Stability between single and segmental maxillary osteotomies in bimaxillary surgery for cleft-associated class III deformity: a CBCT study.

OBJECTIVE: Segmental Le Fort I osteotomy through the cleft is a common strategy to narrow the alveolar cleft in adults. This study compared skeletal stability between single and segmental Le Fort I osteotomies in patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: This retrospective analysis examined 45 adults with complete UCLP-associated class III deformities who underwent bimaxillary surgery with either single (n = 30) or segmental (n = 15) Le Fort I advancement. Cone beam computed tomography (CBCT) scans of the facial skeleton were acquired before surgery, 1-week postsurgery, and at follow-up. Measures of landmarks from the CBCT images for the two treatment groups were compared for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch). RESULTS: Postsurgery, the downward movement of the maxilla was larger in the segmental group than the single group. At follow-up, the maxilla moved backward in both groups, and upward in the segmental group. The mandible moved forward and upward and rotated upward in both groups. The amount of upward movement and rotation was larger in the segmental group than the single group. CONCLUSIONS: Two years after bimaxillary surgery in patients with UCLP-associated class III deformity, greater relapse was found after segmental Le Fort I osteotomies in vertical translation of the maxilla and mandible, and pitch rotation of the mandible compared with single Le Fort I osteotomies. CLINICAL RELEVANCE: The vertical relapse of the maxilla was larger after segmental Le Fort I advancement compared with single Le Fort I advancement in clefts.

Transfer learning for anatomical structure segmentation in otorhinolaryngology microsurgery.

BACKGROUND: Reducing the annotation burden is an active and meaningful area of artificial intelligence (AI) research. METHODS: Multiple datasets for the segmentation of two landmarks were constructed based on 41 257 labelled images and 6 different microsurgical scenarios. These datasets were trained using the multi-stage transfer learning (TL) methodology. RESULTS: The multi-stage TL enhanced segmentation performance over baseline (mIOU 0.6892 vs. 0.8869). Besides, Convolutional Neural Networks (CNNs) achieved a robust performance (mIOU 0.8917 vs. 0.8603) even when the training dataset size was reduced from 90% (30 078 images) to 10% (3342 images). When directly applying the weight from one certain surgical scenario to recognise the same target in images of other scenarios without training, CNNs still obtained an optimal mIOU of 0.6190 ± 0.0789. CONCLUSIONS: Model performance can be improved with TL in datasets with reduced size and increased complexity. It is feasible for data-based domain adaptation among different microsurgical fields.

Gerdy's tubercle as a novel anatomical landmark for the proximal tibial cut in total knee arthroplasty.

OBJECTIVES: This study aimed to explore the use of Gerdy's tubercle (GT) as an innovative and dependable anatomical landmark for the proximal tibial cut in total knee arthroplasty (TKA) in cases with extensive knee degeneration. MATERIALS AND METHODS: One hundred dry tibia bones and 10 formalin-fixed cadaveric knee specimens of both sexes were examined. A Zimmer NexGen tibial cutting guide and a Mitutoyo digital caliper were utilized to align the guide with the tibia's mechanical axis. The procedure was replicated on cadaver knees using a standardized medial parapatellar arthrotomy approach. Measurements included the distance from GT superior border to the resection line and the length of the tibia. A radiological study involving magnetic resonance imaging examinations of 48 patients, which were evaluated focusing on the upper border of GT and the least degenerated segment of the posterolateral part of the lateral tibial condyle, was conducted. RESULTS: Anatomical measurements of GT and proximal tibial areas in 110 specimens showed slight but consistent variations with cadaver measurements. Magnetic resonance imaging analysis of 48 patients revealed notable sex differences in the distance between the superior border of GT and the tibia's posterolateral surface. There was also a significant negative correlation between the distance from GT to the posterolateral corner and cartilage thickness. CONCLUSION: Proper alignment in TKA is crucial for success, but identifying an extra-articular landmark for horizontal tibial resection remains challenging, particularly in severely arthritic knees. This study introduces GT as a novel anatomical landmark for TKA, offering a more reliable reference for achieving desired joint levels in knees with significant degenerative changes.

Determining the position of the lingula and the mandibular foramen using the antilingula in orthognathic surgery.

