The evaluation of systematic measurements errors in the cephalograms showed an acceptable test-retest reliability, yielding ICCs between 0.90 and 0.99 (p < 0.05).
Comparison between the PWS and control groups (Tables 3, 4 and 5)
Sagittal relationships:
A retrognathic mandibula (A-n-B: 5.0°, a difference of +1.9° from the control group) was found in children with PWS resulting in a mean Class II skeletal pattern (Table 3). They also had a more convex skeletal profile (A ḻ n-pg: 4.3mm). Young adults (Table 4) showed a reduced cranial base angle (n-s-ba: 124.5°) and a skeletal class II relationship. Adults with PWS (Table 5) had a skeletal Class III relationship (A-n-B: 1.1°, a difference of – 1.8° from the control group).
Table 3 - Cephalometric measurements for PWS individuals and control group under 12 years of age
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Table 4 - Cephalometric measurements for PWS individuals and control group between 12 and 20 years of age
![](https://myfiles.space/user_files/83064_0857a92044b57365/83064_custom_files/img1628744087.png)
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Table 5 - Cephalometric measurements for PWS individuals and control group over 20 years of age
![](https://myfiles.space/user_files/83064_0857a92044b57365/83064_custom_files/img1628744177.png)
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Vertical dimensions:
Children with PWS (Table 3) had an increased inclination of the maxilla (NL/NSL: 11.6°, a difference of +4.4° from the control group) while in young adults (Table 4) this inclination was reduced (NL/NSL: 5.4°, a difference of -2.0° from the control group). No statistical difference was seen in the adults with PWS (Table 5) compared to the control group.
Growth directions:
In children with PWS (Table 3), the growth direction axis was posterior (FA/n-ba: 88.2°) while adults (Table 5) had an anterior growth direction (FA/n-ba: 96.9°).
Anterior face height
Both upper anterior face height (n-sp: 46.0 mm) and the lower anterior face height (sp-gn: 57.7 mm) were larger in children with PWS (Table 3).
Young adults with PWS (Table 4) showed a longer lower anterior face height (sp-gn: 67.8 mm) and a subsequent smaller n-sp/sp-gn ratio (n-sp/sp-gn: 74.3%) than the control group.
No statistical difference was seen in the adults with PWS (Table 5) compared to the control group.
Dental occlusion:
Dental cephalometric measurements of children and young adults with PWS were no different to the control group (Table 3 and 4).
Adults with PWS (Table 5) had more proclined upper incisors to the maxillary plane (ILs/NSL: 106.7°, a difference of +5.5° from the control group) and retroclined lower incisors to the mandibular plane (ILi/ML: 89.7°, a difference of -6.1° from the control group) and to the A-pg line (ILi/A-pg: 20.3°, a difference of -3.4° from the control group).
Comparing all PWS age groups (Tables 6, 7 and 8)
Sagittal relationships:
Young adults (Table 8) had a more prognathic mandibula (s-n-B: 81.0°) than children did (s-n-B: 76.1°), a difference of -4.9°. Both had a skeletal class II pattern and a convex profile.
Adults (Table 7) showed an even more prognathic mandible than the young adults with a skeletal class III relationship (A-n-B: 1.1° in adults, A-n-B: 3.7° in young adults, a difference of +2.6°).
Vertical dimensions:
The inclination of the maxillary plane angle was larger in children (NL/NSL: 11.6°) than young adults (NL/NSL: 5.4°), (Table 8). Adults had reduced inclination of the maxillary and mandibular planes (NL/NSL, ML/NSL and ML/NL) than children.
Growth directions:
The growth direction axis (FA/n-ba) was more posterior in the young adults and children than in adults (Tables 6, 7 and 8).
Table 6 - Cephalometric measurements for PWS individuals under 12 years and PWS individuals over 20 years of age
![](https://myfiles.space/user_files/83064_0857a92044b57365/83064_custom_files/img1628744229.png)
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Table 7 - Cephalometric measurements for PWS individuals between 12 and 20 years of age and PWS individuals over 20 years of age
![](https://myfiles.space/user_files/83064_0857a92044b57365/83064_custom_files/img1628744291.png)
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Table 8 - Cephalometric measurements for PWS individuals under 12 years of age and PWS individuals between 12 and 20 years of age
![](https://myfiles.space/user_files/83064_0857a92044b57365/83064_custom_files/img1628744339.png)
Abbreviations:
Basal sagittal - n-s-ba: Cranial base inclination, s-n-A: Maxillary prognathism, s-n-B: Mandibular prognathism, A-n-B: Relative prognathism, A ḻ n-pg: Facial convexity.
Basal vertical - NL/NSL: Maxillary inclination, ML/NSL: Mandibular inclination, ML/NL: Mand./Max. inclination, FA/n-ba: Facial axis.
Anterior face height - n-sp: Upper anterior face height, sp-gn: Lower anterior face height, n-sp/sp-gn: Ratio.
Dental - Ii to A-pg: Lower incisor protrusion, ILi/A-pg: Lower incisor inclination to A-pg, ILi/ML: Lower incisor inclination to ML, Is to A-pg: Upper incisor protrusion, ILs/A-pg: Upper incisor inclination to A-pg, ILs/NSL: Upper incisor inclination to NSL, ILi/ILs: Interincisor angle.
Anterior face height
Both upper anterior face height (n-sp) and lower anterior face height (sp-gn) were significantly smaller in children than in adults (Table 6).
Young adults showed a significant larger lower anterior face height than children (Table 8).
Dental occlusion:
Upper incisors were more proclined to the maxillary plane in young adults (ILs/NSL: 103.9°) and adults (ILs/NSL: 106.7°) than in children (ILs/NSL: 96.3°), (Tables 6, 7 and 8).