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The atlas (C1) and axis (C2) have distinct morphologies to support the skull and facilitate head rotation and neck flexion. Congenital defects of C1 posterior arch are rare. We present a case of a 59-year-old man with both an absent C1 posterior arch with concomitant os odontoideum. The patient presented with neck crepitus, moderate neck pain and progressive worsening upper limbs paraesthesia and pain. Computed tomography (CT) revealed non-union between the odontoid process and body of axis as well as absence of C1 posterior arch. An occiput C0-C3 fusion was performed. The patient's symptoms improved significantly, and he is functioning well at 12 months. CT showed solid fusion without implant migration. Concomitant os odontoideum with aplastic C1 posterior arch is rare with limited evidence to guide management. Posterior fixation and fusion may be a potential solution to prevent dynamic compression, thereby preventing further myelopathy and related complications.
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http://dx.doi.org/10.1093/jscr/rjaa019 | DOI Listing |
J Adv Prosthodont
August 2025
Department of Prosthodontics, Faculty of Dentistry, Necmettin Erbakan University, Konya, Turkey.
Purpose: This study aimed to evaluate the effect of clinically practical auxiliary geometric devices (AGD) on measurement trueness and scan time in full-arch implant-supported prostheses, focusing on different intraoral scanners (IOS) and implant angulations.
Materials And Methods: Four implants were planned in an edentulous maxillary arch and divided into two groups based on posterior implant angulation: Model A (Parallel) and Model B (30°). Each model was evaluated under three auxiliary geometric devices (AGD) application types (std, agd1, agd2), and scanned using three different intraoral scanners (IOSs) [3Shape Trios 3 (T), Medit i700 (M), and Cerec Primescan (PS)], resulting in nine groups per model (n = 10).
J Dent
September 2025
Maxillofacial Prosthodontist, Surgical Prosthodontist Private Practice Fort Lee, NJ, and Manhattan, New York, USA. Electronic address:
Objectives: Precise implant placement in the anterior and posterior maxilla often presents challenges due to variable bone and soft tissue anatomy. Many clinicians elect a freehand surgical approach because conventional surgical guides may not always be easy to design, fabricate, or utilize. Guided surgery has been proven to have advantages over freehand surgical protocols and therefore, the present study proposed utilizing the nasopalatine canal (NPC) as an anatomical reference and point of fixation for a novel rotational path surgical template during computer-aided implant surgery (CAIS).
View Article and Find Full Text PDFEur Radiol
September 2025
Department of Radiology, Bilkent City Hospital, Ankara, Turkey.
Objective: To compare tibial tubercle-trochlear groove (TT-TG) and tibial tubercle-Roman arch (TT-RA) distances in patients with patellar dislocation or subluxation, evaluate TT-RA reliability and reproducibility, and determine pathological threshold values for surgical treatment using magnetic resonance imaging (MRI) and computed tomography (CT).
Materials And Methods: Retrospective analysis included 259 patient and 262 control examinations of knee MRIs and/or CTs performed. TT-RA, TT-TG, and tibial tubercle-posterior cruciate ligament (TT-PCL) distances, Roman Arch height, trochlear sulcus angle, and total femoral condyle width were measured by two radiologists, and trochlear morphology was assessed.
JACC Case Rep
September 2025
Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan.
Background: A vascular ring arises during the development of the fetal arches and is often associated with a double aortic arch or right-sided aorta, an aberrant left subclavian artery with a posterior esophageal component, and a left-sided ductus arteriosus.
Case Summary: This is a rare vascular ring formed by a left aortic arch, aberrant right subclavian artery, and right ductus arteriosus that was diagnosed prenatally by fetal echocardiography. The 3-vessels and trachea (3VT) view with 2-dimensional and color Doppler sweeps were helpful in defining the vascular pathology.
Orthod Craniofac Res
September 2025
Department of Orthodontics, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
Hyperdivergent skeletal Class II malocclusion is largely genetically determined and poses significant challenges in orthodontic treatment, particularly due to compromised facial aesthetics, reduced bite force and airway narrowing. Traditionally, orthognathic surgery has been the standard treatment for correcting such skeletal discrepancies. However, the advent of temporary skeletal anchorage devices (TSADs) has expanded the possibilities for orthodontic camouflage by allowing effective vertical control.
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