Abstract:Even though few technological advancements have occurred in Orthodontics recently, the search for more efficient treatments continues. This paper analyses how to accelerate and improve one of the most arduous phases of orthodontic treatment, i.e., correction of the curve of Spee. The leveling of a deep curve of Spee can happen simultaneously with the alignment phase through a method called Early Vertical Correction (EVC). This technique uses two cantilevers affixed to the initial flexible archwire. This paper … Show more
“…15 To counteract this flaring, a rectangular archwire can be applied for leveling after the crowded teeth are aligned. 16 , 17 The amount of incisor intrusion should be introduced little by little to avoid any heavy force.…”
Objective: To determine whether separating the alignment and leveling phases can reduce proclination of the mandibular incisors. Methods: Eligibility criteria included Class I subjects with an irregularity index of 3-5 mm, 3-4 mm curve-of-Spee (COS), and non-extraction treatment. Thirty adults were randomly allocated into two groups: (1) Control group was leveled and aligned simultaneously with flat archwires progressively to 0.016x0.022-in stainless-steel; (2) Experimental group was aligned first with 0.014-in-superelastic NiTi with mild accentuated COS, then leveled using 0.016x0.022-in beta-titanium accentuated COS archwires and gradually reduced the curve until flat. Mandibular incisor position and inclination were evaluated by cephalometric analysis. COS and irregularity index were evaluated in study models. Assessment was conducted twice after 0.016-in NiTi and after 0.016x0.022-in stainless-steel archwire placements. Dental changes from cephalograms and models were compared within group using paired t-test and between groups using independent t-test. Results: Control group: Round-wire-phase, mandibular incisors tipped labially (4.38° and 1 mm) with intrusion (-1.13 mm); Rectangular-wire-phase, mandibular incisors further intruded and proclined (-0.63 mm and 1.38°). Experimental group: During aligning with round accentuated COS archwires, mandibular incisors tipped very slightly labially (0.75° and 0.50 mm) with no significant intrusion; during leveling with rectangular archwires, incisors majorly intruded (1.75 mm) with slight proclination (1.81°). The experimental group had significant less incisor proclination (control: 5.76°, experimental: 2.56°) with more incisor intrusion (control: -1.75 mm, experimental: -2.13 mm). The COS in experimental group showed significant greater reduction (-2.88 mm) than that of the control group (-1.69 mm). Conclusion: In control group, mandibular incisor proclination was markedly observed in round archwires, with further proclination caused by rectangular archwires. In experimental group, minimal proclination was exhibited when accentuated COS round archwires were used for aligning. Leveling with rectangular archwires caused less proclination with more COS reduction.
“…15 To counteract this flaring, a rectangular archwire can be applied for leveling after the crowded teeth are aligned. 16 , 17 The amount of incisor intrusion should be introduced little by little to avoid any heavy force.…”
Objective: To determine whether separating the alignment and leveling phases can reduce proclination of the mandibular incisors. Methods: Eligibility criteria included Class I subjects with an irregularity index of 3-5 mm, 3-4 mm curve-of-Spee (COS), and non-extraction treatment. Thirty adults were randomly allocated into two groups: (1) Control group was leveled and aligned simultaneously with flat archwires progressively to 0.016x0.022-in stainless-steel; (2) Experimental group was aligned first with 0.014-in-superelastic NiTi with mild accentuated COS, then leveled using 0.016x0.022-in beta-titanium accentuated COS archwires and gradually reduced the curve until flat. Mandibular incisor position and inclination were evaluated by cephalometric analysis. COS and irregularity index were evaluated in study models. Assessment was conducted twice after 0.016-in NiTi and after 0.016x0.022-in stainless-steel archwire placements. Dental changes from cephalograms and models were compared within group using paired t-test and between groups using independent t-test. Results: Control group: Round-wire-phase, mandibular incisors tipped labially (4.38° and 1 mm) with intrusion (-1.13 mm); Rectangular-wire-phase, mandibular incisors further intruded and proclined (-0.63 mm and 1.38°). Experimental group: During aligning with round accentuated COS archwires, mandibular incisors tipped very slightly labially (0.75° and 0.50 mm) with no significant intrusion; during leveling with rectangular archwires, incisors majorly intruded (1.75 mm) with slight proclination (1.81°). The experimental group had significant less incisor proclination (control: 5.76°, experimental: 2.56°) with more incisor intrusion (control: -1.75 mm, experimental: -2.13 mm). The COS in experimental group showed significant greater reduction (-2.88 mm) than that of the control group (-1.69 mm). Conclusion: In control group, mandibular incisor proclination was markedly observed in round archwires, with further proclination caused by rectangular archwires. In experimental group, minimal proclination was exhibited when accentuated COS round archwires were used for aligning. Leveling with rectangular archwires caused less proclination with more COS reduction.
