Abstract: PURPOSE: Cone-beam CT (CBCT) was used to measure and analyze the regional sites of mandibular buccal shed for micro-screw implantation, providing guidance for dentists to safely place micro-screws. METHODS: Sixty-two patients receiving orthodontic treatment in our hospital were collected from January 2018 to October 2018. All patients underwent CBCT examination. Three-dimensional reconstruction of CBCT images was performed in the first premolar and 3 mm (D1), 6 mm (D2), 9 mm(D3) below the alveolar crest between the second premolar (A), the second premolar and the first molar (B), between the first molar and the second molar (C) for bone width, the differences in bone width between different genders, left and right side, and different positions were compared with SPSS 22.0 software package. RESULTS: The width of bone in different positions of the mandibular buccal shed in males and females was not significantly different between the left and right side (P>0.05). The bone width of the mandibular cheek shed area was significantly different at different distances and at the same distance (P<0.05). The width of bone at 9 mm of the alveolar crest between the first molar and the second molar was the largest [(10.62±1.38) mm], while the width of the bone at 3 mm of the alveolar crest of the second premolar and the first molar was the smallest [(2.65±0.38) mm]. CONCLUSIONS: The bone width of the mandibular buccal shed area was not significantly different in gender and between left and right side, but different anatomical sites in the mandibular cheek shed area had disparity, and there was an increasing trend from mesial to distal.

Key words: Mandibular buccal shed area, Microscrew, Cone-beam CT, Anatomical implantation site