Root resorption in relation to a modified piezocision technique

ABSTRACT Objectives To evaluate root resorption of lower incisors and canines quantitatively in a group of patients who underwent orthodontic treatment with piezocision and/or a collagen reinforcement technique with a fully resorbable three-dimensional (3D) collagen xenograft matrix compared with a control group. Materials and Methods The study sample of this secondary analysis consisted of 32 periodontally healthy patients with angle Class I malocclusion or mild Class II or III malocclusion and moderate irregularity index scores who underwent orthodontic treatment and had before (T0) and after treatment (T1) cone-beam computed tomography scans. Root resorption of lower incisors and canines was assessed quantitatively in the following four groups: the control group received orthodontic treatment without piezocision, experimental group 1 received orthodontic treatment with piezocision, experimental group 2 received orthodontic treatment with piezocision and a 3D collagen matrix, and experimental group 3 received orthodontic treatment with a 3D collagen matrix. Results An overall statistically significant decrease in root length from T0 to T1 for all groups was observed (P < .05). However, there was no significant difference among the groups in the amount of root length decrease from T0 to T1. Conclusions Orthodontic treatment combined with piezocision does not increase the risk of root resorption of lower incisors and canines when compared with orthodontic treatment without acceleration techniques. More studies with larger samples should be undertaken to confirm these results.

Effects of long-term use of the lower lingual arch from 8.5 years to 13.2 years

ABSTRACT Objectives To investigate the effects of long-term use of the lower lingual arch (LLA) on the sagittal and vertical positions of the permanent lower incisors and first molars. Materials and Methods The sample consisted of 98 patients who were treated with an LLA (LLA group) and 39 patients who were treated without an LLA (no-LLA group). The positional changes of the lower incisors and first molars were analyzed after performing mandibular structural superimpositions on lateral cephalometric radiographs taken before treatment (T1) and at the end of LLA therapy (T2). The mean ages at T1 and T2 were 8.5 years and 13.2 years, respectively. Study casts were analyzed to quantify arch dimensional changes. Results Mesial movement of the lower molar cusp was similar between the LLA and no-LLA groups, but the vertical position was slightly greater at T2 in the LLA group. In the LLA group, there was a molar tip-back effect, and the lower incisors were proclined 4.2° more than in the no-LLA group. Arch perimeter decreased 3.6 ± 2.6 mm without an LLA and 0.97 ± 3.7 mm with an LLA. Intercanine and intermolar widths both increased about 1 mm more with an LLA (P < .0001). Conclusions The LLA does not seem to restrict mesial movement and vertical eruption of the lower incisors and molars in the long term. The LLA effectively preserves the arch perimeter at the expense of a slight lower incisor proclination.

EVALUATION OF ROOT CANAL OBTURATION RESULTS WITH THE CANAL SHAPING SYSTEM WAVE ONE AND GUTTA THERMAFIL

Objective: To evaluate the results of root canal obturation with Wave One (WO) canal shaping system and Gutta Thermafil obturation system. Design: Nonrandomized prospective experimental trial between December 2020 and March 2021. Setting: Central Military Hospital 108. Subject: 30 lower incisors extracted teeth without stem rupture, without root damage such as fracture, stray, fissure. Results: The number of slices with the biggest gaps accounting for 16.7%. The number of slices with the smallest gaps accounting for 10%. The number of slices with gaps over the total slices accounted for 14.4%. The void area in the apical slice was 1,413 ± 519.5 µm2 and the largest void area was 38,654.2 ± 3,939.8 µm2. Conclusion: Thermafil Gutta Percha has a good fit to the canal wall, which can seal the canal more easily and accurately.