BACKGROUND: The antilingula located on the lateral surface of the mandibular ramus has been served as a surgical landmark for the mandibular foramen on the medial surface for decades. However, whether the antilingula truly represents the lingula which is the bony prominence overlapping the mandibular foramen, or the foramen itself, is still unclear. This study thus aimed to examine the position of the antilingula in relation to three reference points: the lingula, the anterior and the posterior borders of the mandibular foramen, as well as to the reference plane used in the inferior alveolar nerve block, and to the posterior border of the mandible. METHODS: This observational study was performed in 113 Thai dry mandibles. The antilingula were identified followed by transferring the reference points to the lateral surface. The distances from the antilingula to the reference points, the reference plane and the posterior border of the ramus were then measured. Chi-square test was calculated for side-dependency of the antilingula. Paired t-test was calculated for difference in measurements in left and right sides. RESULTS: The antilingula could be identified in 92.48% of the mandibles with 86.67 - 90.00% accuracy and 86.67% reliability. There was no significant difference in the presence of the antilingula on left and right sides (p = 0.801). Only 2.5% and 0.83% of the antilingula correspond to the lingula and the anterior border of the mandibular foramen, respectively. However, 85% of the reference points were located within 11 mm radius. The antilingula was found located 2.80 mm inferior to the reference plane and 16.84 mm from the posterior border of the ramus. CONCLUSIONS: The antilingula does not concur with the reference points on the medial surface. Our study also suggests that the safe area for vertical osteotomy is 11 mm posterior to the antilingula or at 30% of the length from the posterior border parallel to the occlusal plane. The use of more accurate techniques in localizing the mandibular foramen combined with the antilingula is more recommended than using the antilingula as a sole surgical guide.

Intraoperative trypan blue central landmark and its use in capsulotomy and capsulorhexis centration.

PURPOSE: To compare 3 capsulotomy centration methods. SETTING: Private clinic, Zlin, Czech Republic. DESIGN: Prospective, consecutive case series. METHODS: 180 eyes undergoing cataract surgery had anterior capsule staining with microfiltered 0.4% trypan blue solution before selective laser capsulotomy. The first 60 eyes (Group 1) had mydriatic dilated pupil centered capsulotomies. The next 60 eyes (Group 2) were centered on the trypan blue central landmark (TCL). The final 60 capsulotomies (Group 3) were centered on the patient fixated coaxial Purkinje reflex (CPR). Measurements between key anatomical landmarks and the TCL, CPR capsulotomies, and implanted intraocular lens (IOL) center were made. RESULTS: The TCL, observed in >94% of eyes in the study, coincided with the CPR with a displacement of <0.1 ± 0.1 mm. Group 1 capsulotomies were noticeably decentered on the IOLs by 0.3 ± 0.2 mm. The Group 2 symmetrical IOL relationship was maintained with a decentration of 0.15 ± 0.1 mm. Group 3 had a similar decentration with the IOLs with 0.15 ± 0.1 mm. Verification with IOLMaster 700 data and CALLISTO Eye System showed that the CPR and the TCL were coincident with the measured visual axis. CONCLUSIONS: The clearly visible TCL served as an alternate landmark to the patient fixated CPR, and being on the anterior capsule was not sensitive to tilt. Further patient compliance was not required. Both were superior to dilated pupil centration, to achieve symmetric IOL coverage. This has application for both capsulotomies and capsulorhexes.

Nerve Block Guided by Anatomic Landmarks Only Reduces Pain in Botulinum Toxin Type A Treatment for Glabellar and Forehead Wrinkles.

BACKGROUND: Botulinum toxin type A is widely used to treat glabellar and forehead wrinkles, but the pain caused by multiple injections often deters patients from receiving long-term treatment. Despite several methods used to alleviate this pain, consistency and effectiveness remain a challenge. Therefore, this study aimed to evaluate the effectiveness and safety of nerve block guided by anatomic landmarks only in reducing pain associated with botulinum toxin type A injections. PATIENTS AND METHODS: Between 2018 and 2022, the study enrolled 90 patients divided into 3 groups: the nerve block group (n = 30), the lidocaine cream group (n = 30), and the control group (n = 30). In the nerve block group, a landmarks-based technique was used to perform the nerve block. The study collected general information and comorbidities, and recorded pain at each point and time spent on preparation and treatment for each patient's forehead and glabellar area on each side. Patient-reported outcomes and complications were followed up at 2, 4, and 12 weeks after the injections. RESULTS: The nerve block group had significantly lower total pain scores in all regions compared to the lidocaine cream and control groups (P < 0.01). There were no significant differences in patient-reported outcomes between the groups at any follow-up point. Additionally, the complication rates related to injection were low and comparable among the 3 groups. CONCLUSIONS: Nerve block guided by anatomic landmarks only is a safe, effective, and consistent approach to reduce pain during botulinum toxin type A treatment for glabellar and forehead lines. This technique may offer advantages over other methods used to alleviate the pain associated with these injections.

