Incision Angle Research Articles

Effects of clear corneal incision location and morphology on corneal surgically induced astigmatism and higher-order aberrations after ICL V4c implantation

PurposeTo evaluate the effects of clear corneal incision (CCI) location and morphology on corneal surgically induced astigmatism (SIA) and higher-order aberrations (HOAs) in patients receiving implantable collamer lens (ICL V4c) implantation.MethodsThis retrospective study classified right eyes that underwent ICL implantation into two groups based on temporal or superior CCI. The Pentacam HR analyzer was used to measure the corneal astigmatism and HOAs. Analysis of the clear corneal incision (CCI) morphology, including incision width (Angle-W), incision length (IL), incision angles (Angle-En/Ex), and distance from the incision to corneal apex (Dis-En/Ex), was conducted using anterior segment optical coherence tomography (AS-OCT).ResultsThere were 75 eyes in the temporal CCI group and 47 eyes in the superior CCI group. Both groups showed satisfactory safety and efficacy postoperatively. In the temporal CCI group, Dis-En and Dis-Ex were considerably longer, whereas the superior CCI group displayed a significantly wider Angle-W. The anterior and posterior corneal SIA were comparable in both groups. Anterior corneal SIA was significantly correlated to Dis-En and Dis-Ex in the superior CCI group. Superior CCI caused a notable rise in corneal Z (3, 3), while temporal CCI led to increased Z (3, 1). CCI morphology was correlated to corneal Z (4, −4) and Z (4, 4) in the superior CCI group.ConclusionCCI locations caused slight variations in postoperative corneal SIA and HOAs following ICL implantation. Optimal postoperative visual outcomes may be better achieved with a CCI design featuring an increased distance from the corneal centroid and a decreased Angle-W.

Eyebrow reconstruction by simple elliptical excision with beveled incision – A case series of twelve patients

Patients seeking reconstructive facial surgery desire aesthetically pleasing outcomes with minimal visible scarring. For scalp incisions, bevelled angle of 45° is typicallypreferred to preserve hair follicles. However, no consensus exists regarding the ideal incision angle for the brow area. This observational study analyzed the surgical outcomes of 12 patients with eyebrow defects treated using a simple elliptical excision with a bevelled incision, addressing various indications such as posttraumatic scars, post-burn scars, and tumors. Outcomes were evaluated using the Physician Global Esthetic Improvement Scale at 7 days and 3 months post-surgery. At 7 days, 50% of patients showed very good improvement, and the other 50%showed moderate improvement. By 3 months, 33% of patients exhibited exceptional improvement, 50% showed very good improvement, and 17% demonstrated moderate improvement. This study concludes that direct excision and approximation with an angled incision along the hair follicle direction provide favorable aesthetic results for eyebrow reconstruction.

Obstetric Anal Sphincter Injury After Episiometer-Guided Versus Conventional Episiotomy in Instrumental Deliveries: A Randomized Controlled Trial.

Guidelines recommend episiotomy for instrumental vaginal delivery with an optimal incision angle of 60° to protect the anal sphincter. The "Episiometer" is a new device promising a 60° incision angle. We compared the incidence of obstetric anal sphincter injury (OASI) and post-repair suture angle of episiotomies made with conventional "eyeballing" versus Episiometer guided during instrumental delivery. We conducted this randomized controlled trial in a tertiary care teaching institute in southern India after ethical committee approval, trial registration, and informed consent. We randomized (block) 328 pregnant women aged 18 years and above with term, singleton fetuses delivered by instruments into Episiometer-guided (164) or conventional episiotomy (164) groups (allocation concealed). We compared the OASI (identified clinically) and the suture angle measured from the midline (assessor blinded) in the two groups. We followed up on the subjects at 6 and 12 weeks to assess perineal pain and fecal/flatus incontinence. The incidence of OASI of 0.61% in the Episiometer group was significantly lower compared with 4.88% in the eyeballing group (Chi-squared = 5.6; p = 0.02; adjusted risk ratio = 5.9; CI 0.7-46.1; p = 0.09). A significantly higher proportion of subjects (59.1%) in the Episometer group had a post-suture angle between 36 and 40° compared with 36.6% in the eyeballing group (Chi-squared = 21.8, p < 0.001). We found no significant difference in the perineal pain or Wexner score during follow-up. The Episiometer-guided episiotomy during instrumental delivery resulted in a significantly higher suture angle and lower obstetric anal sphincter injuries than with conventional eyeballing.