“…In an attempt to decrease the prolonged orthodontic procedure, it was suggested that auxiliary intrusion arches or cantilever springs are combined with resilient archwires during initial stage of treatment. 24 .…”
Deep overbite is a challenging malocclusion facing orthodontists and numerous treatment options were proposed to correct it. The intrusion of lower incisors is found to be particularly practical in patients with adequate upper incisor display. Aim of the study: The purpose of this study is to compare deep overbite correction using auxiliary cantilever springs to relative intrusion during initial stages of orthodontic treatment. Materials and methods: Thirty patients exhibiting deep overbite malocclusion were divided into test and control groups. Test group received auxiliary cantilever springs on top of leveling arches to intrude lower incisors. Control group received sequential leveling arch wires. Treatment effect was evaluated after six months by using lateral cephalometric radiographs to assess incisors, molars and premolars changes. Comparison between T0 (preoperative) and T1 (6 months postoperative) within each group was done using paired samples T-test, while comparison of mean difference of different parameters between both groups was done using Mann-Whitney U test. Results: A mean overbite reduction of 3.2 mm was found in the experimental group. Incisor intrusion was found to be significant in the test group with a mean of -1.33 and -1.31 when measured from center of resistance and apex. Distal tipping of lower 1 st molars was significant in the experimental group (P<0.001) while premolar extrusion was more significant in the control one. Conclusion: Deep bite correction can be achieved during the leveling and alignment phase using cantilever springs with lower incisors intrusion without significant difference in labial tipping other than that created by relative intrusion with continuous sequential archwires.
“…Management of deepbite becomes more difficult with the existence of, or the increased severity of, an underlying skeletal discrepancy. Nonsurgical correction of a deep bite includes molar extrusion, incisor intrusion, or a combination of both, [3,4] with a general understanding that intrusion of teeth is more difficult than extrusion.…”
Objective: To evaluate the effects of anterior bite plane on the masseter and geniohyoid muscle thickness.
Materials and Methods: 14 subjects who needed bite opening were allocated as a single group with mean age of 17.4± 3.4 years and mean overbite of 5.3±0.2 was treated with a fixed anterior bite plane (ABT). The pre-treatment (T1) and post-treatment results (T2) was compared to study the effect of Bite opening. The ultrasonographic imaging was used to evaluate masseter muscle thickness (clenched and relaxed) and geniohyoid muscle thickness.
Results: The study showed, the right masseter muscle thickness (RMT) in (R) at T1 was 8.68 ± 1.13 mm, T2 was 7.68 ± 1.14 mm and in (C) 0.72 ± 1.39 mm and 9.86 ± 1.35 mm respectively While left muscle thickness (LMT) was at 8.54 ± 1.3 mm and 7.68 ± 1.3 mm respectively. The mean geniohyoid muscle thickness before treatment was 6.58 ±0.69 mm and after treatment was 7.40 ± 0.69 mm with an increase in thickness of 0.8 ±0.04 mm.
Conclusion: Bite opening procedure influence the muscles thickness, with reduction of masseter muscle thickness and increase in geniohyoid muscle thickness.
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