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.

Longitudinal changes of the natural craniofacial and dentoalveolar complex in the fourth decade of life.

INTRODUCTION: This study aimed to longitudinally examine the changes in craniofacial and dentoalveolar regions during the third and fourth decades of life. METHODS: The data from this study constitute the cephalometric films and plaster models of 8 female and 8 male dental students or dentists. The mean chronological ages of the subjects at the first observation period was 22.09 years for females and 22.64 years for males. The material was collected over 3 intervals: 1985-1989, 1998-2000, and 2016-2017. The observation period was approximately 28 years. Acquired cephalometric recordings and dental models were assessed for subjects in their 20s (baseline), 30s, and 40s. Maxillary, mandibular, maxillomandibular, soft-tissue, and dentoalveolar cephalometric variables were measured with a cephalometric analysis software, and dental cast measurements were made with a digital caliper. Changes in the cephalometric films and dental casts were evaluated statistically. RESULTS: Statistical analysis showed that the length of the midfacial region increased with age. The height of the lower face increased significantly in females and the mandible can be seen mildly rotating to the posterior as it increased in length. The nose moved slightly forward and downward in males and females. Upper lip height was significantly increased in females; however, there was a significant reduction in upper lip thickness for males and females. Soft-tissue pogonion measurements showed a significant forward and downward chin movement in females. Overjet was significantly increased in females, whereas the mandibular arch length was significantly decreased for both sexes, although it was more prominent in females. There was a loss of space in the anterior segments of males and females, resulting in increased crowding. However, the loss of space was only significant in the mandible. CONCLUSIONS: We observed significant changes in skeletal, soft-tissue, and dentoalveolar variables of subjects in their third and fourth decades of life. The fact that many changes have occurred throughout this study demonstrates that the process of maturation and aging is ongoing.

Transfer Accuracy of Three Indirect Bonding Trays: An In Vitro Study with 3D Scanned Models.

Objective: The goal of the current study is to compare the transfer accuracy of two different conventional indirect bonding trays with 3D-printed trays. Methods: Twenty-two patients' upper dental models were duplicated, scanned and brackets were bonded digitally. Different indirect bonding trays (double vacuum formed, transparent silicone and 3D-printed) were prepared according to three groups. These trays were used for the transfer of the brackets to the patients' models, then models with brackets were scanned. GOM Inspect software was used for the superimposition of virtual bracket setups and models with brackets. A total of 788 brackets and tubes were analyzed. Transfer accuracies were determined according to the clinical limit of 0.5 mm for linear and 2° for angular measurements. Results: 3D-printed trays had significantly lower linear deviation values than other trays for all planes (p<0.05). 3D-printed trays have significantly lower torque and tip deviation values than other groups (p<0.05). Transfer deviations were within the clinically acceptable limit for all transfer trays in horizontal, vertical and transverse planes. Deviation values of the molars were higher than those of the other tooth groups for all trays in the horizontal and vertical planes (p<0.05). Brackets were generally deviated toward the buccal direction in all tray groups. Conclusion: The transfer accuracy of 3D-printed transfer trays was more successful than the double vacuum formed and transparent silicone trays in the indirect bonding technique procedure. Deviations in the molar group were greater than those in the other tooth groups for all transfer trays.

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.

Early Maxillary Expansion with the Ni-Ti Memory Leaf Expander-A Compliance-Free Fixed Slow Maxillary Expansion Screw: A Report of 2 Cases.

Transversal problems such as crowding and crossbite are one of the most common problems dealt with in early orthodontic treatments. Early correction of these problems may ease or even eliminate the future need for treatment. This paper presents the management of 2 cases with transverse discrepancy using the Ni-Ti Memory Leaf Expander--a new compliance-free slow maxillary expansion appliance. The total treatment time for both cases was 9 months. In both cases, the inter-canine, inter-premolar, and inter-molar distances, as well as the arch length, have all increased.

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.

Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances.

