Evaluation of the Consistency of Two Interproximal Reduction Methods in Clear Aligner Therapy: A Preliminary Study.

Objective: To compare the consistency of two interproximal reduction (IPR) methods in terms of the amount of planned and performed IPR during clear aligner therapy (CAT). Methods: Thirty-four patients who received IPR using hand-operated abrasive strips (Group 1, 20 patients, 162 teeth) and motor-driven 3/4 oscillating segmental disks (Group 2, 14 patients, 134 teeth) during CAT were included in this preliminary study. The consistency between the planned and performed IPR amounts was evaluated within and between groups for teeth and quadrants. Results: In Group 1, the amount of IPR performed on teeth numbers 22 and 43 and in the upper left quadrant was found to be statistically less than that of planned. On the other hand, the amount of performed IPR was statistically higher on tooth number 44 and in the upper right quadrant, whereas it was statistically less on tooth number 33 when compared with the planned amount in Group 2. The inconsistency between the planned and performed IPR amounts were statistically significant only in Group 1 and for teeth numbers 11, 21, 32, 33, and 43. No significant difference was found when the same parameter was compared between the groups. Conclusion: The consistency of IPR was found to be better with the motor-driven oscillating disk system than with the hand-operated IPR strip system.

Comparison of the accuracy of three interproximal reduction methods used in clear aligner treatment.

OBJECTIVES: To comparatively assess 3 interproximal reduction (IPR) methods used in clear aligner treatment with regard to accuracy, and patient perception of discomfort and anxiety. MATERIALS AND METHODS: A total of 42 patients, treated with the Invisalign® system, were included in this prospective trial and received one of the following IPR methods: hand-operated abrasive strips (group 1; 14 patients, 150 teeth), motor-driven 3/4 oscillating segmental discs (group 2; 14 patients, 134 teeth), or motor-driven abrasive strips (group 3; 14 patients, 133 teeth). Accuracy was evaluated using the difference between planned and executed IPR. Anxiety and discomfort levels experienced by the patients were evaluated using a questionnaire of 17 questions. RESULTS: The accuracy of IPR was high in groups 2 and 3; however, it was low in group 1 with the executed IPR significantly less than the planned amount. On quadrant-level, executed IPR was significantly less in the upper left quadrant in group 1, and significantly more in the upper right quadrant in group 2. The difference between planned IPR and executed IPR was significant for teeth 11, 21, 32, 33, and 43 in group 1, indicating deficiency. The average difference between planned IPR and executed IPR was 0.08 mm for group 1, 0.09 mm for group 2, and 0.1 mm for group 3. Anxiety and discomfort levels did not differ between the methods, but a negative correlation was observed between age and discomfort and anxiety levels. CONCLUSIONS: The overall accuracy of the 2 motor-driven IPR methods was found to be better than the hand-operated system. Maxillary central incisors and mandibular canines were more prone to IPR deficiency when hand-operated abrasive strips were utilized. Patients were similarly comfortable with all 3 methods, and discomfort and anxiety levels decreased with age. CLINICAL RELEVANCE: Motor-driven methods have proven to be more effective when compared to the hand-operated ones by means of precision, speed, and patient comfort. If the clinician favors a hand-operated method, it may be advised to perform slightly more IPR especially on mandibular canines and maxillary central incisors.

How Similar are the Dentoskeletal Characteristics of Class III Double-Jaw Surgery Patients with Ideal Post-Treatment Profiles and Class I Subjects?

