facts

 Patient Hygiene Performance (PHP) Index 

The Patient Hygiene Performance (PHP) Index  was first used as an oral hygiene assessment method when working with patients. Oral debris for the PHP Index is defined as soft foreign matter consisting of bacteria, mucin, and food loosely attached to tooth surfaces. Teeth are disclosed and a mouth mirror examination is made of specific teeth. The examiner mentally divides each tooth into five subsections and determines the presence or absence of oral debris on each of the subdivisions. Summing the values for each of the five subdivisions provides the oral debris score for the tooth. An overall patient hygiene performance score is tabulated by dividing the sum of the tooth scores by the number of surfaces charted. 

Basement membrane (type IV) collagen

The collagen IV molecule is 400 nm long and consists of two alpha 1 (IV) and one alpha 2 (IV) chains. Their genes COL4A1 and COL4A2 form a transcription unit in which they are arranged head-to-head and connected by a short common promoter region.

cotton wool appearance

 pagets disease