OBJECTIVES: The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance. MATERIALS AND METHODS: Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed. RESULTS: The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05). CONCLUSION: The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors. CLINICAL RELEVANCE: Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.

Treatment of an adult skeletal class II patient with a modified surgery-first approach.

This case report presents an 18-year-old female patient who had skeletal Class II relationship due to a mandibular retrognathia, decreased lower anterior facial height and proclined incisors with increased overjet and overbite. Her main complaints were protruding upper incisors and decreased distance between the tip of the nose and chin. A modified surgery-first approach was performed with two months of presurgical orthodontics to achieve 8mm mandibular advancement. The total treatment time was 11 months. Improved aesthetics, a balanced facial profile and a stable and functional occlusion were obtained in less treatment time due to accelerated tooth movement.

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.

Comparison of short-term effects of mini-implant-supported maxillary expansion appliance with two conventional expansion protocols.

OBJECTIVE: This study evaluates the dentoskeletal effects of a mini-implant-supported maxillary expansion (MISME) appliance in comparison with two types of conventional expansion methods. METHODS: Records of 42 patients with bilateral or unilateral posterior crossbite were included in this study. The patients were divided into three groups. In group 1, four miniscrews were placed to the palatal region and an acrylic expansion device was bonded on these screws. A bonded maxillary expansion appliance was used in group 2, while a banded expansion appliance was used in group 3. Measurements from cephalometric, postero-anterior radiographs, and dental casts taken before and after expansion were evaluated statistically. RESULTS: ANB angle increased significantly in group 1 and 3. MISME group also showed an increase of SNA angle. Measurements regarding the vertical dimension did not change with MISME but significant posterior rotation was found in group 2 and 3. Overbite value showed a significant decrease in group 2 and 3, but remained stable in group 1. The nasal, maxillary, maxillary intermolar widths showed significant increases in all groups. The difference between MISME group and other groups in maxillary width was significant indicating more skeletal expansion in MISME group. The maxillary molars showed significant buccal tipping in group 2 and 3, while lingual tipping of molars was found in MISME group. CONCLUSIONS: MISME can be a better alternative to bonded expansion particularly in patients with vertical growth patterns and lack of anchorage teeth.

Cortical bone strains around straight and angulated immediate orthodontic microimplants: a pilot study.

PURPOSE: To measure strains around orthodontic implants upon torque tightening and loading and to assess correlations between factors influencing primary stability. MATERIALS AND METHODS: Self-drilling implants were placed into bovine iliac crest blocks after CT assessments. Upon bonding of strain gauges on bone adjacent to the implants, strain measurements were performed using a data acquisition system during torque tightening and 250 g orthodontic force application by elastic chains. RESULTS: The torque required to place straight implants (12.16 N.cm) was higher than 30- to 40-degree angulated implants (9.31 N.cm) (P < 0.05). Cortical bone strain amplitudes of both implant placements were comparable (P > 0.05). Strains during torque tightening of straight (196 µÎµ) and tilted (114 µÎµ) implants were higher than those obtained during orthodontic loading (20-30 µÎµ). Despite the positive and direct relationship found between torque and torque strain output, strong correlations between other parameters could not be detected. CONCLUSION: Vertically aligned and 30- to 40-degree angulated immediate orthodontic microimplants are associated with low amplitude strains upon torque tightening and orthodontic loading.

Palatal implant versus zygoma plate anchorage for distalization of maxillary posterior teeth.

This study aimed to examine the skeletal, dental, and soft tissue effects of the implant-supported pendulum (ISP) and the zygoma anchorage system (ZAS) used for the distalization of maxillary posterior teeth. Among 30 patients showing Angle class II malocclusion, 15 patients with a mean age of 14.3±1.6 years and treated with ISP were included in the first group; 15 patients with a mean age of 14.7±2.5 years and treated with ZAS were included in the second group. The predistalization and postdistalization lateral cephalograms were analysed. Statistical evaluation was carried out using SPSS. Point A and upper incisors protruded in the ISP group, retruded in the ZAS group. Upper posterior teeth were distalized in both groups, but more in the ZAS group. Significant differences were observed between the groups for the sagittal movements of Point A, incisors, and posterior teeth. Overbite decreased in the ISP group, overjet decreased in the ZAS group, upper and lower lips retruded only in the ZAS group. Both methods provided absolute anchorage for distalization of posterior teeth, but the skeletal and soft tissue outcome and distalization obtained was greater in the ZAS group. Both methods can be used as alternatives to extraoral traction and conventional molar distalization appliances with different patient requirements.

