pISSN 2234-7518
eISSN 2005-372X

Table. 4.

Predominant type in the skeletodental patterns of the maxillomandibular complex in Korean pre-adolescent patients with Pierre–Robin sequence (PRS)

Skeletodental pattern Korean norm PRS (n = 26) Type Number (%) p-value
Mean SD Mean SD
Sagittal Maxilla SNA (°) 81.3 3.4 74.77 4.74 Protrusion (> 84.7) 1 (3.8) < 0.001***
Normal (77.9–84.7) 5 (19.2)
Retrusion (< 77.9) 20 (76.9)
Mandible SNB (°) 78.9 3.0 69.77 4.53 Protrusion (> 81.9) 0 (0) < 0.001***
Normal (75.9–81.9) 2 (7.7)
Retrusion (< 75.9) 24 (92.3)
Intermaxillary relationship ANB (°) 2.6 1.6 4.99 2.57 Class I relationship (1.0–4.2) 9 (34.6) 0.007**
Class II relationship (> 4.2) 15 (57.7)
Class III relationship (< 1.0) 2 (7.7)
Vertical SN-MP (°) 33.8 4.9 46.89 7.42 Normo-divergent (28.9–38.7) 2 (7.7) < 0.001***
Hyper-divergent (> 38.7) 24 (92.3)
Hypo-divergent (< 28.9) 0 (0)
Size and shape of the mandible Mandibular body length to anterior cranial base ratio (Go-Me/S-N) 1.01 0.06 0.92 0.05 Small ratio (< 0.95) 17 (65.4) < 0.001***
Normal ratio (0.95–1.07) 9 (34.6)
Large ratio (> 1.07) 0 (0)
Gonial angle (°) 123.0 6.0 130.58 7.02 High (> 128.5) 17 (65.4) 0.001**
Normal (117–128.5) 8 (30.8)
Low (< 117) 1 (3.8)
Dental Maxillary incisor inclination U1-SN (°) 106.55 6.13 93.21 9.26 Labioversion (> 112.7) 0 (0) < 0.001***
Normal (100.4–112.7) 6 (23.1)
Linguoversion (< 100.4) 20 (76.9)
Mandibular incisor inclination IMPA (°) 95.34 5.34 82.44 8.07 Labioversion (> 100.7) 0 (0) < 0.001***
Normal (90.0–100.7) 5 (19.2)
Linguoversion (< 90.0) 21 (80.8)

The mean age of patients at the time of cephalometric analysis (T1 stage) was 9.20 ± 1.46 years.

Korean ethnic norms were used to determine the skeletodental pattern of the maxillomandibular complex with reference to the cephalometric analysis chart used in the Department of Orthodontics, Seoul National University Dental Hospital and the findings of a previous study.19

Chi-square goodness of fit test was performed.

SD, standard deviation; SNA, sella-nasion-A point angle; SNB, sella-nasion-B point angle; ANB, A point-nasion-B point angle; SN-MP, sella-nasion to mandibular plane angle; Go-Me, gonion-menton; S-N, sella-nasion; U1-SN, upper incisor to sella-nasion angle; IMPA, incisor mandibular plane angle.

**p < 0.01, ***p < 0.001.

Korean J Orthod 2021;51:337~345 https://doi.org/10.4041/kjod.2021.51.5.337
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