Long-term assessment of conventional and mini-screw–assisted rapid palatal expansion on the nasal cavity

ABSTRACT Objectives To evaluate the long-term effects of mini-screw–assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls on the nasal cavity with cone-beam computed tomography (CBCT). Materials and Methods A total of 180 CBCT scans that were part of a previous randomized trial were evaluated retrospectively for 60 patients at pretreatment (T1), postexpansion (T2), and posttreatment (T3). Patients were randomly assigned into 3 groups: MARPE, RPE, and controls (time period T1 to T3; MARPE: 2 years 8 months; RPE: 2 years 9 months; control: 2 years 7 months). Nasal height, nasal length, nasion–ANS height, ANS–PNS length, pyriform height, and nasal septal deviation angle were measured. The changes in alar width, alar base width, anterior nasal cavity width, posterior nasal cavity width, maxillary intermolar width, and maxillary intercanine width were also evaluated. Results The alar base width, posterior nasal cavity width, anterior nasal cavity width, maxillary intercanine width, and maxillary intermolar width significantly increased (P < .05), and the nasal septal deviation angle significantly decreased (P < .05) in both the MARPE and RPE groups as compared with controls in the short term. In the long term, the nasal septal deviation angle was significantly decreased (P < .05) in the MARPE and RPE groups as compared with controls, and the posterior nasal cavity width was significantly increased (P < .05) in the MARPE group compared with the RPE group and controls. Conclusions MARPE and RPE led to a significant increase in the nasal cavity and alar base width compared with controls in the short term. In the long term, a significant increase was observed only in the posterior nasal cavity width with MARPE. Both MARPE and RPE led to a minimal decrease in nasal septal deviation angle in comparison with controls.

Prismatic correction in the presence of acutely acquired esotropia with diplopia

Purpose. To analyze changes in binocular vision functions in patients with acutely acquired esotropia after preoperative correction by prisms. Material and methods. The study included 16 patients with acutely acquired esotropia with diplopia. Depending on the tactics of preoperative case management, two groups were distinguished. Eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years old (mean age, M±sd – 17.5±1.9 years). This group underwent preoperative prismatic correction of diplopia and the deviation angle, as well as eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years (18.5±1.9 years). Patients in this group underwent surgery without prior prismatic correction. Fresnel prisms were used to select and assign prismatic correction. The patients were monitored dynamically. Results. In the course of treatment 1 group (prismatic correction followed by surgical correction) according to the indicator of Worth's four-dot test color test, revealed a statistically significant increase in the frequency of value of the binocular single vision (p=0.041), the frequency of the presence of stereovision according to the Fly-test (p=0.013), fusion amplitude in the distance by 1.11 times (p=0.033) and near fusion amplitude by 1.15 times (p=0.003). Significant differences between the groups were observed only in the frequency of stereovision presence according to the Fly-test after treatment, which was 2.0 times higher in group 1 (p=0.041). Conclusion. Prismatic correction in combination with surgical treatment had better curative benefits than surgery itself in improving both binocular and stereoscopic visual functions. Key words: acutely acquired esotropia, diplopia, binocular vision, stereoscopic vision, Fresnel prisms

Changes in Hypertropia in Patients with Asymmetric Inferior Oblique Overaction after Symmetric Inferior Oblique Myectomy

