Posterior Zone Research Articles

Evaluation of thin-threaded implants primary stability in type IV bone right after maxillary sinus floor elevation: A human cadaver study.

The bone-implant interface plays a crucial role in obtaining sufficient primary stability for dental implants in weak bone supports. The aim of this human cadaver study was to evaluate the primary stability of new thin-threaded implants when placed in type IV bone right after maxillary sinus floor elevation. The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Twenty-four edentulous maxillary posterior zones with type IV bone and a residual bone height of 4mm were selected using computed tomography scans. First, an osteotome sinus floor elevation was performed (C.M.C Tech, IBS IMPLANT, Daejeon, South Korea). Implants with thin threads (MagiCore, IBS IMPLANT, Daejeon, South Korea) were placed simultaneously. Samples were divided into two groups: Group 1 (G1): 11mm-long implants with an elevation of 8mm; Group 2 (G2): 7mm-long implants with an elevation of 4mm. Primary stability was assessed using resonance frequency analysis (RFA). The average primary stability values in the mesiodistal (MD) direction were 45.67±3.09 Implant Stability Quotient (ISQ) for G1 and 38.76±16.94 ISQ for G2, and in the buccolingual direction were 43.33±13.23 ISQ for G1 and 38.47±16.14 ISQ for G2. The primary stability of the thin-threaded implants was compatible with clinical osseointegration in sinus sites with limited bone contact area in both experimental situations. Clinical studies are needed to confirm these encouraging results.

Adenomyosis Localized in Both the Anterior and Posterior Myometrium Is Associated with Deep Rectal Endometriosis: A Retrospective Study

Background: Endometriosis and adenomyosis are two closely related, estrogen-dependent, benign gynecological diseases. The available evidence on their common pathogenesis and association is limited and often does not address the heterogeneity of both entities. The aim of our study is to investigate the association between different types and localizations of adenomyosis and endometriosis phenotypes, using magnetic resonance imaging (MRI) and laparoscopic findings. Methods: We performed a retrospective observational study involving premenopausal women over 18 years old who underwent laparoscopic surgery for endometriosis and were pre-operatively diagnosed with adenomyosis through MRI examination at the Cantonal Hospital of Schaffhausen, Switzerland between 2011 and 2022. Results: Of 130 patients with adenomyosis, 23 (17.7%) women had adenomyosis only in the anterior wall (group 1), 38 (29.2%) only in the posterior wall (group 2), and 69 (53.1%) in both the anterior and posterior wall (group 3). Women in group 1 experienced significantly more dysuria compared to the two other groups (p = 0.018), while the prevalence of other pain symptoms (dysmenorrhea, dyspareunia, dyschesia) was comparable between the groups. Women in group 3 had significantly thicker anterior and posterior myometrium compared to groups 1 and 2 (p < 0.001). Co-existence of deep rectal endometriosis was more frequent in women from group 3 compared to groups 1 and 2 (p = 0.039) and in women with adenomyosis in the outer (extrinsic) compared to adenomyosis in the inner myometrium (intrinsic) (p < 0.001). Conclusions: This study provides evidence of an association between the localization of adenomyosis and the distribution of concomitant endometriosis. Specifically, adenomyosis localized in both the anterior and posterior wall appears to be more proliferative compared to adenomyosis found only in the anterior or posterior wall. This is indicated by its association with higher uterine volume, thicker posterior junctional zone, and greater myometrial thickness and with a higher co-existence with deep rectal endometriosis. These findings support an association between the development of specific subtypes of both entities, which represents a valuable resource for the identification of future targets for the treatment and clinical management of adenomyosis and endometriosis.

Term infant brain MRI after ROP treatment by anti-VEGF injection versus laser therapy.

Intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents is used to treat posterior type 1 retinopathy of prematurity (ROP). Recent reports indicate that anti-VEGF therapy may be associated with white matter brain injury, according to animal studies, and neurodevelopmental impairments in children born preterm. We investigated whether type 1 ROP treated with bevacizumab is associated with structural brain injury on infant term magnetic resonance images (MRIs) in very low birth weight infants compared with those treated with laser ablation. We retrospectively reviewed the medical records of very low birth weight infants from 2006 to 2021 with type 1 ROP who had been treated with laser or anti-VEGF therapy. Intravitreal bevacizumab injection was used for type 1 ROP in zone 1 or very posterior zone 2 or when laser treatment was not feasible. A pediatric neuroradiologist reviewed brain MRIs at term equivalent age (36-46 weeks' postmenstrual age) and classified infants for severity (no/mild vs moderate/severe) of overall brain and white matter injury using the validated Kidokoro scoring system. Fifty-two infants met inclusion criteria: 35 (67%) treated with laser and 17 (33%) with bevacizumab. Moderate-to-severe brain injury scores were not statistically different between bevacizumab and laser treatment groups in either continuous or binary adjusted analyses, for either the overall score or the white matter subscore. Severity of structural injury on term brain MRI (total and white matter) did not differ between infants with type 1 ROP treated with anti-VEGF agent (bevacizumab) and those treated with laser ablation.