A comparative study of the efficacy of customized titanium plates versus conventional maxillary protraction in the treatment of skeletal class Ⅲ patients

Objective: To compare the clinical efficacy of customized titanium plate and conventional maxillary protraction treatment in patients with skeletal class Ⅲ malocclusion during growth spurt. Methods: During growth spurt, skeletal class Ⅲ patients with maxillary hypoplasia who were treated in the Department of Orthodontics, Capital Medical University School of Stomatology from August 2018 to July 2021 were prospectively enrolled. They were treated with maxillary protraction using customized titanium plates (customized titanium plate group) and conventional methods (conventional protraction group), respectively. Lateral cephalometric radiographs were collected before and after treatment for conventional cephalometric analysis, including SNA angle (angle between Sella, Nasion and A point), ANB angle (angle between A point, Nasion, and B point), FH-MP angle (mandibular plane angle), Y-axis angle, U1-L1 angle (upper to lower central incisor angle), U1-SN angle (upper incisor to SN plane angle), anterior and lower height, maxillary length, etc. The stable basicranial line (SBL) was used as the reference line to measure the distance from each reference point (ANS point, A point, Prn point, Sn point, UL point etc.) to the stable basicranial vertical line (VerT, the perpendicular line of the skull base line at the intersection point of the anterior wall of the sella image and the inferior edge of the anterior bed process). Paired t-tests were performed on the cephalometric data before and after maxillary protraction treatment in the two groups, and two independent samples t-tests were performed to compare the differences in the efficacy of the two maxillary protraction methods. Results: A total of 20 patients (9 males and 11 females), aged (10.8±1.3) years, were included in the personalized titanium plate group. A total of 20 patients (8 males and 12 females), aged (10.5±1.1) years, were included in the conventional protraction group. The SNA angle, ANB angle, FH-MP angle, Y-axis angle, anterior lower height, maxillary length, ANS-VerT distance, A-VerT distance, Prn-VerT distance, Sn-VerT distance, and UL-VerT distance were significantly higher than those before treatment in the two groups (P<0.05). The changes of SNA angle, ANB angle and A-VerT before and after treatment in the personalized titanium plate group [3.15°±2.28°, 4.64°±1.40°, (4.41±3.43) mm, respectively] were significantly higher than those in the traditional group [2.13°±2.69°, 2.81°±1.10°, (3.13±4.76) mm, respectively](P<0.05), and the changes of U1-L1 angle and U1-SN angle before and after treatment (-0.76°±7.42° and 1.74°±6.38°, respectively) was significantly lower than that of the control group (-5.14°±6.62° and 4.57°±5.24°, respectively, P<0.05). Conclusions: Maxillary protraction can effectively improve skeletal class Ⅲ relationships in growing patients. The linear measurements using the SBL line as a reference plane visualize the sagittal improvement in sagittal relationship after maxillary protraction. The customized titanium plate maxillary protraction treatment has a clear therapeutic effect on patients with skeletal class Ⅲ deformities, and its dental effect is relatively small.

Comparison of conventional and cone beam computed tomography synthetized cephalograms in evaluating different skeletal patterns

Abstract Objectives To compare conventional and cone beam computed tomography (CBCT) synthetized cephalograms in evaluating different skeletal patterns. Patients and methods This cross-sectional study was carried out on 30 CBCT scans and lateral cephalograms of Egyptian orthodontic patients of both sexes with different skeletal malocclusion patterns. Their ages ranging from 18 to 25 years old before orthodontic treatment. The conventional radiographs were called LCR images, and the cephalograms dragged from CBCT were called CBCT images. All patients were subjected to cephalometric analysis. Results There was a highly statistically significant difference between both groups in angular measurements SNA°, SNB°, and FMP°. Also, there were statistically significant differences between both groups in SN/MP°, U1/FHP°, and L1/MP°. However, there were no statistically significant differences between both groups regarding ANB°, Y-axis°, and Inter Incisal Angle. Conclusions CBCT-synthesized cephalograms demonstrated more accurate dimensional measurements than conventional lateral cephalograms. CBCT-synthesized cephalograms could be confidently used for the evaluation of different skeletal malocclusion. CBCT could successfully replace conventional cephalograms for orthodontic diagnosis and treatment planning.

Design and Biomechanical Analysis of Customized Angled Abutment Based on Tooth Inclination Angle for Immediate Implant Placement on Maxillary Anterior Region.

