Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle-also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elemen...

The hair follicle is a mini-organ, consisting of many different types and groups of cells, capable of frequent remodeling and cycles of growth. Immune privilege (IP) is believed to exist in the anagen growth stage of the hair follicle (HF). Previous studies using immunohistology have illustrated unique downregulation of major histocompatibility complex Class I in the HF bulb, as well as express...

Single rooted primary mandibular first molar is a rare developmental anomaly. Literatures reveal that failure of invagination of Hertwig's epithelial root sheath leads to this unusual root form. Thorough knowledge of root canal morphology and anatomical variations of primary teeth can help a pediatric dentist in successful root canal treatment. Hereby, we describe two cases of primary mandibula...

Hair follicle growth cycle proceeds through a series of stages in which strict control of cell proliferation, differentiation, and cell death occurs. Transgenic mice expressing human papillomavirus type 16 E6/E7 papillomavirus oncogenes in the outer root sheath (ORS) display a fur phenotype characterized by lower hair density and the ability to regenerate hair much faster than wild-type mice. R...

In endodontics, treatment of an open apex tooth with necrotic pulp is a problem. It seems that with promotion of remnants of Hertwig's epithelial sheath or rest of malassez accompany with a good irrigation of root canal we can expect root formation. (Iranian Endodontic Journal 2008;3:42-43).

during the past few years, researchers and practitioners have developed novel techniques, using ansa cervicalis to innervate muscles of the larynx paralyzed due to surgical procedures carried out in the chest and neck areas. during routine dissection of a middle-age male cadaver, an unusual course of the superior root of the ansa cervicalis was observed. in this case, the superior root of the a...