Single tooth torque correction in the lower frontal area by a completely customized lingual appliance

Abstract Background The aim of the study was to evaluate the efficacy of a novel en masse distalization method in the maxillary arch in combination with a completely customized lingual appliance (CCLA; WIN, DW Lingual Systems, Germany). Therefore, we tested the null-hypothesis of a significant deviation from an Angle-Class I canine relationship and a normal overjet defined by an individual target set-up after dentoalveolar compensation in Angle Class II subjects. Methods This retrospective study included 23 patients, (m/f 3/20, mean age 29.6 years (min/max, 13.6/50.9 years)), with inclusion criteria of an Angle Class II occlusion of more than half a cusp prior to en masse distalization and treatment completed consecutively with a CCLA in combination with a mini-screw (MS) anchorage for uni- or bilateral maxillary distalization (12 bilateral situations, totalling 35). Plaster casts taken prior to (T0) and following CCLA treatment (T3) were compared with the treatment plan / set-up (TxP, with a Class I canine relationship and a normal overjet as the treatment objective). MSs were placed following levelling and aligning (T1) and removed at the end of en masse distalization at T2. Statistical analysis was carried out using Schuirmann’s TOST [two one-sided tests] equivalence test, based on a one-sample t-test with α = 0.025 on each side (total α = 0.05). Results Ninety-seven percent of planned correction of the canine relationship was achieved (mean 3.6 of 3.7 mm) and also 97 % of the planned overjet correction (mean 3.1 of 3.2 mm), with a statistically significant equivalence (p < 0.0001) for canine relationship and overjet between the individual treatment plan (set-up) and the final outcome. Adverse effects were limited to the loss of n = 2 of 35 mini-screws. However, in each instance, the treatment was completed, as scheduled, without replacing them. Accordingly, the null-hypothesis was rejected. Conclusions The technique presented allows for a predictable correction of an Angle-Class II malocclusion via dentoalveolar compensation with maxillary en masse distalization.

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A Clinical Study on Acuris™ - Conometric Concept for Single Tooth Restoration

Case Medical Research ◽

10.31525/ct1-nct04063878 ◽

2019 ◽

Author(s):

Keyword(s):

Clinical Study ◽

Single Tooth

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The frontal longitudinal system as revealed through the fiber microdissection technique: structural evidence underpinning the direct connectivity of the prefrontal-premotor circuitry

Journal of Neurosurgery ◽

10.3171/2019.6.jns191224 ◽

2020 ◽

Vol 133 (5) ◽

pp. 1503-1515 ◽

Cited By ~ 3

Author(s):

Spyridon Komaitis ◽

Aristotelis V. Kalyvas ◽

Georgios P. Skandalakis ◽

Evangelos Drosos ◽

Evgenia Lani ◽

...

Keyword(s):

Primary Motor Cortex ◽

Premotor Cortex ◽

Frontal Area ◽

Frontal Pole ◽

Fiber System ◽

Dorsolateral Prefrontal ◽

Anterior Extension ◽

Brodmann Areas ◽

Longitudinal Fiber ◽

Long Fibers

OBJECTIVEThe purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS).METHODSFifteen normal adult formalin-fixed cerebral hemispheres collected from cadavers were studied using the Klingler microdissection technique. Lateral to medial dissections were performed in a stepwise fashion starting from the frontal area and extending to the temporoparietal regions.RESULTSThe FLS was consistently identified as a fiber pathway residing just under the superficial U-fibers of the middle frontal gyrus or middle frontal sulcus (when present) and extending as far as the frontal pole. The authors were able to record two different configurations: one consisting of two distinct, parallel, longitudinal fiber chains (13% of cases), and the other consisting of a single stem of fibers (87% of cases). The fiber chains’ cortical terminations in the frontal and prefrontal area were also traced. More specifically, the FLS was always recorded to terminate in Brodmann areas 6, 46, 45, and 10 (premotor cortex, dorsolateral prefrontal cortex, pars triangularis, and frontal pole, respectively), whereas terminations in Brodmann areas 4 (primary motor cortex), 47 (pars orbitalis), and 9 were also encountered in some specimens. In relation to the SLF system, the FLS represented its anterior continuation in the majority of the hemispheres, whereas in a few cases it was recorded as a completely distinct tract. Interestingly, the FLS comprised shorter fibers that were recorded to interconnect exclusively frontal areas, thus exhibiting different fiber architecture when compared to the long fibers forming the SLF.CONCLUSIONSThe current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.

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