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J Clin Orthod. 2020 Feb;54(2):82-95.

NO ABSTRACT

PMID:32554910

J Esthet Restor Dent. 2020 Oct;32(7):634-637. doi: 10.1111/jerd.12618. Epub 2020 Jul 9.

ABSTRACT

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.

PMID:32643229 | DOI:10.1111/jerd.12618

J World Fed Orthod. 2020 Mar;9(1):32-43. doi: 10.1016/j.ejwf.2020.01.001. Epub 2020 Feb 12.

ABSTRACT

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.

PMID:32672666 | DOI:10.1016/j.ejwf.2020.01.001

Int Orthod. 2020 Dec;18(4):850-862. doi: 10.1016/j.ortho.2020.08.006. Epub 2020 Sep 15.

ABSTRACT

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.

PMID:32948482 | DOI:10.1016/j.ortho.2020.08.006

Orthod Craniofac Res. 2021 May;24(2):251-260. doi: 10.1111/ocr.12427. Epub 2020 Oct 15.

ABSTRACT

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 21 years ± 0.25) and FAs (13 patients; 8 females and 5 males; mean 14 years ± 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 1 month (T1), 3 months (T3) and 6 months (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 6 months of treatment in the FA group. Unlike red complex species, C rectus and F nucleatum 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.

PMID:32965768 | DOI:10.1111/ocr.12427

Int Orthod. 2020 Dec;18(4):809-819. doi: 10.1016/j.ortho.2020.08.005. Epub 2020 Sep 28.

ABSTRACT

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 (2.0mm and 2.3mm) and five different lengths (9mm, 11mm, 13mm and 15mm) were tested at different angles of insertion (90° and 45°) and distances from a synthetic bone block (3mm, 5mm, 7mm). 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 2.3mm than those of 2.0mm, 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.

PMID:33004287 | DOI:10.1016/j.ortho.2020.08.005

Eur J Dent Educ. 2021 Aug;25(3):621-633. doi: 10.1111/eje.12640. Epub 2020 Dec 14.

ABSTRACT

INTRODUCTION: The outbreak and diffusion of the novel SARS-CoV2 coronavirus have caused an emergency status in the dental education system.

MATERIALS AND METHODS: An anonymous survey composed of 34 questions was delivered to students of the Master Degree Programme in Dentistry and Dental Prosthodontics of the Universities of Emilia-Romagna, the fifth Italian region most affected by the pandemic. The psychological impact of COVID-19 was assessed by means of the Generalised Anxiety Disorder-7 scale (GAD-7). Numerically recoded data were analysed using the Analysis of Variance (ANOVA), whilst to investigate the association between quantitative variables, the Pearson correlation coefficient (R) was computed.

RESULTS: The questionnaire was completed by 399 students (75%) out of 532. Most students experienced difficulties in working at the thesis during the COVID-19 emergency. For over half of them, online teaching could only partially replace traditional face-to-face lessons. The negative impact on the study career was judged as particularly high by sixth-year students. Clinical training activities were considered as exposing to the risk of contracting COVID-19 infection by the majority of the students. The level of concern of contracting COVID-19 infections during future university activities was positively correlated to risk perception related to clinical training.

CONCLUSION: The results of this survey could be used to train students to a correct risk assessment. Students reported experiencing concern whilst thinking of COVID-19 and 6.5% of them showed symptoms related to high levels of anxiety. These data may guide Universities in trying to reduce students’ anxiety by means of correct communication strategies.

PMID:33269536 | PMC:PMC7753295 | DOI:10.1111/eje.12640

Angle Orthod. 2021 Jan 1;91(1):129-137. doi: 10.2319/050520-394.1.

ABSTRACT

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.

PMID:33289804 | PMC:PMC8032276 | DOI:10.2319/050520-394.1

J Clin Orthod. 2020 Nov;54(11):690-704.

NO ABSTRACT

PMID:33476295

BMC Oral Health. 2021 Feb 25;21(1):87. doi: 10.1186/s12903-021-01443-0.

ABSTRACT

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.

PMID:33632190 | PMC:PMC7908704 | DOI:10.1186/s12903-021-01443-0