Patients’ clinicodemographic data
Of 64 patients screened for eligibility, 42 were ineligible. Twenty-two patients were randomized in equal numbers to the two study groups (n = 11 patients/group). Figure (8) shows the consort flow chart of the study. Comparison of the two groups yielded the following results Table (1). The mean age in the COG group was 41 ± 18.5 years (range, 10- 63 years) versus 47.81± 13.6 years (range, 29- 63 years) in the MB group.
Based on Brown’s classification of mandibular defects, in the COG group, 5 (45.4 %) patients had CL II, 2 (18.2 %) patients had CL IIc, 3 (27.3 %) patients had CL III, and 1 (9.1 %) had CL IV. While in the MB group, 5 (45.4 %) patients had CL II, 1 (9.1 %) patient had CL IIc, 2 (18.2 %) patients had CL III, 2 (18.2 %) patients had CL IV, and 1 (9.1 %) had CL IVc. The mean mandibular defects’ length was 8.5 ± 2.56 cm in the COG group versus 9.42 ± 4.65 cm in the MB group. Table (1) shows the clinicodemographic data and tumor characteristics of all patients.
Table (1): Clinicodemographic characteristics of both groups of patients enrolled in this study
Variable
|
|
COG group (N= 11)
|
MB group (N= 11)
|
p-value
|
Count
|
%
|
Count
|
%
|
Gender
|
Male
|
7
|
63.60
|
6
|
54.50
|
|
Female
|
4
|
36.40
|
5
|
45.50
|
Age (yr) (Mean ± SD)
|
|
41
|
±18.54
|
47.81
|
±13.75
|
.339
|
Indication / diagnosis
|
Benign
|
3
|
27.30
|
3
|
27.30
|
|
Malignant
|
8
|
72.70
|
8
|
72.70
|
Site
|
Lt Mandible
|
7
|
63.60
|
6
|
54.50
|
|
Rt Mandible
|
2
|
18.20
|
3
|
27.30
|
Bi Mandible
|
2
|
18.20
|
2
|
18.20
|
Mandibular Defect
|
Length(cm) (Mean ±SD)
|
|
8.50
|
±2.56
|
9.42
|
±4.65
|
.575
|
Classification
|
II
|
5
|
45.40
|
5
|
45.40
|
|
IIc
|
2
|
18.20
|
1
|
09.10
|
III
|
3
|
27.30
|
2
|
18.20
|
IV
|
1
|
09.10
|
2
|
18.20
|
IVc
|
0
|
0.0
|
1
|
09.10
|
Flap harvest side
|
Lt leg
|
6
|
54.50
|
7
|
63.60
|
|
Rt leg
|
5
|
45.50
|
4
|
36.40
|
Abbreviations: Bi, bilateral, CAD/CAM, CL, classification, COG, customized osteotomy guide, F, female, F. fibula flap, Lt, left, M, male, MB, model-based, N, number, Pt, patient, Rt, right, SD, standard deviation, Yr, year.
Aesthetic Outcomes:
Differential Area (DAr):
Quantitively, the CDIA revealed that patients in the COG group showed improved aesthetic outcome (contour symmetry) regarding the sagittal DAr with a mean of (277.28 ± 127.05 mm2) compared to (398.67 ± 139.10 mm2) in the MB group. The difference in the sagittal DAr was statistically significant (P = 0.045). Although the axial DAr was better in the COG group than in the MB group, there was no statistically significant difference between the two groups (P = 0.206) Table (2).
Table (2): Comparison of differential area (Sagittal and Axial DAr, mean ± SD) according to group
Differential area (DAr)
|
COG group
|
MB group
|
P-value
|
Mean (mm2)
|
± SD
|
Mean (mm2)
|
± SD
|
Sagittal DAr
|
277.28
|
± 127.05
|
398.67
|
± 139.10
|
0.045*
|
Axial DAr
|
147.61
|
± 55.42
|
183.68
|
± 72.85
|
0.206
|
Abbreviations: COG, customized osteotomy guide, DAr, differential area, MB, model-based, mm2, square millimeter, SD, standard deviation, * Significant P-value.
