Ridge Thickness Research Articles

Alveolar Kret Ayırma Tekniği ile Atrofik Çenelere Konik ve Silindirik İmplantların Yerleştirilmesinin 3B Sonlu Eleman Analizi ile Değerlendirilmesi: Analitik Çalışma

Objective: Alveolar ridge splitting technique (ARST) is a horizontal bone augmentation technique used in atrophic alveolar ridge. The present study aimed to evaluate the insertion of conical and cylindrical implants with the same surface structure in atrophic alveolar ridges augmented by ARST and to analyze the stress distributions on the implant and adjacent bone surfaces using three dimensional (3D) finite element analysis (FEA). Material and Methods: The thickness of the atrophic alveolar ridge was adjusted to 5 mm. The implants were inserted in the atrophic alveolar ridges that were augmented by ARST with a torque of resistance of 35 Newtons. Stress distributions were evaluated by using FEA. Results: The results indicated that the conical implants resulted in lower strain on the implant and adjacent bone surfaces compared to cylindrical implants. It was also revealed that conical implants had a homogeneous stress distribution on the implant surfaces while the stress in cylindrical implants was mostly concentrated on the neck region. As the diameter of the implants increased, the Von Mises stress values on the adjacent bone surfaces decreased. Conclusion: Although no definitive recommendations can be made regarding the design of the implants used in ARST, the results of the present study indicated that conical implants could be more advantageous than cylindrical implants with regard to stress distribution.

Immediate implants with buccal defects filled with bone from the tuberosity or a xenograft: 1-year randomized trial.

The aim of this study was to compare the use of autologous bone from tuberosity (TUBER) and deproteinized bovine bone mineral (DBBM) in immediate implants with buccal bone defects. A total of 31 patients with one single tooth in the upper anterior region indicated for extraction presenting tomographic buccal bone defect were analyzed. Immediate implantation was conducted for all patients. In one group, DBBM and a collagen membrane were inserted into the buccal defect; in the other group, a small block of bone from tuberosity was used. The primary outcome was facial-palatal ridge thickness (FPT) measured in casts 1 year after function. The implant success rate was 100% in both groups. FPT changes were <0.5 mm and did not differ significantly between groups. FPT reductions in the DBBM and TUBER groups were 1% and 0.6%, respectively, at the gingival margin and 5% and 2%, respectively, at 6 mm apical of the gingival margin (p > 0.05). No significant differences were observed between groups for patient's esthetic, satisfaction, pain and quality of life. Pink esthetic scores for the DBBM and TUBER were 11.5±1.7 and 10.8±1.9, respectively (p=0.37). It can be concluded that DBBM and TUBER did not differ in terms of ridge alterations, peri-implant clinical parameters and patient-reported outcomes.

Seed Micromorphology of Eleven Species of Pleione (Orchidaceae)

The micromorphological characteristics of the seeds of 11 species of Pleione have been studied, both qualitatively and quantitatively, to establish whether they are useful for systematic studies of the genus. The quantitative characteristics include seed length (0.237–0.626 μm), seed width (0.053–0.133 μm), seed length/width ratio (2.631–7.279), seed ridge thickness (1.4 E-3–4 E-3μm) and seed volume (1.88 E-4–3.06 E-3 μm3). The cluster analysis result agrees well with the results of previous systematic studies. The cluster analysis shows that: P. coronaria, P. forrestii and P. yunnanensis form a group, while the remaining eight species form a second group, with three subgroups, namely: P. limprichtii, P. pleionoides, P. formosana as group I; P. hookeriana and P. bulbocodioides as group II; and P. praecox, P. scopulorum and P. maculata for group III. All the Pleione species of Sect. Pleione and Sect. Humiles show the fusion of adjacent seed coat cells into a network. The shape of the seeds of P. praecox and P. maculata are very similar--being oval, and the mesh walls of their adjacent seed coat cells are not fused. Within these sections no clear pattern can be seen between the species, but the addition of further species might clarify the differences between Sect. Pleione and Sect. Humiles.

Alveolar Ridge Preservation in Severely Damaged Molar Socket Using a Polylactic Acid Membrane Without Primary Wound Closure: A Case Series.

