Table 2 Definition of reference points and variables

Dehiscence

Alveolar bone defect involving an alveolar margin 2 mm or greater and concurrent with a v-shaped BM

Fenestration

A circumscribed defect on the alveolar bone exposing the root, not involving the alveolar crest

A

CEJ at labial side

B

Alveolar crest at labial side

C

The coronal border of a fenestration

D

The apical border of a fenestration

d (mm)

The distance between A and B

d₀ (mm)

The distance between A and B at T0

d₁ (mm)

The distance between A and B at T1

f (mm)

The distance between C and D

f₀ (mm)

The distance between C and D at T0

f₁ (mm)

The distance between C and D at T1

CPDC (mm)

Critical point of d for dehiscence on CBCT, the value of d more than which the tooth was classified as dehiscence, otherwise it was considered healthy.

CPFC (mm)

Critical point of f for fenestration on CBCT, the value of f more than which the tooth was classified as fenestration, otherwise it was considered healthy.