Assessment of prevalence and measurement of mandibular lingual concavities using Cone-Beam Computerized Tomography (CBCT) among patients in Jeddah: a cross-sectional study

OBJECTIVE

Dental implant procedure is the most common way to restore missing teeth but also comes with several complications. Success rates for dental implants are expected to be good when proper diagnosis and planning, study of bone morphology and closeness of implant with vital structures, such as nerves and blood vessels, are made pre-surgery.

PATIENTS AND METHODS

This cross-sectional study involved 636 adult patients, aged 18-80 years old, that came for dental implants in screening clinics or referred to specialty clinics in Jeddah, Saudi Arabia for the year 2019 to 2020. Instead of conventional Computed Tomography (CT), Cone Beam Computed Tomography (CBCT) X-Rays have been used to evaluate mandibular lingual concavities.

RESULTS

Prevalence and measurement of lingual concavities were determined. Type U mandibles with a lingual concavity, were found to have a higher chance of lingual cortical plate but this may still vary on factors such as type of population and ethnicity. The typical finding in the mandibular posterior region is the lingual undercut.

CONCLUSIONS

CBCT is a great tool used to study mandibular lingual concavities and it is essential prior the installation of dental implant to prevent life-threatening complications.

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm - volume 3

The total number, morbidity and mortality attributed to viraemic hepatitis C virus (HCV) infections change over time making it difficult to compare reported estimates from different years. Models were developed for 15 countries to quantify and characterize the viraemic population and forecast the changes in the infected population and the corresponding disease burden from 2014 to 2030. With the exception of Iceland, Iran, Latvia and Pakistan, the total number of viraemic HCV infections is expected to decline from 2014 to 2030, but the associated morbidity and mortality are expected to increase in all countries except for Japan and South Korea. In the latter two countries, mortality due to an ageing population will drive down prevalence, morbidity and mortality. On the other hand, both countries have already experienced a rapid increase in HCV-related mortality and morbidity. HCV-related morbidity and mortality are projected to increase between 2014 and 2030 in all other countries as result of an ageing HCV-infected population. Thus, although the total number of HCV countries is expected to decline in most countries studied, the associated disease burden is expected to increase. The current treatment paradigm is inadequate if large reductions in HCV-related morbidity and mortality are to be achieved.

Strategies to manage hepatitis C virus infection disease burden - volume 3

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries in Europe, the Middle East and Asia, and the relative impact of two scenarios was considered: increased treatment efficacy while holding the annual number of treated patients constant and increased treatment efficacy and an increased annual number of treated patients. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. A 90% reduction in total HCV infections within 15 years is feasible in most countries studied, but it required a coordinated effort to introduce harm reduction programmes to reduce new infections, screening to identify those already infected and treatment with high cure rate therapies. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. Among European countries, the majority of patients were born between 1940 and 1985. A wider range of birth cohorts was seen in the Middle East and Asia (between 1925 and 1995).

Historical epidemiology of hepatitis C virus (HCV) in select countries - volume 3

Detailed, country-specific epidemiological data are needed to characterize the burden of chronic hepatitis C virus (HCV) infection around the world. With new treatment options available, policy makers and public health officials must reconsider national strategies for infection control. In this study of 15 countries, published and unpublished data on HCV prevalence, viraemia, genotype, age and gender distribution, liver transplants and diagnosis and treatment rates were gathered from the literature and validated by expert consensus in each country. Viraemic prevalence in this study ranged from 0.2% in Iran and Lebanon to 4.2% in Pakistan. The largest viraemic populations were in Pakistan (7 001 000 cases) and Indonesia (3 187 000 cases). Injection drug use (IDU) and a historically unsafe blood supply were major risk factors in most countries. Diagnosis, treatment and liver transplant rates varied widely between countries. However, comparison across countries was difficult as the number of cases changes over time. Access to reliable data on measures such as these is critical for the development of future strategies to manage the disease burden.

Discriminant value of serum HBV DNA levels as predictors of liver fibrosis in chronic hepatitis B

