The resulting shape can best be assessed from a top view again, which will reveal a somewhat triangular form of the head. Trigonocephaly is also a Greek-derived word, which can be translated as triangular-shaped head. A facial feature of metopic synostosis is hypotelorism; in the frontal view, it can be seen that the width between the eyes is smaller than usual. Plagiocephaly
The Greek word πλάγιος plágios means "skew". Plagiocephaly can be subclassified as anterior plagiocephaly or posterior plagiocephaly. Anterior plagiocephaly
Anterior plagiocephaly is a clinical description of unilateral coronal synostosis. Children born with unilateral coronal synostosis develop due to compensatory mechanisms a skew head; a plagiocephaly.The sagittal suture divides the coronal suture in two halves; unilateral meaning that either the right side or the left side to the sagittal suture is fused. This fact immediately raises an important point. Unlike closure of the sagittal or the metopic suture, right and left are not the same in unilateral coronal synostosis. This asymmetry shows in the skull deformity, as well as in the facial deformity and the complications.This time, the skull deformity can only partly be predicted using Virchows law. Growth is arrested in the plane perpendicular to the fused suture and the forehead is flattened, but only at the ipsilateral side of the head. Ipsilateral indicates the same side of the head as where the suture is closed. Compensatory growth occurs in a parallel plane, as well as in a perpendicular plane.
It is hypothesized that for people with dandruff, skin cells may mature and be shed in 2–7 days, as opposed to around a month in people without dandruff. The result is that dead skin cells are shed in large, oily clumps, which appear as white or grayish flakes on the scalp, skin and clothes. According to one study, dandruff has been shown to be possibly the result of three factors:
Skin oil, commonly referred to as sebum or sebaceous secretions
The metabolic by-products of skin micro-organisms (most specifically Malassezia yeasts)
Individual susceptibility and allergy sensitivity. Microorganisms
Older literature cites the fungus Malassezia furfur (previously known as Pityrosporum ovale) as the cause of dandruff. While this species does occur naturally on the skin surface of people both with and without dandruff, in 2007, it was discovered that the responsible agent is a scalp specific fungus, Malassezia globosa, that metabolizes triglycerides present in sebum by the expression of lipase, resulting in a lipid byproduct: oleic acid. During dandruff, the levels of Malassezia increase by 1.5 to 2 times its normal level. Oleic acid penetrates the top layer of the epidermis, the stratum corneum, and evokes an inflammatory response in susceptible people which disturbs homeostasis and results in erratic cleavage of stratum corneum cells. Seborrhoeic dermatitis
In seborrhoeic dermatitis, redness and itching frequently occur around the folds of the nose and eyebrow areas, not just the scalp. Dry, thick, well-defined lesions consisting of large, silvery scales may be traced to the less common condition of scalp psoriasis.