Cone Beam Computed Tomographic Measurement of Maxillary Central Incisors to Determine Prevalence of Facial Alveolar Bone Width ≥2 mm

Background: The initial thickness of maxillary bone has significant impact on the responding level of facial bone and soft tissue after extraction and immediate implant placement. A prevailing notion is that following implant placement in fresh extraction sites, at least 2 mm of facial bone is needed to prevent soft tissue recession, fenestration, and dehiscence. Purpose: The purpose of this study was to use cone beam computed tomography (CBCT) to measure horizontal width of facial alveolar bone overlying healthy maxillary central incisors and to determine prevalence of bone thickness ≥2 mm. Materials and Methods: Tomographic data from 101 randomly selected patients were evaluated by two independent observers. Assessments were made of facial bone width at levels 1.0 to 10.0 mm apical to the bone crest. Results: Healthy maxillary central incisors (n = 202) were measured from 101 patient scans. The percent of teeth with facial bone ≥2 mm at levels 1, 2, 3, 4, and 5 mm from the bone crest was 0, 1.5, 2.0, 3.0, and 2.5%, respectively. Overall mean thickness of the bone was 1.05 mm for right and left central incisors combined. The range of individual measurements for all levels was 0 to 5.1 mm. The occurrence of ≥2 mm thickness bone measurements increased with increasing depth. However, mean widths observed at levels 6 to 10 mm from the crest ranged only 1.0 to 1.3 mm because of apparent fenestration occurrence (0 mm bone) in approximately 12% of teeth. Overall, no significant differences in bone thickness were found between ethnic, gender, age, or scan groups. Conclusions: Using CBCT, occurrences of ≥2 mm maxillary facial alveolar bone were found on no more than 3% of root surfaces 1.0 to 5.0 mm apical to the bone crest in this sample of maxillary central incisors. The study evidenced prevalence of a thin facial alveolar bone (<2 mm) that may contribute to risk of facial bone fenestration, dehiscence, and soft tissue recession after immediate implant therapy.     

Appetitive Violence: A New Phenomenon?

Youth violence has long been regarded as a major social issue. The past decade has, however, seen the scrutiny which encompasses this violence intensify, largely due to a recent media focus on an apparently increasing tendency amongst some young people to engage in acts of ‘appetitive’ or ‘thrill-seeking’ violence. This is reported to be a new form of violence, in which young people act in an excitable state, rather than the more common form of anger-mediated violence. Whilst incidents of appetitive violence are overly represented in the news media and are presented as a major public concern, there is presently no empirical research exploring the validity of this phenomenon and no systematic analysis of the frequency and severity of this form of violent behaviour. Furthermore, the underlying causes of this type of violence are not understood. As such, preventative practices, risk assessment, treatment requirements and targeted management strategies are lacking. The purpose of this review is to examine the current literature on youth violence, particularly youth involvement in ‘thrill-seeking’ acts of violence, as well as describing a range of contemporary factors highlighted as integral to youth violence; specifically, gang involvement, alcohol use and the possession of weapons. This review will also examine an array of international strategies implemented in response to this form of youth violence. Finally, the General Aggression Model (GAM) will be considered to determine whether its framework can assist in advancing our understanding of appetitive violence, by elucidating those characteristics of the individual and their environment that contribute to its expression.     

Leber hereditary optic neuropathy—new insights and old challenges

Graefe's Archive for Clinical and Experimental Ophthalmology - Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial DNA (mtDNA) disorder with the majority of...     

Diagnostic Ureteroscopy Independently Correlates with Intravesical Recurrence after Nephroureterectomy for Upper Urinary Tract Urothelial Carcinoma

Background

Little is known about the effects of diagnostic ureteroscopy on intravesical recurrence after nephroureterectomy.

Methods

This study was designed to determine the effect of diagnostic ureteroscopy on intravesical recurrence after nephroureterectomy. From 2004 to 2010, 446 patients underwent nephroureterectomy for upper urinary tract cancer at our tertiary medical center. We included 115 patients who underwent preoperative diagnostic ureteroscopy and 281 patients who did not. This study analyzed the impact of the reported risk factors and diagnostic ureteroscopy for intravesical recurrence after nephroureterectomy by multivariate Cox regression model.

Results

The rates of metastasis and cancer-specific mortality did not differ significantly between the two groups. Diagnostic ureteroscopy was associated with a higher incidence of intravesical recurrence in patients with (p = 0.02) and without (p = 0.016) a previous history of bladder cancer. Ureter tumor biopsy (p = 0.272) and ureter involvement (p = 0.743) were not associated with the rate of intravesical recurrence in this study. Multivariate Cox regression analysis showed that only bladder cancer history (p < 0.001), multifocal tumor (p = 0.05), and diagnostic ureteroscopy (p = 0.05) were independently associated with intravesical recurrence.

Conclusions

Diagnostic ureteroscopy for upper urinary tract cancer was not associated with metastasis and cancer-specific mortality. However, ureteroscopy was associated with an increased incidence of intravesical tumor recurrence. Methods of prevention should be considered to decrease intravesical recurrence and avoid repeated surgical interventions or the development of advanced bladder disease in patients at risk.