Objective: To define the dental and skeletal characteristics of Class III surgery patients with ideal final soft-tissue profiles, and to compare them with those of Class I subjects. Also, to show how soft-tissues respond to surgical jaw movements and contribute to the outcome. Methods: This short-term, retrospective study was conducted using pre-treatment (T0), pre-surgery (T1), and post-treatment (T2) records of 50 double-jaw Class III surgery patients who presented with ideal cephalometric characteristics in sagittal (Holdaway and soft-tissue convexity angles) and vertical dimensions (GoGn. SN angle and upper-to-lower face harmony) at the end of treatment, and 50 control subjects. Results: At T2, the horizontal distance between the vertical reference plane (a perpendicular plane to the horizontal reference plane that is angulated 7° clockwise to the SN plane) and hard-tissue A, B and Pog points, lower lip, soft-tissue B, and pogonion points were greater, Wits appraisal was more negative, U1.PP was higher, IMPA was lower, and soft-tissue chin (Pog-Pog') was thicker in Group 1 when compared to Group 2 (p<0.05). Moreover, upper lip and subnasal (A-A') thicknesses were decreased, and chin thickness (Pog-Pog') was increased significantly (p<0.05). Conclusion: Dentoskeletal characteristics of an ideally-treated Class III surgery patient differed from a Class I subject concerning a protrusive maxilla and soft-tissue pogonion, and incisors that were not fully-decompensated. Soft-tissues hindered the actual surgical correction to 66% and 73% in the mid- and lower-faces, respectively.

Clinical effectiveness of buccally and palatally anchored maxillary molar distalization: The miniscrew-supported 3-dimensional maxillary bimetric distalizing arch vs the Beneslider.

INTRODUCTION: This study aimed to investigate the dentoalveolar and skeletal changes achieved with a novel miniscrew-supported 3-dimensional maxillary bimetric distalizing arch (3D-MBDA) and the Beneslider. In addition, the study aimed to compare these changes between each other and with an untreated control group. METHODS: Sixty-five patients with bilateral Class II molar relationship and fully-erupted maxillary second molars were included in the study. Of these patients, 23 received the miniscrew-supported 3D-MBDA (group 1), 21 received the Beneslider (group 2), and 21 served as untreated control subjects (group 3). Lateral cephalometric films and dental casts, taken at the beginning and the end of maxillary molar distalization, were analyzed to study the differences between the groups. RESULTS: The crown distalization of the first molars was similar between the treatment groups (group 1, 3.1 mm; group 2, 3.3 mm); however, root distalization was significantly more in group 1 (5 mm) when compared with group 2 (1.7 mm). The first molars tipped 6.2° in the mesial direction in group 1 and 8.2° in the distal direction in group 2. The mesiobuccal cusp tip of the first molars extruded for 1.2 mm and increased vertical dimensions in group 2, whereas it intruded for 1.7 mm in group 1. Meanwhile, aforementioned parameters presented insignificant changes throughout the observation period in the control group. Inter-first molar width increased significantly in group 2 (2.7 mm). Distalization time was similar between the groups (group 1, 14 months; group 2, 15 months). The distalization rate was higher in group 2 (0.27 mm/mo) than in group 1 (0.23 mm/mo) measured from the crowns; however, it was similar between the groups (group 1, 0.25 mm/mo; group 2, 0.19 mm/mo) when measured from the trifurcation point. CONCLUSIONS: The miniscrew-supported 3D-MBDA was more effective in distalizing molar roots and maintaining vertical parameters and dental arch width while tipping the molars mesially. In contrast, the Beneslider distalized molar crowns faster, resulting in significant distal tipping.

Cephalometric Mandibular Dimensions in Growing Turkish Children: Trends of Change, Sex-Specific Differences, and Comparisons with Published Norms.

OBJECTIVE: The aims of this study were to investigate cephalometric mandibular dimensions in growing Anatolian Turkish children and to identify the periods of rapid growth for boys and girls. Furthermore, the secondary aim was to compare obtained values with published standards in the literature. METHODS: A total of 528 pretreatment lateral cephalometric radiographs, grouped according to age and sex, were analyzed. Effective mandibular length, ramus height, and corpus lengths were comparatively evaluated within age groups for boys and girls and between sexes for the same age group. Data acquired from this study were compared with American, Canadian, Chinese, and European norms. Growth curves for mandible were constructed for each sex group. RESULTS: Effective mandibular length was almost always significantly longer in boys, except for 9- and 12-year-age groups. Effective mandibular length in girls increased significantly between ages 8 and 10, 10 and 12, and 11 and 13 years, while in boys between ages 8 and 10, 9 and 11, and 13 and 15 years. Turkish girls had significantly shorter effective mandibular lengths than American girls at age 14. No significant difference was found between Turkish and Chinese girls and boys. Turkish girls and boys had significantly shorter corpus lengths from their Norwegian counterparts at age 12. CONCLUSION: Except for 9- and 12-year-age groups, effective mandibular length was almost always significantly longer in boys compared to the girls. It is suggested to use norm values from more recently conducted studies and which are representative of the studied population. Growth curves can be used to predict the approximate mandibular dimensions at a particular age.

