Table 2 Definition of measurements

V-LA, mm³

Labial surrounding alveolar bone volume

V-L, mm³

Lingual surrounding alveolar bone volume

V-W, mm³

Whole surrounding alveolar bone volume

PDLA, mm²

The part of the root surface area that is covered by PDL and alveolar bone

RL, mm

Root length

T-ALA, mm

Labial alveolar bone thickness at apex level

T-AL, mm

Lingual alveolar bone thickness at apex level

T-AW, mm

Whole alveolar bone thickness at apex level

T-MLA, mm

Labial alveolar bone thickness at middle root level

T-ML, mm

Lingual alveolar bone thickness at middle root level

T-MW, mm

Whole alveolar bone thickness at middle root level

VBL-LA, mm

Distance from CEJ to alveolar crest on the labial side parallel to root length

VBL-L, mm

Distance from CEJ to alveolar crest on the lingual side parallel to root length

VBL-M, mm

Distance from CEJ to alveolar crest on the mesial side parallel to root length

VBL-D, mm

Distance from CEJ to alveolar crest on the distal side parallel to root length