Table 1 Summary of the metrics obtained during the cross-validation and testing phases of the regression models used to predict chronological age based on mandibular size and sex, along with their optimal hyperparameters.

From: Age estimation of children and adolescents from mandibles using machine learning

Model

Optimal hyperparameters

Test data results [CI95%]

Cross-validation results [CI95%]

Gradient boosting

learning_rate: 0.1

MSE = 3.74 [2.73–4.81]

MSE = 2.37 [1.96–2.84]

max_depth: 4

RMSE = 1.93 [1.65–2.19]

RMSE = 1.54 [1.40–1.69]

min_samples_split: 2

R2 = 0.38 [0.21–0.53]

R2 = 0.56 [0.46–0.64]

n_estimators: 100

MAE = 1.54 [1.33–1.76]

MAE = 1.21 [1.09–1.32]

Linear regression

fit_intercept: True

MSE = 4.12 [3.24–5.02]

MSE = 4.28 [2.64–6.07]

copy_X: True

RMSE = 2.03 [1.80–2.24]

RMSE = 2.06 [1.62–2.46]

n_jobs: -1

R2 = 0.31 [0.21–0.41]

R2 = 0.20 [-0.13–0.51]

positive: True

MAE = 1.71 [1.49–1.91]

MAE = 1.56 [1.31–1.78]

Support vector machine

C: 1

MSE = 4.06 [3.09–5.16]

MSE = 2.84 [2.38–3.34]

kernel: rbf

RMSE = 2.01 [1.76–2.27]

RMSE = 1.68 [1.54–1.83]

degree: 2

R2 = 0.32 [0.14–0.49]

R2 = 0.47 [0.37–0.55]

 

MAE = 1.62 [1.40–1.83]

MAE = 1.33 [1.20–1.47]

K-nearest neighbors

n_neighbors: 9

MSE = 3.94 [3.02–4.98]

MSE = 2.97 [2.45–3.55]

p: 1

RMSE = 1.98 [1.74–2.23]

RMSE = 1.72 [1.57–1.88]

weights: uniform

R2 = 0.34 [0.17–0.49]

R2 = 0.45 [0.34–0.54]

 

MAE = 1.62 [1.42–1.83]

MAE = 1.37 [1.23–1.51]

Random forest

max_depth: None

MSE = 3.81 [2.81–4.92]

MSE = 2.29 [1.91–2.71]

max_features: sqrt

RMSE = 1.95 [1.68–2.22]

RMSE = 1.51 [1.38–1.65]

min_samples_leaf: 4

R2 = 0.36 [0.19–0.52]

R2 = 0.57 [0.48–0.65]

min_samples_split: 10

MAE = 1.55 [1.33–1.77]

MAE = 1.18 [1.06–1.29]

n_estimators: 200

  

AdaBoost

learning_rate: 0.1

MSE = 4.01 [3.00–5.14]

MSE = 2.58 [2.17–3.02]

loss: linear

RMSE = 2.00 [1.73–2.27]

RMSE = 1.60 [1.47–1.74]

n_estimators: 100

R2 = 0.33 [0.16–0.49]

R2 = 0.52 [0.42–0.60]

 

MAE = 1.61 [1.39–1.82]

MAE = 1.30 [1.19–1.42]

Decision tree

max_depth: 10

MSE = 4.83 [3.65–6.12]

MSE = 2.94 [2.31–3.65]

max_features: sqrt

RMSE = 2.19 [1.91–2.47]

RMSE = 1.71 [1.52–1.91]

min_samples_leaf: 4

R2 = 0.19 [-0.02–0.40]

R2 = 0.45 [0.31–0.57]

min_samples_split: 10

MAE = 1.74 [1.50–1.99]

MAE = 1.29 [1.14–1.45]

MLP regressor

activation: relu

MSE = 4.11 [3.18–5.12]

MSE = 3.02 [2.52–3.65]

alpha: 0.001

RMSE = 2.02 [1.78–2.26]

RMSE = 1.73 [1.59–1.91]

hidden_layer_sizes: (100,)

R2 = 0.31 [0.14–0.47]

Rv = 0.44 [0.31–0.53]

learning_rate: constant

MAE = 1.65 [1.44–1.87]

MAE = 1.40 [1.27–1.53]

solver: adam