Association Between Impacted Maxillary Canines and Adjacent Lateral Incisors: A Retrospective Study With Cone Beam Computed Tomography.

OBJECTIVE: The goal of this study was to evaluate the association between the morphologic characteristics of maxillary lateral incisors and maxillary canine impaction by using cone beam computed tomography (CBCT) images. METHODS: CBCT images of 52 patients (19 male and 33 female) with unilateral impacted maxillary canines were selected. The volume, root, and total lengths of the lateral incisor, mesiodistal and buccolingual widths of the lateral incisor crowns, angles between the central axis of the lateral incisor and the midline, occlusal plane, and the central axis of canines in both the impacted and non-impacted side were measured and compared. RESULTS: Statistically significant differences were obtained when comparing the volume of the lateral incisor, the mesiodistal and buccolingual widths of the lateral incisor crown, the root and total lengths of the lateral incisors, and angles between the central axis of the lateral incisor and the midline and the central axis of the adjacent canine (P < .05). There were no significant differences in lateral incisor axis and the maxillary occlusal plane angulation. CONCLUSION: The association between the morphologic and angular features of the maxillary lateral incisors and maxillary canine impaction was confirmed. The volume of the lateral incisor, mesiodistal and buccolingual width of the lateral incisor crown, root and the total length of the lateral incisor, and the lateral incisor angulation to the midline and the axis of adjacent canine were found to be strong predictors of maxillary canine impaction.

An unusual case of invasive cervical resorption after piezosurgery-assisted en masse retraction.

A 16-year-old patient sought orthodontic correction for profile improvement and labially inclined maxillary incisors. She had Class II malocclusion, protrusive maxillary and mandibular incisors, and increased overjet and overbite with an American Board of Orthodontics discrepancy index value of 25. She was treated with maxillary premolar extractions and miniscrew-supported en masse retraction assisted with piezoincisions. Extraction spaces (7.5 mm per side) were closed with maximum anchorage in 10 months. Total treatment time was 23 months. Twenty-seven months after debonding, a pink spot was noted at the buccocervial region of the left central incisor. Radiographic evaluation on cone-beam computed tomographic scans revealed a severe case of invasive cervical resorption on both central incisors, around which the piezosurgical cuts had been made. Treatment proceeded with a nonintervention approach and the affected teeth were reinforced with a lingual retainer.

Assessing the influence of chin prominence on profile esthetics: A survey study.

PURPOSE: The aim of this survey study was to assess the influence of chin prominence on the perception of profile esthetics between genders by orthodontists, oral and maxillofacial surgeons (OMF), plastic surgeons, orthognathic patients and laypersons. MATERIALS AND METHODS: A total of 731 observers participated in this study. Profile photographs of one female and one male showing ideal soft tissue values, skeletal class 1 relationship, and normodivergent facial type were modified with photo editing program (Adobe Photoshop CC software), so that the chin was moved posteriorly up to 10 mm and anteriorly up to 8 mm at 2-mm intervals. Participants were asked to rate 11 female and 11 male profile images and to assess whether surgery was needed. RESULTS: Within the limits of this study, ideal, slightly concave and slightly convex profiles for females, and ideal and slightly concave profiles for males were found more acceptable. Surgery was desired for 50.9% of retrusive profiles and 57.3% of protrusive profiles. Female participants had a higher rate of desire for surgery than male participants, and clinicians desired surgery significantly less than others. Desire for surgery started from 4 mm in males and females for all groups, from -6 mm in orthodontists and OMFs, from -4 mm in other groups in females, and from -6 mm in males for all groups. CONCLUSION: Clinicians tend to operate more pronounced cases when compared to laypeople. A significantly higher rate of surgery was desired for protrusive chin profiles, and female participants had a higher desire for surgery.

Osseous outgrowth on the buccal maxilla associated with piezosurgery-assisted en-masse retraction: A case series.

