locStra: Fast analysis of regional/global stratification in whole‐genome sequencing studies

locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing.     

Angiolipoma of the tongue: report of a case

Angiolipoma is a rare variety of lipoma in the maxillofacial region. Only eight cases have been documented so far. A case in which an angiolipoma occurred within the tongue of a 49-year-old man is described here. The difference from earlier cases occurring in the tongue is noted. Close follow-up has, as yet, revealed no recurrence.     

Expression of CD44s, CD44v5, CD44v6 and CD44v7-8 in betel quid chewing-associated oral premalignant lesions and squamous cell carcinomas in Taiwan

Aberrant expression of the cell surface adhesion molecule CD44 and its variant forms has been shown to be associated with the invasive and metastatic potential of cancer cells, and with poor prognosis in several types of cancers. Expression of CD44 standard (CD44s) and variant (CD44v) forms in oral squamous cell carcinoma (SCC), epithelial dysplasia (ED), epithelial hyperkeratosis (EH) and normal buccal mucosa (NBM) have been examined using antibodies to CD44s, CD44v5, CD44v6 and CD44v7-8. Positive CD44s, CD44v5, CD44v6 and CD44v7-8 staining was detected in all the specimens from NBM, EH and ED. Positive staining of CD44s, CD44v5, CD44v6 or CD44v7-8 was detected in 55 (88.7%), 48 (77.4%), 59 (95.2%) and 22 (35.5%) of the 62 SCC specimens, respectively. The positive staining of CD44v7-8 in oral SCC was significantly less than that in NBM ( P <0.01). No significant correlation was found between CD44v7-8 expression and daily or total consumption of betel quids or cigarettes by the SCC patients. The 5-year survival rate for patients with CD44v7-8-positive tumours was significantly higher than that for the CD44v7-8-negative group ( P <0.03). These results indicate that loss of CD44v7-8 expression may be a valuable factor for determining prognosis in oral SCC patients.     

Biomechanics of the mandible and growth extension

Background and objective

One way of determining the direction of growth of the mandible is to consider the temporomandibular joint and movement of the mandible as a four-joint gear system, regarding growth then as an extension of the gear system. Our aim was to examine any correlations between the type of biomechanical growth extension and change in the maxilomandibular relation after Class?II therapy.

Subjects and methods

A total of 130?lateral cephalograms??before and after orthodontic treatment??were available from 65?adolescent class?II patients with open bite or deep bite. The two lateral cephalograms from each patient were superimposed on the occlusal plane. Cephalometric values and the vertical base point deviation were determined from biomechanical analyses, together with three distances and three angles.

Results

No correlation between the cephalometric data and distances or angles were observed. Although there were no significant differences in the distances, we did note significant differences in all three angles (p?Conclusion If gear system extension during growth is considered, this can be interpreted as meaning that the occlusal plane of those patients with an initially open bite dropped during treatment, but that it rose in patients with an initially deep bite.     

Aesthetic enhancement of pontic sites for fixed partial dentures

The ridge expansion technique using tapered osteotomes can be used anywhere in the maxilla when a change in external ridge morphology would be advantageous for both aesthetics and/or proper dental implant placement. Usually subsequent to tooth loss, the maxilla is generally somewhat undercut in form. This ridge expansion technique can be used to reduce the undercut by bulging out the base of the facial/buccal plate. This would recreate the illusion of root prominences (Figure 12) or permit implant fixtures to be inserted in a more upright position. The tapered osteotomes can therefore predictably be used to expand the buccal bone to simulate the presence of a root prominence for optimal aesthetics for placement of a fixed partial denture prosthesis (Figure 13).     

Fracture characteristics of carbon fibre, ceramic and non-palladium endodontic post systems at monotonously increasing loads

A carbon fibre post system, three non-palladium and one palladium metal post systems, two ceramic post systems, and a metal post system with a ceramic core were studied in vitro. The control group consisted of root-filled test teeth without posts. The test teeth were identical artificial roots of an upper central incisor made from a posterior composite whose module of elasticity was similar to that of natural dentine. All posts were cemented in the roots using Panavia 21 TC. Subsequently, standardized full crowns were cemented onto all roots. On a universal testing machine, the test teeth were loaded palatally at monotonously increasing loads until root fracture. The highest mean fracture loads were found for the carbon fibre post system (312.5 +/- 58.8 N). The fracture load of non-palladium metal posts (242.3-300.4 N) did not differ significantly from that of the Perma-dor post (265.9 N), which does contain palladium. Values of 300.3 +/- 89.3 N (aluminium oxide ceramics) and 193.5 +/-57.0 N (zirconia ceramics) were found for the ceramic posts. The control group exhibited a fracture load of 228.8 +/- 35.7 N. The mean distance between the vestibular end of the fracture gap and the point of force application was between 10.1 +/- 2.3 and 14.7 +/- 1.2 mm.     

Reposition of intruded permanent incisor by a combination of surgical and orthodontic approach: a case report

This report presents a case of a completely intrusive luxation of an immature permanent central incisor in a 7 years 9 months-old girl. Because there are severe intrusive trauma and cortical alveolar bone fracture, it was impossible to reposition with orthodontic or surgical method alone. The intruded tooth was repositioned to healthy alveolar bone level by using surgical extrusion and stabilization with sutures and periodontal pack. After healing of adjacent bone, the intruded maxillary central incisor erupted orthodontically by removable orthodontic appliance. It was moved from a high position to level of adjacent tooth in about 7 months. A radiograph was taken 6 months after ceasing forced eruption, which demonstrated minor root resorption, but the alveolar bone height had increased.