resistance. Although examined orthodontic wires showed good chemical stability and low toxicity, surface corrosion from exposure to fluorinated agents was observed. Home use must be accompanied by clinician prescription and, for household dental gels, must follow manufacturers' recommendations, ensuring prophylactic action without damaging alloys surfaces.

Clear Aligner Treatments in Orthoperio Patients.

INTRODUCTION: Orthodontic treatment is a recognized approach to support specific periodontal issues thanks to its capability to manipulate periodontal tissues. This concept is certainly not new, but the use of aligners in certain clinical conditions can be considered as being innovative when a multidisciplinary treatment is necessary. Moreover, aligners enable to plan 3D tooth movements, root placement, staging, and range of dental movements, alongside the improvement of oral hygiene. Thus, aligners can be suitable for the treatment of periodontal issues. In this article, the authors present two clinical cases with different periodontal issues: one with superficial periodontal problems and the other with a deep one. Both cases were successfully treated with aligners, highlighting how this invisible and comfortable tool can simplify the management of complex adult treatments. CONCLUSION: Digital workflow is the key for success in the aligner technique. The possibility to design a virtual plan of treatment and to transfer it in the real clinical world represents a way to limit errors and to reduce the time of orthodontic therapy.

Cone beam CT evaluation of skeletal and nasomaxillary complex volume changes after rapid maxillary expansion in OSA children.

OBJECTIVE: The first objective of this study was to evaluate skeletal changes and changes in dimensions and volume of the upper airways before and after rapid maxillary expansion (RME) therapy in children with obstructive sleep apnoea (OSA), by Cone Beam computed tomography (CBCT). The second objective was to evaluate if RME therapy could improve both the patency of the nasal airways and the Obstructive Sleep Apnoea Syndrome (OSAS). METHODS: 19 children with OSA and malocclusion took CBCT scans with a Dentascan and 3D reconstruction program before (T0) and 4 months after (T1) RME. Patients underwent an ENT visit with auditory and respiratory tests, including a daytime sleepiness questionnaire, a 19-channel polysomnography, and an orthognatodontic examination before orthodontic therapy (T0), after 2 months (T1) with the device still on, and 4 months after the end of the orthodontic treatment (T2). RESULTS: In all cases opening of the mid-palatal suture was demonstrated. Nasal osseous width, volume of the total upper airways, nasal cavity and nasopharynx and oropharynx increased significantly (P, .001). The increased W-ANS, W-mid and WPNS were closed linked to the enlarged midpalatal suture (P, .001). The increased WPNS were closed linked to the enlarged pterygoid processes (P, .001). The increased V-NC and V-NPA was closely linked to the enlarged W-PNS (P, .001) as well as VOPA and consequently to the enlarged midpalatal suture and pterygoid processes. CONCLUSION: RME treatment had a positive effect on children affected by chronic snoring and OSA, causing an increase in volume of the nasal cavity and nasopharynx, with expansion of the nasal osseous width and maxillary width. Enlarged nasal width at the PNS plane contributed to the increase in nasopharynx volume. Enlarged maxillary width showed a direct correlation to increased airways volume, bringing a functional improvement. The results show that the RME therapy can restore and improve a normal nasal airflow with disappearance of obstructive sleep breathing disorder.

Treatment of impacted canines with aligners: An alternative and viable option.

To recover impacted canines without esthetic issues, the aligners can be a resolutive tool allowing by pontics the camouflage of absent canines during orthodontic treatment. Knowledge of biomechanics, correct staging of dental movements, and surgery planification are strategic to achieve a good result.

In Vitro Evaluation of Structural Factors Favouring Bacterial Adhesion on Orthodontic Adhesive Resins.