Finite element analysis and an in vitro experiment were employed to investigate the loading effects of angled abutments, comparing various customized angled abutments derived from the average angle of incisors in patients with a commercial 15°∆ angled abutment, on both the implant and surrounding bone. Four customized angled abutment models (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) were developed using cone-beam computed tomography (CBCT) images of incisor inclination from various age groups of patients. 3D maxillary bone models were created from CBCT images of four individual patients. Finite element analysis and in-vitro strain gauge experiments were conducted, applying 100N or 50N of axial or oblique force, to assess the differences in stress/strain between the customized and the commercial 15°∆ angled abutments in both the implants and surrounding bone. Under axial loading, the stress values in the dental implant and surrounding bone were elevated due to the relatively higher angles of the customized angled abutments (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) when compared to the commercial 15°∆ angled abutment; however, under oblique loading the commercial 15°∆angled abutment exhibited higher stress values in both the implant and surrounding bone. For in vitro experiment, there is no statically difference in bone strain between the customized (21.9°∆) and the commercial 15°∆ angled abutments in axial loading. Nevertheless, in oblique loading using a commercial 15°∆ angled abutment induced the higher bone strains. Customized angled abutments offer lower stress/strain under oblique loads but higher stress/strain under axial loads compared to commercial ones. Therefore, in the design and application of angled abutments, careful consideration of the occlusal load direction is paramount for achieving biomechanical success of dental implant.

Factors influencing root resorption in retained mandibular second deciduous molars with congenital absence of second premolars: a cross-sectional study

BackgroundThere are currently no studies that quantitatively compare the relationship of root resorption to the patient’s systemic history or craniofacial and intraoral morphology, especially in relation to possible host factors. Thus, this study aimed to clarify the factors associated with root resorption in retained mandibular second deciduous molars with the congenital absence of second premolars and predict the prognosis of retained mandibular second deciduous molars.MethodsA cohort of 5547 patients who visited the orthodontic clinic at Tokyo Medical and Dental University Dental Hospital between 2013 and 2022 was screened. Lateral cephalometric radiographs, panoramic radiographs, upper and lower dental models, and orthodontic treatment questionnaires were used as reference materials to apply the inclusion and exclusion criteria. Ultimately, 111 patients were included in the analyses. The patients were divided into two groups based on the root resorption levels of the retained mandibular second deciduous molars. Those with less root resorption were classified under the good condition (GC) group, whereas those with more root resorption were classified under the poor condition (PC) group. Demographic, clinical, and cephalometric parameters were compared between the groups. A multivariate logistic regression model was used to predict the probability of root resorption.ResultsThe prevalence of congenitally missing mandibular second premolars with persistent mandibular second deciduous molars was 2.0%. In a total of 111 patients, eighty-three teeth (53.2%) were classified into the GC group, whereas 73 teeth (46.8%) were classified into the PC group. The Frankfort-mandibular plane angle (FMA) [odds ratio (OR): 0.87], Frankfort-mandibular incisor angle (FMIA) (OR: 0.93), overbite (OR: 1.38), adjacent interdental space (OR: 1.46), distance from occlusal plane (OR: 0.80), and caries treatment (OR: 7.05) were significantly associated with the root resorption of the retained mandibular second deciduous molars.ConclusionsOur findings suggest that skeletal morphology, oral morphological patterns, and history contribute to root resorption in retained mandibular second deciduous teeth with congenital absence of subsequent permanent teeth.

Midwives' approach to the prevention and repair of obstetric perineal trauma in Spain.

Different clinical practice guidelines include recommendations on how to prevent and repair obstetric perineal trauma, as well as the use of episiotomy. To evaluate the variability in midwives' professional practices for preventing and repairing perineal trauma, as well as the professional factors that may be associated with the restrictive use of episiotomy. Observational cross-sectional study. Three hundred five midwives completed an anonymous questionnaire developed by the authors and distributed across various midwifery scientific societies. The main outcomes measured were the frequencies of adopting specific practices related to perineal injury prevention and repair, episiotomy technique and restrictive episiotomy use (<10%). Odds ratios (OR) and adjusted odds ratios (aOR) with 95% confidence intervals were estimated. Intrapartum perineal massage was not normally used by 253 (83%) of midwives, and 186 (61%) applied compresses soaked in warm water to the perineum. Regarding episiotomy, there was a great deal of variability, noting that 129 (42.3%) adopted a restrictive use of this procedure, 125 (41%) performed it between 10% and 20%, while 51 midwives (16.7%) performed it in more than 20% of cases. In addition, 165 (54.1%) midwives followed an incision angle of 60º. Concerning tears, 155 (50.8%) usually sutured first-degree tears and 273 (89.5%) always sutured second-degree tears. Midwives attending home births (aOR = 6.5; 95% CI: 2.69-15.69), working at a teaching hospital (aOR = 3.69; 95% CI: 1.39-9.84), and the ones who recently completed their professional training (aOR = 3.58; 95% CI: 1.46-8.79) were significantly more likely to adopt a restrictive use of episiotomy. There is a significant variability in Spanish midwives' practices for preventing and repairing perineal tears. Moreover, the restrictive use of episiotomy is associated with midwives attending home births, working in teaching hospitals and having recent professional training. No patient or public contribution.

