How studies of twins can inform our understanding of dental morphology.

Two metaphors are presented to highlight concepts that could lead to a paradigm shift in dental studies of twins. The first, derived from the Song of Solomon in the Bible, refers to teeth as being twins. This viewpoint emphasises that each tooth should be viewed as a paired structure, not only with its antimere (within the same arch) but also with its isomer (in the opposing arch).

Spinal cord stimulation: a basic approach.

Chronic back pain and other refractory pain syndromes are a documented burden on our society. They also are a huge cost in quality of life and dollars spent on health care. Neuromodulation and specifically dorsal column stimulation of the spinal cord has been shown to decrease pain with minimal risk to the patient.

Sacroplasty.

Sacral vertebroplasty, or sacroplasty, entails the percutaneous insertion of 1 or more bone needles into the sacral ala and, less commonly, the sacral vertebra with fluoroscopic and/or computed tomographic guidance. Acrylic bone cement is then injected under imaging guidance to treat the lesion and stabilize the sacrum. Sacroplasty is indicated for the treatment of painful sacral insufficiency fractures and painful sacral masses, both of which destabilize the sacrum.

The relationship between the mid-point and most-prominent point on the labial curve of upper anterior teeth.

Objectives: This study investigates coincidence of the most-prominent point and the mid-point on upper anterior teeth in relation to the use of straight-wire appliances.

Materials And Methods: Alginate impressions of the upper jaw were obtained from forty Caucasian patients. Impressions were cast using hard dental stone.

A large X-chromosomal deletion is associated with microphthalmia with linear skin defects (MLS) and amelogenesis imperfecta (XAI).

A female patient is described with clinical symptoms of both microphthalmia with linear skin defects (MLS or MIDAS) and dental enamel defects, having an appearance compatible with X-linked amelogenesis imperfecta (XAI). Genomic DNA was purified from the patient's blood and semiquantitative multiplex PCR revealed a deletion encompassing the amelogenin gene (AMELX). Because MLS is also localized to Xp22, genomic DNA was subjected to array comparative genomic hybridization, and a large heterozygous deletion was identified.

Role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells.

Saffron (Crocus sativus), widely used as a spice in Middle Eastern cuisine and is known for anti-cancer properties. The mechanism of saffron-induced cytotoxicity, in tumor cells has not been adequately explored. Therefore, we investigated the role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells, a commonly used cell culture system for in vitro studies on breast cancer.

Endovascular transvenous embolization of sinus pericranii. Case report.

Sinus pericranii (SP) is an abnormal communication between the intra- and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for reasons of cosmesis and prevention of hemorrhage. The authors report a novel endovascular transvenous route for definitive treatment of SP.

Introduction: philosophy in and philosophy of cognitive science.

Despite being there from the beginning, philosophical approaches have never had a settled place in cognitive research and few cognitive researchers not trained in philosophy have a clear sense of what its role has been or should be. We distinguish philosophy in cognitive research and philosophy of cognitive research. Concerning philosophy in cognitive research, after exploring some standard reactions to this work by nonphilosophers, we will pay particular attention to the methods that philosophers use.

Direct toxicity of Rose Bengal in MCF-7 cell line: role of apoptosis.

Current therapies for breast cancer are often limited by short-term efficacy due to the emergence of drug resistance. In view of this, there is much interest in the identification of new agents for the treatment of breast cancer. Rose Bengal (RB) has been used as a photosensitiser in photodynamic treatment.

Variability and patterning in permanent tooth size of four human ethnic groups.

Aims: Dental dimensions vary between different ethnic groups, providing insights into the factors controlling human dental development. This paper compares permanent mesiodistal crown diameters between four ethnic groups highlighting patterns of tooth size between these groups and considers the findings in relation to genetic and environmental influences.

Methods And Results: Mesiodistal crown dimensions were recorded using standardised manual measurements on dental casts derived from four different human populations: Southern Chinese, North Americans of European ancestry, Modern British of European ancestry and Romano-British.

Multiple crown size variables of the upper incisors in patients with supernumerary teeth compared with controls.

Aims: As part of ongoing studies of the aetiology of dental anomalies the aims of this study were to identify multiple components of tooth size of the upper permanent incisors in 34 patients with supernumerary teeth and to compare them with those in a control group to determine whether the presence of a supernumerary tooth has a local effect on the size of the surrounding dentition.

Methods And Results: The labial and occlusal aspects of the clinical crowns of the upper permanent central and lateral incisors on the study models of 74 subjects were digitally imaged and measured using an image analysis system and automated macro (34 patients with supernumerary in the upper incisor region: 17 males and 17 females and 40 controls: 20 males and 20 females). The macro-defined 17 variables from each view.

