Objective:To study the clinical characteristics of odontogenic cutaneous fistula.Methods:6 cases of odontogenic cutane-ous fistula were represented and the reports of 60 cases of the lesion were reviewed.Results:The fistula was mainly located in cheek, chin,para-nasal part,sub-mandibular area and the lower border of the mandible,and respectively corresponding to mandibular third molar,mandibular incisor,maxillary canine,mandibular first and second molar,the corresponding teeth were mainly in mandible (71 .2%).In middle and old aged patients the lesion usually in para-nasal or mandible area,In younger patients the lesion mostly loca-ted in cheek or sub-mandibular area.After root canal therapy for the teeth with apical periodontitis or extraction of none-curable teeth,the odontogenic cutaneous sinus tract disappeared.Conclusion:Proper treatment of focal teeth can cure the odontogenic cutaneous fistulas.

Objective:To study the effects of miR-20a on the osteogenic differentiation potential of inflammatory periodontal liga-ment cells(IPDLSCs).Methods:Cells were isolated and cultured from the healthy and inflammatory periodontal ligament samples (HPDLSCs and IPDLSCs)respectively.miR-20a expression was analyzed by qRT-PCR.Alizarin red staining,Western blot and PCR were used to evaluate the osteogenic differentiation potential of IPDLSCs after transient transinfection of miR-20a mimics or inhib-itor.Results:miR-20a expression in IPDLSCs was lower than that in HPDLSCs,and the osteogenic differentiation potential of IP-DLSCs were promoted by miR-20a mimics,and reduced by miR-20a inhibitor.Conclusion:The miR-20a in IPDLSCs was down reg-ulated.miR-20a can promote the osteogenic differentiation potential of IPDLSCs.