Prog Orthod. 2017 Dec;18(1):26. doi: 10.1186/s40510-017-0178-9. Epub 2017 Sep 11.

ABSTRACT

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 < 0.05).

CONCLUSIONS: Of the nine cleaning strategies examined, only that involving 5 min of ultrasonication at 42 k Hz combined with a 0.3% germicidal cationic detergent was observed to be statistically effective at removing the bacterial biofilm from the surface of F22 aligners.

PMID:28782094 | PMC:PMC5592163 | DOI:10.1186/s40510-017-0178-9

J Clin Orthod. 2017 Apr;51(4):198-207.

NO ABSTRACT

PMID:28652504

Prog Orthod. 2018 Sep 1;19(1):32. doi: 10.1186/s40510-018-0221-5.

ABSTRACT

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.

PMID:30171391 | PMC:PMC6119177 | DOI:10.1186/s40510-018-0221-5

Cranio. 2020 May;38(3):158-167. doi: 10.1080/08869634.2018.1507094. Epub 2018 Aug 14.

ABSTRACT

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.

PMID:30105940 | DOI:10.1080/08869634.2018.1507094

Prog Orthod. 2018 Jul 23;19(1):24. doi: 10.1186/s40510-018-0228-y.

ABSTRACT

BACKGROUND: This study aims to evaluate if invisible orthodontic retainers can affect sleep-time masticatory muscle activity (sMMA) over a short-term period in healthy individuals.

METHODS: Nineteen (N = 19) healthy subjects underwent an in-home evaluation with a portable device for electromyographic (EMG) assessment. The study protocol provided two baseline recording nights, a night off, and then two additional nights with passive customized orthodontic retainers in situ. For each recording night, the sleep bruxism (SB) index (i.e., average number of SB events/hour) and the overall number of masseter muscle contractions were assessed. Comparison between values gathered over the four recording nights was made with a parametric test, based on the null hypothesis that there was no difference between wearing or not wearing the retainers as far as the sMMA variables are concerned.

RESULTS: Average SB index of the first two nights without the retainers was 3.0 ± 1.5, whilst the average values with the retainers in situ was 3.6 ± 1.9. ANOVA test showed the absence of significant differences between the four nights. Similarly, no differences were shown between the four nights as for the total number of sMMA events. Based on that, the null hypothesis was not rejected.

CONCLUSIONS: Findings suggest the absence of relevant effects of invisible orthodontic retainers on sMMA in healthy individuals during the short-term period.

PMID:30033479 | PMC:PMC6055222 | DOI:10.1186/s40510-018-0228-y

J Clin Orthod. 2018 May;52(5):284-296.

NO ABSTRACT

PMID:29952765

Angle Orthod. 2018 Sep;88(5):649-664. doi: 10.2319/111617-790.1. Epub 2018 May 1.

ABSTRACT

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.

PMID:29714067 | PMC:PMC8183134 | DOI:10.2319/111617-790.1

Eur J Orthod. 2019 Aug 8;41(4):444. doi: 10.1093/ejo/cjy084.

NO ABSTRACT

PMID:30649318 | DOI:10.1093/ejo/cjy084

Prog Orthod. 2019 Jan 7;20(1):1. doi: 10.1186/s40510-018-0251-z.

ABSTRACT

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).

PMID:30613836 | PMC:PMC6321830 | DOI:10.1186/s40510-018-0251-z

J Orofac Orthop. 2019 Mar;80(2):57-67. doi: 10.1007/s00056-018-00164-4. Epub 2019 Jan 4.

ABSTRACT

AIMS: 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.

MATERIALS AND METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.

PMID:30610250 | DOI:10.1007/s00056-018-00164-4