Untreated severely damaged molar sockets often complicate implant placement. This study evaluated membrane degradation, soft tissue healing, and alveolar crest dimensional changes after alveolar ridge preservation (ARP) in severely damaged molar sockets using a polylactic acid membrane (PLA) and xenograft without primary wound closure. A total of 14 damaged molar sockets in 12 patients were grafted with deproteinized bovine bone mineral, which was covered with a PLA membrane without primary wound closure. Wound healing was evaluated at set times. Three sets of CBCT data taken before surgery, at 1 to 2 weeks, and at 6 to 12 months after surgery were reconstructed and superimposed to analyze dimensional changes of the alveolar crest with volumetric imaging software. Two weeks after ARP, no degradation of PLA membrane was present, and the xenograft had either no exfoliation (7 sites, 50%) or mild exfoliation (6 sites, 42.9%). One to 2 months following ARP, the membrane was partially degraded in 6 sites (42.9%) and completely degraded in 8 sites (57.1%). Nine sites (64.3%) presented with mild graft particle exfoliation, and four sites (28.6%) had granulation tissue covering the bone graft. All sites were fully covered by keratinized mucosa by 6 to 12 months. Compared with baseline measurements, the vertical bone graft height decreased by 2.2 ± 2.2 mm, and central alveolar ridge thickness measured at the level of the virtual implant platform decreased by 5.0 ± 5.1 mm after 6 to 12 months. The exposed PLA membrane maintains some barrier function for at least 3 to 4 weeks after ARP in severely damaged molar extraction sites. This technique allowed for implant placements without additional grafting. Future studies should include histologic assessment of the augmented bone and nongrafted control sockets.

Mechanical failure of posterior teeth due to caries and occlusal wear- A modelling study

ObjectivesThe purpose of the present work is to explore the effect of occlusal wear and different types and degrees of caries on the mechanical performance and structural integrity of posterior teeth. MethodsThree-dimensional (3D) computational models with different combinations of caries parameters (caries location, caries size and caries induced pulp shrinkage) and occlusal wear factors (enamel thickness, marginal ridge height and cuspal slope) were developed and analyzed using the extended finite element method (XFEM) to identify the stress distribution, crack initiation load and ultimate fracture load values. The effect of a non-drilling conservative treatment using resin infiltration on the recovery of mechanical properties of carious molar teeth was also investigated. ResultsPresence of fissural caries, worn proximal marginal ridge and decreased enamel thickness due to occlusal wear, imparted a significant negative effect on the crack initiation load value of the lower molar models. Accordingly, models with intact and strong proximal marginal ridge, generally exhibited higher crack initiation loading, regardless of caries size and location. Presence of fissure caries drastically decreased (55%–70%) the crack initiation load compared to sound teeth. The depth of the fissural lesion and the presence of proximal caries did not have a major effect on crack initiation load values. However, increasing the caries size resulted in lower final fracture load values in most of the cases. Accordingly, the groups with combined and connected large fissural and proximal lesions experienced the largest drop in the fracture load values compared to sound tooth models. The worst condition consisted of two connected large proximal and fissural caries with no proximal marginal ridge, in which the fracture load dramatically decreased to only 25% of that for sound teeth with intact marginal ridge. On the other hand, decreased cuspal slope due to occlusal wear and shrinkage of the pulp due to caries appeared to have a protective role and a direct relation with the fracture resistance of the tooth. Following the application of resin infiltration on the carious models, the crack initiation load and the fracture load could recover up to 75% and 90% of the values for the corresponding sound tooth models, respectively. SignificancePresence of fissural caries, if not treated (either with remineralization, resin infiltration or restoration), can be a major risk factor in the initiation of tooth fracture. When combined with decreased enamel thickness and loss of proximal marginal ridge due to mechanical or chemical wear, the weakening effect of the caries will be amplified specially in teeth with steep cuspal slopes. The application of a conservative treatment with resin infiltration can be an effective approach in prevention of further mechanical failure of demineralized enamel. The findings of this study emphasize the importance of early interventions in the management of caries for the prevention of future cuspal or tooth fracture especially in subjects with higher risk factors for tooth fracture such as caries, wear and bruxism.