Differential Angle (DAn):
The mean difference (Δ) and thus deviation for the sagittal and coronal DAn were significantly lower in the COG group than in the MB group (6.11 ± 3.46 and 1.77 ± 1.12° vs 9.53 ± 4.17 and 3.44 ± 2.34°, P < 0.05), respectively. While in the axial DAn, there was no statistically significant difference between the two groups (P = 0.386). Although these results indicate that the mandibular contour symmetry was improved, and even that better symmetry results have been found regarding the sagittal, coronal, and axial mandibular angles in favor of the COG group. However, there were no statistically significant differences in the symmetry for sagittal, coronal, and axial angles between the two groups (P > 0.05) Table (3)
Table (3): Comparison of the mean difference (Sagittal, Coronal and Axial DAn) and symmetry according to group.
Differential and symmetry angle (affected /contralateral side)
|
COG group
|
MB group
|
P-value
|
Mean (°)
|
± SD
|
Mean (°)
|
± SD
|
Sagittal
|
DAn (Δ)
|
6.11
|
± 3.46
|
9.53
|
± 4.17
|
0.049*
|
Symmetry angle
|
1.09
|
± 0.13
|
1.15
|
± 0.19
|
0.389
|
Coronal
|
DAn (Δ)
|
1.77
|
± 1.12
|
3.44
|
± 2.34
|
0.046*
|
Symmetry angle
|
1.00
|
± 0.03
|
1.03
|
± 0.05
|
0.083
|
Axial
|
DAn (Δ)
|
2.60
|
± 0.74
|
2.93
|
± 0.97
|
0.386
|
Symmetry angle
|
1.05
|
± 0.10
|
1.11
|
± 0.09
|
0.185
|
Abbreviations: COG, customized osteotomy guide, DAn, differential angle, MB, model-based, Δ, mean difference, (°), degrees, * Significant P-value.
Subjective evaluation of aesthetic outcome by VAS and PSS:
The mean assessment score of the aesthetic outcome in VAS was higher in the COG group than in the MB group (8.18 ± 0.75 vs 7.64 ± 0.84), respectively. However, there were no statistically significant differences between the two groups (P = 0.12). On the other hand, the mean PSS was better in the COG group than in the MB group (8.14 ± 0.67 vs 7.45 ± 0.79), with statistically significant differences reflecting enhanced aesthetic outcome and better satisfaction (P = 0.041) Table (4).
Table (4): Comparison of Visual analogue scale (VAS) and Patient’s satisfaction score (PSS) according to group
Subjective evaluation
|
COG group
|
MB group
|
P-value
|
Mean (score 1- 10)
|
± SD
|
Mean (score 1- 10)
|
± SD
|
VAS
|
8.18
|
± 0.75
|
7.64
|
± 0.84
|
0.124
|
PSS
|
8.14
|
± 0.67
|
7.45
|
± 0.79
|
0.041*
|
Abbreviations: COG, customized osteotomy guide, MB, model-based, PSS, patient satisfaction score, VAS, visual analogue scale.
Secondary outcome (operation and ischemic time):
In the COG group, the total operation time ranged from 467 to 645 minutes (562.91 ± 51.22 min, mean ± SD) compared to 571- 728 minutes (663.55 ± 53.43 min, mean ± SD) in the MB group, there were statistically significant differences between the two groups (P = 0.0002). The mean ischemia time was 97.55 ± 16.80 minutes in the COG group, compared to 172.45 ± 21.87 minutes in the MB group. The difference in the ischemia time was statistically significant (P = 0.000) Table (5).
Table (5): Comparison of total operation time and ischemia time according to group (in minutes)
|
COG group
|
MB group
|
P-value
|
Mean (min)
|
± SD
|
Mean (min)
|
± SD
|
Total operation time
|
562.91
|
± 51.22
|
663.55
|
± 53.43
|
0.0002*
|
Ischemia time
|
97.55
|
± 16.80
|
172.45
|
± 21.87
|
0.0000*
|
Abbreviations: COG, customized osteotomy guide, MB, model-based, Min, minutes.