The tooth's long axis was used as reference. In order to obtain the mentioned locations, a straight line was drawn intersecting perpendicularly the tooth's long axis and crossing the vestibular CEJ (A). Afterwards, a new straight line was drawn parallel to the previous one, intersecting the tooth's long axis, 4 mm apical to the previous straight line. This new line intersected the buccal bone plate and created P1. In order to obtain P2, the midpoint of the root's length was determined; to do so, a line was drawn joining the palatal and buccal bone crest (B), creating an intersection point with the tooth's long axis (Pm1). In parallel, a straight line was drawn crossing the most apical point in the root apex (C) and intersecting the tooth's long axis (Pm2). Between these two intersections, a midpoint was drawn in the tooth's long axis (Pm3). Lastly, this point was also intersected by a straight line perpendicular to the tooth's long axis and intersecting the buccal bone plate in P2. After establishing the positions, the buccal bone thicknesses were measured, from the root's buccal wall to the external surface of the buccal bone plate.
CEJ = cementoenamel junction.