Soft Tissue Contours at Pontic Sites With or Without Soft Tissue Grafting-A 15-Year Follow-Up of a Controlled Clinical Study.

To report on soft tissue contour changes at pontic sites with or without soft tissue grafting over an observation period of 15 years. Fourteen patients received a fixed dental prosthesis (FDP) in the posterior zone in a controlled clinical study and were available at the 15-year follow-up. Eight patients received a subepithelial connective tissue graft in the pontic area (test) while six received the FDP without soft tissue grafting (control). Impressions were taken after FDP cementation and at 15 years. Casts were digitized and a profilometric analysis was performed (mean distance) and the pontic height (PH) and ridge width (RW) were analyzed at the mid-buccal area. A descriptive analysis and Wilcoxon-Mann-Whitney test was performed (level of significance: 5%). Profilometric changes (mean distance) from baseline to 15 years amounted to -0.68 mm (test) and to -0.33 mm (control) (p = 0.208), 95% CI for group difference (0.290; -0.750). PH measured -0.47 mm (test) and 0.0 mm (control) (p = 0.079) and RW amounted to -1.05 mm (test) and -0.38 mm (control) (p = 0.138). Remodeling of the soft tissue contour at pontic sites of FDPs was evident in both groups, but slightly more accentuated following soft tissue grafting. This study is the first to report on soft tissue changes at pontic sites over more than 10 years. It investigates whether tissue contour changes with and without soft tissue grafting before the insertion of FDPs. Remodeling of the soft tissue contour at pontic sites was observed over 15 years, with more pronounced changes when soft tissues were augmented with SCTGs before FDP insertion. The volume loss at the augmented site must be considered in relation to the overall tissue changes over long periods. Connective tissue grafts reliably improve shape and esthetics around the pontic unit. Further long-term studies with more patients are needed to evaluate the initial gains and long-term performance of these augmentations.

Observation of dynamic position and morphological changes of temporomandibular joint discs under Angle's classification

Objective: To observe the dynamic changes of the temporomandibular joint (TMJ) disc in joint movement under different Angle's classification, providing reference for understanding joint functional movement and providing a basis for more accurate clinical imaging diagnosis. Methods: A total of 30 patients (13 males and 17 females) with temporomandibular disorders who were admitted to Beijing Friendship Hospital, Capital Medical University and General Hospital of the People's Liberation Army from January 2022 to April 2024 were enrolled. Thirty adults (13 males and 17 females) with different Angle's classification, with an average age of (34.4±8.5) years, were subjected to dynamic imaging of their TMJ from the closed position to the maximum opening position, and then to the closed position using MRI. The position and morphological changes of the articular discs were observed. Results: The results showed that volunteers with no displacement of the articular disc in class Ⅰ, Ⅱ, and Ⅲ relationships had different shapes of the articular disc during open and closed mouth movements. However, in the maximum opening position, the articular disc were all located directly below the maxillary nodules, and their shape is double concave. In terms of irreversible anterior displacement of the articular disc, in class Ⅰ Angle, the posterior zone of the disc contacts the anterior inclined plane of condyle from the maximum opening position back to the front of the closing position. In class Ⅱ, the posterior zone of the disc contacts the anterior inclined plane of condyle from the beginning of opening position to maximum opening position. In class Ⅲ, the posterior zone of the disc is always in contact with the anterior inclined plane of condyle throughout the entire movement process. And among them, the articular disc presents a forward displacement state at the closing position, its morphology undergoes folding phenomenon. When the openness is 2.5 cm, the articular disc moves up to a certain extent, and is closer to the anterior inclined plane of condyle, and its shape is also partially changed. When the openness is 4.3 cm, the shape of the articular disc, located between the anterior inclined plane of the joint node and the posterior inclined plane of the condyle, is typical double concave, which is sufficient to show that the articular disc is reversible when maximum opening position is reached. In terms of reversible anterior disc displacement, in class Ⅰ Angle, the posterior zone of the disc contact with the anterior inclined plane of condyle at the beginning of the opening position and the end of the closing position. In classⅡ Angle, the posterior zone of the articular disc is not in contact with the anterior inclined plane of condyle. In class Ⅲ Angle, the posterior zone of the articular disc contact with the anterior inclined plane of condyle at the end of the closing position. Conclusions: Multi level dynamic MR imaging data of the temporomandibular joint can dynamically observe the movement of the temporomandibular joint, intuitively and accurately display the position and shape of the articular disc during movement, and can serve as a useful supplement to static conventional MR imaging of the TMJ. The patient's TMJ needs to reach the maximum opening position in order to determine whether the joint disc displacement can be reversible or not.

