Horizontal Width Research Articles

Hard and soft tissue evaluation of alveolar ridge preservation compared to spontaneous healing: a retrospective clinical and volumetric analysis

The remodeling process following tooth extraction can be observed as horizontal and vertical bone reduction of the alveolar ridge. Preservation procedures such as alveolar ridge preservation (ARP) aim to maintain the 3D volume of the extraction site. This retrospective study analyzed differences in the hard and soft tissue changes in patients treated with either spontaneous healing or ARP. After tooth extraction, the patients were treated either by spontaneous socket healing (SH group) or with ARP using a xenograft and a resorbable membrane (ARP group). One week before and 6months after extraction, the patients underwent cone beam computed tomography. A volumetric analysis was performed by superimposing the digital models of the two time points. Intraoral radiography was performed after implant placement, upon prosthesis delivery, and at 1-year post-treatment. An esthetic assessment was conducted using the Pink Esthetic Score (PES). The patients' overall satisfaction with the implant restoration was investigated at 12months. Intragroup comparisons revealed significant differences between baseline and the 6-month follow-up in both groups at the measured locations (1mm, 3mm, and 5mm below the most coronal aspect of the alveolar ridge) showing a reduction of the horizontal width (P < 0.05). Additionally, after treatment, the horizontal width at 1mm was significantly different in the SH and ARP groups (P < 0.001), with mean changes of 2.03 ± 0.54mm and 0.86 ± 0.49mm, respectively. ARP was associated with an increased PES (11.6 ± 2.2) and a reduction in patients requiring additional grafting procedures in subsequent treatment phases (9% vs 26%; P = 0.11). In both groups, significant horizontal and vertical bone loss was observed after the extraction. ARP can reduce linear and volumetric shrinkage of the alveolar ridge, leading to improved outcomes. It can also simplify implant restoration.

Efficient generation of longitudinally polarized light needle with diffractive optical elements

Longitudinally polarized beams have unique properties that are different from a traditional transversely polarized beam. By modulating the amplitude, phase and polarization of the incident beam, various longitudinal polarization fields can be obtained in a large-numerical aperture focusing system. Here we propose a simple and efficient method to generate longitudinally polarized light needle with pure phase element and radially polarized Gaussian beam. The phase element is designed with simulated annealing algorithm. The high purity longitudinally polarized light needle formed near the focal point has a horizontal full width at half maximum of 0.39λ and a non-diffraction distance of 4λ. This method can be employed to design other pure phase elements for generating beams with special longitudinal polarization distributions.

Reconstruction of vertical alveolar ridge deficiencies utilizing a high-density polytetrafluoroethylene membrane /clinical impact of flap dehiscence on treatment outcomes: case series/

ObjectivesThe aim of this study was to evaluate the effects of membrane exposure during vertical ridge augmentation (VRA) utilizing guided bone regeneration with a dense polytetrafluoroethylene (d-PTFE) membrane and a tent-pole space maintaining approach by registering radiographic volumetric, linear and morphological changes.MethodsIn 8 cases alveolar ridge defects were accessed utilizing a split-thickness flap design. Following flap elevation VRA was performed with tent-pole space maintaining approach utilizing the combination of a non-reinforced d-PTFE membrane and a composite graft (1:1 ratio of autogenous bone chips and bovine derived xenografts). Three-dimensional radiographic evaluation of hard tissue changes was carried out with the sequence of cone-beam computed tomography (CBCT) image segmentation, spatial registration and 3D subtraction analysis.ResultsClass I or class II membrane exposure was observed in four cases. Average hard tissue gain was found to be 0.70 cm3 ± 0.31 cm3 and 0.82 cm3 ± 0.40 cm3 with and without membrane exposure resulting in a 17% difference. Vertical hard tissue gain averaged 4.06 mm ± 0.56 mm and 3.55 mm ± 0.43 mm in case of submerged and open healing, respectively. Difference in this regard was 14% between the two groups. Horizontal ridge width at 9-month follow-up was 5.89 mm ± 0.51 mm and 5.61 mm ± 1.21 mm with and without a membrane exposure respectively, resulting in a 5% difference.ConclusionsWith the help of the currently reported 3D radiographic evaluation method, it can be concluded that exposure of the new-generation d-PTFE membrane had less negative impact on clinical results compared to literature data reporting on expanded polytetrafluoroethylene membranes.