The aetiology of hypodontia: the prevalence, severity and location of hypodontia within families.

Aims: Previous studies have indicated that hypodontia has a significantly higher prevalence in the relatives of affected individuals than in the general population. This study aims to examine further the roles of genetic and environmental factors in the aetiology of hypodontia by investigating the relationship between the severity and distribution of hypodontia between family members, and any discernable effect of maternal health during pregnancy and birth weight.

Methods And Results: 117 first degree relatives of 41 index patients were examined clinically and radiographically to identify the presence, severity and location of hypodontia.

The effects of multiple identities on psychological well-being.

The authors propose that the effects of multiple identities on psychological well-being depend on the number of identities, importance of those identities, and relationship between them. Specifically, this model predicts that when identities are highly important, having many versus few identities leads to greater psychological well-being if the identities are in harmony with each other-providing resources and expecting similar behaviors-but leads to lower psychological well-being if the identities conflict with each other-depleting resources and expecting incompatible behaviors. However, when identities are less important, neither the number of identities nor identity harmony should affect well-being.

Vertebral augmentation with a flexible curved needle: preliminary results in 17 consecutive patients.

This report details a trial demonstrating the viability of a blunt-tipped curved needle for use as a cement injection device for vertebral body augmentation. Between January and September 2007, 17 consecutive patients (eight men and nine women; average age, 76 years; age range, 52-97 years) underwent vertebral body augmentation with a blunt-tipped curved nitinol injection needle via a single pedicle to treat pain due to acute vertebral body compression fractures. All patients were successfully treated without complication.

Computed tomography-guided lumbar drain placement.

The authors describe a technique for lumbar drain placement using CT guidance. Midline or paramidline interlaminar approaches to the thecal sac can be used. The major advantage to CT guidance is direct visualization of the needle tip in relation to the thecal sac.

Cytotoxic effect of saffron stigma aqueous extract on human transitional cell carcinoma and mouse fibroblast.

Introduction: Saffron has been suggested to have inhibitory effects on tumoral cells. We evaluated the cytotoxic effect of aqueous extract of saffron on human transitional cell carcinoma (TCC) and mouse non-neoplastic fibroblast cell lines.

Materials And Methods: Human TCC 5637 cell line and mouse fibroblast cell line (L929) were cultivated and incubated with different concentrations of aqueous extract of saffron stigma (50 microg/mL to 4000 microg/mL).

Study of cytotoxic and apoptogenic properties of saffron extract in human cancer cell lines.

Saffron (dried stigmas of Crocus sativus L.) has been used as a spice, food colorant and medicinal plant for millennia. In this study cytotoxic effect of saffron extract was evaluated in HepG2 and HeLa cell lines.

Enamel defects in extracted and exfoliated teeth from patients with Amelogenesis Imperfecta, measured using the extended enamel defects index and image analysis.

Aims: To enhance the phenotypic description and quantification of enamel defects from a North Sweden sample of extracted and exfoliated teeth originating from families with Amelogenesis Imperfecta by use of the extended enamel defects index (EDI) and image analysis to demonstrate the comparable reliability and value of the additional measurements.

Methods And Results: The sample comprised 109 deciduous and 7 permanent teeth from 32 individuals of 19 families with Amelogenesis Imperfecta in Northern Sweden. A special holder for individual teeth was designed and the whole sample was examined using the extended EDI and an image analysis system.

Morphogenetic fields within the human dentition: a new, clinically relevant synthesis of an old concept.

This paper reviews the concept of morphogenetic fields within the dentition that was first proposed by Butler (Butler PM. Studies of the mammalian dentition. Differentiation of the post-canine dentition.

Genetic and environmental influences on human dental variation: a critical evaluation of studies involving twins.

Utilising data derived from twins and their families, different approaches can be applied to study genetic and environmental influences on human dental variation. The different methods have advantages and limitations and special features of the twinning process are important to consider. Model-fitting approaches have shown that different combinations of additive genetic variance (A), non-additive genetic variance (D), common environmental variance (C), and unique environmental variance (E) contribute to phenotypic variation within the dentition, reflecting different ontogenetic and phylogenetic influences.

Tooth size patterns in patients with hypodontia and supernumerary teeth.

Aims: Anomalies of tooth number may not be isolated conditions but may have wider associations in the development of the dentition including tooth size. This study aimed to examine links between hypodontia, supernumerary teeth and crown size, considering the effect on the development of the whole dentition and so increase understanding of the aetiology of these conditions.

Methods And Results: The patients, who were all of European ancestry, were 60 young adults (30 males and 30 females) with hypodontia and 60 age and sex matched controls together with 60 young adults (39 males and 21 females) with supernumerary teeth and 60 age and sex matched controls.