7295 Giant Pituitary Adenoma with Rapid Symptomatic Progression and Postoperative Mortality

Abstract Disclosure: R.D. Kennedy: None. M. Nicholson: None. Introduction: Giant pituitary adenomas, defined as pituitary adenomas measuring greater than 4 cm, present a therapeutic challenge because of their size, clinical features, and increased potential for complications following surgical intervention. Early detection and intervention to prevent growth and progression is paramount. We present a case of a patient with a giant 6.3 cm pituitary adenoma who had significant neurologic compromise, requiring surgical intervention, with resultant postoperative complications and death. Case:Patient is a 41 year old male with known history of pituitary adenoma who presented on 11/1/2023, from outside hospital, to the Neuroendocrine clinic with complaints of excessive truncal obesity, impotence, fatigue, and apathy. Vital signs were within normal limits. Physical exam revealed clouding of consciousness, grossly intact cranial nerve function, truncal obesity, and diminished power, tone, and bulk of the extremities. Formal visual field testing revealed bitemporal hemianopsia. A head CT scan revealed a 6.3 cm sellar mass with expansion of the sella, invasion of soft tissue into the sphenoid sinus, and extension of soft tissue cranially to the level of the third ventricle eccentric to the left. There was no evidence of apoplexy. Lab results revealed Prolactin of 924 ng/mL. The patient had been taking Bromocriptine, 2.5 mg daily, for at least three weeks. Less than three weeks after his initial evaluation, he returned to the hospital with complaint of acute ataxia. Pituitary MRI revealed 6.3 cm sellar mass with evidence of acute and subacute blood products, stretching of the optic chiasm from mass effect, extension into the bilateral cavernous sinuses, superior left MCA displacement, posterior left PCA displacement, 5 mm midline shift, uncal herniation and descending transtentorial herniation. The patient underwent endoscopic transsphenoidal resection with subsequent craniotomy for debulking. Postoperatively, he developed new right sided hemiplegia with aphasia with subsequent MRI finding of watershed infarct at the left MCA/PCA lateral posterior border zone territories with increasing mass effect over a 30 day hospital stay. He developed progressive global edema with worsening uncal and tonsillar herniations. Brain death was pronounced on 11/30/23. Discussion:This case highlights the importance of early intervention in patients with giant pituitary adenomas. Our patient had been experiencing right sided weakness for at least one year prior to his admission to our facility. In this case, earlier treatment with a dopamine agonist may have decreased the size of the adenoma or prevented rapid growth. This may have precluded the need for surgical intervention on an adenoma of this size, which carries increased risk for postoperative complications. Presentation: 6/2/2024

Dual hyperpolarized [1-13C]pyruvate and [13C]urea magnetic resonance imaging of prostate cancer

