Sercan Akyalcin

Enhanced Effect of Combined Treatment With Corticotomy and Skeletal Anchorage in Open Bite Correction

PURPOSE To determine the effects of combined treatment with corticotomy and skeletal anchorage in open bite correction. PATIENTS AND METHODS Ten patients (6 females, 4 males) with ages ranging from 15 to 25 years were involved. All of the individuals received combined subapical corticotomy and skeletal anchorage procedure and intrusion forces of 200 to 300 g were applied on the attachments of each molar and both premolars during 12 to 15 weeks. Mean changes for the measurements for the sample group were evaluated with Wilcoxon signed ranks test. RESULTS Significant intrusion of maxillary posterior teeth provided counterclockwise rotation of the mandible and open bite was successfully corrected. SNB angle increased and the ANB angle decreased (P< .05). Significant decreases were noted for vertical skeletal characteristics and overbite increased accordingly (P< .05). CONCLUSIONS Our results indicated that the use of combined treatment with corticotomy and skeletal anchorage provided safe and noncompliance intrusion of posterior teeth in a short period and may be regarded as an alternative method for skeletal open bite correction in adults who reject orthognathic surgery.

Diagnostic accuracy of impression-free digital models

INTRODUCTION Impression-free techniques might eliminate the potential shortcomings of digital dental models. Chairside scanners offer the advantage of obtaining digital dental models directly from the patient without the need for dental impressions. The aim of this study was to evaluate the accuracy of 3-dimensional digital models acquired from a chairside intraoral scanner compared with both manual and cone-beam computed tomography measurements of the same dental anatomy. METHODS The study sample comprised 60 dry skulls. Each skull had the maxillary and mandibular arches scanned with a Cadent iTero scanner (Align Technology, San Jose, Calif) and had a cone-beam computed tomography scan taken with a CS 9300 unit (Carestream Health, Atlanta, Ga). Linear measurements in all 3 dimensions of the space in each dental arch together with tooth-size arch-length analysis for both the maxillary and mandibular arches were carried out manually on the dry skulls with calipers and digitally on the scanned 3-dimensional models and cone-beam computed tomography images. Intraclass correlation (ICC) analysis was performed for all variables tested in the study groups, with the manual measurements on the dry skulls as the gold standard. The Bland-Altman analysis was also applied to the data to graphically display the agreement of the diagnostic measurements obtained from these methods. RESULTS Measurements from the iTero models demonstrated near-perfect agreement (ICC, 0.91-0.99) with the caliper measurements. Cone-beam computed tomography measurements had moderate to high levels of agreement (ICC, 0.65-0.99) compared with the caliper measurements. CONCLUSIONS Direct digital acquisition of the dental arches with a chairside scanner provided almost 1-to-1 diagnostic information of the investigated anatomy and was superior to the cone-beam computed tomography measurements.

Bolton tooth size discrepancies in skeletal class I individuals presenting with different dental angle classifications

The objective of this study was to investigate the frequency and association of Bolton tooth size discrepancies with dental discrepancies. Forty-eight skeletal Class I, 60 Class II, and 44 Class III subjects with similar skeletal characteristics were included in this study. Analysis of variance was performed to compare the mean ratios of Bolton analysis as a function of the Angle classification and sex. To determine the prevalence of tooth size imbalances among the three groups of occlusions and the two sexes, chi-square tests were performed. To determine the correlation of tooth size imbalances with certain dental characteristics, Pearsons correlation coefficients were calculated. No statistically significant differences were determined for the prevalence of tooth size discrepancies and the mean values of Boltons anterior and overall ratios among the occlusal groups and sexes. Boltons anterior ratio discrepancies had significant correlations with midline shifts (P < .05) in Angle Class I cases, with U1-SN angle (P < .01) in Angle Class II cases, and with L1-APog distance (P < .05) in Angle Class III cases. Bolton discrepancies related to overall ratio had significant correlations with overjet (P < .05) in Class I cases, with overbite (P < .05) and U1-SN angle (P < .01) in Class II cases, and with IMPA (P < .01) in Class III cases. A high prevalence of tooth size discrepancies in an orthodontic patient population and the statistically significant correlation of some of these with some dental characteristics suggest that the measurement of interarch tooth size ratios might be clinically beneficial for treatment outcomes.