Evaluation of perineal wound healing and pain outcomes after low-angle mediolateral episiotomy in women undergoing vaginal childbirth: A systematic review and meta-analysis.

The efficacy of episiotomy, particularly the angle of incision in mediolateral episiotomies, remains a significant area of inquiry in obstetrics. This meta-analysis aimed to evaluate the impact of low-angle mediolateral episiotomy on perineal wound healing and pain outcomes in women undergoing vaginal childbirth. Adhering to PRISMA guidelines, a systematic review was conducted using the PICO framework. Studies were selected based on predefined inclusion and exclusion criteria, focusing on randomised controlled trials (RCTs) involving low-angle mediolateral episiotomies. Comprehensive literature searches were performed across major electronic databases including PubMed, Embase, Web of Science and Cochrane Library. Data extraction and quality assessments were meticulously carried out by independent reviewers, employing the Cochrane Collaboration's risk of bias tool. A total of 1246 articles were initially identified, with 8 articles meeting the strict inclusion criteria for the final analysis. The meta-analysis revealed significant heterogeneity among studies regarding postoperative pain (p < 0.0001, I2 = 77.5%), and employed a random-effects model. Results showed that low-angle episiotomies significantly reduced postoperative pain (OR = 0.27, 95% CI: 0.17-0.42, p < 0.001), and increased first-degree healing rates (OR = 2.95, 95% CI: 2.20-3.96, p < 0.001) compared to traditional angles. Sensitivity analyses confirmed the stability of these findings, and no significant publication bias was detected. The analysis suggests that low-angle episiotomies can potentially reduce postoperative perineal pain and enhance wound healing. However, the limited number and varying quality of the included studies warrant cautious interpretation of these results. Further well-designed studies are needed to corroborate these findings and guide clinical practice.

THE RELATIONSHIP BETWEEN SKELETAL AND DENTO-ALVEOLAR INDICATORS IN CLASS II MALOCCLUSION

In instances of a distal bite, significant variability exists in the angles of inclination of frontal teeth, potentially impacting the condition of the alveolar bone, soft tissue profile of the face, and the aesthetics of the smile. The aim of this study is to establish correlations between sagittal, vertical, and dento-alveolar cephalometric indicators, and to assess which skeletal cephalometric variables in Class II skeletal patterns influence the variability of changes in the dento-alveolar complex.&#x0D; Materials and methods. A total of 47 cephalograms from patients with II class according to Engle were analyzed. Eighteen cephalometric measurements were performed using the following methods: SNA, SNB, ANB, SN_Ba, SN_Pg, NL_NSL, ML_NSL, NL_ML, Facial axis, PFH_AFH, the sum of Bjork angles, Gonian angle, I1_NL, I1_NA, i1_ML, i1_NB, i1_APg, I1_i1 license program "Audax Ceph" v. 6.6. A total of 846 measurements were made.&#x0D; Results. Class II bite pathology is characterized by prognathism of the upper jaw (increase in the SNA angle) and distal displacement of the lower jaw (decrease in the SNB, SN_Pg angles). Vertical parameters indicate a predominantly neutral type of growth. The average indicators of the inclination of the upper incisors indicate their slight retrusion. Lower incisors are characterized by a vestibular inclination. The most significant correlations of the angle i1_ML with indicators PFH_AFH (Ро=.513**, р=0), ML_NSL (Ро=-.512**, р=0), NL_ML (Ро=-.434**, р=0.002), Bjork (Ро=-.512**, р=0). Significant correlations between the incisal angles of the upper and lower jaws indicate their significant variability. Conclusions. The growth of the facial skeleton in the vertical and sagittal planes is related to the position of the incisors of the upper and lower jaws, which determines the impact on the morphology of bone tissue and facial aesthetics. Considering the interrelationships between parameters is an essential component for achieving successful functional and aesthetic outcomes in orthodontic treatment.

