The relationship between different levels of facial attractiveness and malocclusion perception: an eye tracking and survey study.

INTRODUCTION: The aim of this study was to investigate the relationship between levels of facial attractiveness and the perception of different types of malocclusion. METHODS: A preliminary questionnaire was used to assign photographs of three female patients to low, moderate, and high facial attractiveness designations. Seven modified photographs for each smile photograph of each of these three patients were created. The evaluated photographs were as follows: P0: at rest position, P1: ideal smile, P2: - 2-mm (low) smile line, P3: + 4-mm gummy smile, P4: + 6-mm gummy smile, P5: maxillary anterior crowding, P6: median diastema, P7: polydiastema. An eye tracking device and a questionnaire were used to collect data from orthodontists, dentists, orthodontic patients, and laypeople. RESULTS: Total fixation duration varied depending on the type of malocclusion, the level of facial attraction, and the participants' occupations. In general, orthodontists and dentists had higher total fixation duration scores than orthodontic patients and laypersons. The maxillary anterior crowding photograph had the lowest visual analysis scale score at each attractiveness level (low, medium, and high). Visual analysis scale scores became similar at each attractiveness level only in the P4 photographs, and thus the difference in facial attractiveness disappeared. CONCLUSION: While a worsening of the ideal smile had a smaller impact on aesthetic perceptions in an individual with low facial attractiveness, it had a significant negative impact on a person with high facial attractiveness. Anterior crowding and diastema had a more negative impact on facial attractiveness than low or high smile lines.

Manual vs. interactive power toothbrush on plaque removal and salivary Streptococcus mutans and Lactobacillus casei levels : Single-center, examiner-blinded, randomized clinical trial in orthodontic patients.

INTRODUCTION: The purpose of this study was to compare efficacy of a manual and an interactive power toothbrush in orthodontic patients by assessing periodontal indexes and bacterial content of saliva samples. METHODS: Forty patients (20 females, 20 males; age range 12-18 years) with fixed orthodontic appliances were included in the study. The patients were randomly divided into two groups in a 1:1 ratio using sealed envelopes: group 1: manual toothbrush (Oral­B Ortho Brush, Procter&Gamble Company, Dublin, Ireland), group 2: interactive power toothbrush (Oral­B Genius 8900, Procter&Gamble Company, Marktheidenfeld, Germany). All participants were given the same toothpaste (Colgate Triple Action, Colgate-Palmolive, New York, NY, USA). The brushing procedure for each patient was described in detail, both orally and visually, utilizing a video demonstration. Plaque and bleeding index scores were recorded for both the lower and upper arches at the beginning of the study (T0) and at weeks 6 (T1) and 12 (T2). In addition, the numbers of Streptococcus (S.) mutans, Lactobacillus (L.) casei, and Porphyromonas (P.) gingivalis bacteria were determined using a real-time polymerase chain reaction (PCR) analysis in saliva samples collected at T0, T1, and T2 times. Mann-Whitney U test and Student's t test were used to compare data between the groups, and one-way analysis of variance (ANOVA) and Friedman tests were used to compare data from different time intervals for each group. RESULTS: Plaque index values were greater in group 1 at T1 and T2, although there was no difference between the groups at T0. The gingival index scores of both groups were similar at T0, T1, and T2. While group 2 had a larger number of salivary S. mutans at T0 and T2, there was no significant difference between the groups at T1. At all three time points, there was no significant difference in salivary L. casei levels between the groups. CONCLUSIONS: Although the interactive power toothbrush was more effective at removing plaque than the manual toothbrush, the results of the gingival index did not reflect the plaque scores. The number of certain salivary bacteria and brush type did not appear to have a clear relationship.

Comparing the esthetic impact of virtual mandibular advancement, bichectomy, jawline, and their combination.

INTRODUCTION: The purpose of this study was to compare the effects of mandibular advancement (MA), bichectomy, jawline, and their combination on facial attractiveness. The 3-dimensional (3D) visual sculpting is a method to perform the task. METHODS: FaceBuilder software, a Blender 2.93 LTS add-on, was used to generate a 3D head and face model of a female patient with Class II Division I malocclusion. MA, bichectomy, jawline, and combination modifications were performed on the model using a 3D virtual sculpting tab, and 4 new head models were created. Five hundred thirteen participants scored lateral and frontal views of the modified and reference models. The Mann-Whitney U, Kruskal-Wallis, and Wilcoxon tests were used for statistical analysis. RESULTS: MA modification received the highest frontal and lateral image scores. The raters found the jawline frontal photograph to be the least attractive. Significant differences were observed between the lateral and frontal attractiveness scores in all modifications except bichectomy. The combination of 3 modifications in both frontal and lateral images received the second-lowest score. CONCLUSIONS: Facial esthetic modifications receive different attractiveness scores in lateral or frontal evaluations. MA outperforms bichectomy and jawline augmentation in terms of improving facial attractiveness.