Surface analysis of study models generated from OrthoCAD and cone-beam computed tomography imaging.

INTRODUCTION The purpose of this research was to determine the accuracy of digital models generated by cone-beam computed tomography and compare it with that of OrthoCAD models (Cadent, Carlstadt, NJ) for orthodontic diagnosis and treatment planning by using surface area analysis. MATERIALS Two sets of maxillary and mandibular digital models of 30 subjects were obtained. The models were made from impressions scanned with OrthoCAD and by conversion of related cone-beam computed tomography files. Each patients matched pairs of maxillary and mandibular models were superimposed by using a software program and a best-fit algorithm; surface-to-surface analysis was then performed. The average linear differences between the 2 files at all points on the surfaces were measured, and tolerance levels of 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mm were set to determine the surface correlation amounts between the 2 files. Additionally, 6 linear measurements from predetermined landmarks were also measured and analyzed. RESULTS The average maxillary model linear difference was 0.28 to 0.60 mm, whereas the average mandibular model linear difference ranged between 0.34 and 0.61 mm. Greater than a 90% surface correlation was obtained on average at 1.00 mm in the maxillary models and at 1.25 mm in the mandibular models. The mean differences obtained from the linear measurements of the maxillary and mandibular models were 0.071 and 0.018 mm, respectively. CONCLUSIONS Surface-to-surface analysis of OrthoCAD and digital models generated by cone-beam computed tomography pointed to a fair overlap between the protocols. The accuracy of digital models generated by cone-beam computed tomography is adequate for initial diagnosis and treatment planning in orthodontics.

Impact of orthodontic retainers on periodontal health status assessed by biomarkers in gingival crevicular fluid.

OBJECTIVE To evaluate whether biomarkers of inflammation and periodontal remodeling are differentially expressed in the gingival crevicular fluid (GCF) of patients wearing different types of orthodontic retainers. MATERIALS AND METHODS Thirty-one adult subjects (17 men and 14 women with an age range of 20 to 35 years) were allocated to three different groups. Group 1 consisted of 10 patients wearing fixed retainers, group 2 included 11 patients using lower removable retainers, and group 3 comprised 10 patients without retainers (control). Periodontal health assessment and GCF collection were carried out at two sites per subject: the lingual side of a central lower incisor and the lingual side of a lower second premolar. Aliquots from diluted GCF were screened for the presence of biomarkers using a microarray technique. RESULTS Group 1 patients exhibited a higher percentage of sites with visible plaque in the incisor region than the other groups (P = .03); no differences were noted in gingival bleeding and probing depths. The median concentrations (pg/mL) of interferon-gamma and interleukin-10 were significantly higher in the premolar sites of patients in group 2 (P = .01 and P = .04, respectively), whereas the concentration of matrix metalloproteinase-9 was significantly higher at the incisors of patients wearing fixed retainers (P = .02). A significant difference between the two sites was seen only in group 2. CONCLUSIONS The presence of different orthodontic retainers may promote specific alterations in the GCF composition. With retention periods potentially becoming longer, this finding may be of clinical significance.

Skeletal Open Bite Correction with Rapid Molar Intruder Appliance in Growing Individuals

OBJECTIVE To determine the dentofacial effects of a fixed functional appliance, the rapid molar intruder (RMI). MATERIALS AND METHODS One control group (n = 10) and two study groups (n = 10 each) were formed. The first experimental group consisted of growing children in the mixed dentition period who received RMI therapy alone. The second experimental group consisted of growing children in the early permanent dentition period who received both RMI and fixed appliance (edgewise) therapy together. Mean changes for the measurements for each group were evaluated by the Wilcoxon signed rank test. Comparisons of the mean changes between the groups were made by the Kruskal-Wallis test. RESULTS Open bite correction was achieved by counterclockwise rotation of the mandible as a consequence of redirecting growth in both treatment groups. The ANB angle decreased significantly (P < .05). Significant decreases were also noted for vertical skeletal characteristics in both treatment groups (P < .05). Molar intrusion was statistically significant for both maxillary and mandibular first molars (P < .05) in both treatment groups. CONCLUSIONS The RMI appliance provided effective bite closure and favorable dentofacial changes for nonsurgical open bite treatment in growing patients. It was concluded that this method could be regarded as a safe and noncompliance alternative for early intervention of skeletal open bite correction.

