The research was carried out on 60 CBCT films of patients at the department of dentistry at Vietnam Cuba hospital. The goal was to determine the distance between the roots in some positions on which usually implant orthodontic anchorage screws. Reasearch methodology: cross-sectional describle study. On CBCT, measured the distance between the roots cutting at the apices and about one second of the roots. The results indicated the distance between the roots at the apices of maxillary teeth were: between teeth 1-2:5,5 + or - l,3mm, teeth 5-6: 7,1 + or - l,6mm.... The distance between roots at one second of the roots in the maxillary were: between teeth 1-2: 2,7 + or - 0,9mm, teeth 5-6: 3,9 + or - 0,8mm... Conclusions: The space for implantation of orthdontic anchorage screws between two central maxillary incisors, maxillary second premolar and first molar... is safe. The space for implantation of orthdontic anchorage screws between mandibular incisor roots is the most dangerous.