BackgroundAlthough multiparametric (mp) 1H magnetic resonance imaging (MRI) is increasingly used to detect and localize prostate cancer (PC), its correlation with tumor grade is limited. Hyperpolarized (HP) carbon-13 (13C) MR is an emerging imaging technique, which can be used to interrogate key biologic processes through in vivo detection of various HP probes. A distinct attribute of HP 13C MRI is the ability to detect multiple HP probes within a single acquisition. Here we report on the first simultaneous dual HP [1-13C]pyruvate and [13C]urea MRI with correlations to histopathologic findings in a patient with localized PC scheduled for radical prostatectomy. Material and methodsPaired HP 13C and standard mp 1H MRI were performed in a patient with biopsy-proven Gleason score 4 + 3 = 7 adenocarcinoma of the prostate scheduled for radical prostatectomy through a first-in-human pilot study of dual-agent HP MRI (NCT02526368). HP 13C MRI was performed using a clinical 3T scanner with 13C transmit-and-receive capabilities. Dynamic series of HP 13C pyruvate, lactate and urea imaging were acquired following intravenous (IV) injection of co-hyperpolarized [13C]urea (25 mM) and [1–13C]pyruvate (125 mM). The [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) was calculated using an inputless two-site exchange model; AUCurea was the [13C]urea signal summed over time. Following radical prostatectomy, whole-mount prostate histopathological slides were prepared and reviewed by an experienced genitourinary pathologist. ResultsFollowing informed consent, the patient underwent paired mp 1H MRI and dual-agent HP MRI. mp 1H MRI revealed a 1.2 cm lesion in the left apical posterior zone. Dual-agent HP MRI identified a focus of increased [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) extending from the left apical posterior peripheral zone to the right gland. A corresponding area of abnormal tissue perfusion (AUCurea) was seen in the left gland. Metabolism-perfusion mismatch (with several foci of increased kPL/AUCurea) was observed throughout the tumor. Tumor extension to the right midgland was confirmed at the time of radical prostatectomy and staining for lactate dehydrogenase-A was increased throughout the tumor relative to surrounding benign prostatic tissue. ConclusionThis first-in-human radiopathologic study demonstrates the feasibility of dual-agent HP MRI in PC patients. Simultaneous assessment of tumor metabolism and perfusion was able to detect occult disease as well as to show a significant mismatch between intra-tumoral metabolism and tissue perfusion in high-grade PC. Prospective validation of these findings is warranted.

Revealing regional variations in scleral shear modulus in a rabbit eye model using multi-directional ultrasound optical coherence elastography

The mechanical properties of the sclera play a critical role in supporting the ocular structure and maintaining its shape. However, non-invasive measurements to quantify scleral biomechanics remain challenging. Recently introduced multi-directional optical coherence elastography (OCE) combined with an air-coupled ultrasound transducer for excitation of elastic surface waves was used to estimate phase speed and shear modulus in ex vivo rabbit globes (n = 7). The scleral phase speed (12.1 ± 3.2 m/s) was directional-dependent and higher than for corneal tissue (5.9 ± 1.4 m/s). In the tested locations, the sclera proved to be more anisotropic than the cornea by a factor of 11 in the maximum of modified planar anisotropy coefficient. The scleral shear moduli, estimated using a modified Rayleigh-Lamb wave model, showed significantly higher values in the circumferential direction (65.4 ± 31.9 kPa) than in meridional (22.5 ± 7.2 kPa); and in the anterior zone (27.3 ± 9.3 kPa) than in the posterior zone (17.8 ± 7.4 kPa). The multi-directional scanning approach allowed both quantification and radial mapping of estimated parameters within a single measurement. The results indicate that multi-directional OCE provides a valuable non-invasive assessment of scleral tissue properties that may be useful in the development of improved ocular models, the evaluation of potential myopia treatment strategies, and disease characterization and monitoring.

Effects On Palatal Surface Area In Mixed Dentition Patients Treated With Leaf Expander And Rapid Palatal Expander, Compared To Untreated Subjects: A Randomised Clinical Trial.

To evaluate palatal surface effects induced by LE and RPE, alongside spontaneous changes in an untreated group, and to compare differences in canine and molar inclination among the three groups. This randomised clinical trial aimed to compare digital models pre- and post-treatment over 12 months in patients receiving tooth-borne Leaf Expander® (LE) and tooth-borne Hyrax-type maxillary expander (RPE) treatments, alongside untreated patients. Analysis included 24 LE patients (13 males, 11 females, mean age 8.5±1.5), 22 RPE patients (10 males, 12 females, mean age 7.9±1.6), and 17 untreated subjects (7 males, 10 females, mean age 8.1±1.2). Inclusion criteria comprised indications for maxillary expansion treatment, mixed dentition, CVMS ≤ 3, erupted first molars, and good oral hygiene. Digital models were obtained using an intraoral scanner pre- and post-treatment. Palatal surface, segmented into anterior, median, and posterior zones, and canine/molar inclination were measured at T0-T1 using VAM software as the primary and secondary endpoint. Statistical analyses involved paired-sample T-tests for intra-group comparisons and ANOVA tests with Bonferroni correction for inter-group comparisons. No significant difference in palatal surface increment was found between the two experimental groups (LE and RPE); both demonstrated a significant increase in palatal surface. The greatest increment occurred in the median palate zone for both experimental groups. The increment in the untreated control group was not significant. Furthermore, the RPE group showed a greater inclination of permanent molars compared to those treated with LE, indicating that expansion with lighter and continuous forces may lead to fewer dental side effects.

Posterior Segment Manifestations of Syphilis and Correlation With Serologic Markers of Infection.

