Background
Materials and methods
Patients
Surgical variable | Mean ± SD | P value | |
---|---|---|---|
Group1 (n = 23) | Group2 (n = 14) | ||
Maxillary posterior impaction (mm)a | – | 4.23 ± 3.14 | – |
Advancement of maxilla (mm)b | – | 0.81 ± 2.11 | – |
Mandibular setback amount (mm)c | 4.85 ± 4.34 | 6.81 ± 5.14 | 0.223 |
Changes of mandibular plane angle (°)d | 3.54 ± 4.56 | 2.17 ± 4.24 | 0.371 |
CBCT examination and measurements
Landmark (abbreviation) | Definition |
---|---|
Landmarks | |
Na (nasion) | “V” notch of frontal and nasal bones |
Ba (basion) | Most inferior point of the occipital bone |
Or (orbitale) | Most inferior point of the orbital contour |
Po (porion) | Most superior point of the external auditory meatus |
Se (sella) | Center of sella turcica |
Anterior nasal spine (ANS) | Tip of the anterior nasal spine |
B point (B) | Deepest point between pogonion and lower incisal alveolus |
CV1 | Most anterior inferior point of the anterior arch of the atlas |
CV2 | Most anterior inferior point of the body of the 2nd cervical vertebra |
CV4 | Most anterior inferior point of the body of the 4th cervical vertebra |
Reference plane | |
Frankfort horizontal (FH) plane | Faces through the right porion and both sides of the orbitalia |
Midsagittal plane | A plane perpendicular to the FH plane passing through Na and Ba |
Sella vertical (SV) plane | A plane perpendicular to the FH plane passing through Se, Ba, and Na |
CV1 plane | A plane parallel to the FH plane passing through CV1 |
CV2 plane | A plane parallel to the FH plane passing through CV2 |
CV4 plane | A plane parallel to the FH plane passing through CV4 |
Measurements | Definition |
---|---|
Nph AP | Nasopharyngeal airway distance, anteroposterior distance at CV1 level |
Oph AP | Oropharyngeal airway distance, anteroposterior distance at CV2 level |
Hph AP | Hypopharyngeal airway distance, anteroposterior distance at CV4 level |
Nph vol | Nasopharyngeal airway volume, top of the pharyngeal airway to CV1 plane |
Oph vol | Oropharyngeal airway volume, between the CV1 plane and CV2 plane |
Hph vol | Hypopharyngeal airway volume, from CV2 plane to CV4 plane |
Whole pharynx volume | Sum of the Nph volume, Oph volume, and Hph volume |
SV-B | The distance from the sella vertical plane to the B point |
Statistical analysis
Results
Variable | T0 | T1 | T2 | T3 | T0–T1 | T0–T2 | T0–T3 | T1–T2 | T2–T3 |
---|---|---|---|---|---|---|---|---|---|
Mean ± SD | |||||||||
Nph AP | 13.35 ± 2.80 | 12.39 ± 2.63 | 12.60 ± 2.70 | 12.48 ± 2.16 | 0.022* | 0.070 | 0.065 | 0.630 | 0.761 |
Oph AP | 12.30 ± 4.31 | 10.05 ± 4.20 | 10.20 ± 3.72 | 11.12 ± 4.33 | 0.000** | 0.001** | 0.025* | 0.783 | 0.095 |
Hph AP | 17.70 ± 4.55 | 15.93 ± 4.00 | 15.30 ± 4.14 | 16.67 ± 4.98 | 0.016* | 0.003** | 0.184 | 0.279 | 0.038* |
