Fig. 1

Cross-sectional image perpendicular to the dental arch passing through the mesiodistal midpoint of the maxillary first molar: an implant in the mandible first molar region. A: reference point of the maxillary first molar: the buccopalatal midpoint of the occlusal surface of the maxillary first molar. B: reference point of the maxillary first molar: buccolingual midpoint of the occlusal side of the implant