Retrospective analysis correlating serologic titers of ocular syphilis with posterior segment manifestations. This study consisted of 40 patients (80 eyes imaged, 68 affected) with positive rapid plasma reagin (RPR) and Treponema Pallidum immunoglobulin G. We collected demographic and presentation data including HIV status, absolute CD4 count, RPR, cerebrospinal fluid-venereal disease research laboratory (CSF-VDRL) test, and retinal zone. We categorized imaging into syphilitic outer retinopathy (SOR), acute syphilitic posterior placoid chorioretinopathy, retinitis/chorioretinitis (RC), and papillitis. Multivariate analysis correlated HIV status, RPR, and VDRL titers with posterior segment findings and zone. Mean age of 42.8 ± 10.7 years, with 70% male patients. Presenting visual acuity (logMAR) 0.66 ± 0.74 did not correlate with RPR, nor was it associated with papillitis, RC, or acute syphilitic posterior placoid chorioretinopathy. Higher RPR (≥ 1:128) positively associated with SOR (P = 0.031) and zone 1 (odds ratio [OR], 1.62; P = 0.02), but negatively associated with zone 2 (OR 0.35; P = 0.005). HIV positivity increased RC odds (OR, 4.45; P = 0.047). Higher RPR correlated with SOR and zone 1, whereas HIV positivity correlated with RC. [Ophthalmic Surg Lasers Imaging Retina 2024;55:511-516.].

New Ultrasound-Guided Approach to Access to the Posterolateral Part of Intervertebral Lumbar Discs: A Cadaveric Study.

Background: Approximately 40% of chronic low back pain patients have a discogenic origin. In relation to intervertebral disc injuries, most of them are in the posterior and lateral zone of the disc, involving the anterior lumbar roots and the spinal cord. Objective: The objective was to analyze and describe the accuracy and safety of a new ultrasound-guided approach to target the posterolateral part of the intervertebral lumbar discs in cadaveric specimens. Methods: A cross-anatomical study on sixty cadaver intervertebral lumbar discs was performed. A needle was introduced in the posterolateral part of the discs using ultrasound guidance. A transducer was placed in the anterior abdomen to visualize the discs in cross-section as well. A dissection of the specimen was performed to visualize the final position of the needle tip and its distance from the main lumbar structures. The angulation, length, and distance of the needle from the vertebral spine, the relevant ultrasound anatomical references, and the accuracy of the procedure were evaluated. Results: The needle tip reached the posterolateral part of the discs in 93.3% of the attempts. The mean length of the needle inserted was 79 ± 15 mm, the angulation 129 ± 20.2°, the distance from the spinous process was 77 ± 19 mm, and the distance of the needle to the nerve roots was 2.0 ± 1.2 mm. No statistically significant differences between genders were found. Conclusions: An ultrasound-guided technique can be an accurate and safe technique to perform invasive procedures on the posterolateral part of the intervertebral lumbar discs.

Clinical, radiographic and patient-reported outcomes of zirconia and titanium implants in the posterior zone after 1 year of loading-A randomized controlled trial.

To assess the clinical, radiographic and patient-reported outcomes (PROMs) of posterior zirconia and titanium implants at 1 year of implant loading. Forty-two patients with two adjacent missing teeth were enrolled in a randomized controlled trial with a within-subject controlled design. Each patient received one zirconia (Zr) and one titanium (Ti) implant, with the mesial and distal positions randomized. The implant restoration consisted of multiple layered zirconia, with the buccal aspect veneered. In group Zr, the restoration was intraorally cemented onto the one-piece Zr implant, whereas in group Ti, the restoration was extraorally cemented onto the titanium base abutment and intraorally screw-retained onto the Ti implant. Examinations were performed following restoration delivery at baseline (BL) and at 1 year. Measurements included clinical parameters, radiographic outcomes (MBL) and PROMs. Bleeding on probing showed an increase from BL to 1 year (34 ± 30% for Zr; 25 ± 21% for Ti). MBL remained stable with minimal changes from BL to 1 year, measuring 0.1 ± 0.4 mm (mean ± SD) for Zr and -0.1 ± 0.7 mm for Ti. Veneering fractures were the most frequent technical complication and amounted to 17.5% in group Zr and 5% in group Ti (p = .100). Patients preferred Zr implants for their soft tissue color, with a significant difference in perception between patients and clinicians (p < .017). The study showed that both Zr and Ti implants had similar clinical outcomes, despite a high prevalence of mucositis and a few technical complications. Both implant types demonstrated stable marginal bone levels and similar patient-reported outcome measures.