Purpose: This study assessed the effects of bilateral inferior oblique myectomy for hypertropia on the preoperative vertical deviation angle in patients with asymmetric primary inferior oblique overaction (IOOA).Methods: This study included patients who underwent bilateral inferior oblique myectomy and lateral rectus recession due to asymmetric primary IOOA and intermittent exotropia, and were followed up for at least 6 months postoperatively. Pre- and post-operative vertical deviation angles were compared. The correlation between the extent of correction of vertical deviation after surgery and residual hypertropia, according to the preoperative degree of vertical deviation and difference between bilateral IOOA, was evaluated.Results: This study included 178 eyes from 89 patients. The angle of hypertropia in the primary position was reduced from 3.2 ± 2.2 prism diopters (PD) preoperatively to 0.5 ± 2.5 PD postoperatively (Wilcoxon signed-rank test, p < 0.001). No significant correlation was observed between the preoperative interocular difference in IOOA and postoperative extent of correction of the vertical deviation (r = 0.044, p = 0.684), or between the preoperative difference in bilateral IOOA and residual hypertropia (Spearman's rank-order correlation, r = -0.084, p = 0.432). Increased preoperative hypertropia correlated with a greater extent of surgical correction of the vertical deviation (r = 0.733, p < 0.001). Preoperative hypertropia had no significant correlation with residual hypertropia (Spearman's rank-order correlation, r = 0.182, p = 0.087).Conclusions: In symmetric bilateral inferior oblique myectomy with bilateral lateral rectus recession for asymmetric bilateral primary IOOA with V-type intermittent exotropia, a positive correlation between the degree of preoperative vertical deviation and extent of correction of the vertical deviation was observed. Additionally, IOOA and hypertropia were significantly improved postoperatively.

Adaptive Preview based Control System for Unmanned Vehicle Path Tracking

The unmanned vehicle control technology is constantly updated. How to accurately track the path has become a key issue. For this reason, a path tracking control system for an unmanned vehicle is designed. The system control module solves the lateral and longitudinal control problems of the unmanned vehicle. The preview compensation controller corrects the deviation of the vehicle approaching the normal track. The steering control module changes the direction of the vehicle based on the motor command signal. In the software part, the kinematics model of the unmanned vehicle in the plane rectangular coordinate system is built. In this model, the steering geometric track is constructed based on the Stanley algorithm. Track tracking preview model can adjust the preview adaptively according to the lateral deviation and heading angle deviation of the vehicle and gets the adaptive preview point. The simulation results show that the maximum absolute value of preview deviation angle, the root mean square of preview deviation angle and the root mean square of tracking error are lower. The effect of path tracking control is better. The effect of path tracking control is less affected by vehicle speed and road environment.

Radiological study of the nasal septal body

Objectives The nasal septal body (NSB) is the thickened area of the septum located superior to the inferior turbinates and anterior to the middle turbinates. NSB contributes to nasal breathing via functionally and anatomically. The aim of the present study was to analyze NSB size and its association with such variables as age, septal deviation, and nasal turbinate size Material and Methods This retrospective study included 381 randomly selected patients that underwent paranasal sinus CT between 2014 and 2019. NSB size, septal deviation angle, and middle and inferior turbinate size were analyzed. Results NSB, inferior turbinate, middle turbinate, and inferior turbinate-P were significantly smaller on the deviated side. NSB, inferior turbinate, middle turbinate, and inferior turbinate-P size according to nasal septal angle was also significantly smaller on the deviated side. NSB and inferior turbinate size was positively correlated. Conclusion The NSB is an important structure for the regulation of air flow in the nose and should be evaluated in routine examination of the nose especially before the nasal surgery.

Factors influencing surgical success in concomitant horizontal strabismus

Objective: To identify the factors affecting surgical success in patients who underwent horizontal concomitant strabismus surgery. Materials and Methods: Medical records of 143 patients who underwent concomitant horizontal strabismus surgery and who were followed up at least 6 months at Ordu University, Faculty of Medicine, Department of Ophthalmology between January 2015 and December 2020 were reviewed retrospectively. Surgical success was defined as postoperative orthophoria or deviation angle of 10 prism diopters (PD) or less at 6 months after surgery. Results: 101 (70.63%) patients with esotropia and 42 (29.37%) patients with exotropia were operated. The mean follow-up period was 18.54 ± 17.51 months, the mean distance and near preoperative deviation were 46.94 ± 11.62 PD and 47.29 ± 11.81 PD, respectively. The surgical success was 83.92% in all patients, 87.13% in esotropic patients, and 76.19% in exotropic patients. Additional surgery was performed in 8 (5.59%) patients with >20 PD residual strabismus in the following year. Preoperative distance and near deviations were found to be significantly related with surgical success (p=0.020 and p=0.026). As the preoperative deviation decreases, the surgical success increases significantly. The deviation type, age at onset, age at the time of surgery, the interval between diagnosis and surgery, gender, or preoperative amblyopia were not significantly related to surgical success (p>0.05). Conclusion: The surgical success was found to be high following concomitant horizontal strabismus surgery. Since the preoperative deviation angle is the significant factor determining surgical success, preoperative evaluations should be done carefully. Patients and their parents should also be warned about the probability of additional surgery.