Dentoalveolar, skeletal, pharyngeal airway, cervical posture, hyoid bone position, and soft palate changes with Myobrace and Twin-block: a retrospective study.

BACKGROUND: The primary aim of this study was to evaluate the dentoalveolar, skeletal, pharyngeal airway, cervical posture, hyoid bone position, and soft palate effects of the Myobrace and Twin-block appliances. The second was to compare them in terms of ease of use by assessing the factors that may influence patient compliance. METHODS: The study included thirty-six Class II division 1 patients (19 females, 17 males; mean age, 12.14 ± 1.23) who had previously been treated in the Orthodontic Clinic at Sivas Cumhuriyet University Faculty of Dentistry. The patients were divided into two groups: Group 1: Myobrace (n = 18), and Group 2: twin block (n = 18). The effects of the appliances on the skeletal, dentoalveolar, soft tissue, craniocervical, and other anatomic structures were assessed using 46 measurements (22 linear and 24 angular), on pre and post-treatment cephalometric radiographs. AudaxCeph 5.0 software (Ljubljana, Slovenia) was used for the analysis. To analyze the changes after one year of treatment, a paired sample t-test and Wilcoxon signed-rank test were used. Intergroup comparison was performed using the Student t-test and the Mann-Whitney U test. RESULTS: In the Myobrace and Twin-block groups, there was a significant increase in SNB (°) (p = 0.004, p = 0.001), IMPA (°) (p = 0.005, p = 0.001) and a significant drop in U1/SN (°) (p = 0.021, p = 0.005). The lengths of Cd-Gn (mm), Go-Pg (mm), and Cd-Go (mm) increased significantly in the Twin-block group (p = 0.003, p = 0.010, p = 0.001), whereas the Myobrace group did not change. Similarly, there was no significant difference in pharyngeal and soft palate measurements in the Myobrace group but a statistically significant decrease in SP length and angle in the Twin-block group (p = 0.001, p = 0.006). Increases in SN/OPT (°) (p = 0.032, p = 0.001) and SN/CVT (°) (p = 0.012, p = 0.001) were statistically significant in both groups. Myobrace was more difficult to use while sleeping, whereas the twin block caused more nausea. CONCLUSIONS: Both appliances can be used for mandibular advancement. The Twin-block appliance, on the other hand, was more effective and patient-friendly.

Comparison of skeletal and dentoalveolar effects of two different mandibular advancement methods: conventional technique vs aesthetic approach.

Purpose: The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements. Materials and methods: The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements. Results: The mandibular base was observed to move forward significantly in both groups (p<0.05). However, the forward movement of the mandibular base was greater in the TB group than in the EA group (p<0.05). There was no difference in lower incisor protrusion between the two treatment methods. The EA device was found to cause a significant increase in vertical direction parameters (p<0.05). Conclusion: Both methods resulted in Class II malocclusion correction as well as an acceptable occlusion plus profile. The effects of EA were primarily dentoalveolar. In patients with high aesthetic expectations, EA could be an alternative for TB.

Estimating the size of unerupted teeth: Moyers vs deep learning.

INTRODUCTION: This study aimed to design a deep learning (DL) system for estimating the sum of the mesiodistal widths (MDWs) of unerupted mandibular canines and premolars in the mixed dentition period and to clarify its performance by comparing DL estimates with Moyers' table (MT) results. METHODS: The training dataset was obtained from 974 patients with permanent dentition. On the 3-dimensional digital models, MDWs of the mandibular right teeth were measured using Ortho Analyzer software (3Shape, Copenhagen, Denmark). A system was designed that could predict the total width of the mandibular canines and premolars using the mandibular central, lateral incisor, and first molar MDWs. This artificial neural system had 5 layers (4 hidden and 1 output) and 886 neurons. The MDWs of the mandibular teeth were introduced to the DL system in the form of datasets. The DL system's predicted results for 100 randomly selected patients were compared with the probability values obtained from the MT. RESULTS: The estimation performance of the DL system for the unerupted mandibular canines and premolars was acceptable, with 49.5% accuracy. The success rate for the MT, in comparison, was 45.0%, with an error margin of 1.00 mm. CONCLUSIONS: The DL system offers a potential alternative to current methods in estimating unerupted tooth size. The results of the DL system are expected to provide diagnostic support for mixed dentition analysis on dental casts.