Excellent accuracy of trained neonatal nurses in the detection of referral-warranted retinopathy of prematurity within an established telemedicine screening programme.

To evaluate level of agreement of specialist trained retinopathy of prematurity (ROP) nurses compared with an experienced paediatric ophthalmologist in detection of referral-warranted ROP (RWROP) using wide-field digital retinal imaging. This is a prospective, observational, blinded study of neonates in a level III neonatal intensive care unit, from July 2020 to November 2022. Image capture using wide-field digital retinal imaging followed by ROP grading and staging was completed by trained ROP nurses. This was then compared with findings by an experienced paediatric ophthalmologist. The primary outcome was presence of RWROP in either eye. One hundred and ninety-five neonates (55% male) with a total of 768 screening visits were included. At the initial screen, nurse and ophthalmologist agreed about presence of RWROP for 191 of 195 neonates (98%, kappa = 0.79, P < 0.0001), with 100% sensitivity for RWROP detection. Including all 768 screening episodes, agreement was 98% for RWROP. There was disagreement in 16 screenings (2%) for 11 (6%) neonates. Of the five screenings (0.7%) that the ophthalmologist thought were RWROP and the nurse did not, three were disagreements about whether the zone was posterior zone 2 or zone 1. We found excellent levels of agreement and add evidence that interpretations by specialist trained nurses could be safely integrated into a 'hybrid ROP screening system'.

Differential impact of chronic intermittent hypoxia and stress changes on condylar development

ObjectivesThis study aimed to determine the effects of chronic intermittent hypoxia (CIH) and stress change (SC) on the development of the condyle in mouth breathing rats. DesignA total of 120 4-week-old rats were randomly assigned to one of five groups. The control (Ctrl) group was the blank control and the intermittent nasal obstruction (INO) group was the positive control. Mild CIH (mCIH) and severe CIH (sCIH) groups were developed by adjusting environmental oxygen concentration and monitoring real-time blood oxygen saturation (SpO2). The SC group was developed using INO, increased environmental oxygen concentration, and real-time SpO2 monitoring. Six rats from each group were sacrificed for analysis at 0, 1, 2, or 4 weeks. ResultsSimilar to the INO group, condyle and mandibular body development in the sCIH group, but not in the mCIH group, was significantly inhibited compared with the Ctrl group. The SC group had inhibited development of the condyle, especially of the posterior zone, but had minimal impact on the growth of the mandible. ConclusionThe inhibitory effects of CIH on the development of the condyle and mandibular body were SpO2-dose-dependent. When SC occurred, inhibited development was observed in the posterior zone of condyle but not the whole mandible. These findings provide important insights for targeted interventions that address the consequences of mouth breathing in children.

Prosthodontic criteria for maxillary immediate occlusal loading, surgical classifications of atrophic maxillae, and presentation of a new implant/anatomic classification system for immediate maxillary rehabilitation.

Immediate full-arch occlusal loading for patients with atrophic edentulous maxillae satisfies critical needs for this specific type of edentulous patient after placement of implants with high levels of primary implant stability. The needs include improved aesthetics, limited immediate improved function, and elimination of removable prostheses. Classification systems exist for edentulous maxillae but they do not include specifics regarding posterior implant placement. In conjunction with anterior implants, posterior implants improve Anterior/Posterior (A/P) spreads, decrease cantilevered segments (CLs), and likely will improve implant and prosthetic success rates. The purposes of this article include presenting a new classification system that outlines the different types of implants now available which will likely achieve the requisite primary stability for immediate fixed rehabilitation. This proposed classification system identifies a relationship between different implant options currently available and the remaining quantity of bone in the first and second maxillary molar zones. The available literature regarding current classification systems was reviewed. The benefits and limitations of each system were described. The parameters associated with Immediate Occlusal Loading (IOL) for full arch maxillary prostheses include: posterior cantilever lengths of full arch fixed prostheses; existing A/P spread considerations for full arch prostheses; and introduction of a new classification system for atrophic posterior maxillary edentulous ridges were identified. Currently, there are no available classification systems that outline specific implant options for posterior maxillae which will likely achieve the minimum primary stability needed for immediate rehabilitation. A new classification system was proposed where the rationale was to show clinicians that when a certain amount of bone remains in the posterior maxilla, there are specific implants designed to maximize primary stability. High implant primary stability is required for rehabilitation with immediate fixed implant-supported provisional prostheses. The proposed classification system assists clinicians in understanding what implant geometry is available and can be expected to achieve the requisite primary stability for immediate occlusal loading based on the available bone in the posterior maxillary molar zone. This article reviewed current classification systems for edentulous maxillary patients, as well as clinical parameters required for full arch, immediate occlusal loading. It also presented a new classification system to assist clinicians in selecting appropriate implants and surgical techniques for immediate fixed rehabilitation of patients with atrophic maxillae.