Splitting expansion and palatal approach technique for implant placement in severely resorpted maxilla

The treatment of patients with atrophic maxillary alveolar ridge who need oral rehabilitation is a common problem in Implant Dentistry. One of the techniques used is the alveolar ridge splitting technique to expand alveolar ridges with a horizontal bone decrease. The palatal approach technique is also recommended in cases with an insufficient thickness of the alveolar ridge for the placement of implants in the bone envelope. The aim of this work is to describe the splitting expansion and palatal approach technique for the treatment of atrophic maxillary ridges with a horizontal bone deficit and rehabilitation with implant placement. This technique combines the alveolar ridge splitting/expansion technique and the palatal approach technique. It allows alveolar ridge expansion using piezosurgery and immediate placement of implants without thread exposure in the palatal aspect. With one surgical time, this technique avoids the fracture of the buccal bone plate due to the expansion, eliminates the need for bone graft and donor-site morbidity, is simple and effective, and shows great esthetic results and implant success.

Association of Geometric Characteristics of Knee Anatomy (Alpha Angle and Intercondylar Notch Type) With Noncontact ACL Injury

Background: The femoral intercondylar notch type and the alpha angle (the angle between the femoral notch roof and the long axis of the femur) are easily measured in clinical settings; however, their associations with anterior cruciate ligament (ACL) injury remain unclear. Hypothesis/Purpose: The purpose was to determine if the alpha angle and the femoral notch type are associated with noncontact ACL injury univariately and in combination with previously identified knee geometric risk factors. We hypothesized that the alpha angle and the femoral notch type are associated with noncontact ACL injury and that the association differs between men and women. Study Design: Case control study; Level of evidence, 3. Methods: The alpha angle and the femoral notch type were measured via 3T magnetic resonance imaging (MRI) acquired from 61 women and 25 men with a first-time noncontact ACL injury. Each injured patient was matched with a control participant based on age, sex, and participation on the same sports team. A conditional logistic regression was used to assess univariate associations with ACL injury as well as multivariate associations using MRI-based risk factors of knee geometry identified in previous analyses: femoral intercondylar notch width at the anterior outlet, femoral intercondylar notch anteromedial ridge thickness, volume of the ACL, tibial plateau lateral compartment subchondral bone slope, lateral compartment middle articular cartilage slope, lateral compartment meniscus-cartilage height, lateral compartment meniscus-bone angle, and medial tibial spine volume. Results: For female athletes, the alpha angle (odds ratio, [OR], 1.82 per 1-degree increase; P = .001), the tibial lateral compartment articular cartilage slope (OR, 1.25 per 1-degree increase in the posterior-inferior directed slope; P = .022), and the femoral notch anteromedial ridge thickness (OR, 3.36 per 1-mm increase; P = .027) were independently associated with ACL disruption. For men, no other variables entered the models after the alpha angle was inputted as the first step (OR, 2.19 per 1-degree increase; P = .010). Conclusion: For women, ACL injury was most strongly associated with increased alpha angle, increased tibial plateau slope, and increased femoral notch ridge thickness. For men, increased alpha angle was the most significant factor associated with ACL injury. The mechanism of injury might be associated with a combination of impingement of the ACL against the bone and increased ligament loading.

Evaluation of alveolar process resorption after tooth extraction using the socket shield technique without immediate installation of implants: a randomised controlled clinical trial

Our aim was to evaluate resorption of the alveolar ridge using the socket shield technique (SST) without immediate placement of dental implants. This randomised controlled clinical trial included 27 patients: 14 maxillary non-molar teeth were partially extracted using the SST (test group) and 13 were extracted using a minimally traumatic extraction approach (control group). Alterations in height and thickness of the alveolar ridge were evaluated by cone beam computed tomograms taken immediately after, and 100 days after, surgery. Minor resorption was observed in the height of the buccal and palatal plates, without intergroup difference (p ≥ 0.10). The test group showed significantly better preservation of the buccal-to-palatal crest dimension (p ≤ 0.05). In the control group, preservation of buccal plate thickness was significantly greater (p ≤ 0.05), but intragroup vertical resorption of the buccal plate and reduction in the buccal-to-palatal crest distance were greater (p ≤ 0.05). The SST without the immediate placement of implants showed greater preservation of the buccal-to-palatal crest dimension and lower preservation of buccal wall thickness compared with minimally traumatic extraction. In addition, it provided superior maintenance of the baseline buccal wall height. The modified SST is a promising approach, but factors that interfere with the results should be investigated.

Fractional Erbium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Primary Cutaneous Amyloidosis.