Current guidelines recommend antiviral therapy in chronic hepatitis B (HBV) patients with significant histological disease. We aimed to compare histological fibrosis (METAVIR, ≥F2) in patients with HBV DNA ≥20,000 IU/mL vs. ≥2000 IU/mL and identify predictors of fibrosis. We performed prospective liver biopsies on 203 HBeAg-negative patients in four groups: Group I (n = 55): HBV DNA ≥20,000 IU/mL and persistently elevated alanine aminotransferase (ALT) levels (PEALT; >40 U/L); Group II (n = 34): HBV DNA ≥20,000 IU/mL and persistently normal ALT (PNALT); Group III (n = 40): HBV DNA <20,000 IU/mL and PEALT; and Group IV (n = 74): HBV DNA <20,000 IU/mL, and PNALT. We reanalysed all groups in relation to updated cut-off for treatable viremia (2000 IU/mL). Genotype D was detected in 86% of patients. Hepatic fibrosis ≥F2 was detected in 72.7%, 52.9%, 57.5% and 18.9% in Groups I-IV, respectively (P < 0.0001). Except in Group II with a trend for lower ≥F2 fibrosis (P = 0.067), there was no significant difference by using HBV DNA cut-off 20,000 vs. 2000 IU/mL. Multivariate logistic regression analysis identified study Group IV (OR, 0.0276; CI: 0.088-0.868; P = 0.0276) and milder (A0-1) necroinflammatory grade (OR, 0.135; CI: 0.063-0.287; P < 0.0001) as independent predictors of ≥F2 fibrosis. The specificity, positive and negative predictive values for PEALT in detection of ≥F2 fibrosis for viremia ≥2000 IU/mL (80%, 69% and 65%, respectively) or ≥20,000 IU/mL (86%, 73% and 63%, respectively) were similar, with a marginal gain in sensitivity (51% vs. 42%, respectively). Significant fibrosis is prevalent in a large proportion of HBeAg-negative patients with high viremia and persistently normal ALT. Lower HBV DNA cut-offs could be adopted with marginal gains in fibrosis detection and without loss of diagnostic accuracy.

Components in seminal plasma regulating sperm transport and elimination

Seminal plasma has been suggested to be involved in sperm transport, and as a modulator of sperm-induced inflammation, which is thought to be an important part of sperm elimination from the female reproductive tract. This article reports on recent experiments on the importance of seminal plasma components in sperm transport and elimination. In Experiment 1, hysteroscopic insemination in the presence (n = 3) or absence (n = 3) of 2 ng/mL PGE showed an increased portion of spermatozoa crossing the utero-tubal junction in the presence of PGE in two mares, while no difference was observed between treatments in a third mare. In Experiment 2, whole seminal plasma, heat-treated seminal plasma (90 degrees C for 45 min), and charcoal-treated seminal plasma were added to: (1) sperm samples during opsonization prior to polymorphonuclear neutrophil(s) (PMN)-phagocytosis assays (n = 5); or to (2) phagocytosis assays (n = 5). Opsonization of spermatozoa was suppressed in the presence of whole seminal plasma, compared with samples without seminal plasma (p < 0.05). Charcoal treatment did not remove the suppressive effect of seminal plasma on opsonization, but heat treatment of seminal plasma reduced its suppressive properties (p < 0.05). The addition of whole seminal plasma to opsonized spermatozoa almost completely blocked phagocytosis (p < 0.05). Charcoal treatment did not remove the suppressive effect of seminal plasma. However, heat-treated fractions of seminal plasma removed the suppressive effect of seminal plasma on phagocytosis (p < 0.05). In Experiment 3, viable and non-viable (snap-frozen/thawed) spermatozoa were subjected to in vitro assays for PMN binding and phagocytosis with the following treatments (n = 3): (1) seminal plasma (SP), (2) extender; (3) ammonium sulfate precipitated seminal plasma proteins with protease inhibitor (SPP+); or (4) ammonium sulfate precipitated seminal plasma proteins without protease inhibitor (SPP-). Treatment was observed to impact binding and phagocytosis of viable and non-viable spermatozoa (p < 0.05). SP and SPP+ suppressed PMN-binding and phagocytosis of viable sperm. This effect was also seen, but to a lesser degree, in SPP- treated samples. Non-viable spermatozoa showed less PMN-binding and phagocytosis than live sperm in the absence of SP. The addition of SP promoted PMN-binding and phagocytosis of non-viable spermatozoa. SPP- treated samples also restored PMN-binding of non-viable spermatozoa. The addition of protease inhibitors removed this effect. In Experiment 4, seminal plasma proteins were fractionated based on MW by Sephacryl S200 HR columns (range 5000-250,000 kDa). Fractionated proteins were submitted to sperm-PMN binding assays. A protein fraction <35 kDa suppressed PMN-binding to live and snap-frozen spermatozoa. A greater MW protein fraction appeared to promote binding between PMNs and snap-frozen spermatozoa. While the addition of protease inhibitors was necessary to maintain the protective effect of seminal plasma proteins on viable spermatozoa, the promotive effect of seminal plasma on non-viable spermatozoa appeared to require some protease activity. It was concluded from these experiments that components of seminal plasma play active roles in transportation and survival of viable spermatozoa in the female reproductive tract and in the elimination of non-viable spermatozoa from the uterus.

