|Author||Year and country||Sample size (n) and study population||Methodology||Formula||Error estimatea|
|Morse (Morse et al. 1994)||1993 Pennsylvania||n= 500 and only mandibular anterior teeth were evaluated.||Root canal shrinkage was calculated vertically and horizontally comprising of length and width.||-||The first study to suggest use of radiology in age estimation.|
|Kvaal (Kvaal et al. 1995)||1995 Norway||
IOPA was used
Molars were not included.|
Length and width ratios were calculated for pulp and teeth.
|Age= 129.8 – (316.4 x M) (6.8 x [W-L])||Standard error= ±9.8 years|
|Cameriere (Cameriere et al. 2004b)||2004 Bologna, Italy||
n= 312 Italian population with 135 males and 177 females.|
OPGs were used.
|OPGs of second molars were processed using Adobe Photoshop 7.0. Twenty points from each tooth edge and ten points for the pulp edge were identified and used to evaluate tooth and pulp areas.||
logit(p) = b0 + b1 RA + b2 Tm + b3 sex.|
RA= ratio pulp/tooth area
Tm= third molar development
A cutoff value of RA= 0.088 if Tm= 0 and RA= 0.097 if Tm= 1.|
|Cameriere (Cameriere et al. 2004a)||2004 Italy||n= 100 Italian population (Caucasians) with 46 males and 54 females. OPGs were used.||Single rooted maxillary canines were used and tooth and pulp areas were computed using AutoCAD software.||
Age = 86.53−457.15 AR−22.98 c|
AR= pulp tooth area ratio
c = pulp/root width at midroot level
Median of the absolute value of residual error= <4 years|
Standard error= ±5.35 years.
|Bosman (Bosmans et al. 2005)||2005 Belgium||n= 197 OPGs with age range of 19 to 75 years.||Molars were excluded.||-||Standard error= ±8.6 to ±9.5 years depending on various teeth used.|
|Cameriere (Cameriere et al. 2007)||2007 Bologna, Italy||n= 200 IOPAs of age range from 20–79 years, with 114 males and 86 females.||Maxillary and mandibular canines were used and tooth and pulp areas were computed using AutoCAD software.||
Age= 114.624–431.183x1–456.692x2 + 1798.377x1x2|
X1 = pulp areas of upper canines
X2= pulp areas of lower canines
Age= 99.937–532.775x1 (when only the upper canine is included)
Age= 89.456–461.873x2 (when only the lower canine is included)
Residual standard error= ±4.06 years Mean prediction error (ME) = ±3.36 years.|
Residual standard error= ±5.44 years ME= ±4.38 years.
Residual standard error= ±5.45 years ME= ±4.46 years
|Jagannathan (Jagannathan et al. 2011)||2008 India||
n= 188 (140 cases and 48 conyrols) from age 10–70 years.|
CBCT was used to measure pulp and tooth volumes.
CBCT scanner (3D accuitomo, Japan) was used with slide thickness of 250 μm.|
Multiplanar volume reconstruction was performed with Advantage Windows workstation (USA).
Age= 57.18 + (-413.41 x PTV)|
PTV= pulp/tooth volume ratio
|Mean absolute error (MAE)= ±8.54 years|
|Drusini (Drusini 2008)||1991 Italy||
n= 846 intact teeth from 433 Caucasian individuals|
OPGs were used to measure the tooth-coronal index (TCI).
|Only mandibular posterior teeth where the pulp chamber is normally fully visible were considered excluding third molars.||
TCI= (CPCH X 100)/CL|
CPCH= coronal pulp cavity height or length, CL= coronal length
|Standard error varies from ±5 to ±20 years.|