Effect of sinus proximity, alveolar bone level, and initial buccolingual inclination on behavior of maxillary first molar under expansion force: a finite element analysis.

BACKGROUND: The primary aim of this study is to determine whether sinus proximity increases or decreases molar tipping under the force of expansion; a secondary aim is to compare the effect of the initial buccal inclination, alveolar bone loss, and sinus proximity to molar movement under expansion force, by assessing the stress distribution of the periodontal ligament and the changes in the moment/force (M/F) ratio). METHODS: Twenty different 3-dimensional models were created by changing the buccal inclination (0°,5°,10°,15°, and 20°) value of maxillary molar and simulating different amounts of alveolar bone loss (0, 2,4, and 6 mm) in the basic model. Additionally, an artificial sinus was added to the basic model, and the penetration of the roots into the sinus to different levels (2, 4, and 6 mm) was simulated separately. Thus, 9 additional models were created. The M/F ratio, location of the center of resistance, and principal stresses on the periodontal ligament were analyzed for each of the 29 models separately in a finite element analysis. RESULTS: The M/F ratio increased as initial buccal inclination or bone loss increased. As the amount of simultaneous penetration of 3 roots into the sinus increased, the M/F ratio decreased. Incremental changes of both the initial inclination value and the amount of bone loss resulted in higher maximum compressive stress on the apices of the buccal roots. CONCLUSIONS: Increases in alveolar bone loss and buccal inclination caused increases in the periodontal stress. Penetration of the roots into the sinus provides bicortical anchorage and could prevent unwanted crown tipping.

Three-dimensional assessment of two different canine retraction techniques: a randomized split-mouth clinical trial.

INTRODUCTION: The aim of this split-mouth trial was to compare power-arm sliding (PAS) and direct sliding (DS) canine retraction mechanics in terms of speed, rotation, angulation, and anchorage loss. METHODS: Thirty-six class II division 1 patients (20 females, 16 males; mean age, 16.94 ± 3.23) requiring upper first premolar extraction were included in the study. Miniscrews were used as anchorage units, and a retraction force of 150 gr was applied from the power arm on one side and from the bracket on the opposite side by using elastomeric chains. Randomization was achieved by block randomization with a 1:1 allocation ratio either to the right or the left with allocations concealed in opaque, sealed envelopes. Digital models were acquired using an intraoral scanner at the beginning of the retraction (T0), the first month (T1), the second month (T2), and the third month (T3). Before the scans, the archwire was removed, and custom metal jigs were inserted into the vertical slot of the canine brackets to evaluate the canine angulation. The digital models of each patient were separately superimposed with the local best-fit algorithm, and the retraction rate, angulation, rotation, and anchorage loss were measured. The digital measurements were performed using the Geomagic Control X software. RESULTS: The DS technique's total retraction rate was higher than that of the PAS technique (2.09 and 1.57, respectively, p = .002). There was, however, no significant difference between the two techniques in terms of angulation, rotation, and anchorage loss. A negative correlation was observed between the retraction rate and age, but it was not statistically significant. No significant difference was observed between the retraction rates of female and male participants in either retraction technique. CONCLUSIONS: For both orthodontists and patients, the DS technique is simpler and more convenient; thus, it is the preferred method for canine retraction. TRIAL REGISTRATION: The trial was not registered. PROTOCOL: The protocol was not published before the trial commencement.

A new technique for testing accuracy and sensitivity of digital bite registration: A prospective comparative study.

INTRODUCTION: Intraoral scanners (IOS) use certain algorithms to provide articulations of the upper and lower digital models. The study was primarily designed to test the accuracy and sensitivity of these virtual articulations. The secondary objective was to compare virtual occlusal recording to traditional methods. MATERIALS AND METHODS: A total of one hundred and sixty bite registrations (BR) were obtained from forty class I patients using four different methods. Samples were divided into four groups: Group 1: BR from wax, Group 2: BR from C type silicone, Group 3: BR from A type silicone, Group 4: Virtual BR created with Appliance Designer (Copenhagen, Denmark) software from the automatically articulated digital models. Traditional BRs of the first three groups were scanned and digitalized with IOS (3Shape TRIOS). Group 3 BRs were then taken as a reference and each of the BRs in Group 1, Group 2, and Group 4 were separately superimposed using Geomagic Control X. Numeric data such as Mpos (mean of positive deviations), Mneg (Mean of negative deviations), ITA (In total area), OTA (Out total area) were used in the comparison. RESULTS: The values for OTA were: Group 1:57.0%, Group 2:28.4%, and Group 4:22.3% respectively. That meant a general deviation in thickness on nearly all of the occlusal registration surfaces. The Mpos values representing the discrepancy in thickness were Group 1:185.5µ, Group 2:82.7µ, and Group 4:72.2µ. The surface deviation of Group 1 was significantly different from the other groups (P<0.01). CONCLUSION: Virtual bite registrations could safely be used as an alternative to conventional BRs. The performance of wax as a bite registration material was far behind other methods.