Fenestration of the facial nerve by the stylomastoid artery.

BACKGROUND: Anatomic landmarks such as the tympanomastoid suture line, posterior belly of the digastric muscle, tragal pointer, and styloid process can assist the parotid surgeon in identifying and preserving the facial nerve. Vascular structures such as the posterior auricular artery and its branch, the stylomastoid artery, lay in close proximity to the facial nerve and have been proposed as landmarks for the identification of the facial nerve. In this case report, we describe an anatomic variation in which the stylomastoid artery has fenestrated the main trunk of the facial nerve, dividing it in two. METHODS: Two patients underwent parotidectomy (one for a pleomorphic adenoma, the second for a parotid cyst) through a standard anterograde approach with identification of the usual facial nerve landmarks. RESULTS: The appearance of the main trunk of the facial nerve was unusual in both patients due to its being fenestrated by the stylomastoid artery. The stylomastoid artery was divided, and the remainder of the facial nerve dissection was performed uneventfully with subsequent resection of the parotid mass in both patients. CONCLUSIONS: In rare instances, the stylomastoid artery can penetrate through the common trunk of the facial nerve. This is an important anatomic variant for the parotid surgeon to be aware of, as it can increase the difficulty of facial nerve dissection.

BM-BronchoLC - A rich bronchoscopy dataset for anatomical landmarks and lung cancer lesion recognition.

Flexible bronchoscopy has revolutionized respiratory disease diagnosis. It offers direct visualization and detection of airway abnormalities, including lung cancer lesions. Accurate identification of airway lesions during flexible bronchoscopy plays an important role in the lung cancer diagnosis. The application of artificial intelligence (AI) aims to support physicians in recognizing anatomical landmarks and lung cancer lesions within bronchoscopic imagery. This work described the development of BM-BronchoLC, a rich bronchoscopy dataset encompassing 106 lung cancer and 102 non-lung cancer patients. The dataset incorporates detailed localization and categorical annotations for both anatomical landmarks and lesions, meticulously conducted by senior doctors at Bach Mai Hospital, Vietnam. To assess the dataset's quality, we evaluate two prevalent AI backbone models, namely UNet++ and ESFPNet, on the image segmentation and classification tasks with single-task and multi-task learning paradigms. We present BM-BronchoLC as a reference dataset in developing AI models to assist diagnostic accuracy for anatomical landmarks and lung cancer lesions in bronchoscopy data.

Deep learning for automatic detection of cephalometric landmarks on lateral cephalometric radiographs using the Mask Region-based Convolutional Neural Network: a pilot study.

OBJECTIVE: We examined the effectiveness and feasibility of the Mask Region-based Convolutional Neural Network (Mask R-CNN) for automatic detection of cephalometric landmarks on lateral cephalometric radiographs (LCRs). STUDY DESIGN: In total, 400 LCRs, each with 19 manually identified landmarks, were collected. Of this total, 320 images were randomly selected as the training dataset for Mask R-CNN, and the remaining 80 images were used for testing the automatic detection of the 19 cephalometric landmarks, for a total of 1520 landmarks. Detection rate, average error, and detection accuracy rate were calculated to assess Mask R-CNN performance. RESULTS: Of the 1520 landmarks, 1494 were detected, for a detection rate of 98.29%. The average error, or linear deviation distance between the detected points and the originally marked points of each detected landmark, ranged from 0.56 to 9.51 mm, with an average of 2.19 mm. For detection accuracy rate, 649 landmarks (43.44%) had a linear deviation distance less than 1 mm, 1020 (68.27%) less than 2 mm, and 1281 (85.74%) less than 4 mm in deviation from the manually marked point. The average detection time was 1.48 seconds per image. CONCLUSIONS: Deep learning Mask R-CNN shows promise in enhancing cephalometric analysis by automating landmark detection on LCRs, addressing the limitations of manual analysis, and demonstrating effectiveness and feasibility.