Although various treatments are currently available for primary cutaneous amyloidosis (PCA), there is no entirely satisfactory treatment. Recently, fractional ablative lasers are claimed to have therapeutic effects for PCA. To evaluate the efficacy and safety of fractional Er:YAG laser for the treatment of PCA. Ten patients with macular and lichen amyloidosis received 4 treatment sessions with 4-week intervals. The outcome was assessed clinically (degree of pigmentation, rippling, lichenification, and itching) through photographs and histologically (amount of amyloid, melanin, epidermal thickness, and depth of rete ridges) through biopsy specimens stained with hematoxylin-eosin, Congo red, and Fontana-Masson stain. Patients were followed up for 3 months after the final treatment. At 3-month follow-up, fractional Er:YAG laser exhibited a significant clinical and histological improvement. Patient satisfaction concurred with physicians' evaluations. Recurrence was detected in 1 patient. In light of the authors' findings, fractional Er:YAG laser offered a great clinical and histological efficacy with excellent safety profile. Careful laser selection based on making a compromise between efficacies and safeties may improve outcome.

Quantitative feature extraction of turbulent premixed flames by photofragmentation laser-induced fluorescence

Planar laser-induced fluorescence (PLIF) techniques have been widely used for flame structure visualization in recent years. Nevertheless, most of the studies were concerned with qualitative analysis of the obtained images and the quantitative analysis were much fewer. This work presents a quantitative feature extraction method to process the ribbon structures that are captured in images and represent the radical layers in flames. The extracted features include ridge lines, curvatures, and thicknesses. This method was demonstrated by processing the images of methyl (CH3) photofragmentation laser-induced fluorescence (PF-LIF) and formaldehyde (CH2O) PLIF measurements in stoichiometric, premixed methane/air flames. The flames were generated by a McKenna burner under the Reynolds numbers of 1930, 3870, and 5800. The ridge lines followed well with the wrinkled layers of CH3 and CH2O. The CH2O layers were thickened, but the CH3 layers had minor change with increased Reynold numbers.

Sex estimation from fingerprint ridge density. A review of literature.

Identification has always been very vital in forensic casework. Fingerprint patterns are population-specific and individualistic, that makes fingerprinting an important biological trait in human biology and forensics. Fingerprint is an impression of the friction ridges of the finger-ball, where friction ridges are raised portions of the epidermis. Skin on human fingertips contains ridges and valleys which together forms distinctive patterns. These patterns are fully developed in intra-uterine life and remain unaltered until the death of the individual. Injuries such as cuts, burns and bruises can temporarily damage quality of fingerprints but when fully healed, the patterns are restored. The number of ridges present in a unit area on a fingerprint is called the Fingerprint Ridge Density (FPRD). The epidermal ridge density can be determined by examining two parameters - ridge width and distance between the ridges. The thickness of the epidermal ridges varies between individuals and between the sexes. The present review of literature focuses on the sexual dimorphism on the basis of the FPRD and its possible use in forensic examinations. Most of the studies pertaining to the estimation of sex from the FPRD have been conducted in the last two decades when Mark A. Acree in 1999, devised a method of estimation of sex on Caucasian and African-American descent. The present analysis evaluates the studies found in the PubMed database conducted after Acree, 1999. The estimation of sex from the FPRD is based upon the fact that the females have a fine detailing of ridges and consequently more ridges are covered in a unit space in the fingerprints of females as compared to males. The paper also highlights recent advancements and future perspectives in the area of FPRD. (www.actabiomedica.it)

Comparison of anterior maxillary and mandibular alveolar parameters in African American and Caucasian women: A retrospective pilot study

PurposeThe primary objective of this study was to analyze the thickness and height of alveolar bone around the maxillary and mandibular incisors. Additionally, this study aimed to compare bone parameters between Caucasian (CC) and African American (AA) female patients.Materials and MethodsIn this retrospective pilot study, 50 female subjects (25 CC and 25 AA) were included. The inclusion criteria were AA or CC women between the ages of 18 and 50 with a normo-divergent facial pattern and Angle's class I, end-on class II, or mild class III malocclusion. The distance from the cementoenamel junction (CEJ) to the buccal and lingual alveolar crest; the alveolar ridge thickness at the mid-root and apex; and the buccal and lingual bone thickness at 3, 6, and 9 mm from the CEJ were measured.ResultsNo significant difference was found (P>0.05) in the cortical bone thickness at 3 mm, 6 mm, or 9 mm from the alveolar crest between CC and AA populations for most measurements. A significant difference in bone thickness was found (P<0.05) for the lingual surface of the central incisor, with maxillary bone thickness found to be higher than mandibular bone thickness. The measurements of lingual thickness were larger than those of buccal thickness for both races.ConclusionThere were no differences in maxillomandibular anterior alveolar bone measurements between normo-divergent adult AA and CC women, except for a few parameters at varying locations. However, future studies can be planned based the current pilot study data, which may provide valuable information.