Assessment of the shaping ability of three systems used in long oval canals

The aim of this study was to analyze volume variation, untouched walls, transportation, and centralization in long oval canals prepared with ProTaper Next (PTN), X File (XF) and X Gray (XG) by microcomputed tomography (micro-CT). Forty-five lower incisors were divided into three groups (PTN, XF and XG) with 15 specimens each, according to the micro-CT pre-instrumentation (PI) analysis. After the use of each instrument new exams were performed. Volume variation and untouched walls data were analyzed by two-way ANOVA, and for the first one, Tukey HSD or Games-Howell tests were applied in the sequence; data of transportation and centralization were compared by Kruskal-Wallis and Mann-Whitney test. The statistical significance was set at p < 0.05. Between thirds, higher wear values were found in the cervical (p <0.001). PI and the instrument X3 (30/.07) differed in all systems (p < 0.05). No significant difference concerning the percentage of untouched walls between the systems occurred (p = 0.836), while the degree of transportation and centralization was similar between then, with p values of 0.531 and 0.155, respectively. However, between thirds, significant difference was found (pc = 0.029), with the middle third presenting superior centralization than the apical (p = 0.010). In conclusion, PTN, XF and XG had similar results in the shaping ability, transportation, and centralization of long oval canals.

The efficiency of mandibular mini-implants in reducing adverse effects of class II elastics in adolescent female patients: a single blinded, randomized controlled trial

Background Excessive proclination of lower incisors and other undesirable consequences usually result from the use of class II elastics during orthodontic treatment. The purpose of this study was to attempt to limit the adverse effects of class II elastics by the use of mini implants placed in the mandibular arch in adolescent class II female patients. Methods The sample comprised 28 patients, (a mean age of 15.66 ± 2 years for intervention group and 15.1 ± 2.2 years for conventional group) with one-fourth or one-half unit class II canine relationship. The sample was divided into two equal groups. Randomization was carried out by a computer sequence generator with a 1:1 allocation ratio. In the intervention group, the mini implants were inserted between the lower second premolar and first molar, while the conventional group underwent regular class II elastics therapy. The active elastics treatment time was 8 months for both groups. Results were assessed by measurements from pre- and post-elastics lateral cephalometric radiographs. Results The change in L1 inclination (0.97 ± 0.92°) and L1 AP position (0.31 ± 0.63 mm) did not show a statistically significant difference between the two groups, but a statistically significant difference was found in the U1 retroclination (5.23 ± 1.92°) and U1 distal movement (4.05 ± 1.4 mm) [P ˂ 0.001] and [P ˂ 0.05] respectively in favor of the intervention group. Conclusion Mini-implants in conjunction with class II elastics had no skeletal effect, mainly dentoalveolar and it did not prevent the proclination of lower incisors. There was more distal movement in the upper incisors in the skeletal anchorage group which helped in enhancing the camouflaging of class II malocclusion. Trial registration Trial registered “FUE.REC (10)/10-2018” at the FUE registration council for clinical trials/IOP Orthodontic Program October 2018.

Precision bite ramps and aligners: An elective choice for deep bite treatment

Objective: To review a series of clinical studies demonstrating the clinical efficiency of aligners with bite ramps in the treatment of severe deep bite. Materials and Methods: In order to predictably manage the correction of deep bite with aligners, precision bite ramps on maxillary incisors have been used while posterior extrusion and anterior intrusion in the lower jaw with lateral attachments and proper levelling of the curve of Spee have been planned. Transverse correction and controlled upper and lower incisors proclination completed the treatment plan. Results: Full deep bite correction with normal overbite was obtained in nine months of treatment by a combination of anterior intrusion and posterior torque correction, distal tipping and relative extrusion. Conclusion: The use of bite ramps represents a valid option for the successful treatment of deep bite with aligners creating proper space for lateral sector extrusion and supporting lower anterior intrusion and controlled proclination.