Measurements of oculo-palpebral landmarks and evaluation of patient's head position.

PURPOSE: Keeping the head in a neutral position is requisite for glasses/lenses/head-up designs, the suitability of oculo-plastic surgery and for the grading the eye shift. Anatomically incompatible glasses are one of the common problems affecting accommodation, reducing comfort and disturbing by causing symptoms such as dizziness and nausea. The oculo-palpebral measurements act as a key determinant in symmetrical facial attractiveness. This study aims to investigate the most effective oculo-palpebral landmarks, head-neutral as the ideal position, taking into account of individual anatomical differences of these patients. METHODS: 100 females and 100 males aged between 18 and 20 years were photographed. Digital photogrammetric measurements were made with the ImageJ program. Interpupillary and interhelical distances, besides bilateral palpebral fissure length and height, and iris diameter were calculated on front-facing photographs. RESULTS: Mean interpupillary distance was measured wider in males than in females. The mean length of palpebral fissure was 31 mm; palpebral fissure height was 10 mm. These figures were valid in both eyes and gender. The interhelical distance was calculated as the mean and was measured longer in men. Since the measurement values were the same in both sexes and on both sides, they were determined as important landmarks for controlling the head-neutral position, evaluating whether there was a deviation in the eye, and measuring the numerical value when detected. CONCLUSION: It is essential to check the side-symmetry of the patient's palpebral fissure height, palpebral fissure length, diameter of iris and corneal depth during oculo-plastic invention and artificial design.

Quantifying nasal deformities using a novel mathematical method to complement preoperative assessment in rhinoplasty patients.

BACKGROUND: Rhinoplasty enhances facial symmetry and functionality. However, the accurate and reliable quantification of nasal defects pre-surgery remains an ongoing challenge. AIM: This study introduces a novel approach for defect quantification using 2D images and artificial intelligence, providing a tool for better preoperative planning and improved surgical outcomes. MATERIALS AND METHODS: A pre-trained AI model for facial landmark detection was utilised on a dataset of 250 images of male patients aged 18 to 24 who underwent rhinoplasty for cosmetic nasal deformity correction. The analysis concentrated on 36 different distances between the facial landmarks. These distances were normalised using min-max scaling to counter image size and quality variations. Post-normalisation, statistical parameters, including mean, median, and standard deviation, were calculated to identify and quantify nasal defects. RESULTS: The methodology was tested and validated using images from different ethnicities and regions, showing promising potential as a beneficial surgical aid. The normalised data produced reliable quantifications of nasal defects (average 76.2%), aiding in preoperative planning and improving surgical outcomes and patient satisfaction. APPLICATIONS: The developed method can be extended to other facial plastic surgeries. Furthermore, it can be used to create app-based software, assist medical education, and improve patient-doctor communication. CONCLUSION: This novel method for defect quantification in rhinoplasty using AI and image processing holds significant potential in improving surgical planning, outcomes, and patient satisfaction, marking an essential step in the fusion of AI and plastic surgery.

PELE scores: pelvic X-ray landmark detection with pelvis extraction and enhancement.

PURPOSE: Pelvic X-ray (PXR) is widely utilized in clinical decision-making associated with the pelvis, the lower part of the trunk that supports and balances the trunk. In particular, PXR-based landmark detection facilitates downstream analysis and computer-assisted diagnosis and treatment of pelvic diseases. Although PXR has the advantages of low radiation and reduced cost compared to computed tomography (CT), it characterizes the 2D pelvis-tissue superposition of 3D structures, which may affect the accuracy of landmark detection in some cases. However, the superposition nature of PXR is implicitly handled by existing deep learning-based landmark detection methods, which mainly design the deep network structures for better detection performances. Explicit handling of the superposition nature of PXR is rarely done. METHODS: In this paper, we explicitly focus on the superposition of X-ray images. Specifically, we propose a pelvis extraction (PELE) module that consists of a decomposition network, a domain adaptation network, and an enhancement module, which utilizes 3D prior anatomical knowledge in CT to guide and well isolate the pelvis from PXR, thereby eliminating the influence of soft tissue for landmark detection. The extracted pelvis image, after enhancement, is then used for landmark detection. RESULTS: We conduct an extensive evaluation based on two public and one private dataset, totaling 850 PXRs. The experimental results show that the proposed PELE module significantly improves the accuracy of PXRs landmark detection and achieves state-of-the-art performances in several benchmark metrics. CONCLUSION: The design of PELE module can improve the accuracy of different pelvic landmark detection baselines, which we believe is obviously conducive to the positioning and inspection of clinical landmarks and critical structures, thus better serving downstream tasks. Our project has been open-sourced at https://github.com/ECNUACRush/PELEscores .