A cone-beam computed tomography evaluation of buccal bone thickness following maxillary expansion

Purpose This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Materials and Methods Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. Results The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. Conclusion RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

Relapse of orthodontically corrected deepbites in accordance with growth pattern

INTRODUCTION A common orthodontic problem is a deep overbite malocclusion. Because of its high relapse tendency, it is also one of the most challenging problems to treat. To minimize relapse, the morphologic characteristics of patients need to be considered. The aim of this study was to compare deepbite relapse in 3 groups of patients categorized by vertical growth type. METHODS The total sample included 60 patients treated at the University of Washington in Seattle, all with initial overbites greater than 50%. Data were collected from casts and cephalometric radiographs at 3 time points: pretreatment, posttreatment, and 10 years postretention. A mixed-effects model (analysis of variance) and post-hoc t tests were used for the statistical evaluations. RESULTS The high-angle subjects showed the least deepbite relapse (0.1 ± 1.1 mm), whereas the low-angle (1.2 ± 0.9 mm) and the normal-angle (1.4 ± 1.3 mm) subjects had statistically significant relapses P <0.001. This overbite relapse might be partially due to changes in the mandibular and interincisal angles, which were also observed in these 2 groups. CONCLUSIONS High-angle subjects tend to relapse less in overbite than do low-angle and normal-angle subjects in the long term.

Analysis of smile esthetics in American Board of Orthodontic patients

OBJECTIVE To investigate the common denominators of an esthetically pleasing smile in patients who were considered to be successfully treated upon the submission to American Board Orthodontics (ABO) clinical examination. MATERIAL AND METHODS A total of 462 patients were examined. Ninety subjects that fulfilled the inclusion criteria were included. Standardized digital smile photographs of the subjects were rated by 30 panel members, including orthodontists, general dentists, and parents of orthodontic patients, using a numeric version of the visual analog scale. Three groups were formed using the mean esthetic score±standard deviation range: unattractive (n=21), average (n=47), and attractive (n=22) smiles. Eleven smile characteristics were digitally measured on the photographs and compared between the groups using one-way analysis of variance and χ2 tests. Additionally, regression analyses were used to investigate the association of the smile characteristics with the esthetic score. RESULTS A significant difference was found between the three groups for the comparison of smile arc relationship (P<.001). When all the variables used in this study were entered in the regression analysis, a positive association was found (r=0.658; r2=0.434; P<.001). Additionally, two models were defined using stepwise regression. The first model included the smile arc (r=0.478; r2=0.228; P<.001), and the second model had both the smile arc and right gingival display/visible dentition display ratio (r =0.567; r2=0.321; P<.001). CONCLUSIONS A harmonious smile arc relationship and less gingival display during a smile are significantly associated with smile attractiveness in patients considered successfully treated according to ABO standards.

Does hyrax expansion therapy affect maxillary sinus volume? A cone-beam computed tomography report

Purpose The aim of this study was to investigate the initial effects of maxillary expansion therapy with Hyrax appliance and to evaluate the related changes in maxillary sinus volume. Materials and Methods Thirty patients (20 females, 10 males; 13.8 years) requiring maxillary expansion therapy, as part of their comprehensive orthodontic treatment, were examined. Each patient had cone-beam computed tomography (CBCT) images taken before (T1) and after (T2) maxillary expansion therapy with a banded Hyrax appliance. Multiplanar slices were used to measure linear dimensions and palatal vault angle. Volumetric analysis was used to measure maxillary sinus volumes. Student t tests were used to compare the pre- and post-treatment measurements. Additionally, differences between two age groups were compared with Mann-Whitney U test. The level of significance was set at p=0.05. Results Comparison of pre-treatment to post-treatment variables revealed significant changes in the transverse dimension related to both maxillary skeletal and dental structures and palatal vault angle, resulting in a widened palatal vault (p<0.05). Hard palate showed no significant movement in the vertical and anteroposterior planes. Nasal cavity width increased on a mean value of 0.93mm(SD=0.23, p<0.05). Maxillary sinus volume remained virtually stable. No significant age differences were observed in the sample. Conclusion Hyrax expansion therapy did not have a significant impact on maxillary sinus volume.