Equine seminal plasma reduces sperm binding to polymorphonuclear neutrophils (PMNs) and improves the fertility of fresh semen inseminated into inflamed uteri

Seminal plasma (SP) is known to have immunosuppressive properties in several species. Equine SP has been reported to reduce or inhibit chemotaxis, phagocytosis and complement activityin vitro. The type and amount of the SP component that suppresses sperm–polymorphonuclear neutrophil (PMN) bindingin vitrowas determined, and the effect of such suppression on the fertility of mares inseminated in the presence of uterine inflammation, was analyzed. Sperm cells were suspended in either SP, semen extender or a mixture of both, and each was mixed with PMN-rich uterine secretions collected at 12 h after artificial insemination (AI). SP reduced binding between spermatozoa and PMNs significantly (P< 0.05). Fertile spermatozoa were suspended in SP or semen extender and used to inseminate mares 12 h after the induction of uterine inflammation. The pregnancy rate was normal (77%) when spermatozoa were suspended in SP, but was dramatically reduced to only 5% when spermatozoa were suspended in extender. The proteins from SP, blood plasma (BP) and a skim-milk-based semen extender (skim milk extender, SME) were precipitated by ammonium sulfate, resuspended in PBS and dialyzed. The effect of the precipitated proteins on sperm–PMN binding was compared with fresh, untreated SP. Both fresh SP, and isolated SP proteins reduced sperm–PMN binding (P< 0.001). Conversely, proteins isolated from either BP or SME did not reduce sperm–PMN binding. The different concentrations of SP proteins used showed a dose-dependent suppression of sperm–PMN binding. Concentrations of 1 mg/ml SP protein significantly reduced sperm–PMN binding and 6 mg/ml reduced the binding to a level similar to that observed with fresh whole SP (P< 0.001). Finally, SP protein digested with proteinase K resulted in the complete loss of SP suppressive activity confirming that the effective component is a proteinaceous substance.

Measured effect of collection and cooling conditions on the motility and the water transport parameters at subzero temperatures of equine spermatozoa

The effects of extracellular ice and cryoprotective agents on the measured volumetric shrinkage response and the membrane permeability parameters of equine spermatozoa have been reported previously. The volumetric shrinkage data were obtained using a differential scanning calorimeter technique that was independent of cell shape. The aim of this study was to examine the effects of collection and cooling conditions on the motility and the water transport parameters at subzero temperatures of equine spermatozoa. Stallion semen samples were collected using either a commercial lubricating agent, which caused osmotic stress to the spermatozoa, or water-insoluble Vaseline( trade mark ) as the artificial vagina lubricant. In some experiments, spermatozoa were cooled at 1 degrees C min(-1) from 20 degrees C to 4 degrees C to induce cold shock. An Equitainer was used to achieve control cooling rates (< or = 0.3 degrees C min(-1)) at temperatures > 0 degrees C. The water transport response of spermatozoa that were cold-shocked and osmotically shocked was significantly different from that of control spermatozoa (P < 0.01). Osmotic stress appeared to have an effect on the water transport response, although this effect was not significant. These results indicate that cold shock alters the behaviour of equine spermatozoa in cryopreservation protocols as a result of changes in the water transport properties of the plasma membrane. Although osmotic stress did not significantly affect water transport in equine spermatozoa, it did significantly decrease sperm motility in the extended semen samples (P < 0.01), which would, in turn, lower the quality of cold-stored or cryopreserved spermatozoa.

Measured effect of collection and cooling conditions on the motility and the water transport parameters at subzero temperatures of equine spermatozoa

The effects of extracellular ice and cryoprotective agents on the measured volumetric shrinkage response and the membrane permeability parameters of equine spermatozoa have been reported previously. The volumetric shrinkage data were obtained using a differential scanning calorimeter technique that was independent of cell shape. The aim of this study was to examine the effects of collection and cooling conditions on the motility and the water transport parameters at subzero temperatures of equine spermatozoa. Stallion semen samples were collected using either a commercial lubricating agent, which caused osmotic stress to the spermatozoa, or water-insoluble Vaseline( trade mark ) as the artificial vagina lubricant. In some experiments, spermatozoa were cooled at 1 degrees C min(-1) from 20 degrees C to 4 degrees C to induce cold shock. An Equitainer was used to achieve control cooling rates (< or = 0.3 degrees C min(-1)) at temperatures > 0 degrees C. The water transport response of spermatozoa that were cold-shocked and osmotically shocked was significantly different from that of control spermatozoa (P < 0.01). Osmotic stress appeared to have an effect on the water transport response, although this effect was not significant. These results indicate that cold shock alters the behaviour of equine spermatozoa in cryopreservation protocols as a result of changes in the water transport properties of the plasma membrane. Although osmotic stress did not significantly affect water transport in equine spermatozoa, it did significantly decrease sperm motility in the extended semen samples (P < 0.01), which would, in turn, lower the quality of cold-stored or cryopreserved spermatozoa.