Evaluation of Maxillary Sinus Volume of Class III Individuals with Different Jaw Positions by Cone-Beam Computed Tomography.

Objective: To compare maxillary sinus volumes and surface areas among individuals with Class III skeletal patterns, with different sagittal positions of maxilla and Class I patients with normal jaw positions using cone-beam computed tomography (CBCT). Methods: CBCT images of 168 patients were analyzed retrospectively. The calculated surface areas and sinus volumes of 58 patients with Class I, normal mandibular and maxillary position (0SNA>80, 82>SNB>78) were compared with 61 patients with Class III retrognathic maxillary and normal mandibular positions (MRs) (ANB<0, SNA<80, 82>SNB>78) and 49 patients with Class III normal maxillary and prognathic mandibular positions (MP) (ANB<0, 84>SNA>80, SNB>82). Also, volume differences between genders and sides were investigated. One-way ANOVA and t-test were used to compare age, gender, skeletal patterns, and maxillary sinus measurements. Results: CBCT images of 94 females and 74 males were examined. There was no statistically significant difference in the right and left maxillary sinus volume and surface area measurements among Class I, Class III MR, and Class III MP groups (p>0.05). When the maxillary sinus volume and surface area were evaluated according to gender, the right maxillary sinus surface area and volume of males were found to be statistically significantly higher than those of females (p=0.012 and p=0.024). Similarly, the left maxillary sinus surface areas and volumes of males were also found to be significantly higher than those of females (p=0.000 and p=0.002). Conclusion: Different sagittal positions of the maxilla do not appear to affect maxillary sinus volume, and males tend to have greater maxillary sinus volume than females. CBCT images can be used to calculate intrabony air spaces.

Assessment of the relationship between fractal analysis of mandibular bone and orthodontic treatment duration : A retrospective study.

PURPOSE: This retrospective study aimed to determine whether a correlation exists between the fractal dimension value and overall orthodontic treatment duration in children and young adults. METHODS: The study included a total of 643 patients (age: 10-25 years) who received orthodontic treatment between January 2015 and March 2020. Patient records and pretreatment panoramic radiographs were evaluated. The regions of interest selected for calculating fractal dimension were the bilateral mental foramen regions of the mandible. Fractal dimension was set in relation to orthodontic treatment duration using a linear regression model which was also adjusted for potential confounding variables. Total treatment duration was the outcome variable of interest used as a continuous variable. The predictor variables of interest included age, gender, type of dental and skeletal malocclusion, vertical growth pattern, extraction type, and fractal dimension. RESULTS: The mean age, treatment duration, and fractal dimension were 14.56 years, 27.01 months, and 1.23 mm, respectively. Multiple linear regression analysis showed that the fractal dimension had a significant influence on overall treatment duration (P < 0.001). From the other variables, Angle class II malocclusion significantly influenced treatment duration (P < 0.01), age showed a significant negative correlation with treatment duration (P < 0.01), and treatment duration significantly increased for patients with tooth extractions (P < 0.001). CONCLUSION: There was a negative correlation between fractal dimensions at the mandibular mental region and total orthodontic treatment duration. Fractal dimension analysis may help to understand physiologic features of alveolar bone and predict orthodontic tooth movement.

Customized lingual brackets vs. conventional labial brackets for initial alignment : A randomized clinical trial.

PURPOSE: The aim of this randomized prospective clinical study was to determine whether there are differences between customized lingual brackets and conventional labial brackets regarding the alignment of the mandibular arch and a reduction of the irregularity index during an 18-week treatment interval. METHODS: A total of 20 patients who presented with class I malocclusion for scheduled orthodontic treatment without tooth extraction were included. The patients were randomly assigned by numbered, opaque, sealed envelopes to treatment with customized lingual brackets or conventional labial brackets. During the initial alignment (T0), 0.012″ (T1), 0.014″ (T2), and 0.016″ (T3) nickel-titanium archwires were applied, respectively, and the control visits were scheduled at 6­week intervals. In all sessions, digital models were obtained by an intraoral scanning device after removal of the archwire and were analyzed by software. Little's irregularity index, intercanine width, intermolar width and arch length were evaluated at three time points and were statistically analyzed with a repeated measures analysis of variance (ANOVA). Changes in these measurements at the three intervals (T1-T0, T2-T1, T3-T2) and overall treatment effects were also compared using the Student t­test. RESULTS: Comparing the two treatments regimes, intergroup mean values at T0, T1, T2, and T3 were not significantly different regarding the irregularity index, intercanine width, intermolar width and arch length. CONCLUSION: In this pilot study, no differences between the two treatment approaches could be detected for the phase of initial mandibular alignment.

The Assessment of Impact of the COVID-19 Pandemic on Patients Receiving Orthodontic Treatment.

OBJECTIVE: The aim of this study was to determine the difficulties experienced by patients receiving orthodontic treatment during the COVID-19 pandemic and to evaluate the problems experienced by orthodontic patients, along with their attitudes toward these problems. METHODS: A cross-sectional survey study including a total of 502 patients (291 female; 211 male) receiving orthodontic treatment at a public or private clinic was conducted via a web-based questionnaire. RESULTS: Of all participants, 70.1% (352) were between the ages of 12 and 18 and 77.1% (387) were treated in a public clinic. According to the results, 97.3% (372) of the patients in the public clinic and 71.1% (79) of the patients in the private clinics had not been able to continue their treatment for 2 months or longer. Most of the participants were concerned about extended treatment duration (349, 69.5%) during this period. While the most common problems in patients with fixed appliances were soft tissue irritation (230, 52.5%), bracket failure (142, 32.4%), gingival swelling (88, 20.1%), and pain (88, 20.1%); there were issues of new spaces between teeth (41, 64.1%), pain (37, 57.8%), and gingival swelling (29, 45.3%) among patients with removable appliances. CONCLUSION: Most patient appointments were delayed during the COVID-19 pandemic. Patients experienced various problems with their treatment, and as a result, concerns about extended treatment duration increased. Therefore, orthodontists should pay more attention to teleorthodontics during the pandemic process.