Relationship of temporomandibular joint disorders with cervical posture and hyoid bone position.

Objective: To evaluate craniocervical posture and hyoid bone position in patients with and without temporomandibular joint disorder (TMD).Methods: A total of 113 people were included in the study, including 55 TMD patients and 58 healthy controls. Using lateral cephalograms, the craniofacial, craniocervical, and hyoid bone positions of the participants were evaluated in terms of 27 variables.Results: There was no significant difference in craniocervical angles between participants with or without TMD. While the Hy-B, Hy-NSL, Hy-NL measurements and FMA (°), AFH (mm) measurements of participants with TMD were lower than the control group, the hyoid angle was greater than the control group.Conclusion: These study findings provide evidence that TMD is not related to craniocervical posture but to the position of the hyoid bone and craniofacial morphology.

Effects of Type and Amount of Orthodontic Tooth Movement on Digital Model Superimposition Accuracy.

OBJECTIVE: To assess the impact of type or amount of tooth movement on the success of 3D model superimposition by using two different algorithms. METHODS: The sample consisted of pre-treatment digital maxillary models of forty patients. Eight different groups were created by applying 8 different virtual setups to each model. Teeth crowns were moved 1mm or 2mm in different directions (sagittal, transversal, vertical, combination) using the Ortho Analyzer software. Each model obtained from the virtual setup was overlapped with the original model using the landmark-based (LB) and local-best-fit (LBF) algorithms. In the post-superimposition assessment, the area of the palate vault which was not affected by teeth movements was selected. Both groups and algorithms were compared using RMS (root mean square) and PMA (percentage of perfectly matched areas) numeric data. In addition, the displacement of the right canine (RC) was measured after superimposition. The comparison of the superposition outcomes among the groups was evaluated with one-way ANOVA and Kruskal Wallis. The student t-test was used to compare two algorithms. RESULTS: Both algorithms were not affected by the type of tooth movement. However, the increase in the amount of tooth movement negatively affected the performance of the LB algorithm. LBF achieved the model superimpositions more effectively and faster than LB. No difference was found in RC measurements between the LB and LBF algorithms. CONCLUSION: The results indicate that LBF offers more sensitive and successful 3D superimposition models. The performance of the LB algorithm was, however, acceptable for analysis of 3D teeth movement.

Effect of saliva isolation and intraoral light levels on performance of intraoral scanners.

INTRODUCTION: The use of digital models in orthodontics is becoming increasingly widespread. This study aimed to evaluate the accuracy and performance of digital intraoral scanning under 4 different intraoral environmental conditions. METHODS: Four digital models were acquired with TRIOS intraoral scanner (3Shape, Copenhagen, Denmark) for 50 subjects. A total of 200 digital models were divided into 4 groups as follows: daylight and saliva (group 1), daylight with saliva isolation (group 2), reflector light and saliva (group 3), and relatively dark oral environment and saliva (group 4). The 4 digital models were superimposed, and the edges of the models were trimmed to create common boundaries (Geomagic Control X; 3D Systems, Rock Hill, SC). Group 2 models were used as a reference and superimposed separately with the models of the other 3 groups. Deviations between corresponding models were compared as means of negative deviation, means of positive deviation, in total area, out total area, positively positioned areas, and negatively positioned areas. In addition, all groups were compared in terms of scanning time, the total number of images, and the mesiodistal width of teeth. RESULTS: Overlapping of group 1 with the reference model (group 2), a surface deviation of 13.1% (out total area) was observed. This analysis revealed that a 13% deviation was caused by the presence of saliva alone. This rate was 12.6% in group 3 and 15.5% in group 4, respectively. The values for means of negative deviation were -55 µ in group 1,-63 µ in group 3, and -68 µ in group 4. Means of positive deviation values were distributed among groups as follows: 68 µ in group 1, 69 µ in group 3, and 78 µ in group 4. The total number of images was observed, at least in group 4. CONCLUSIONS: The intraoral scanner performance was affected by different environmental conditions, and that caused variations on the surface of digital models. However, the performance of the intraoral scanner was independent of the scanning time and mesiodistal width of the teeth.