(140) What Spatulation Angle Most Optimally Increases Anastomosis Circumference While Maintaining The Flap Length: Width Ratio To &amp;lt; 2:1? Three-Dimensional Modelling Applications for Surgical Spatulation for Urologic Reconstruction

Abstract Introduction Spatulation is a surgical technique used to anastomose tubular structures in urology, including the urethra, ureter, and in transgender surgery, the neovaginal canal-end to a peritoneal pouch. This is critical in restoring normal function with a water-tight repair, and reducing the risk of stricture-formation secondary to post-operative scarring at the site of repair within a tubular structure. Considerations such as the optimization of the length-to-width ratio of the spatulated tube to &amp;lt;2:1 have been described as a means of ensuring adequate blood supply to the distal-most spatulated end, however, no studies to date have evaluated the optimal angle of spatulation to achieve this. We used CAD models to 3-D print tubular structures that would maintain their internal measurements as we conducted our analysis to ascertain the optimal angles of spatulation. (Figure 1a) Objective 1) To ascertain the optimal angle of spatulation using 3-D tubular structures maintain a 2:1 ratio of length to width for consideration during operative repair of tubular structures. Methods Three-dimensional CAD files of hollow, tubular structures were designed and printed with an internal circumference of 110mm. Each of the four models were then cut at 30°, 45°, 60°, and 75° to represent each of the different incision angles (Figure 1b). The inner circumferences and added length of each of the resulting flaps were measured on each CAD models. Using this information, the optimal angle of spatulation was calculated using geometric and mathematical analysis. We used the accepted convention of the 2:1 length to width ratio to ensure sufficient perfusion to the distal-most point of the flap as the limit when calculating the optimal angle of spatulation. Results The inner circumferences and added length is shown in Figure 1c. Overall, as expected, increasing the angle of spatulation from 30° to 75° increased the circumference of the anastomotic site and decreased the risk of stricture-formation post-operatively. It was noted that as the angle of spatulation increases, the inner circumference and the length of the resulting flap both increase exponentially. The angle of spatulation corresponding to the widely accepted criterion of 2:1 for the Length-to-Width ratio is 63.4°. Conclusions Our findings show that as the angle of spatulation increases, the circumference of the spatulation site increases. However, a competing limit to increasing spatulation-angle is that the spatulated ends become increasingly narrow and far from the source of the blood vessels, which compromises the blood supply to the distal tip-ends. To help ensure adequate perfusion of the spatulated limbs, it is desirable to maintain a Length-to-Width ratio of &amp;lt;2:1. Our work finds that the maximum spatulation angle that maintains Length-to-Width at &amp;lt;2:1 is 63.4 degrees. Disclosure No.

CAN SENSORY DISTURBANCES DUE TO INJURY TO THE INFRAPATELLAR BRANCH OF THE SAPHENOUS NERVE BE PREVENTED BY AN OBLIQUE INCISION?

To evaluate the incidence of injuries to the infrapatellar branch of the saphenous nerve (IPBSN) after anterior cruciate ligament reconstruction (ACLR) with an oblique incision for hamstring graft harvesting. In total, 59 knees (from 57 patients) were evaluated in the follow-up of ACLR for six months. We drew a horizontal line parallel to the ground, passing through the most medial portion of the surgical incision and another, perpendicular to the first, starting at the tibial tuberosity (TT). We measured the length and angle of the cut, the distances from its most medial point to the perpendicular line, and from the TT to the horizontal line. Skin sensitivity was tested with a brush and the altered sensitivity area was measured. Patients were asked about difficulties in activities daily of living (ADL). A total of 27 knees (45.7%) had sensory disorders, which persisted until the sixth postoperative month in 92.6% of them. The ADL were compromised in one knee (3.7%). No significant differences were found between the groups with and without changes in sensitivity regarding age, affected side, incision angle, or measured distances. The incision size was larger in the group without alteration in sensitivity. An oblique incision did not avoid IPBSN injuries. This condition rarely compromised the ADL. Level of Evidence II, Lesser Quality Prospective Study.