Phenotypic and Genetic Identification of Mercenaria mercenaria, Mercenaria campechiensis, and Their Hybrids

The goal of this study was to evaluate the efficacy of phenotypic traits and two genetic assays to distinguish between Mercenaria mercenaria, an important aquaculture species, and Mercenaria campechiensis, a conspecific species that is partially sympatric, but that has not been successfully farmed. The objectives were to evaluate (1) four established diagnostic phenotypic traits (lunule shape, thickness of concentric shell ridges, prominence of anterior side of the concentric ridges, and presence of purple nacre inside of the shells) to distinguish between species, (2) size polymorphism of PCR fragments from four genes [16S rRNA, 18S rRNA, Internal Transcribed Spacer genes (ITS1 and ITS2)], and (3) PCR-restriction fragment length polymorphism (RFLP) on three of these genes (16S, ITS1, and ITS2). Phenotypic traits correctly distinguished two geographically distant conspecific populations (two locations in Maine for M. mercenaria and in Bradenton, FL, for M. campechiensis); however, among all other locations, both species had overlapping phenotypic trait values. Although PCR fragments were obtained for all genes tested, size polymorphism was not identified between the two species. Restriction enzyme digestion of PCR fragments resulted in diagnostic fragments distinguishing the two species for 16S, ITS1, and ITS2. Although phenotypic scores failed to delineate between the two species in most locations, PCR-RFLP results failed to identify hybrids in wild or hatchery samples. Further investigation is needed to apply the PCR-RFLP assays on known hybrid offspring from crosses of M. mercenaria and M. campechiensis. Results have elucidated the difficulties in confidently detecting hybridization in quahogs; however, determining effective methods for species identification and hybrid detection will be important to address issues such as the prevalence and distribution of hybridization in aquaculture and in wild populations, and to determin the presence of M. campechiensis which are currently difficult to find.

ДИНАМИКА МОРФОМЕТРИЧЕСКИХ ПАРАМЕТРОВ ЭПИТЕЛИЯ РУБЦА КРУПНОГО РОГАТОГО СКОТА В ПОСТНАТАЛЬНОМ ОНТОГЕНЕЗЕ

The aim of the study was to study the morphological adaptation of the epithelium of rumen papillae under the influence of age-related changes in the type of nutrition. The research was conducted on the material taken from the slaughteries of the Stavropol territory from 60 heads of black-and-white cattle of six age groups: newborns (1, 3, 7 days), 30 days, 3 months, 6 months, 18 months, 3-5 years. Histological and immunohistochemical methods (marker of proliferating cells Ki-67) and morphometric methods were used. It was established that the thickness of epithelial ridges of interstitial zones significantly increases from birth to six months of age by 1.64 times and from eighteen months of age to 3-5 years by 12%. The thickness of the epithelium above the papillae of the mucosal lamina proper remains stable. With age, the ratio of the thickness of the epithelium above connective tissue papillae of the mucosal plate to the thickness of epithelial ridges of the interstitial zones decreases twice: from 81.42% in newborns to 41.69 % in lactating cows 3-5 years old. The thickness of the surface layer of the papillary epithelium of the scar changes in waves with the maximum values of this indicator in newborns at the age of 1 day (10.01±0.19 microns) and in animals of eighteen months of age (9.96±0.57 microns). High proliferative activity of basal epithelial cells is observed in the first day after birth (64.8 %), significantly decreases from three to seven days of age (32.7 %), there is a significant decrease in this indicator also at six (23.9 %) and eighteen months (15.6 %), and then it remains stable.