Primary stability and histomorphometric bone-implant contact of self-drilling and self-tapping orthodontic microimplants.

INTRODUCTION: The aim of this study was to evaluate the primary stability and the histomorphometric measurements of self-drilling and self-tapping orthodontic microimplants and the correlations between factors related to host, implant, and measuring technique. METHODS: Seventy-two self-drilling and self-tapping implants were placed into bovine iliac crest blocks after computed tomography assessments. Insertion torque values, subjective assessments of stability, and Periotest (Medizintecknik Gulden, Modautal, Germany) measurements were performed for each implant. Twelve specimens of each group were assigned to histologic and histomorphometric assessments. RESULTS: The differences between insertion torque values, most Periotest values, and subjective assessments of stability scores were insignificant (P >0.05). The bone-implant contact percentage of the self-drilling group (87.60%) was higher than that of the self-tapping group (80.73%) (P <0.05). Positive correlations were found between insertion torque value, cortical bone thickness, and density in both groups (P <0.05). Negative correlations between insertion torque values and Periotest values were mostly observed in the self-drilling group (P <0.05). Positive correlations were found between bone-implant contact percentages, cortical bone densities, and insertion torque values in both groups (P <0.05). The differences between insertion torque values and corresponding subjective assessments of stability scores were different in both groups (P <0.05). CONCLUSIONS: The differences in insertion torque values, Periotest values, and subjective assessments of stability scores of self-drilling and self-tapping implants were insignificant. Self-drilling implants had higher bone-implant contact percentages than did self-tapping implants. Significant correlations were found between parameters influencing the primary stability of the implants.

Comparative evaluation of maxillary protraction with or without skeletal anchorage.

INTRODUCTION: The aim of this prospective clinical study was to evaluate the skeletal, dentoalveolar, and soft-tissue effects of maxillary protraction with miniplates compared with conventional facemask therapy and an untreated Class III control group. METHODS: Forty-five subjects who were in prepubertal or pubertal skeletal growth periods were included in the study and divided into 3 groups of 15 patients each. All subjects had skeletal and dental Class III malocclusions with maxillary deficiency, vertically normal growth pattern, anterior crossbite, Angle Class III molar relationship, normal or increased overbite, and retrusive nasomaxillary complex. Before maxillary protraction, rapid maxillary expansion with a bonded appliance was performed in both treatment groups. In the first group (MP+FM), consisting of 5 girls and 10 boys (mean age, 10.91 years), facemasks were applied from 2 titanium miniplates surgically placed laterally to the apertura piriformis regions of the maxilla. The second group (FM) of 7 girls and 8 boys (mean age, 10.31 years) received maxillary protraction therapy with conventional facemasks applied from hooks of the rapid maxillary expansion appliance. The third group of 8 girls and 7 boys (mean age, 10.05 years) was the untreated control group. Lateral cephalometric films were obtained at the beginning and end of treatment or observation in all groups and analyzed according to a structural superimposition method. Measurements were evaulated statistically with Wilcoxon and Kruskal-Wallis tests. RESULTS: Treatment periods were 6.78 and 9.45 months in the MP+FM and FM groups, respectively, and the observation period in the control group was 7.59 months. The differences were significant between the 3 groups (P <0.05) and the MP+FM and FM groups (P <0.001). The maxilla moved forward for 2.3 mm in the MP+FM group and 1.83 mm in the FM group with maxillary protraction. The difference was significant between 2 groups (P <0.001). The protraction rates were 0.45 mm per month in the MP+FM group and 0.24 mm per month in the FM group (P <0.001). The maxilla showed anterior rotation after facemask therapy in the FM group (P <0.01); there was no significant rotation in the MP+FM group. Posterior rotation of the mandible and increased facial height were more evident in the FM group compared with the MP+FM group (P <0.01). Both the maxilla and the mandible moved forward significantly in the control group. Protrusion and mesialization of the maxillary teeth in the FM group were eliminated in the MP+FM group. The maxillomandibular relationships and the soft-tissue profile were improved remarkably in both treatment groups. CONCLUSIONS: The undesired effects of conventional facemask therapy were reduced or eliminated with miniplate anchorage, and efficient maxillary protraction was achieved in a shorter treatment period.