Bacterial adhesion to the surface of orthodontic materials is an important step in the formation and proliferation of plaque bacteria, which is responsible for enamel demineralization and periodontium pathologies. With the intent of investigating if adhesive resins used for bracket bonding are prone to bacteria colonization, the surface roughness of these materials has been analyzed, combining information with a novel methodology to observe the internal structures of orthodontic composites. Scanning electron microscopy, combined with focus ion bean micromachining and stylus profilometry analyses, were performed to evaluate the compositional factors that can influence specific pivotal properties facilitating the adhesion of bacteria to the surface, such as surface roughness and robustness of three orthodontic adhesive composite resins. To confirm these findings, contact angle measurements and bacteria incubation on resin slide have been performed, evaluating similarities and differences in the final achievement. In particular, the morphological features that determine an increase in the resins surface wettability and influence the bacterial adhesion are the subject of speculation. Finally, the focused ion beam technique has been proposed as a valuable tool to combine information coming from surface roughness with specific the internal structures of the polymers.

SEM characterization and ageing analysis on two generation of invisible aligners.

BACKGROUND: The purpose of the in vitro study is to investigate and compare the morphological features and the chemical stability in weight of two different polyurethane-based blends, Smart Track (LD30) and Exceed30 (EX30), used for orthodontic aligners manufacture before and after the oral usage. METHODS: Twenty orthodontic aligners were randomly selected: 10 LD30 and 10 EX30, each group was divided in two subgroups, never used and intra-orally aged. By the employment of a Stereomicroscope, a section of 5 × 5 mm was cut from the buccal surface of the incisal region of each aligner. All samples were subjected to Scanning Electron Microscopy and Ageing tests in different solutions to simulate the hostility of the oral environment. The statistical method used was t-test. RESULTS: At SEM images, LD30 appears more homogeneous in texture respect to EX30. However, after clinical usage, both materials show significant structural alterations: findings have been supported by higher magnifications at SEM, by which it is clearly to observe many superficial cracks cross through the polymer structures of LD30U, absent in never used samples. LD30U surface becomes also smoother due to the disappearance of most of the conglomerates, but at the same time also rougher while EX30U shows a greater irregularity and porosity in which large and deep cracks are also highlighted. Although these changes occur persistently, in the aging tests no significant weight loss from both materials has been found, confirming the initial hypothesis of a good chemical stability and safety of both polyurethane mixtures even in conditions of severe hostility. CONCLUSION: LD30 is the expression of the technological evolution of EX30, this is made evident above all by its morphological architecture, more homogeneous and defined but also by the chemical stability that can be appreciated even in evident critic situations.

Skeletal changes after rapid maxillary expansion in children with obstructive sleep apnea evaluated by low-dose multi-slice computed tomography.

OBJECTIVE: The objective of this study was to evaluate the skeletal effects of rapid maxillary expansion (RME) therapy performed using teeth as anchors, in obstructive sleep apnea (OSA) children, by low-dose computed tomography (CT) of the midpalatal suture opening, maxillary base width, nasal cavities width, first molar angulation and, unlike most studies in the literature, on the pterygoid processes distance. METHODS: Fourteen children (mean age 8.68 years) with OSA presenting a malocclusion characterized by upper-jaw contraction had 16-Multislice CT (MSCT) scans taken before (T0) and after (T1) RME. All exams were performed using a rigid protocol to ensure reproducibility of image collection over time, with a 16-row MSCT scanner equipped with a Dentascan reconstruction program. Scanning parameters were as follows: scout view in the anteroposterior (AP) and laterolateral (LL); 1.25-mm slice thickness with 0.6-mm collimation from the dentoalveolar and basal areas of the maxilla up to the nasal cavity, parallel to the palatal plane; 80 kV, 100 mA with an 11.25-mm table speed/rotation, rotation time 0.6 s. Matrix size was 512 × 512. RESULTS: Opening of the midpalatal suture was demonstrated in all cases. The results showed statistically significant T0 to T1 increments in all treated cases and clear imaging findings. CONCLUSION: Use of three-dimensional (3D)-CT for follow-up studies requires a very rigid protocol to maintain reproducible positions in the scanner over time. The images confirm the real remodeling of craniofacial structure. However, to be valid such an imaging approach needs great attention to reproducibility of anatomic images over time. The changes in volume of the UA, even with a rigid protocol, cannot be affirmed with 3D-CT. There is a need to improve the definition of markers using this imaging approach when performing longitudinal studies; currently this issue is unresolved.