Hydrodynamic analyses of multiple porous plates attached to the front of a vertical composite breakwater

Based on the dual boundary element method, hydrodynamic performance analyses including the wave transmission, reflection, dissipation, forces, and moments were conducted on a vertical composite breakwater comprising a submerged rubble-mound breakwater with a vertical wall affixed to its top with horizontal porous plates. These analyses were performed over a wide range of relative water depths, horizontal plate configurations, horizontal plate quantities, widths, porosities, and plate depths of immersion and inclinations. The effects of altering the immersion depth of the vertical barrier and the submerged rubble-mound breakwater height were also investigated. Adding more horizontal plates to the vertical wall was found to help reduce wave transmission, energy dissipation, horizontal wave force, and wave-induced moments; however, this also increased the vertical wave force. Further, increasing the horizontal plate's relative width from 0.25 to 1.0 did not reduce the wave transmission significantly; this also reduced the horizontal wave force considerably, albeit at the expense of increasing the vertical wave force. Based on the results, a medium porosity of approximately 20% is recommended for the horizontal plates to ensure the optimal overall performance. Notably, the results of this study are expected to be useful for the optimal designs of this type of wave barrier.

CBCT Evaluation of Sticky Bone in Horizontal Ridge Augmentation with and without Collagen Membrane-A Randomized Parallel Arm Clinical Trial.

Guided bone regeneration (GBR) is a reliable technique used to treat ridge deficiencies prior or during implant placement. Injectable-platelet rich fibrin (i-PRF) laced with a bone substitute (sticky bone) has heralded the way for advancing the outcomes of bone regeneration. This study evaluated the efficacy of sticky bone in horizontal ridge augmentation with and without collagen membrane. A total of 20 partially edentulous patients (Group-I n = 10; Group-II n = 10) that indicated GBR were included, and the surgical procedure was carried out. In Group-I, the sticky bone and collagen membrane were placed in ridge-deficient sites and Group-II received only sticky bone. At the end of 6 months, 20 patients (Group-I (n = 10); Group-II (n = 10)) completed the follow-up period. A CBCT examination was performed to assess changes in the horizontal ridge width (HRW) and vertical bone height (VBH). A statistically significant increase in HRW (p < 0.05) was observed in both groups with mean gains of 1.35 mm, 1.55 mm, and 1.93 mm at three levels (crest, 3 mm, and 6 mm) in Group-I and 2.7 mm, 2.8 mm, and 2.6 mm at three levels in Group-II. The intergroup comparison revealed statistical significance (p < 0.05) with respect to HRW and KTW (Keratinised tissue width) gains of 0.775 at the 6-month follow-up. Sticky-bone (Xenogenic-bone graft + i-PRF) served as a promising biomaterial in achieving better horizontal bone width gain.

Comparison of Allogeneic Bone Plate and Guided Bone Regeneration Efficiency in Horizontally Deficient Maxillary Alveolar Ridges

(1) Background: Bone Lamina Technique and Guided Bone Regeneration (GBR) are commonly used for horizontally-deficient maxillary ridge reconstruction, although more detailed evaluation to assess the differences between such techniques is necessitated. (2) Methods: In this retrospective study, patients having a horizontal bone width of ≤4 mm in the maxilla, who were treated with Cortical Strut (CS), were collected to represent the “test group”, and those treated with GBR with no CS involvement represented the “control group”. A 1:1 mixture of autogenous bone (AB) and anorganic bovine bone (ABB) with resorbable collagen membrane was applied to both groups. Volumetric changes between groups were measured with cone-beam computed tomography (CBCT). The primary outcome represented volumetric graft resorption rate whilst the secondary outcomes represented any probable complications and implant insertion torque. (3) Results: A total of 36 patients were included in this study (36 grafted sites; 18 for CS group and 18 for GBR group). Mean bone graft volume reduction in the CS and GBR groups was 8.26 ± 1.60% and 14.36 ± 3.55%, respectively. The GBR group showed significantly more bone resorption than the CS group (p &lt; 0.001). Complications and insertion torque were similar between the groups (p &gt; 0.05). (4) Conclusions: Both CS and GBR techniques for hard-tissue augmentation provided sufficient bone graft mass volume for implant insertion, whereas CS demonstrated lower resorption rate at maxillary augmented sites, compared to GBR.

