title: Histopathological changes in oral mucosa due to takhzeen al-qat: a study of 70 biopsies.
abstract: BACKGROUND
  Chewing qat leaves (takhzeen al-qat) is a common habit in East Africa and Yemen. It has been reported to cause different systemic effects. At the oral mucosa, it causes clinical changes that appear as white lesions. The aim of this paper was to study the histopathological changes in the oral mucosa related to takhzeen al-qat.
  
  
  METHODS
  Seventy biopsies were studied. Biopsies were divided into three groups: (G1) Forty biopsies were taken from the oral mucosa of the chewing side. (G2) Twenty biopsies were taken from the oral mucosa of the opposite side and (G3) 10 biopsies were taken from the oral mucosa of non-chewing volunteers. All biopsies were conventionally prepared, paraffin embedded and histopathological protocol was followed for each case to study the histopathological changes.
  
  
  RESULTS
  Acanthosis appeared in 97.5% (G1) and 50% (G2), parakeratosis in 45% (G1) and 0% (G2), orthokeratosis in 25% (G1) and 10% (G2), abnormal rete ridges in 97.5% (G1) and 25% (G2), intracellular edema in 80% (G1) and 65% (G2), inflammatory infiltration in the subjacent connective tissue of 55% (G1) and 5% (G2), increased amount of collagenous fibers in 47.5% (G1) and 0% (G2), and mild epithelial dysplasia in 25% (G1) and 0% (G2). Biopsies taken from G3 showed no histopathological changes except one case with intracellular edema. Differences were statistically significant.
  
  
  CONCLUSIONS
  Takhzeen al-qat caused histopathological changes in the oral mucosa at the side of chewing; however, these changes were innocuous and without any evidence of malignancy.
authors.affiliation: Department of Oral Pathology and Medicine, Faculty of Dentistry, University of Sana'a, Yemen. euskal_15@hotmail.com
authors.forename: Aiman A
authors.initials: AA
authors.lastname: Ali
authors.forename: Ali K
authors.initials: AK
authors.lastname: Al-Sharabi
authors.forename: José M
authors.initials: JM
authors.lastname: Aguirre
mesh_terms: D000328:Adult; D001706:Biopsy; D029754:Catha / Q000009:adverse effects*; D002481:Cellulitis / Q000473:pathology; D003094:Collagen; D003238:Connective Tissue / Q000473:pathology; D004487:Edema / Q000473:pathology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007972:Leukoplakia, Oral / Q000473:pathology; D008297:Male; D008409:Mastication; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology*; D018515:Plant Leaves / Q000009:adverse effects
chemical_list: D003094:Collagen