Endoscopic trans-eustachian tube approach: identifying the precise landmarks, a novel radiological and anatomical evaluation.

PURPOSE: The endoscopic trans-eustachian approach (ETETA) is a less invasive approach to the infratemporal fossa (ITF), providing superior exposure compared to traditional transcranial approaches. The anatomy of the pharyngotympanic (eustachian) tube and adjacent neurovascular structures is complex and requires in-depth knowledge to safely perform this approach. We present a cadaveric and radiological assessment of critical anatomic considerations for ETETA. METHODS: Six adult cadaveric heads were dissected alongside examination of 50 paranasal sinus CT scans. Key anatomic relationships of the pharyngotympanic tube and adjacent structures were qualitatively and quantitatively evaluated. Descriptive statistics were performed for quantitative data. RESULTS: Anatomical and radiological measurements showed lateralization of the pharyngotympanic tube allows access to the ITF. The pharyngotympanic tube has bony and cartilaginous parts with the junction formed by the sphenoid spine and foramen spinosum. The bony part and tendon of the tensor tympani muscle were located at the posterior genu of the internal carotid artery. The anterior and inferior wall of the carotid canal was located between the horizontal segment of the internal carotid artery and petrous segment of the cartilaginous pharyngotympanic tube. CONCLUSION: The combination of preoperative radiographic assessment and anatomical correlation demonstrates a safe and effective approach to ETETA, which allowed satisfactory visualization of ITF. The morphological evaluation showed that the lateralization of the pharyngotympanic tube and related structures allowed a surgical corridor to reach the ITF. Endoscopic surgery through the pharyngotympanic tube is challenging, and in-depth understanding of the key anatomic relationships is critical for performing this approach.

Use of lateral femoral cutaneous nerve blocks by landmark technique is ineffective in decreasing narcotic usage after skin grafts: A retrospective case-control study.

INTRODUCTION: Cutaneous burns are commonly treated with autologous skin grafts. Following skin grafting, many patients complain of pain at the donor site. Donor sites are taken most commonly from the lateral thigh, which is innervated by the lateral femoral cutaneous nerve (LFCN). Use of a LFCN blocks should decrease nociception from the donor site. METHODS: Our group began utilizing LFCN blocks in 2019. Utilizing anatomic landmarks, LFCN blocks were performed on all patients who received autologous skin grafts to reduce perioperative pain. A retrospective cohort study was performed on all patients with 10% or less total body surface areas burns who received an autologous skin graft. A similar cohort from 2016, prior to use of any local or regional analgesia, was used as a historical control. Post-operative enteral and parenteral narcotic analgesics were collected for each post-operative day up to day 5 or discharge (whichever came first) and converted to morphine milligram equivalents (MME) to quantify analgesia after surgery. RESULTS: Chart review identified 55 patients in the 2020 cohort. Fifty-five patients from the 2016 cohort were matched based upon size of skin graft, total body surface area (TBSA) burned, gender, and age. There were no statistically significant differences between the two groups in terms of size of graft, TBSA burned, age, gender, or type of burn. When examining narcotics usage in the immediate perioperative period (days 0-2), we found no difference between the two groups for total MME (113 vs 133, p = 0.28) or IV MME (38 vs 33, p = 0.45). Similar relationships existed in the extended post-operative period (days 1-5) for total MME (149 vs. 188, t = 0.22) or IV MME (37 vs. 50, t = 0.25). Examining daily narcotic usage also yielded no statistically different values. CONCLUSION: Our data shows that use of LFCN block by landmark technique did not reduce narcotic usage in patients that undergo skin grafting procedures. Future studies should consider ultrasound-guided LFCN blocks.