Influence of differences in mandibular incisor inclination on skeletal stability after orthognathic surgery in patients with skeletal class III malocclusion

Objective: The preoperative inclination angle of mandibular incisors was crucial for surgical and postoperative stability while the effect of proclined mandibular incisors on skeletal stability has not been investigated. This study aimed to evaluate the effects of differences in presurgical mandibular incisor inclination on skeletal stability after orthognathic surgery in patients with skeletal Class III malocclusion.Methods: A retrospective cohort study of 80 consecutive patients with skeletal Class III malocclusion who underwent bimaxillary orthognathic surgery was conducted. According to incisor mandibular plane angle (IMPA), patients were divided into 3 groups: retroclined inclination (IMPA < 87°), normal inclination (87° ≤ IMPA < 93°) and proclined inclination (IMPA ≥ 93°). Preoperative characteristics, surgical changes and postoperative stability were compared based on lateral cephalograms obtained 1 week before surgery (T0), 1 week after surgery (T1), and at 6 to 12 months postoperatively (T2).Results: The mandible demonstrated a forward and upward relapse in all three groups. No significant differences in skeletal relapse were observed in the 3 groups of patients. However, the proclined inclination group showed a negative overbite tendency postoperatively compared with the other two groups and a clinically significant mandibular relapse pattern. Proclined IMPA both pre- and postoperatively was correlated with mandibular relapse.Conclusion: Sufficient presurgical mandibular incisor decompensation was of crucial importance for the maintenance of skeletal stability in patients with skeletal Class III malocclusion who subsequently underwent orthognathic surgery.

Characteristics of Unilaterally Impacted Maxillary Canines and Effect on Environmental Tissues: A CBCT Study.

The prognosis of orthodontic treatment for a patient with impacted canine teeth can be affected by many factors and understanding some of the characteristics of impacted teeth can increase the effectiveness and reduce the duration of treatment. This study aims to explore the effects of positions and dentoalveolar morphological characteristics of impacted maxillary canines on the prognosis of orthodontic treatment. In this study, forty-six adolescent individuals who applied for treatment of impacted teeth were divided into three groups: CC (no impacted maxillary canine group), BC (unilateral buccally positioned impacted maxillary canine group), and PC (unilateral palatally positioned impacted maxillary canine group). The impacted canine and adjacent teeth were evaluated in terms of position, angulation, inclination, mesiodistal and buccolingual widths, root length, dilaceration angle, and root resorption. The mean values of U3 Ang (angulation of the maxillary impacted canine) and U3/U2 angles (maxillary impacted canine and lateral incisor angle) were statistically significantly higher in the BC and PC groups (p < 0.001). The mean values of U2 RL (lateral incisor root length) and U3 RD (canine root dilaceration angle) were statistically significantly lower in the BC and PC groups. The results of this study suggest that shorter root lengths and increased angulation values may lead to the ectopic eruption of canines. The higher canine angulations in the PC group increase the degree of root resorption.

Evaluation of collum angle of maxillary incisors on impacted vs non impacted canine Side: A CBCT analysis

The angle which is formed between the crown axis and root axis of an upper central incisor is called collum angle and this angle serves as an important morphological feature for normal development of the dentition and plays a vital role during diagnosis and treatment planning and may vary in different malocclusions i.e; skeletal and dental malocclusions. To quantify and compare the collum angle (crown root angulation) of maxillary incisors (central and lateral incisor) in subjects with unilateral permanent maxillary canine impaction between the impacted and non impacted side using Cone Beam Computed Tomography (CBCT). Thirty subjects with unilateral permanent maxillary canine impaction who had to undergo fixed orthodontic treatment were selected and their CBCT images were analysed. The collum angle of maxillary central and lateral incisor on impaction and non impaction side was measured using CBCT imaging. Descriptive statistical analysis was carried out and the mean±standard deviation was calculated and comparison between two sides was made by using paired t-test and a p value of less &amp;#60;0.05 was considered as statistically significant. The collum angle of central and lateral incisor between impacted and non impacted side were averaged. Thus, the mean±standard deviation and standard error of the collum angle (n-30) were calculated for maxillary central incisor and lateral incisor on both sides. The mean±sd of the collum angle of maxillary central incisor on impacted and non impacted side was 1.39±7.16 and 2.33±5.86 respectively with a p value of 0.282, while as the mean±sd of the collum angle of maxillary lateral incisor on impacted and non impacted side was 3.09±6.26 and 5.24±5.28 respectively with a p value of 0.060 which was considered as statistically insignificant between the two sides. A decrease in collum angle was found on impaction side with a more decreased value for lateral incisor when comparison was made with non impaction side, but no statistically significant difference was found.