Assessment Of Changes In Alveolar Bone Width Around Dental Implants At Native And Reconstructed Bone Sites With CBCT

Background: The extraction of a tooth initiates a series of reparative processes involving alveolar bone, periodontal ligaments, and thegingiva.The present study was conducted to assess changes in alveolar bone width around dental implants at native and reconstructedbone sites with CBCT.Materials &amp; Methods: 56 patients who received dental implants of both genderswere subjected to thorough oral examination followedby CBCT scan of the implant recipient site. Dental implant insertion was done following all standardized measures. Horizontal alveolarbone widths around implants at three levels (subcrestal width 1 mm (CW1), subcrestal width 4 mm (CW4), and subcrestal width 7 mm(CW7)) were measured in all patients.Results: Out of 56 patients, males were 36 and females were 20. The mean bone width at CW1 pre- surgery was 7.04 mm and postsurgery was 6.82 mm, at CW4 pre- surgery was 9.81 mm and post- surgery was 9.12 mm and at CW7 pre- surgery was 11.36 mm andpost- surgery was 11.15 mm. The difference was significant (P&lt; 0.05). The bone width at CW1 at native bone was 0.35 mm and atARP/GBR was -0.03 mm, at CW4 at native bone was 0.58 mm and at ARP/GBR was 0.22 mm and at CW7 at native bone was 0.24mm and at ARP/GBR was 0.03 mm. The difference was non- significant (P&gt; 0.05).Conclusion: Significant alveolar bone width resorption was observed at only the middle third of all sites.CBCT scans can be used toobserve long-term changes in the alveolar bone width around dental implants at native and reconstructed bone sites.

Extended Superficial Musculoaponeurotic System Face-Lift With Vertical Vector for Asian Patients: A 3-Dimensional Analysis of Facial Contour.

In this study, the authors report the experience of extended superficial musculoaponeurotic system (SMAS) face-lift with the vertical vector in Asian ethnicity and investigate the 3-dimensional change of facial contour. A total of 32 patients with Korean ethnicity underwent extended SMAS face-lift with vertical vector from 2015 to 2018. Patients with aging face were included for the study subjects, whereas those who were diagnosed with any craniofacial deformity were excluded. Using 3-dimensional photogrammetry, surface contour analysis was performed in the cheek region to calculate the mean, maximal, and minimal difference of surface projection and global root mean square error between the preoperative and 1-year postoperative period. The change of horizontal facial widths and jawline angle was evaluated. In contour analysis, the mean difference of surface contour was highest in anterior, followed by lateral cheek and lower face, sequentially. The maximal difference of surface contour was highest in anterior cheek, followed by lateral cheek and lower face, whereas the minimal difference of surface contour was lowest in lower face, followed by anterior cheek and lateral cheek, sequentially. No significant differences in the midfacial and lower facial distances were observed between the preoperative and postoperative periods. There was significant increase of jawline angle, from 20.78 to 23.14 degree of mean value ( P =0.001). In conclusion, the extended SMAS face-lift with vertical vector can be an optimal option for Asian subjects in terms of the midfacial volumetric shift, sharpening of jawline and avoidance of midfacial widening.

Banana Pseudostem Width Detection Based on Kinect V2 Depth Sensor.

This study used Kinect V2 sensor to collect the three-dimensional point cloud data of banana pseudostem and developed an automatic measurement method of banana pseudostem width. The banana plant was selected as the research object in a banana plantation in Fusui, Guangxi. The mobile measurement of banana pseudostem was carried out at a distance of 1 m from the banana plant using the field operation platform with Kinect V2 as the collection equipment. To eliminate the background data and improve the processing speed, a cascade classifier was used to recognize banana pseudostems from the depth image, extract the region of interest (ROI), and transform the ROI into a color point cloud combined with the color image; secondly, the point cloud was sparse by down-sampling; then, the point cloud noise was removed according to the classification of large-scale and small-scale noise; finally, the stem point cloud was segmented along the y-axis, and the difference between the maximum and minimum values in the x-axis direction of each segment was calculated as its horizontal width. The center point of each segment point cloud was used to fit the slope of the stem centerline, and the average horizontal width was corrected to the stem diameter. The test results show that the average measurement error is only 2.7 mm, the average relative error was 1.34%, and the measurement time is only about 300 ms. It could provide an effective solution for the automatic and rapid measurement of stem width of banana plants and other similar plants.

