Determination of potential of cellular proliferation and mucous cell prosoplasia in the odontogenic epithelia of the dental follicle of the asymptomatic impacted third molars

It has well known thatthe epithelium of inflammatory and developmental cyst arised from tooth isprimarily composed of squamous epithelium and the presence of mucous andciliated cells in the epithelial linings of odontogenic cysts is to be prosoplasic inorigin but the cause and biological significance of this phenomenon is notcertain. The changes in the proliferation rates of the epithelium cells of the oralodontogenic epithelium rests may play an important role in the pathogenesis ofthe cysts and tumors developed from the dental follicle (DF) and the surfaceepithelia of oral mucosa. The aim of this study is to determine mucous cellprosoplasia (MCP) and proliferative potentials by using Ki-67 and MCM-2proliferation markers in DF of radiographically asymptomatic impacted thirdmolar teeth (ITMT) and to determine whether there is any necessity for theremoval of all impacted third molar by detecting the potential of the developingcysts and tumors of its DF. This study involved 59 DF of 54 patients (39 femaleand 15 male) ranging 16 to 69 (mean age 28,20±11,89 years) referred forclinically and radiologically asymptomatic lower ITMT. Thirteen healthygingival tissues obtained during the ITMT operation in 13 patients (7 femaleand 3 male, mean age (30,54±13,89), ranging 18 to 69) served as a control group.The widths of all DF on periapical radiographs obtained by parallel techniqueand scaned by using the Scion Image Viewer program were measured and DFwidth below 2,5 mm was included in the study. Squamous epithelia wasdetected in 33 (55,9%) of 59 DF and of 20 (54,1%) DF with squamos changes wasobserved between 20 and 29 years. MCP was observed in 7 of 59 DF (11,9%)and most frequently in mesioangular and vertical position (9,4% and 15,8%),class II (13,5%) and the position B and C (11,1% and 13%). Ki-67 expression wasfound to have higher values than MCM-2 expression in both controls and DF(respectively, 6,15±3,18 and 10,53±5,77 and 4,46±1,39 and DF 5,89±2,89). Theexpression of both proliferation markers in the basal membrane, the epitheliumof mucous, squamous and inflammation were statistically significant (p<0,01).It was concluded that the squamous epithelia in DF of asymptomatic ITMT?smight be prosoplasic in origin, actively to be proliferated, and MCP may be as aindicator for the differentiation potential of the follicle and that theinflammation observed in the mesenchymal components of DF upregulate thecell turnover of odontegenic epithelium and lead to proliferation. Based onthese observations we agree with prophylactically removal of ITMT.Keywords: Impacted third molar, dental follicle, Ki-67, MCM-2