word

1. Frictional keratosis
Introduction
The oral mucosa Is consist of stratified squamous epithelium which may
be keratinized or non kertinized ,(para) . the keratinized epithelium is
consist of 4 layers which are basal cell layer , prickle cell layer , granular
cell layer and cornified celllayer , but non keratinized epithelium is consist
of 3 layers only which are the basal,prickle and granular layers . oral
epithelium is consist of a- keratinocytes as basal cells , prickle cells ,
granular cells and cornified cells . and b- non keratinocytes (clear cells )as
melanocytes,langerhan cells, merkle cells and lymophocytes .
keratinocytes have the ability to form keratin as basal and parabasal
cells(stratum germinativum ) form the new cells which becom squamous
(flattened) as they rise up toward surface then nuclei and organelles
disappear and becom keratin .
Keratinocytes have the ablilty to form keratin but it is not obligatory to form
keratin , but according to fuctional demand . gingival tissues are
keratinized to better respond to masticatory demands.. in non kertinized
epithelium , tissue need elasticity(as buccalmucosa)and permeability(as
floorof mouth) so keratin should not be formed in such normal condition but
we fined it in abnormal codition as irritation(chemical,thermal,physical irritant)
This article focuses on the oral hyperkeratinization that results from
friction. The hyperkeratinization is a protective effectfor tissue other than
severe damage will occur .
Difinition : painless white patches affect oral mucosa due to chronic
friction against mucosal surface .
Etiology
mild abrasion of mucosal membrane by sharp tooth , check and lip
bitting , denture .
clinical features
age : 40 – 60
sex : male more than female
site : buccal mucosa , lip , lateral border of tongue , floor of mouth and
sometimes gingiva due to tooth brush .

2. s&s : asymptomatic except in aggressive lip bitting at first , it is pale and
translucent then dense and white .
D&D
clinically diagnosed but biopsy must be taken if the cause is unknown.
Histopathology
Hyperkeratosis , prominent granular cell layer , acanthosis and mild
infilamatory infiltrate in C.T .
Prognosis and treatment
prognosis for frictional keratosis is excellent , most lesions resolve within
1-3 weeks following removal of causative factor .