Piezoelectric surgery is a novel surgical approach used in orthodontic treatment for rapid tooth movement. This paper presents a case series wherein osseous outgrowths were observed in response to piezosurgery-assisted en-masse retraction. Sixteen patients requiring upper premolar extractions were treated with miniscrew-supported en-masse retraction and received minimally invasive decortication via piezosurgery. Computed tomography (CT) of the maxillary anterior region was performed to investigate the nature of the outgrowths. In 8 of the 16 patients, hemispheric or disc-shaped osseous outgrowths were observed on the sites where piezosurgery was performed during retraction. CT images revealed that these outgrowths were alveolar bone. This case series presents a previously unreported osseous response to piezosurgery-assisted tooth movement during orthodontic treatment. The response is mostly transient and is observed in 50% of the treated patients, suggesting a bone turnover that can be assessed clinically and radiographically.

Efficiency of piezosurgery technique in miniscrew supported en-masse retraction: a single-centre, randomized controlled trial.

BACKGROUND: Piezoelectric surgery is a newly introduced technique for rapid tooth movement. However, the efficiency of this technique has not been investigated on en-masse retraction cases yet. OBJECTIVE: To investigate the efficiency of piezosurgery technique in accelerating miniscrew supported en-masse retraction and study the biological tissue response. In addition, to show if this technique induces a difference in dental, skeletal and soft tissue changes on lateral cephalograms, and in canine and molar rotations, besides intercanine and intermolar widths on dental casts. DESIGN, SETTING, PARTICIPANTS: We conducted a randomized, single-centred, parallel-group, controlled trial, requiring upper right and left first premolar extractions on 30 patients above the minimum age of 14 years at the beginning of retraction. INTERVENTIONS: Piezosurgery-assisted versus conventional en-masse retraction anchored from miniscrews placed between second premolars and first molars, bilaterally. OUTCOMES: The main outcome was the en-masse retraction rate. Secondary outcomes were gingival crevicular fluid (GCF) volume and GCF content of receptor activator of nuclear factor κß ligand (RANKL), changes regarding cephalometric and dental cast variables, and miniscrew success rates. RANDOMIZATION: Accomplished with opaque, sealed envelopes. BLINDING: Applicable for data assessment only. RECRUITMENT: Commenced in February 2013 and ended in October 2014. RESULTS: Thirty-one patients were included in the study and divided into 2 groups of piezosurgery (n = 16) and control (n = 15). After 9.3 months of follow-up, no statistically significant difference was observed between groups for neither retraction rates (P = 0.958) nor GCF parameters (P > 0.05). Changes in lateral cephalometric and dental cast variables, and miniscrew success rates did not show significant differences either. CONCLUSION: Based on the results of this study, piezosurgery technique was found to be ineffective in accelerating en-masse retraction, and promoting a difference in the studied GCF parameters, skeletal and dental variables. REGISTRATION: The trial was not registered. PROTOCOL: The full protocol of this PhD thesis study can be accessed from tez.yok.gov.tr. FUNDING: This work was supported by Baskent University Research Fund. No conflict of interest was declared.

Treatment of Class II, Division 2 Malocclusion with Miniscrew Supported En-Masse Retraction: Is Deepbite Really an Obstacle for Extraction Treatment?

A 17-year-old female patient, whose chief complaint was her unpleasing smile, had skeletal and dental class II malocclusion, hypodivergent facial type with a severely increased overbite. Among the treatment options, upper-first-premolar extractions followed by miniscrew-supported en-masse retraction was the treatment of choice. After the initial levelling and alignment, miniscrews with 1.5- to 1.4-mm diameter and 7-mm lenght, were installed between the roots of the second premolars and the first molars, bilaterally. En-masse retraction was achieved on a 0.016×0.022-inch stainless steel archwire with 7-mm long power hooks placed distal to the lateral incisors, and with nickel-titanium (NiTi) closed coil springs exerting 250-gr of force per side. At the end of the treatment, deepbite, incisor inclinations and interincisal angle were corrected, and Class II molar relationship with good intercuspation was achieved. Upper 2-2, lower 3-3 retainers were bonded for retention. As a result, deepbite and Class II canine relationship was successfully corrected with simultaneous incisor intrusion and retraction using miniscrew-supported en-masse retraction.