The effect of concha bullosa and nasal septal deviation on palatal dimensions: a cone beam computed tomography study

Introduction Nasal septal deviation (NSD) and concha bullosa (CB) are associated with airway obstruction in mouth breathers. Mouth breathing is associated with alterations in maxillary growth and palatal architecture. The aim of our study was to determine the effect of the presence of CB and NSD on the dimensions of the hard palate using cone-beam computed tomography (CBCT). Materials and methods A retrospective study was conducted using CBCT scans of 200 study subjects. The study subjects were divided into four groups based on the presence of CB and NSD. Septal deviation angle (SDA), palatal interalveolar length (PIL), palatal depth (PD) and maxillopalatal arch angle (MPAA) were measured in the study groups. Results The presence of NSD and CB was associated with significant (p < 0.001) differences in the palatal dimensions of the study subjects. The PIL and MPA (p < 0.001) were significantly reduced (p < 0.001), whereas the PD was significantly increased (p < 0.001) in study subjects with NSD and CB. There was no significant change in the palatal dimensions between the unilateral and bilateral types of CB. Among the palatal dimensions, the PIL had the most significant association (R2 = 0.53) with SDA and CB. There was a significant correlation between the palatal dimensions and SDA when CB was present along with NSD. Conclusion Based on the results of this study, it can be concluded that the presence of NSD and CB have a significant effect on the palatal dimensions and, therefore, they may be associated with skeletal malocclusion.

Visual positioning control of fuze detection manipulator

This paper designs a fuze automatic detection manipulator. Aiming at the problem of autonomous alignment and docking between operation manipulator and detection device, a visual positioning control algorithm for autonomous alignment between fuze and detection device based on fuzzy logic is proposed. Taking the relative position and deviation angle of fuze and detection device as control variables, a two-dimensional fuzzy controller is designed. Through the dynamic adjustment of the controller, the optimal motion parameters can be output. Compared with the traditional fuze detection method, the algorithm further improves the efficiency and positioning accuracy of fuze detection.

Experimental Study of Hydraulic Fracture Propagation Behavior during Multistage Fracturing in a Directional Well

Due to the limited space of offshore platform, it is unable to implement large-scale multistage hydraulic fracturing for the horizontal well in Lufeng offshore oilfield. Thus, multistage hydraulic fracturing technology in directional well was researched essentially to solve this problem. Modeling of fracture propagation during multistage fracturing in the directional and horizontal wells in artificial cores was carried out based on a true triaxial hydraulic fracturing simulation experiment system. The effects of horizontal stress difference, stage spacing, perforation depth, and well deviation angle on multifracture propagation were investigated in detail. Through the comparative analysis of the characteristics of postfrac rock and pressure curves, the following conclusions were obtained: (1) multistage fracturing in horizontal wells is conducive to create multiple transverse fractures. Under relatively high horizontal stress difference coefficient (1.0) and small stage spacing conditions, fractures tend to deflect and merge due to the strong stress interference among multiple stages. As a consequence, the initiation pressure for the subsequent stages increases by more than 8%, whereas in large stage spacing conditions, the interference is relatively lower, resulting in the relatively straight fractures. (2) Deepening perforation holes can reduce the initiation pressure and reduce the stress interference among stages. (3) When the projection trace of directional wellbore on horizontal plane is consistent with the direction of the minimum horizontal principal stress, fractures intersecting the wellbore obliquely are easily formed by multistage fracturing. With the decrease of well deviation angle, the angle between fracture surface and wellbore axis decreases, which is not conducive to the uniform distribution of multiple fractures. (4) When there is a certain angle between the projection trace of directional wellbore on horizontal plane and the direction of minimum horizontal principal stress, the growth of multiple fractures is extremely ununiform and the fracture paths are obviously tortuous.