Personalized Orthodontics: From the Sagittal Position of Lower Incisors to the Facial Profile Esthetics

Background: One of the goals of orthodontic treatment is to obtain maximum facial harmony. The sagittal position of the lower incisors plays a significant role in the planning of orthodontic treatment. The aim of the study was to evaluate the relationship between the sagittal position of lower incisors and facial profile esthetics with reference to the skeletal vertical dimension. Methods: There were 200 patients included in the study. Patients were allocated into three groups, depending on the vertical growth pattern: normal-angle, low-angle, and high-angle cases. Tweed–Merrifield cephalometric analysis was used to assess the sagittal and vertical position of the mandible, as well as to assess the sagittal position of the lower incisors. Results: Z-angle and Frankfort mandibular incisor plane angle (FMIA) decreased significantly (p < 0.001) with the increase of the skeletal vertical dimension. Incisor mandibular plane angle (IMPA) was significantly higher (p < 0.001) in low-angle patients compared to the high-angle ones. Z-angle appeared to be the most accurate parameter (area under curve, AUC = 0.957) describing patients with a convex profile. The cutoff value of Z-angle 68.0° was characterized by the sensitivity of 94.1% and the specificity of 84.3%. Conclusions: The sagittal position of the lower incisors significantly affects the facial profile convexity. The Z-angle is the parameter which most accurately describes the patients with a convex profile.

A influência de diferentes cimentos de obturação de canal na infiltração apical

It is an "in vitro" study to evaluate the sealing ability of 3 root canal sealers using a dye leakage/clearing method. 40 lower incisors were instrumented by the step-back technique and divided into 4 groups. The teeth were filled with lateral condensation of guta-percha varying the root canal sealer. Fill Canal, Sealer 26, N-Rickert were tested and compared to the control group in which guttapercha cones with no seater were used. Linear dye penetration was measured after demineralizatÎon and clearing. Statistical analysÏs showed significant differences among the groups. The lowest leakage values were found in the Fill Canal group followed by the N-Rickert and the Sealer 26 groups.

APPLICATION OF THE TWIN-FORSE DEVICE IN COMBINATION WITH A BRACKET SYSTEM FOR THE CORRECTION OF DISTAL OCCLUSION IN ADULT PATIENTS

The aim of the study was to analyze the effectiveness of treatment of patients using the Twin-Forse apparatus in adulthood. A case of a 25-year-old patient was treated with a retroposition of the lower jaw, distal occlusion of the posterior teeth, sagittal incisal disocclusion, deep incisal disocclusion, narrowing of the deformation of the dental alveolar arches, protrusion of the upper and lower incisors, crowded position of the lower teeth. Fixed orthodontic appliances of the Damon Q system (Ormco, USA) were used. Half a year after the fixation of the bracket system, a Twin-Forse apparatus (Ortho Organizers Inc., USA) was installed. After half a year of wearing, the device was removed, the patient was assigned to wear intermaxillary elastics to achieve maximum fissure-tubercular contacts. It has been found that the use of the Twin-Forse device in adult patients helps to achieve optimal functional and aesthetic results.

Evaluation of effect of PowerScopeTM class II corrector on skeletal, dental and Oro-pharyngeal airway dimension in Skeletal class II cases - A controlled prospective clinical study

: The aim of this study was to evaluate the effect of PowerScope (Class II Corrector) on skeletal, dental and oro-pharyngeal airway dimensions in class II malocclusion with retrusive mandible. Twenty patients with age group of 11 to 14 were selected for this study. Experimental group underwent Power scope class II corrector therapy and control group, alignment of only upper arch respectively. Lateral cephalometric radiographs were taken in both experimental group and control group before and after 6 month of treatment. Sixteen measurements in that eight skeletal, five dental and three pharyngeal airway were assessed to know the effect of PowerScope Class II corrector on skeletal, dental and pharyngeal airway PowerScope Class II corrector after treatment showed significant change in SNB (P = 0.01*), ANB (P=0.001*), Inferior airway space (IAS) (P=0.006*), lower incisors position (P=0.0001*) and overjet (P=0.0001*) where as these values were insignificant on comparison with control group except for lower incisors position (P=0.001*) and overjet (P=0.0001*) indicating that PowerScope corrects class II malocclusion mainly by dento alveolar changes not have significant effect on skeletal and oro-pharyngeal airway. Power Scope (Class II corrector) corrects skeletal class II malocclusion mainly by dental changes and has insignificant effect on skeletal and oro-pharyngeal airway.