Cephalometric Evaluation of Anterior Cranial Base Slope in Patients with Skeletal Class I Malocclusion with Low or High SNA and SNB Angles.

OBJECTIVE: In the cephalometric analyses, it is observed that both SNA and SNB angles are higher or lower than normal for some skeletal Class I patients. The aim of this study was to assess the correlation between low or high SNA, SNB angles, and anterior cranial base (ACB) slope. METHODS: One hundred and seventeen skeletal Class I patients (45 males with a mean age of 14.5 years, 72 females with a mean age of 14.4 years) were evaluated in three groups. Group 1(n=40): Control group, individuals with normal SNA(82°±2°), and SNB(80°±2°) values. Group 2 (n=37): Patients with SNA>84° and SNB >82°, Group 3 (n=40): Patients with both SNA and SNB values lower than 78°. On the cephalometric radiographs, three angulars (SN/FH; anterior cranial base, Ba-S/FH; posterior cranial base, SN-Ba; total cranial base) and seven linear (S-FH, N-FH, Δ, Ba-S, Ba-N, Ba-A, Ba-B) measurements were performed to analyze the vertical and horizontal positions of the S and N points and thereby the ACB slope. One-way ANOVA and Kruskal Wallis tests were used for statistical analysis. RESULTS: The ACB slope was observed to be relatively flatter in Group 2, and steeper in Group 3 (p<0.05). The location of the S and N points in the sagittal plane did not significantly affect the SNA and SNB. However, the vertical position of the S and N points was a factor determining the inclination of the ACB, therefore the SNA and SNB. CONCLUSION: ACB slope directly affected SNA and SNB measurements. ACB might lead to misleading results when used as a reference plane.

Effect of Strontium Ranelate on Condylar Growth during Mandibular Advancement in Rats.

OBJECTIVE: Strontium ranelate (SR), unlike other anti-osteoporotic agents, might not only prevent bone resorption but also might induce bone formation. The aim of this experimental study was to evaluate the effects of systemic SR on condylar growth during mandibular advancement (MA) in growing rats. METHODS: Fifty-six, 8-week-old Wistar male rats weighting 160-190 g were randomly divided into four groups; one control (n=14) and three experimental (n=14). Group 1: Control group, Group 2: SR (900mg/kg daily dose), Group 3: MA, Group 4: SR +MA. The amount and direction of mandibular growth were assessed by linear measurements on the computed tomography (CT) images taken on days 1, 15, and 30. For immunohistochemical evaluation, half of the subjects in the groups were sacrificed on the 15th day (early phase) and the rest of them on the 30th day (late phase). New cartilage and bone formation areas on the condyle were analyzed by using Sox9 and Osteopontin antibodies. RESULTS: Early and late CT images measurements showed no significant difference between the groups (p<0.05). However, there were significant differences between the control and experimental groups in the immunohistochemical assessment. Severe immunolocalization of SOX9 and Osteopontin was observed in Group 4, while the immunolocalization scores were moderate in Group 2 and Group 3. In addition, early histological findings were similar to late results in all groups. CONCLUSION: In mandibular advancement therapy, Strontium ranelate could be therapeutically effective in avoiding relapse and reducing the duration of retention.

Treatment of Midline Deviation with Miniscrews: A Case Report.

A 15-year-old female presented with the chief complaint of crowding. Extraoral examination revealed little facial asymmetry, which was related with mandibular deviation caused by constriction of the maxilla. Upon intraoral examination, Class III molar and Class II canine relationships were seen on the right side, and Class III molar and Class III canine relationships were seen on the left side. A morphological lower midline shift was detected (4 mm to the right). After the start of treatment with rapid maxillary expansion, miniscrews were inserted into the buccal shelf and canine-premolar areas in order to solve the morphological deviation without extractions. Because there was a need to shift the lower midline to the right side, miniscrews were inserted into the left buccal shelf at the right canine-premolar area. The miniscrews were placed vertically so that the angle between the long axes of the teeth and the long axes of the screws were approximately 20 degrees. Acceptable correction of the midline deviation lasted for four months. At the end of the treatment, a good occlusal relationship was obtained.

Camouflage Treatment of a Severe Deep-Bite and Orthognathic Surgery Required Case with En Masse Retraction.

In adult patients with severe class II division 2 malocclusion, the ideal treatment option is the orthognathic surgery. However, camouflage therapy is also an acceptable treatment option due to its less traumatic and acceptable esthetic and functional results. In this case report, the camouflage treatment with two maxillary premolar extractions in a 21-year-old female patient who did not accept orthognathic surgery is presented. Acceptable esthetic and functional results were obtained at the end of the treatment.