Correlation analysis of airway-facial phenotype in Crouzon syndrome by geometric morphometrics: A promising method for non-radiation airway evaluation.

AIM: This study aimed to verify the correlation of the airway-facial phenotype and visualize the morphological variation in Crouzon syndrome patients. Additionally, to develop a non-radiation methodology for airway assessments. METHOD: In this study, 22 patients diagnosed with Crouzon syndrome (Age: 7.80 ± 5.63 years; Gender distribution: 11 females and 11 males) were analysed. The soft tissue surface and airway were three-dimensionally reconstructed, and the entire facial phenotype was topologized and converted into spatial coordinates. Geometric morphometrics was employed to verify the correlation and visualize dynamic phenotypic variation associated with airway volume. A total of 276 linear variables were automatically derived from 24 anatomical landmarks, and principal component analysis (PCA) identified the 20 most significant parameters for airway evaluation. Correlation analyses between parameters and airway volume were performed. Then, patients were classified into three groups based on airway volume, and the differences among the groups were compared for evaluating the differentiating effectiveness of parameters. RESULTS: The facial phenotype was strongly correlated with the airway (coefficient: 0.758). Morphological variation was characterized by (i) mandibular protrusion and anticlockwise rotation; (ii) midface retrusion; (iii) supraorbital frontward and (iv) lengthening of the facial height. All the anthropometric parameters were strongly associated with the airway, and the differences among the groups were statistically significant. CONCLUSION: This study confirmed the strong correlation between facial phenotype and airway parameters in Crouzon syndrome patients. Despite the development of the airway, pathological midface retrusion was still aggravated, suggesting that surgical intervention was inevitable. Three-dimensional facial anthropometry has potential as a non-radiation examination for airway evaluation.

The Sellar Region as Seen from Transcranial and Endonasal Perspectives: Exploring Bony Landmarks Through New Surface Photorealistic Three-Dimensional Model Reconstruction for Neurosurgical Anatomy Training.

BACKGROUND: Virtual reality-based learning of neuroanatomy is a new feasible method to explore, visualize, and dissect interactively complex anatomic regions. We provide a new interactive photorealistic three-dimensional (3D) model of sellar region microsurgical anatomy that allows side-by-side views of exocranial and endocranial surfaces to be explored, with the aim of assisting young neurosurgery residents in learning microsurgical anatomy of this complex region. METHODS: Four head specimens underwent an endoscopic endonasal approach extended to the anterior and posterior skull base to expose the main bony anatomic landmarks of the sellar region. The same bony structures were exposed from a transcranial perspective. By using a photogrammetry method, multiple photographs from both endocranial and exocranial perspectives, different for angulations and depth, were captured, fused, and processed through dedicated software. RESULTS: All relevant bony structures were clearly distinguishable in the 3D model reconstruction, which provides several benefits in neuroanatomy learning: first, it replicates bony structures with high degrees of realism, accuracy, and fidelity; in addition, it provides realistic spatial perception of the depth of the visualized structures and their anatomic relationships; again, the 3D model is interactive and allows a 360° self-guided tour of the reconstructed object, so that the learner can read the bones and their anatomic relationship from all desired points of view. CONCLUSIONS: Detailed knowledge of key surgical landmarks representing keyholes and/or anatomic structures to not violate is mandatory for safer surgery, especially for a complex region such as the skull base. Highly accurate virtual and functional neurosurgical models, such as photogrammetry, can generate a realistic appearance to further improve surgical simulators and learn neuroanatomy.

Accuracy of Cutaneous Landmarks Compared to Ultrasound to Locate the Calcaneal Footprint of the CFL.