Comparison of masticatory myofunctional rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion. A retrospective cohort study

ObjectiveTo estimate the clinical efficacy of early masticatory myofunction rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion in orthodontic children during the growing phase. Materials and methodA comparative retrospective cohort study, enrolled patients diagnosed with class Ⅱ/1 in the stage of late mixed or early permanent dentition. Patients were divided into a TBA group (Cohort 1): receiving Twin-block appliance treatment; and a MMR group (Cohort 2): receiving either early masticatory myofunction rehabilitation as adjunctive therapy combined with the same conventional functional appliances. The study variables were active (Phase 1) treatment duration, oral esthetic subjective impact score (OASIS), several cephalometric indices calculated from X-ray photographs, the maximum voltage (mV) and asymmetry index (AsI) of anterior temporalis (TA) and masseter muscles (MM) before and after treatment. Complications were also recorded. ResultsA total of 424 cases were enrolled. The mean treatment duration in the MMR group was 168.33 days (SD: 25.43) and 215.00 days (SD: 28.81) in the TBA group; mean difference: -46.67 days (95% CI: [-81.62, -11.71]), P<0.001. For the OASIS outcome measure, there was no statistically significant difference between the mean total scores for the MMR group (18.83±7.73) or TBA group (17.67±6.47) groups adjusted to include pre-treatment OASIS scores (P = 0.783). After treatment, sella-nasion-B point (SNB), mandibular incisor angle, maxillary base and mandibular base in both two groups were significantly increased, while AB plane angle (ANB), maxillary incisor angle, overjet and overbite were significantly decreased. The mV and AsI of TA and MM were also improved following treatment. However, no significant differences were observed between two groups. ConclusionOur results confirmed that early masticatory myofunction rehabilitation in combination with conventional TBA for patients in the growing phase was significantly effective in the management of class Ⅱ/1 in orthodontic treatment, which could significantly shorten the treatment duration and had the similar improvement in the cephalometry data, OASIS scores and masticatory muscles function when comparing to conventional TBA alone.

The efficacy of muscle function training combined with occlusal inducer in the treatment of malocclusion in children with OSA

Objective:This study aims to investigate the clinical effectiveness of muscle function training combined with occlusal inducers in the treatment for children's malocclusion after obstructive sleep apnea（OSA） surgery. Methods:A total of 40 pediatric patients who underwent surgery for OSA at Shanghai Children's Medical Center, affiliated with Shanghai Jiao Tong University School of Medicine, from January 2020 to December 2021 were involved in this study. They were divided into a treatment group（n=20） and a control group（n=20）. The treatment group received muscle function training combined with occlusal inducers, while the control group received muscle function training alone. Cephalometric measurements of hard tissues were compared between the two groups before and 12 months after surgery. Additionally, the OSA-18 questionnaire, which includes 18 items to assess the life quality of children with OSA, was filled out before surgery, 6 months after surgery, and 12 months after surgery by these patients. Results:①The scores of sleep disorders, physical symptoms, emotional status, daytime sleepiness and energy status and the degree of influence on guardians in the two groups were significantly improved at 12 months after operation（P<0.05）. The scores of sleep disorders, physical symptoms, emotional status and the degree of influence on guardians in the treatment group were better than those in the control group（P<0.05）. ②Cephalometric data at 12 months after operation showed that the upper and lower alveolar seat angle（ANB）, Overbite, upper and lower central incisor angle（U1-L1） and Overjet in the treatment group were lower than those in the control group at 12 months after operation, and the difference was statistically significant（P<0.05）. Conclusion:Children with OSA can improve the dentition irregularity by muscle function training combined with occlusal inducer after operation, and the effect is better than that of muscle function training alone.

Comparing morphologic features and complications of main clear corneal incision between junior and senior residents observed using anterior segment optical coherence tomography.