Characteristics of retinal vascularization in reactivated retinopathy of prematurity requiring treatment and clinical outcome after reinjection of ranibizumab

This study aimed to determine whether the state of retinal vascularization after anti-vascular endothelial growth factor (anti-VEGF) injection can help predict the risk of reactivated retinopathy of prematurity (ROP) requiring treatment and whether repeated ranibizumab injection will be effective in such cases. We retrospectively reviewed 24 infants (43 eyes) who received ranibizumab monotherapy between January 2021 and December 2022. All eyes were classified as having non-retreated ROP or retreated ROP. The state of ROP at the time of treatment, the time required for resolution of plus disease, and the extent of vascularization at 4 and 8 weeks after treatment were analyzed. Extent of temporal retinal vascularization was measured with serial fundus images using disc-fovea distance (DF) unit and disc diameter (DD). Reactivated ROP requiring treatment occurred in six infants (25.0%) and ten eyes (23.3%) after ranibizumab treatment. The mean retreatment interval was 9.0 ± 3.3 weeks (range 4–16). In the retreated ROP group, the time required for the resolution of plus disease after primary injection was longer compared to the control group (13.3 days vs 5.2 days), with a mean ROP regression time of 3.4 weeks. All eyes in the retreated ROP showed retinal vascularization < 0.5 DF from the original site at 4 weeks after injection. In 90% of cases with retreated ROP, the extent of vascularization at 8 weeks after injection was within 1 DF from the original ROP site, and all cases showed reactivation in the posterior Zone II area. The extent of retinal neovascularization in the retreated group was an average of 0.7 DD (vs 1.7 DD) and 1.3 DD (vs 3.3 DD) at 4 and 8 weeks after injection, respectively. After ranibizumab retreatment, only one reactivated case with vitreous traction progressed to focal retinal detachment, while all other cases regressed with peripheral vascular development. The continuation of delayed retinal blood vessel development after ≥ 8 weeks may indicate a high likelihood of reactivated ROP requiring treatment. In the absence of vitreous traction, ranibizumab reinjection is likely to be effective in treating reactivated ROP requiring treatment.

The detection rate for prostate cancer in systematic and targeted prostate biopsy in biopsy-naive patients, according to the localization of the lesion at the mpMRI: A single-center retrospective observational study.

Evaluate the detection rates of systematic, targeted and combined cores at biopsy according to tumor positions in biopsy-naïve patients. A retrospective analysis of a single-center patient cohort (n = 501) that underwent transrectal prostate biopsy between January 2017 and December 2019 was performed. Multi-parametric MRI was executed as a prebiopsy investigation. Biopsy protocol included, for each patient, 12 systematic cores plus 3 to 5 targeted cores per lesion identified at the mpMRI. Pearson and McNemar chi-squared tests were used for statistical analysis to compare tumor location-related detection rates of systematic, targeted and combined (systematic + targeted) cores at biopsy. Median age of patients was 70 years (IQR 62-72), with a median PSA of 8.5 ng/ml (IQR 5.7-15.6). Positive biopsies were obtained in 67.7% of cases. Overall, targeted cores obtained higher detection rates compared to systematic cores (54.3% vs. 43.1%, p < 0.0001). Differences in detection rates were, however, higher for tumors located at the apex (61.1% vs. 26.3%, p < 0.05) and anteriorly (44.4% vs. 19.3%, p < 0.05). Targeted cores similarly obtained higher detection rates in the posterior zone of the prostate gland for clinically significant prostate cancer. A poor agreement was reported between targeted and systematic cores for the apex and anterior zone of the prostate with, respectively κ = 0.028 and κ = -0.018. A combined approach of targeted and systematic biopsy delivers the highest detection rate in prostate cancer (PCa). The location of the tumor could however greatly influence overall detection rates, indicating the possibility to omit (as for the base or posterior zone of the gland) or add (as for the apex or anterior zone of the gland) further targeted cores.

Material and abutment selection for CAD/CAM implant-supported fixed dental prostheses in partially edentulous patients - A narrative review.