Evaluation of deformation in the buccal lamellar bone with finite element analysis in alveolar ridge-splitting/expansion technique

PurposeThe aim of this study was to investigate deformation and stress distribution in the buccal lamellar bone via finite element analysis (FEA) in the application of alveolar ridge-splitting/expansion technique (ARST) in atrophic maxilla and mandible. Material and methodThree-dimensional (3D) solid models of maxilla and mandible were formed using computer software, with an alveolar ridge thickness of 4 mm in the right first molar region. In both models, one horizontal and two releasing vertical osteotomies were made in the atrophic region. Vertical forces varying from 50 N to 1000 N were continuously applied on the midpoint of the horizontal osteotomy and then the axial and total deformation and von Mises stress distribution in the buccal lamellar bone was assessed by FEA. ResultsThe degrees of axial deformation and total deformation and the maximum von Mises stress value under a 50 N force were 0.22 mm, 0.23 mm, and 4.52 MPa in the maxillary buccal lamellar bone and were 0.04 mm, 0.06 mm, and 5.90 MPa in the mandibular buccal lamellar bone, respectively. Similarly, under a 1000 N force, the values were 4.44 mm, 4.75 mm, and 90.49 MPa in the maxillary buccal lamellar bone and were 0.96 mm, 1.1 mm, and 118.02 MPa in the mandibular buccal lamellar bone, respectively. ConclusionThese findings implicate that the ARST used for implant placement or alveolar augmentation can be achieved with the application of lower amounts of force in the maxilla compared to the mandible. It was also revealed that in ARST, the maximum von Mises stress value was lower in the maxillary buccal lamellar bone than in the mandibular buccal lamellar bone. Based on these findings, we consider that the administration of ARST could be biomechanically more stable in the maxilla than in the mandible.

Russeting in Apple Is Initiated After Exposure to Moisture Ends-I. Histological Evidence.

Russeting (periderm formation) is a critical fruit-surface disorder in apple (Malus × domestica Borkh.). The first symptom of insipient russeting is cuticular microcracking. Humid and rainy weather increases russeting. The aim was to determine the ontogeny of moisture-induced russeting in ‘Pinova’ apple. We recorded the effects of duration of exposure to water and the stage of fruit development at exposure on microcracking, periderm formation and cuticle deposition. Early on (21 or 31 days after full bloom; DAFB) short periods (2 to 12 d) of moisture exposure induced cuticular microcracking—but not later on (66 or 93 DAFB). A periderm was not formed during moisture exposure but 4 d after exposure ended. A periderm was formed in the hypodermis beneath a microcrack. Russeting frequency and severity were low for up to 4 d of moisture exposure but increased after 6 d. Cuticle thickness was not affected by moisture for up to 8 d but decreased for longer exposures. Cuticular ridge thickness decreased around a microcrack. In general, moisture did not affect cuticular strain release. We conclude that a hypodermal periderm forms after termination of moisture exposure and after microcrack formation. Reduced cuticle deposition may cause moisture-induced microcracking and, thus, russeting.

Cartilage and subchondral bone distributions of the distal radius: a 3-dimensional analysis using cadavers

To quantify the spatial distributions of cartilage and subchondral bone thickness of the distal radius. Using 17 cadaveric wrists, three types of 3-dimensional models were created: a cartilage-bone model, obtained by laser scanning; a bone model, rescanned after dissolving the cartilage; and a subchondral bone model, obtained using computed tomography. By superimposing the bone model onto the cartilage-bone and the subchondral bone models, the cartilage and subchondral bone thickness were determined. Measurements along with the spatial distribution were made at fixed anatomic points including the scaphoid and lunate fossa, sigmoid notch and interfossal ridge, and compared at each of these four regions. Cartilage thickness of the interfossal ridge (0.89±0.23mm) had a larger average thickness compared to that of the scaphoid fossa (0.70±0.18mm; p=0.004), lunate fossa (0.75±0.17mm; p=0.044) and sigmoid notch (0.64±0.13mm; p<0.001). Subchondral bone was found to be thickest at the scaphoid (2.18±0.72mm) and lunate fossae (1.94±0.93mm), which were both thicker than that of sigmoid notch (1.63±1.06mm: vs scaphoid fossa, p=0.020) or interfossal ridge (1.54±0.84mm: vs scaphoid fossa, p=0.004; vs lunate fossa, p=0.048). In the volar-ulnar sub-regions of the scaphoid and lunate fossa, the subchondral bone thickened. Our data can be applied when treating distal radius fractures. Cartilage thickness was less than 1mm across the articular surface, which may give an insight into threshold for an acceptable range of step-offs. The combined findings of subchondral bone appreciate the importance of the volar-ulnar corner of the distal radius in the volar locking plate fixation.