Wound construction is a critical step in phacoemulsification. Using anterior segment optical coherence tomography (AS-OCT), we compared the morphological features and complications of main incisions made by junior or senior residents during phacoemulsification. This cross-sectional comparative study included eyes with senile cataracts that underwent uneventful phacoemulsification with a clear corneal incision made by seven senior and eight junior ophthalmology residents. All eyes underwent postoperative image acquisition using AS-OCT on day one and at three months, examining for morphological features and potential complications of the main incision. We included 50 eyes of 50 patients with a male-to-female ratio of 22 (44%) to 28 (56%); 26 (52%) were operated on by junior residents and 24 (48%) by seniors. The mean geometric features of the main incisions and the frequency of early and late wound complications were comparable between the two groups (all P > 0.05). A significant correlation was found between the incision length and angle with the superior (r = + 0.80; P < 0.001 and r = - 0.63; P < 0.001, respectively) and inferior (r = + 0.84; P < 0.001 and r = - 0.68; P < 0.001, respectively) areas of the incision, as well as between the length and angle of incision (r = - 0.74; P < 0.001). The number of planes in the wound architecture was not significantly different according to senior or junior resident status (P > 0.05). Although the number of eyes with stromal hydration was significantly greater for junior residents than for seniors (P < 0.001), the corneal thickness at the entrance to the cornea or the anterior chamber, presence of endothelial wound gaping, and Descemet's membrane detachment were comparable between eyes with and without stromal hydration (all P > 0.05). At three months, 29 (58%) patients returned for examination, in whom seven (24%) had late wound complications. This study found no significant differences in the performances of junior and senior residents in terms of wound construction or its associated complications. However, considering the overall rate of some observed wound-related complications, we recommended revision of the resident educational curriculum concerning the structure and complications of the main incision.

Augmented Reality Surgical Navigation System Integrated with Deep Learning.

Most current surgical navigation methods rely on optical navigators with images displayed on an external screen. However, minimizing distractions during surgery is critical and the spatial information displayed in this arrangement is non-intuitive. Previous studies have proposed combining optical navigation systems with augmented reality (AR) to provide surgeons with intuitive imaging during surgery, through the use of planar and three-dimensional imagery. However, these studies have mainly focused on visual aids and have paid relatively little attention to real surgical guidance aids. Moreover, the use of augmented reality reduces system stability and accuracy, and optical navigation systems are costly. Therefore, this paper proposed an augmented reality surgical navigation system based on image positioning that achieves the desired system advantages with low cost, high stability, and high accuracy. This system also provides intuitive guidance for the surgical target point, entry point, and trajectory. Once the surgeon uses the navigation stick to indicate the position of the surgical entry point, the connection between the surgical target and the surgical entry point is immediately displayed on the AR device (tablet or HoloLens glasses), and a dynamic auxiliary line is shown to assist with incision angle and depth. Clinical trials were conducted for EVD (extra-ventricular drainage) surgery, and surgeons confirmed the system's overall benefit. A "virtual object automatic scanning" method is proposed to achieve a high accuracy of 1 ± 0.1 mm for the AR-based system. Furthermore, a deep learning-based U-Net segmentation network is incorporated to enable automatic identification of the hydrocephalus location by the system. The system achieves improved recognition accuracy, sensitivity, and specificity of 99.93%, 93.85%, and 95.73%, respectively, representing a significant improvement from previous studies.

Short-Term Outcomes of Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Graft: A Randomized Trial Comparing Risk of Injury to the Infrapatellar Branch of Saphenous Nerve in Terms of Knee Hypoesthesia Among Different Oblique Incision Angles

Purpose: To study the short-term outcomes of anterior cruciate ligament reconstruction (ACLR) with hamstring grafts by comparing the risk of injury to the infrapatellar branch of the saphenous nerve (IPBSN) in terms of the incidence of knee hypoesthesia using 30°, 45°, and 60° oblique incisions. Methods: We conducted a randomized controlled trial among patients who underwent ACLR with hamstring grafts in Buriram Hospital between December 1, 2020 and December 31, 2021. We randomly allocated 111 patients to three groups of 37 patients each, and each group underwent either a 30°, 45°, or 60° oblique incision for hamstring graft harvesting. When incisions were being performed, the age, sex, body mass index, diagnosis, incision length, and operating time were recorded. The incidence and area of knee hypoesthesia were evaluated at 1-, 3-, and 6- month follow-ups. Results: Demographic and surgical data were similar in all three groups. The incidence of knee hypoesthesia was significantly lower in the 45°-incision group than that in other groups at 1-, 3-, and 6-month follow-ups. At the 6-month follow-up, the incidence was 8.1% in the 45° group, 45.9% in the 30° group, and 35.1% in the 60° group. The area of sensory loss in the 45° group was significantly smaller than that in the other two groups at 3- and 6-month follow-ups. Conclusions: Performing a 45° oblique incision reduced the risk of the IPBSN injury after ACLR with a hamstring graft more significantly than a 30° or 60° incision. This technique is safe, uncomplicated, and efficacious.