The Three-dimensional Study Of Craniofacial Morphology With Class Ⅱ Skeletal Pattern In Different Vertical Facial Types

ObjectiveThis study uses CBCT as the research approach to investigate the three dimensional features of the craniofacial bone of the patients with Class II ske letal pattern in different vertical facial type. Measuring index indicators of the high angle group, average angle group and low angle group were compared, to provide anatomical basis, scientific and theoretical support for the diagnosis and prognosis of orthodontic patients.Materials and methodThe CBCT images of 90 skeletal Class II patients(30 hypodivergent, 30 hyperdivergent,30 normodivergent)were selected randomly, 10 measurements of mandible and 15 measurements of the skull of zygomatic maxillary complex were selected, then compare the differences between the three divergent classes in order to investigate the three dimensional features of the craniofacial bone of the patients with Class II skeletal pattern in different vertical facial type.Results1 Compared with the normal angle patients, Co-Go, Co-Co’, Go-Go’,∠Go-Me-Go’,∠Go-N-Go’,∠Go- S- Go’,∠Co-Me-Co’ in high angle patients are smaller,but ∠Co-Go-Me is larger; Co-Go,Go-Go’,Go-Me,the depth in mandible,∠Go-Me-Go’,∠Go-N-Go’,∠Go- S- Go’ in low angle patients are larger,but ∠Co-Go-Me is smaller.All the Measurements in high angle patients are smaller than the low angle patient’s.2. Compared with the normal angle patients, N- Ba,∠N-S-Ba,ANS-N, the depth of the palate in high angle patients are larger,but Sm-Sm’,Tzl-Tzl’,Tz2-Tz2’,Ore-Ore’,Maz- Maz′,the width of the palate are smaller; Sm-Sm’,Tzl-Tzl’,Tz2-Tz2’,Ore-Ore’,Ori-Ori’,ANS-Ptm,Maz- Maz′,ANS-PNS, the width of the palate in low angle patients are larger,but N- Ba,∠N-S-Ba,ANS-N,the depth of the palate are smaller;Sm-Sm’,Tzl-Tzl’,Tz2-Tz2’,OreOre’,Ori-Ori’,ANS-Ptm,Maz- Maz′,ANS-PNS,the width of the palate in l ow angle patients are larger than high angle patients,but N- Ba,∠N-S-Ba,ANS-N,the depth of the palate are smaller than high angle patients.Conclusion1 High angle patients have shorter mandibular height, mandibular length is longer, posterior mandibular is narrow; Low angle patients have longer mandibular height and length, posterior mandibular is wider.2 The skull base length among different vertical facial skeletal types is similar, increased cranial base angle leads to overall length of skull base higher in high angle patients.3 Low angle patients with orbital distance,midface width,maxillary width and len gth,palatal width and length of the high angle type significantly increases, in th e maxillary palatal height and high value, high angle patients with low angle wer e bigger.4 The vertical development of High angle patients was significant, while the horizontal and sagittal development of low angle patients was more obvious.5 Craniofacial morphology in patients with different vertical facial skeletal types has different structural features, in the orthodontic treatment, this must be considered.