Blog

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

Korean J Orthod. 2021 Mar 25;51(2):135-141. doi: 10.4041/kjod.2021.51.2.135.

ABSTRACT

OBJECTIVE: To assess the effects of thermoforming on aligner thickness and gap width in six aligner systems with the same nominal thickness.

METHODS: Six passive upper aligners of different brands were adapted to a single printed cast. Each sample was evaluated with high-resolution micro-computed tomography. To investigate aligner thickness and gap width, two-dimensional (2D) analysis was conducted assessing the effects of the following variables: tooth type (central incisor, canine, and first molar), 2D reference points, and aligner type. Data were analyzed and compared using analysis of variance and Tukey’s post-hoc tests (p < 0.05).

RESULTS: Tooth type, dental region, and aligner type affected both the gap width and aligner thickness. The aligner thickness remained moderately stable across the arch only in the F22.

CONCLUSIONS: All thermoformed samples displayed smaller aligner thickness and gap width at anterior teeth and both gingival and coronal centers than at posterior teeth and occlusal surfaces.

PMID:33678629 | PMC:PMC7940810 | DOI:10.4041/kjod.2021.51.2.135

Int Orthod. 2021 Jun;19(2):235-242. doi: 10.1016/j.ortho.2021.03.002. Epub 2021 Mar 27.

ABSTRACT

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 Grünheid 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.

PMID:33785290 | DOI:10.1016/j.ortho.2021.03.002

J Clin Orthod. 2021 Jan;55(1):69-70.

NO ABSTRACT

PMID:33822764

Angle Orthod. 2021 Sep 1;91(5):641-649. doi: 10.2319/092720-823.1.

ABSTRACT

OBJECTIVES: To compare the degree of accuracy of the Face Hunter facial scanner and the Dental Pro application for facial scanning, with respect to both manual measurements and each other.

MATERIALS AND METHODS: Twenty-five patients were measured manually and scanned using each device. Six reference markers were placed on each subject’s face at the cephalometric points Tr, Na’, Prn, Pog’, and L-R Zyg. Digital measurement software was used to calculate the distances between the cephalometric reference points on each of the scans. Geomagic X Control was used to superimpose the scans, automatically determining the best-fit alignment and calculating the percentage of overlapping surfaces within the tolerance ranges.

RESULTS: Individual comparisons of the four distances measured anthropometrically and on the scans yielded an intraclass correlation coefficient index greater than .9. The t-test for matched samples yielded a P value below the significance threshold. Right and left cheeks reached around 60% of the surface, with a margin of error between 0.5 mm and -0.5 mm. The forehead was the only area in which most of the surface fell within the poorly reproducible range, presenting values out of tolerance of more than 20%.

CONCLUSIONS: Three-dimensional scans of the facial surface provide an excellent analytical tool for clinical evaluation; it does not appear that one or the other of the measuring tools is systematically more accurate, and the cheeks are the area with the highest average percentage of surface in the highly reproducible range.

PMID:33826690 | PMC:PMC8376172 | DOI:10.2319/092720-823.1

Insects. 2021 May 13;12(5):446. doi: 10.3390/insects12050446.

ABSTRACT

Xylella fastidiosa subsp. pauca, strain CoDiRO is the bacterium responsible for the onset of the disease known as the olive quick decline syndrome, which has been causing a phytosanitary and economic emergency in the Apulia region since 2013. To date, three insect species have been identified as pathogenic carriers of X. fastidiosa. With the advancement of the infection front, and the possibility of pathogenic insects being “hitchhiked” over long distances, the monitoring of the vectors of X. fastidiosa in the Italian regions bordering Apulia is an increasingly contingent issue for the rapid containment of the bacterium and the protection of the olive-growing heritage. Accordingly, the present research concerned the capture and recognition of the vector insects of X. fastidiosa in the upper Ionian coasts of Calabria (Italy) to evaluate the possible presence of the bacterium through molecular diagnostic techniques. The sampling allowed us to ascertain the presence of Philaenus spumarius and Neophilaenus campestris and their preferential distribution in olive groves and meadows, whereas all the 563 individuals tested negative for the pathogen.

PMID:34068247 | PMC:PMC8153157 | DOI:10.3390/insects12050446

J Orofac Orthop. 2022 Jan;83(1):13-22. doi: 10.1007/s00056-021-00314-1. Epub 2021 Jun 29.

ABSTRACT

INTRODUCTION: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.

PMID:34185103 | DOI:10.1007/s00056-021-00314-1

J Clin Orthod. 2021 May;55(4):265-282.

NO ABSTRACT

PMID:34464330

J Clin Orthod. 2021 Jun;55(6):343-353.

NO ABSTRACT

PMID:34464346