Facemask performance during maxillary protraction: a finite element analysis (FEA) evaluation of load and stress distribution on Delaire facemask.

BACKGROUND: To evaluate load and stress distribution on Delaire facemask (FM) during maxillary protraction in class III growing patients by means of finite element analysis (FEA). A three-dimensional geometry of a Delaire FM was reconstructed from the original CAD 3D prototype, using software package (ANSYS 5.7). FM presented forehead and chin supports and stainless steel framework characterized by two lateral vertical bars connected to a crossbar with two pawls for elastic attachment. Two traction intensities (7.8 and 9.8 N) were applied on the FM pawls along three different downward inclined directions with respect to the occlusal plane (0°, 30°, or 50°, respectively). Resulting stresses and deformations were then tested through the von Mises yield criterion in order to underline the FM wear performance. RESULTS: The analysis showed that higher stresses and deformations are mostly related to axial forces of 9.8 N rather than 7.8 N. Stresses also progressively increased with increasing downward force inclinations (0°, 30°, and 50° with respect to the occlusal plane). The overall tensions were inferior to the limit of the elastic behavior (yield point) characterizing the material they are applied on. Thus, the FM structure absorbed the load applied with an elastic deformation of the lateral and horizontal bars. CONCLUSIONS: Resulting stresses and deformations were directly proportional to protraction load amounts and to increasing downward inclination of forces. In all tested conditions, protraction forces were not able to determine plastic deformation on FM structure compromising its performance and efficiency.

Use of clear aligners in open bite cases: an unexpected treatment option.

In open bite case treatments, a proper diagnostic differentiation is essential in determining the appropriate corrective procedures. Dental open bites are generally more responsive to treatment with orthodontics alone, whereas skeletal open bites often require a combination of orthodontics and orthognathic surgery. Patient selection and treatment principles for non-surgical open bite treatment routinely include fixed appliances both labial or lingual. However, removable clear aligners have gained a consistent popularity in the treatment of complex cases including open bite malocclusions. In this article, the authors describe three different clinical cases in which open bite cases had been satisfactorily treated by using clear aligners.

Management of missing second premolars using miniscrews: an elective solution for critical anchorage conditions.

Growing patients with congenital missing second premolars should be accurately evaluated in order to establish an appropriate treatment plan. The decision whether to close or maintain spaces in dental arches caused by missing teeth should be based on the consideration of biomechanical factors and the aesthetic traits of individual patients. Accordingly, the choice of closing spaces requires an adequate consideration of biomechanical principles in order to avoid detrimental effects on the occlusion and profile. The effective use of titanium miniscrews for immediate loading, combined with efficient sliding mechanics, represents an elective way of successfully treating such cases. The aim of this article is to describe the procedure and highlight its advantages by giving details of a clinical case coupled with the results of a long-term follow-up.

Lower incisor extraction treatment with the Invisalign® technique: three case reports.

The extraction of a lower incisor can lead to satisfactory orthodontic results for patients with moderate to severe lower incisor crowding. Invisalign(®) is a treatment modality for such treatments, moving teeth with precision and reducing inconvenience for the patient. Three case reports are presented in this article supporting the above statements.

Invisalign technique in the treatment of adults with pre-restorative concerns.

The Invisalign method is gaining an increasing interest as an alternative treatment option in adult patient in multidisciplinary complex cases to simplify the treatment plan. The aim of this work is to show the importance of planning a multidisciplinary approach to respond at the esthetic requests of adult patients and to treat complex cases with high predictability.