The purpose was to determine the accuracy of the techniques of Lopes et al. and Michels et al., compared to ultrasound, to locate the center of the calcaneal footprint of the CFL in healthy volunteers. The authors recruited 17 healthy adult volunteers at 1 center with no current ankle pathologies and no previous surgical antecedents on either ankle. The authors recorded the age, sex, height, BMI, and ankle side for each volunteer. Measurements were made on both ankles of the 17 volunteers to increase the sample size and ensure less dispersion of data, independently by 2 surgeons: 1 senior surgeon with 15 years' experience and 1 junior with 3 years' experience. The location of the center of the calcaneal footprint of the CFL was determined by each surgeon using 3 methods: (1) the cutaneous technique of Lopes et al., (2) the cutaneous technique of Michels et al., and (3) ultrasound imaging. The 17 volunteers (34 feet) had a mean age of 26.3 ± 8.7 and a BMI of 21.7 ± 2.9. The Michels point was significantly closer (4.6 ± 3.7 mm) than the Lopes point (11.1 ± 5.4 mm) to the true center of the calcaneal footprint of the CFL determined by ultrasound, notably in the vertical direction. The Michels point was located significantly closer to the true center of the calcaneal footprint of the CFL and demonstrated less dispersion than the Lopes point, indicated by significantly lower absolute mean deviation from the true center of the calcaneal footprint of the CFL, and that ultrasound is therefore preferred to locate the footprint the CFL.

The accuracy and reliability of different midsagittal planes in the symmetry assessment using cone-beam computed tomography.

Symmetry is an essential component of esthetic assessment. Accurate assessment of facial symmetry is critical to the treatment plan of orthognathic surgery and orthodontic treatment. However, there is no internationally accepted midsagittal plane (MSP) for orthodontists and orthognathic surgeons. The purpose of this study was to explore a clinically friendly MSP, which is more accurate and reliable than what is commonly used in symmetry assessment. Forty patients with symmetric craniofacial structures were analyzed on cone-beam computed tomography (CBCT) scans. The CBCT data were exported to the Simplant Pro software to build four reference planes that were constructed by nasion (N), basion (Ba), sella (S), odontoid (Dent), or incisive foramen (IF). A total of 31 landmarks were located to determine which reference plane is the most optimal MSP by comparing the asymmetry index (AI). The mean value of AI showed a significant difference (p < 0.05) among four reference planes. Also, the mean value of AI for all landmarks showed that Plane 2 (consisting of N, Ba, and IF) and Plane 4 (consisting of N, IF, and Dent) were more accurate and stable. In conclusion, the MSP consisting of N, Dent, and IF shows more accuracy and reliability than the other planes. Further, it is more clinically friendly because of its significant advantage in landmarking.

Angle Evaluation of Possible Routes that Can Be Used to Reach the Foramen Ovale in the Anterior Approach / Evaluación Angular de Posibles Rutas que se Pueden Utilizar para Alcanzar el Foramen Oval en el Abordaje Anterior

SUMMARY: For the treatment of trigeminal neuralgia, the foramen ovale is reached by entering the cheek with a needle. Thermocoagulation is performed with balloon compression, administration of alcohol or radiofrequency. Apart from the classical method, it is theoretically possible to reach the foramen ovale through the mouth with the anterior approach. In our study, it was aimed to examine horizontally and vertically the angular values that must be given to the needle to reach the foramen ovale in the anterior approach. Three landmark points were determined on both right and left sides of 25 dry skulls. A rod was inserted starting from these landmark points and passing through the center of the foramen ovale. The vertical and horizontal angular values of this bar were measured. For each foramen ovale, 3 vertical angles, 3 horizontal angles and 4 distance measurements were made. There was a significant difference between the right and left sides in terms of horizontal angular values. Average values of horizontal angles (in degrees); on the right, 7.29 for H1, 12.15 for H2, 32.29 for H3; 1.26 for H1, 9.46 for H2, and 30.56 for H3 on the left side (p<0.005). The angle value was measured as 0 or negative value in 5 (20 %) of the H1 angle measurements made on the right side and 14 (56 %) on the left side. The H2 angle value was found to be smaller than the H1 angle in the skull 2 (8 %) on the right and 3 (12 %) on the left. There was no difference between the right and left sides in terms of vertical angular values. A significant difference was found between the right and left sides in the D1, D2, D4 distances (p<0.005). Six important anatomical features affecting angular values were encountered.