Ocular dimensions by three-dimensional magnetic resonance imaging in emmetropic versus myopic school children.

Magnetic resonance imaging (MRI) has been used to investigate eye shapes; however, reports involving children are scarce. This study aimed to determine ocular dimensions, and their correlations with refractive error, using three-dimensional MRI in emmetropic versus myopic children. Healthy school children aged < 10 years were invited to take part in this cross-sectional study. Refraction and best-corrected distance visual acuity (BCDVA) were determined using cycloplegic refraction and a logarithm of the minimum angle of resolution (logMAR) chart, respectively. All children underwent MRI using a 3-Tesla whole-body scanner. Quantitative eyeball measurements included the longitudinal axial length (LAL), horizontal width (HW), and vertical height (VH) along the cardinal axes. Correlation analysis was used to determine the association between the level of refractive error and the eyeball dimensions. A total of 70 eyes from 70 children (35 male, 35 female) with a mean (standard deviation [SD]) age of 8.38 (0.49) years were included and analyzed. Mean (SD) refraction (spherical equivalent, SEQ) and BCDVA were -2.55 (1.45) D and -0.01 (0.06) logMAR, respectively. Ocular dimensions were greater in myopes than in emmetropes (all P < 0.05), with no significant differences according to sex. Mean (SD) ocular dimensions were LAL 24.07 (0.91) mm, HW 23.41 (0.82) mm, and VH 23.70 (0.88) mm for myopes, and LAL 22.69 (0.55) mm, HW 22.65 (0.63) mm, and VH 22.94 (0.69) mm for emmetropes. Significant correlations were noted between SEQ and ocular dimensions, with a greater change in LAL (0.46 mm/D, P < 0.001) than in VH (0.27 mm/D, P < 0.001) and HW (0.22 mm/D, P = 0.001). Myopic eyeballs are larger than those with emmetropia. The eyeball elongates as myopia increases, with the greatest change in LAL, the least in HW, and an intermediate change in VH. These changes manifest in both sexes at a young age and low level of myopia. These data may serve as a reference for monitoring the development of refractive error in young Malaysian children of Chinese origin.

Clinical tool to measure fluorescein patterns in orthokeratology.

BackgroundOrthokeratology (ortho-k) is an overnight clinical contact lens wear technique to correct myopia and to reduce myopia progression wearing reverse-geometry rigid gas-permeable lenses. The lens fitting procedure in clinical practice usually requires subjective assessment of fluorescein pattern (fluorescein “bull’s eye” pattern). The aim of this study was to develop a novel tool for fluorescein pattern measurements to reduce subjective practitioner dependency, especially in inexperienced practitioners, in ortho-k practice.MethodsA new MATLAB customized algorithm to measure the horizontal width of the four main zones of ortho-k fluorescein patterns (central bearing, tear reservoir, mid-peripheral bearing and edge lift) was designed. The algorithm was tested on a small image database consisting of 26 ortho-k fluorescein pattern images of 13 volunteers fitted with reverse geometry lenses (Seefree, Conoptica-Hecht Contactlinsen). The agreement between two independent observers and the ImageJ measurements was determined.ResultsThe new clinical tool provided similar measurements to ImageJ software for the central bearing (4.20 ± 0.74 and 4.27 ± 0.69 mm; P = 0.21), tear reservoir (1.69 ± 0.41 and 1.69 ± 0.45 mm; P = 0.69), mid-peripheral bearing (1.17 ± 0.11 and 1.13 ± 0.10 mm; P < 0.01) and edge lift (0.48 ± 0.06 and 0.48 ± 0.06 mm; P = 0.81) zones. Good agreement between the software (limits of agreement lower than ±0.55 mm) and inter-observer measurements (limits of agreement lower than ±0.66 mm) was found.ConclusionsThe proposed clinical tool for semiautomatic fluorescein pattern measurements in ortho-k could help to reduce practitioner dependency in fluorescein pattern assessment with future potential to introduce prediction algorithms or artificial intelligence methods in myopia control management.

Natural history and biomarkers of retinal dystrophy caused by the biallelic TULP1 variant c.148delG.