Restorative material selection has become increasingly challenging due to the speed of new developments in the field of dental material science. The present narrative review gives an overview of the current indications for implant abutments and restoration materials for provisional and definitive implant-supported fixed dental prostheses in partially edentulous patients. For single implant restorations, titanium base abutments for crowns are suggested as an alternative to the conventional stock- and customized abutments made out of metal or zirconia. They combine the mechanical stability of a metallic connection with the esthetic potential of ceramics. For multiple-unit restorations, conical titanium bases especially designed for bridges are recommended, to compensate for deviating implant insertion axes and angulations. Even though titanium base abutments with different geometries and heights are available, certain clinical scenarios still benefit from customized titanium abutments. Indications for the definitive material in fixed implant restorations depend on the region of tooth replacement. In the posterior (not esthetically critical) zone, ceramics such as zirconia (3-5-Ymol%) and lithium-disilicate are recommended to be used in a monolithic fashion. In the anterior sector, ceramic restorations may be buccally micro-veneered for an optimal esthetic appearance. Lithium-disilicate is only recommended for single-crowns, while zirconia (3-5-Ymol%) is also recommended for multiple-unit and cantilever restorations. Attention must be given to the specific mechanical properties of different types of zirconia, as some feature reduced mechanical strengths and are therefore not indicated for all regions and restoration span lengths. Metal-ceramics remain an option, especially for cantilever restorations.

Temporal control of RNAi reveals both robust and labile feedback loops in the segmentation clock of the red flour beetle

Animals from all major clades have evolved a segmented trunk, reflected in the human spine or the insect segments. These units emerge during embryogenesis from a posterior segment addition zone (SAZ), where repetitive gene activity is regulated by a mechanism described by the clock and wavefront/speed gradient model. In the red flour beetle Tribolium castaneum, RNA interference (RNAi) has been used to continuously knock down the function of primary pair-rule genes (pPRGs), caudal or Wnt pathway components, which has led to the complete breakdown of segmentation. However, it has remained untested, if this breakdown was reversible by bringing the missing gene function back to the system. To fill this gap, we established a transgenic system in T. castaneum, which allows blocking an ongoing RNAi effect with temporal control by expressing a viral inhibitor of RNAi via heat shock. We show that the T. castaneum segmentation machinery was able to reestablish after RNAi targeting the pPRGs Tc-eve, Tc-odd, and Tc-runt was blocked. However, we observed no rescue after blocking RNAi targeting Wnt pathway components. We conclude that the insect segmentation system contains both robust feedback loops that can reestablish and labile feedback loops that break down irreversibly. This combination may reconcile conflicting needs of the system: Labile systems controlling initiation and maintenance of the SAZ ensure that only one SAZ is formed. Robust feedback loops confer developmental robustness toward external disturbances.

Multiparametric-magnetic resonance imaging (mp-MRI) of the prostate and Urolift: Identifying artefact size, location and clinical implications.

We sought to define the degree of artefact caused by prostatic urethral lift (PUL) on multiparametric-magnetic resonance imaging (mp-MRI) to determine the location, size of artefact and if the device could potentially obscure a diagnosis of prostate cancer. Ten patients were prospectively enrolled to undergo PUL for treatment of benign prostatic hyperplasia and follow-up imaging. A standard mp-MRI protocol using a 3.0 Tesla scanner was performed prior to and following Urolift insertion. Pre- and post-PUL images were compared to measure maximum artefact diameter around each implant in each MRI parameter. A transverse relaxation time weighted (T2) artefact reduction protocol was also evaluated. The location of each artefact was then compared to a separate database of 225 consecutive patients who underwent magnetic resonance guided prostate biopsies. Artefact occurred around the stainless steel urethral implant component only. Mean T2 artefact maximum diameter was 7.7mm (sd = 1.71 mm), with an artefact reduction protocol reducing this to 5.4mm (sd = 1.43). Mean dynamic-contrast-enhancement artefact was 10mm (sd = 2.5mm), and mean diffusion-weighted-imaging artefact was 28.2mm (sd = 7.8mm). All artefacts were confined to the posterior transition zone only. In the 225 consecutive patients who had undergone magnetic resonance guided prostate biopsies, there were 55 positive biopsies with prostate cancer, with 13 cases found in the transition zones and no cancer identified solely in the posterior transitional zone. The stainless steel urethral component of the PUL does cause artefact, which is confined to the posterior transition zone only. PUL artefact occurs in an area of the prostate that has a very low incidence of a single focus of prostate cancer. If there is concern for prostate cancer in the posterior TZ (e.g. if every other area is clear with a high PSA), this area can undergo targeted biopsy.