Comparison of the intrusive effects of miniscrews and utility arches.

INTRODUCTION: The aim of this prospective study was to compare the effects of incisor intrusion obtained with the aid of miniscrews and utility arches. METHODS: Twenty-four patients (10 male, 14 female) with a deepbite of at least 4 mm were divided to 2 groups. In group 1, 13 patients (3 male, 10 female; mean age, 20.90 ± 7.12 years) in the postpubertal growth period were treated by using miniscrews; in group 2, 11 patients (7 male, 4 female; mean age, 15.25 ± 3.93 years) were treated with utility arches. Lateral cephalometric headfilms were taken at the beginning of treatment and after intrusion for the evaluation of the treatment changes. Statistical analyses of the data were performed with a significance level of P <0.05. RESULTS: Intrusion lasted 6.61 ± 2.95 months for group 1 and 6.61 ± 2.46 months for group 2. The changes in the center of resistance of the incisors were 1.75 ± 0.4 mm (P <0.05) for group 1 and 0.86 ± 0.5 mm (P >0.05) for group 2; the difference between the groups was significant (P <0.05). In the miniscrew group, the incisors were protruded 0.79 ± 1.4 mm (P >0.05) relative to pterygoid vertical and 3.85° ± 2.4° (P >0.05) relative to the palatal plane. In group 2, the incisors showed 3.91 ± 0.7 mm (P <0.05) of protrusion relative to pterygoid vertical and 13.55° ± 2.4° (P <0.05) relative to the palatal plane. The maxillary first molars showed significant distal tipping in group 2 (P <0.05). CONCLUSIONS: Unlike with utility arches, true maxillary incisor intrusion can be achieved by application of intrusive forces close to the center of resistance by using miniscrews with no counteractive movements in the molars.

Effects of the zygoma anchorage system on canine retraction.

The aim of this study was to compare the effects of the Gjessing (PG) retraction spring used with and without the zygoma anchorage system (ZAS) on canine retraction. Thirty patients, with an Angle Class I or Class II malocclusion, whose upper first premolars were scheduled for extraction, were divided into two equal groups. Group 1 comprised maximum anchorage cases (nine females and six males with a mean age of 16 years 8 months) in which the ZAS was used to improve posterior anchorage and the PG retraction springs for canine retraction. Moderate anchorage cases (10 females and 5 males with a mean age of 15 years 5 month) were included in group 2 and canine retraction was achieved using only PG retraction springs. Study models and lateral cephalometric radiographs obtained at the initial and final stages of canine retraction were used for comparison of the groups to determine the effects of zygoma anchorage on canine retraction. All measurements were evaluated statistically using a Student's t-test, 2 × 2 repeated measures analysis of variance, Bonferroni-adjusted t-test, and Mann-Whitney U and Wilcoxon tests according to the normality of the distribution of the variables. Mesial crown movement of the molars was 0.63 mm (P < 0.05) in group 1 and 1.50 mm (P < 0.001) in group 2. There was a statistically significant difference (P < 0.05) between the groups. No significant difference was observed between the groups for the rate of canine retraction or sagittal and vertical movement of the canines. The ZAS is a reliable and successful anchorage reinforcement method for canine retraction in extraction cases.