Is There a Role of Meniscal Morphology in the Risk of Noncontact Anterior Cruciate Ligament Rupture? A Case–Control Study

The purpose of this study was to identify the anatomical risk factors and determine the role of meniscal morphology in noncontact anterior cruciate ligament (ACL) rupture. A total of 126 patients (63 with noncontact ACL rupture and 63 age- and sex-matched controls) with intact menisci were included in this retrospective case-control study. On knee magnetic resonance imaging (MRI), meniscal morphometry (anterior, corpus, and posterior heights and widths of each meniscus), tibial slope (medial and lateral separately), notch width index, roof inclination angle, anteromedial bony ridge, tibial eminence area, and Q-angle measurements were assessed. The data were analyzed using multiple regression analyses to identify independent risk factors associated with ACL rupture. Using a univariate analysis, medial and lateral menisci anterior horn heights (p < 0.001; p < 0.003), medial and lateral menisci posterior horn heights (p < 0.001; p < 0.001), lateral meniscus corpus width (p < 0.004), and notch width index (p < 0.001) were significantly higher in the control group. Lateral tibial slope (p < 0.001) and anteromedial bony ridge thickness (p < 0.001) were significantly higher in the ACL rupture group. Multivariate analysis revealed that decreased medial meniscus posterior horn height (odds ratio [OR]: 0.242; p < 0.001), increased lateral meniscus corpus width (OR: 2.118; p < 0.002), increased lateral tibial slope (OR: 1.95; p < 0.001), and decreased notch width index (OR: 0.071; p = 0.046) were independent risk factors for ACL rupture. Notch stenosis, increased lateral tibial slope, decreased medial meniscus posterior horn height, and increased lateral meniscus corpus width are independent anatomical risk factors for ACL rupture. Meniscal morphological variations also play a role in ACL injury. This is a Level III, retrospective case-control study.

Implant and Prosthetic Success Following Peri-implant Guided Bone Regeneration in the Esthetic Zone Using an Equine Cortical Bone Membrane and an Equine Enzyme-Treated Bone Graft: A Retrospective Study with 9-year Follow-Up.

A barrier membrane consisting of an equine-derived, demineralized cortical bone sheet has been made available, yet evidence of its effectiveness is currently only anecdotal. This study aimed to obtain preliminary evidence concerning the medium-term prosthetic and implant success rates that may be achieved when such a membrane is used in combination with an equine, enzyme-treated bone graft, concomitantly to implant placement in the esthetic zone. Records of patients who had one or two implants placed in the anterior sectors of the two arches and had peri-implant bone regeneration carried out using the equine-derived membrane and equine-derived collagen-preserving bone granules were retrospectively collected. Peri-implant marginal bone loss (MBL) was used to assess implant survival. When available, histologic data concerning the equine membrane and cone beam computed tomography (CBCT) scans were analyzed as well. Records of 32 patients (ages 36 to 73 years), corresponding to 44 implants placed, were retrieved and analyzed. The mean follow-up was 113.9 ± 10.2 months. Two implants failed. The implant success rate was 90.9%. Twelve membrane samples could be retrieved and analyzed, showing the membrane was still occlusive at 4.2 ± 1.1 months and only beginning to undergo remodeling. Twelve CBCT scans showed that 65.1 ± 9.8 months after surgery, a newly formed cortical layer could be observed in the zone that had undergone grafting. The equine cortical bone membrane and the enzyme-treated bone graft used in this case series achieved a medium-term implant and prosthetic success rate that was not dissimilar to that of other resorbable membranes and grafts for peri-implant guided bone regeneration augmentation. Preliminary medium-term histologic and CBCT data suggest that the membrane may be occlusive for a period of at least 4 months and may contribute to preserve the ridge thickness over time.

АНАЛИЗ ИЗНОСА КОЛЕСНЫХ ПАР ВАГОНОВ УЛАН-БАТОРСКОЙ ЖЕЛЕЗНОЙ ДОРОГИ

The article is devoted to the analysis of the wear of the crest of the wheel pairs of freight cars of the Ulanbator Railway. Based on numerous experimental data, the factors affecting wear are investigated. According to the change in ridge thickness, the wear rate of the first wheelset over 5000 km is less than the third, and the wear of the second wheelset is less than the fourth. Subsequent 10,000 km and 30,000 km of run, this indicator changes in the opposite direction, therefore, it is necessary to change the sequence of wheelsets.