To report clinical features and potential disease markers of inherited retinal dystrophy (IRD) caused by the biallelic c.148delG variant in the tubby-like protein 1 (TULP1) gene. A retrospective observational study of 16 IRD patients carrying a homozygous pathogenic TULP1 c.148delG variant. Clinical data including fundus spectral-domain optical coherence tomography (SD-OCT) were assessed. A meta-analysis of visual acuity of previously reported other pathogenic TULP1 variants was performed for reference. The biallelic TULP1 variant c.148delG was associated with infantile and early childhood onset IRD. Retinal ophthalmoscopy was primarily normal converting to peripheral pigmentary retinopathy and maculopathy characterized by progressive extra-foveal loss of the ellipsoid zone (EZ), the outer plexiform layer (OPL), and the outer nuclear layer (ONL) bands in the SD-OCT images. The horizontal width of the foveal EZ showed significant regression with the best-corrected visual acuity (BCVA) of the eye (p< 0.0001, R2 = 0.541, F= 26.0), the age of the patient (p< 0.0001, R2 = 0.433, F= 16.8), and mild correlation with the foveal OPL-ONL thickness (p= 0.014, R2 = 0.245, F= 7.2). Modelling of the BCVA data suggested a mean annual loss of logMAR 0.027. The level of visual loss was similar to that previously reported in patients carrying other truncating TULP1 variants. This study describes the progression of TULP1 IRD suggesting a potential time window for therapeutic interventions. The width of the foveal EZ and the thickness of the foveal OPL-ONL layers could serve as biomarkers of the disease stage.

Correlation between extreme/ unusual ozone events and corona effect from electric power transmission &amp;#x26; distribution grids. Assessing the health and environmental impact of high-voltage direct current (HVDC) grid on ozone ground levels in Sao Paulo metropolitan area, Brazil.

• BACKGROUND AND AIM 1- Ozone ground levels pose a risk for public health 2- The increasing ozone levels measured in parts of the metropolitan area of Sao Paulo have brought the attention of researchers. Proposed mechanisms do not provide a clear outcome for establishing root causes, and for clarifying sources of ozone. Spatial distribution of ozone also depends on wind patterns. 3- As an alternate hypothesis for explaining unusual high levels of ozone, the corona discharge from electric transmission grid, known as corona effect, can play a significative role in the absence of, or in coincidence with other concomitant factors, to explain ozone (O3) and nitric oxide (NO) unusual levels. Negative coronas emits more ozone than Positive coronas. 4- The Environmental Protection Agency- EPA, found in a report of 1973 (EPA-650/4-73-003), following a research carried out in areas of high concentration of transmission lines that &amp;#x22;under minimal wind conditions, such transmission line concentrations can produce sizeable local ozone levels.” 5- Research applies geospatial and statistical analysis with the aim of better understanding correlations between exposures and ozone levels. • METHODS Geographic Information System (GIS)-based systems with average grid cell edge length of 10 km minimum. Global InMAP (Intervention Model for Air Pollution) with a variable resolution grid (4 km horizontal grid cell widths) in combination with GEOS- Chem simulations. Data analysis by machine-learning model. • RESULTS Applying Predictive Machine Learning algorithm as regression models, research found that coronas could generate significant ozone levels downwind of the power line. • CONCLUSIONS Evidence of correlation between unusual ozone measurements and location of key power electric grid transmission lines and distribution centers with potential for corona effect are found in Sao Paulo state and Sao Paulo city metropolitan area. • KEYWORDS Corona effect, ozone, electric grids, spatial simulation, wind patterns, air pollution

Seismic Performance of ‘Rocking’ Dual-slot Track Internal Partition Walls with Concealed Joints under Lateral Cyclic Drift Demands

ABSTRACT This paper reports the seismic performance of two ‘rocking’ internal plasterboard partition wall specimens comprising dual-slot tracks (DST) with a) sacrificial L-trim (SLT) joints and b) boxed end-studs and standard plastered joints investigated under quasi-static cyclic drift demands. The top gap between the top DST and the wall allows it to rock up to the desired level of inter-story drift. The SLT joints between adjacent plasterboard panels failed after the top gap in the DST was exhausted. The plaster cracks in the joints between the in-plane and out-of-plane plasterboard panels occurred early at 0.20% drift. However, the ‘rocking’ specimen with boxed end-studs exhibited a comparable seismic resilience to partition walls with horizontal seismic gap widths along the partition wall indicating that these gaps can be significantly reduced when the wall is allowed to rock using the DST details for the same inter-story drift capacities.