Para el tratamiento de la neuralgia del trigémino, se alcanza el foramen oval introduciendo una aguja en la mejilla. La termocoagulación se realiza con compresión con balón, administración de alcohol o radiofrecuencia. Aparte del método clásico, en teoría es posible alcanzar el foramen oval a través de la cavidad oral mediante el abordaje anterior. En nuestro estudio se tuvo como objetivo examinar horizontal y verticalmente los valores angulares que se deben dar a la aguja para alcanzar el foramen oval en el abordaje anterior. Se determinaron tres puntos de referencia en los lados derecho e izquierdo de 25 cráneos secos. Se insertó una varilla comenzando desde estos puntos de referencia y pasando por el centro del foramen oval. Se midieron los valores angulares verticales y horizontales de esta barra. Para cada foramen oval se realizaron mediciones de 3 ángulos verticales, 3 ángulos horizontales y 4 distancias. Hubo una diferencia significativa entre los lados derecho e izquierdo en términos de valores angulares horizontales. Valores medios de ángulos horizontales (en grados); a la derecha, 7,29 para H1, 12,15 para H2, 32,29 para H3; 1,26 para H1, 9,46 para H2 y 30,56 para H3 en el lado izquierdo (p<0,005). El valor del ángulo se midió como 0 o valor negativo en 5 (20 %) de las mediciones del ángulo H1 realizadas en el lado derecho y 14 (56 %) en el lado izquierdo. Se encontró que el valor del ángulo H2 era menor que el ángulo H1 en el cráneo 2 (8 %) a la derecha y 3 (12 %) a la izquierda. No hubo diferencia entre los lados derecho e izquierdo en términos de valores angulares verticales. Se encontró diferencia significativa entre el lado derecho e izquierdo en las distancias D1, D2, D4 (p<0,005). Se encontraron seis características anatómicas importantes que afectan los valores angulares.

Analysis of the Asterion Morphology in Relation to Its Clinical Significance / Análisis de la Morfología del Asterion en Relación con su Importancia Clínica

SUMMARY: The asterion presents a significant anthropological marking and meeting point between three sutures. It is a surface landmark for the transverse-sigmoid venous sinus complex and is also a surgical landmark for access to the posterior cranial fossa, giving it clinical importance. The aim of this research was to analyze the shape of the asterion and to set the measurement methods that will determine distance between the asterion and surrounding features. The study sample, as a part of the Osteological collection of the Department of Anatomy, Faculty of Medicine Novi Sad, consisted of 43 skulls. Morphometric analysis was related to the measurement of the defined parameters and descriptive analysis presented the classification of asterion in relation to the presence of sutural bones, as well as the determination of the position of the asterion according to the transverse-sigmoid venous complex. There was a statistically significant difference between male and female skulls for all the measured parameters. The results show that 34.88 % were type 1 (one or more sutural bones are present) and 65.12 % were type 2 asteria (no sutural bones are present). More frequent occurrence of asteria type 2 was seen on both, male and female skulls. The most frequent position of the asteria on both sides of the skull was in the transverse- sigmoid venous complex (76.92 % on the right side vs. 72.22 % on the left cranial side). Clinical significance of knowing the area of asterion is reflected in order to make the surgical, as well as diagnostic procedures, as successful as possible.

El asterion presenta una importante marca antropológica y punto de encuentro entre tres suturas. Es un punto de referencia de superficie para el complejo del seno venoso sigmoideo transverso y también es un punto de referencia quirúrgico para el acceso a la fosa craneal posterior, lo que le confiere importancia clínica. El objetivo de esta investigación fue analizar la forma del asterión y establecer los métodos de medición que determinarán la distancia entre el asterión y las características circundantes. La muestra del estudio, que forma parte de la colección osteológica del Departamento de Anatomía de la Facultad de Medicina de Novi Sad, estuvo compuesta por 43 cráneos. El análisis morfométrico se relacionó con la medición de los parámetros definidos y el análisis descriptivo presentó la clasificación del asterion en relación a la presencia de huesos suturales, así como la determinación de la posición del asterion según el complejo venoso transverso-sigmoideo. Hubo una diferencia estadísticamente significativa entre los cráneos masculinos y femeninos para todos los parámetros medidos. Los resultados muestran que el 34,88 % eran tipo 1 (hay uno o más huesos suturales presentes) y el 65,12 % eran asteria tipo 2 (no hay huesos suturales presentes). Se observó una aparición más frecuente de asteria tipo 2 en cráneos tanto masculinos como femeninos. La posición más frecuente de la asteria en ambos lados del cráneo fue en el complejo venoso sigmoideo transverso (76,92 % en el lado derecho vs. 72,22 % en el lado craneal izquierdo). La importancia clínica de conocer el área de asterion se refleja en que los procedimientos quirúrgicos y de diagnóstico tengan el mejor resultado posible.