Nph vol | 6.23 ± 2.84 | 5.89 ± 2.93 | 5.65 ± 2.53 | 5.53 ± 2.73 | 0.239 | 0.049* | 0.089 | 0.308 | 0.645 |
Oph vol | 6.04 ± 2.80 | 4.24 ± 2.27 | 4.46 ± 2.49 | 4.10 ± 2.06 | 0.000** | 0.000** | 0.000** | 0.516 | 0.245 |
Hph vol | 7.80 ± 3.99 | 5.94 ± 3.84 | 5.93 ± 3.09 | 6.04 ± 3.65 | 0.000** | 0.000** | 0.002** | 0.982 | 0.750 |
Whole pharynx vol | 20.07 ± 8.22 | 16.07 ± 7.52 | 16.03 ± 6.70 | 15.67 ± 7.17 | 0.000** | 0.000** | 0.001** | 0.962 | 0.622 |
SV-B | 64.97 ± 7.88 | 60.12 ± 5.46 | 60.52 ± 6.09 | 60.86 ± 5.51 | 0.000** | 0.000** | 0.000** | 0.466 | 0.321 |
Variable | T0 | T1 | T2 | T3 | T0–T1 | T0–T2 | T0–T3 | T1–T2 | T2–T3 |
---|---|---|---|---|---|---|---|---|---|
Mean ± SD | |||||||||
Nph AP | 13.24 ± 2.87 | 12.79 ± 2.72 | 12.27 ± 2.96 | 12.58 ± 3.39 | 0.366 | 0.038* | 0.173 | 0.312 | 0.644 |
Oph AP | 14.52 ± 4.35 | 13.07 ± 5.53 | 12.11 ± 3.36 | 15.72 ± 9.75 | 0.427 | 0.076 | 0.614 | 0.377 | 0.196 |
Hph AP | 18.00 ± 2.83 | 18.82 ± 3.76 | 18.69 ± 3.25 | 18.40 ± 3.48 | 0.367 | 0.447 | 0.634 | 0.838 | 0.619 |
Nph vol | 7.43 ± 4.81 | 6.59 ± 4.00 | 6.72 ± 4.40 | 7.76 ± 4.30 | 0.185 | 0.129 | 0.525 | 0.762 | 0.009** |
Oph vol | 7.39 ± 4.00 | 6.14 ± 3.29 | 5.26 ± 2.57 | 7.11 ± 3.86 | 0.126 | 0.005* | 0.328 | 0.064 | 0.010* |
Hph vol | 8.32 ± 3.75 | 8.53 ± 3.81 | 7.21 ± 2.91 | 7.94 ± 2.69 | 0.762 | 0.198 | 0.527 | 0.098 | 0.147 |
Whole pharynx vol | 23.14 ± 10.78 | 21.25 ± 9.02 | 19.19 ± 7.68 | 22.81 ± 9.17 | 0.287 | 0.030* | 0.721 | 0.083 | 0.007** |
SV-B | 63.93 ± 7.88 | 57.13 ± 7.45 | 57.35 ± 6.40 | 57.51 ± 6.60 | 0.000** | 0.000** | 0.000** | 0.740 | 0.621 |
Variable | T0–T1 | T1–T2 | T2–T3 | T0–T3 | |||||
---|---|---|---|---|---|---|---|---|---|
Average of change | P value | Average of change | P value | Average of change | P value | Average of change | P value | ||
ΔNph AP (mm) | Group 1 | 0.96 | 0.422 | − 0.21 | 0.284 | 0.12 | 0.549 | 0.87 | 0.756 |
Group 2 | 0.45 | 0.51 | − 0.31 | 0.66 | |||||
ΔOph Ap (mm) | Group 1 | 2.25 | 0.668 | − 0.15 | 0.306 | − 0.92 | 0.221 | 1.18 | 0.333 |
Group 2 | 1.44 | 0.96 | − 3.61 | − 1.20 | |||||
ΔHph AP (mm) | Group 1 | 1.76 | 0.025* | 0.63 | 0.568 | − 1.37 | 0.078 | 1.03 | 0.225 |
Group 2 | − 0.82 | 0.14 | 0.30 | − 0.40 | |||||
ΔNph vol (cm3) | Group 1 | 0.33 | 0.392 | 0.24 | 0.409 | 0.11 | 0.008** | 0.69 | 0.116 |
Group 2 | 0.84 | − 0.14 | − 1.04 | − 0.33 | |||||
ΔOph vol (cm3) | Group 1 | 1.80 | 0.500 | − 0.21 | 0.049* | 0.37 | 0.004** | 1.95 | 0.003** |
Group 2 | 1.26 | 0.88 | − 1.85 | 0.29 | |||||
ΔHph vol (cm3) | Group 1 | 1.86 | 0.011* | 0.01 | 0.094 | − 0.11 | 0.293 | 1.76 | 0.093 |
Group 2 | − 0.21 | 1.32 | − 0.74 | 0.38 | |||||
ΔWhole pharynx volume (cm3) | Group 1 | 3.99 | 0.246 | 0.01 | 0.141 | 0.37 | 0.004** | 4.40 | 0.023* |
Group 2 | 1.89 | 2.06 | − 3.62 | 0.34 |