Single access upper blepharoplasty and lower lid lateral fat pad removal: A proven technique with low recurrence rate

The transconjunctival approach is commonly performed in lower lid blepharoplasty so as not to violate the orbicularis oculi muscle integrity and avoid additional scars. This technique does not, however, permit easy access to the lateral fat pad (LFP). As upper and lower blepharoplasty are frequently combined in our clinical practice, the removal of LFP via upper blepharoplasty is a surgical approach that we found most applicable with good outcomes. A prospective review of 47 consecutive bilateral combined upper and lower blepharoplasty cases using a single access technique was conducted; patient outcomes and the occurrence of any complications were recorded, in addition to preoperative and postoperative measurements between standardized anatomical landmarks. Forty-seven patients were included in our study. Postoperative measurements showed a decrease of both lateral cantus to inferior orbital border distance and horizontal width of LFP. Good esthetic outcomes and patient satisfaction with surgical results were achieved in the majority of patients. The single access upper blepharoplasty and lower lid LFP removal technique can improve esthetic outcomes in lower blepharoplasty. The advantages are many; a low risk of missing the lateral pad, ease of achieving a uniform contour of lower eyelid; short lower transconjunctival incision, minimizing complications associated with an intra-conjunctival scar. This technique, based on cadaveric anatomical studies, has been found to be safe and is of great utility to those patients requiring upper and lower lid blepharoplasties.

Can surgeons rely on growth-related changes to achieve lip height and width symmetry in unilateral complete cleft lip repair?

Surgeons face difficulties achieving simultaneous lip height and width symmetry while repairing unilateral complete cleft lip, so one is often sacrificed at the expense of the other. The aim of this study was to evaluate the effect of growth on lip height and width symmetry, to guide the surgeon to the best decision. The study patients (N = 105) were divided into two groups based on the treatment method: 42 were treated with the modified rotational advancement technique (MRA group) and 63 with the Millard rotation-advancement technique (RA group). Furthermore, based on lip height and width symmetry at 6 months postoperative, the patients were divided into three groups: 38 with symmetrical lip height and width (SL), 41 with horizontal lip width more symmetrical than lip height (RAW), and 26 with vertical lip height more symmetrical than lip width (RAH). Measurements were taken preoperatively (T0), 6 months (T1) and 5 years (T2) postoperatively. The MRA group had significantly more symmetrical lip height than the RA group at T1 (P = 0.003) and T2 (P = 0.002); however no statistically significant difference in lip width symmetry was observed between the two groups. In relation to the effects of growth, only lip width symmetry in the RAH group improved significantly between T1 and T2 (P = 0.023). In conclusion the improvement in lip width symmetry following 5 years of postoperative growth did not achieve the same symmetry as when lip width symmetry was achieved intraoperatively. Thus, the MRA technique could be used to obtain intraoperative symmetry of lip height and width.

Longitudinal Evaluation of Changes in Retinal Architecture Using Optical Coherence Tomography in Achromatopsia.

PurposeThis prospective study investigates longitudinal changes in retinal structure in patients with achromatopsia (ACHM) using optical coherence tomography (OCT).MethodsSeventeen patients (five adults, 12 children) with genetically confirmed CNGA3- or CNGB3-associated ACHM underwent ocular examination and OCT over a follow-up period of between 2 and 9.33 years (mean = 5.7 years). Foveal tomograms were qualitatively graded and were segmented for quantitative analysis: central macular thickness (CMt), outer nuclear layer thickness (ONLt), and size of the foveal hyporeflective zone (vertical HRZ thickness: HRZt and horizontal HRZ width: HRZw) were measured. Data were analyzed using linear mixed regression models. Both age and visit were included into the models, to explore the possibility that the rate of disease progression depends on patient age.ResultsFifteen of 17 patients (88%) showed longitudinal changes in retinal structure over the follow-up period. The most common patterns of progression was development of ellipsoid zone (EZ) disruption and HRZ. There was a significant increase in HRZt (P = 0.01) and HRZw (P = 0.001) between visits and no significant change in CMt and ONLt. Retinal parameters showed no difference in changes by genetic mutation (CNGA3 (n = 11), CNGB3 (n = 6)).ConclusionsThis study demonstrates clear longitudinal changes in foveal structure mainly in children, but also in adults with ACHM, over a long follow-up period. The longitudinal foveal changes suggest that treatment at an earlier age should be favored.

On the Hydrostatic Approximation of Compressible Anisotropic Navier–Stokes Equations–Rigorous Justification

In this work, we derive the hydrostatic approximation by taking the small aspect ratio limit to the Navier–Stokes equations. The aspect ratio (the ratio of the depth to horizontal width) is a geometrical constraint in the general large scale geophysical motions meaning that the vertical scale is significantly smaller than horizontal. We derive the versatile relative entropy inequality. Applying the versatile relative entropy inequality we gave the rigorous derivation of the limit from the compressible Navier–Stokes equations to the compressible Primitive Equations. This is the first work where the relative entropy inequality was used for proving hydrostatic approximation - the compressible Primitive Equations.

Evolutionary trends in human mandibles and dentition from Neolithic to current Chinese

ObjectivesThis study aimed to systematically compare Neolithic mandibles and dentition with modern Chinese, and thereby discern human evolutionary trends. Materials and MethodsNeolithic remains of 45 adults unearthed at the Zhangqiu Jiaojia site, were compared with clinical records of 48 patients at Shandong University. All samples were scanned by cone beam computed tomography (CBCT) using identical parameters. Digital imaging and communications in medicine images were collected, three-dimensional models reconstructed, and morphology measurements obtained using Mimics software. ResultsNeolithic mandibles were significantly larger in their vertical and sagittal dimensions (P < .05), but similar in horizontal width to modern humans. Their condyles had fewer bird beak and crooked finger shaped morphologies than modern mandibles (P < .05). Neolithic third molars were more often erupted than in modern mandibles, and their Position A, class I and II, and vertical impactions were more common (P < .05). Neolithic teeth were generally smaller in crown lengths and in cross-sectional areas, than their modern counterparts (P < .05). ConclusionsNeolithic mandibles were larger than modern humans, who have refined diets and mandibular atrophy. They had fewer abnormally shaped condylar morphologies, and much fewer third molar impactions than in modern humans. However, modern dentition particularly their crowns are larger, likely through genetic influx from migrations.

Ridge augmentation using autologous concentrated growth factors enriched bone graft matrix versus guided bone regeneration using native collagen membrane in horizontally deficient maxilla: A randomized clinical trial.

Facial resorption of maxillary alveolar ridges is a challenging situation for implant rehabilitation, which mandates a preparatory surgery of bone augmentation. Guided bone regeneration using a 1:1 mixture of autogenous particulate and anorganic bovine bone mineral (ABBM) showed reliable outcomes in treating horizontally deficient ridges. Twenty-eight patients were randomly assigned into two groups; in the control group, the 1:1 mixture of particulate autogenous bone and ABBM was covered with native collagen membrane, while in the study group, it was mixed with autologous fibrin glue (AFG) to make a sticky bone that was covered by concentrated growth factor (CGF) membrane. For each proposed implant site, the average bone width gain was calculated preoperatively, immediately after augmentation and after 6 months. Implants were placed after 6 months and the implant stability quotient (ISQ) was measured after insertion and after 6 more months. The graft consolidation period went uneventful in both groups; however, two cases in the sticky bone group showed total resorption of the graft upon re-entry. The mean horizontal bone width after 6months was 9 mm ± 0.71 in the guided bone regeneration (GBR) group which was higher than 7.9 mm ± 0.92 for the sticky bone group. The mean primary stability was higher in the GBR group; 67.19 ± 2.23 compared to 66.7± 3.22 for the sticky bone group, while the mean secondary stability was higher in the sticky bone group; 72 ± 2.15 compared to 71.7± 2.27 for the GBR group. Results of Shapiro-Wilk's for bone width data and model residuals were both statistically not significant (p> 0.05). Comparing CGF membrane versus native collagen membrane as barriers for GBR showed no statistically significant difference regarding bone gain. However, from a clinical point of view, CGF membrane is not a predictable barrier for guided bone regeneration.