Analysis Of Cranio-facial Hard And Soft Tissue Characteristics Of Adolescents With Aesthetic And Unaesthetic Soft Tissue Facial Profile

ObjectiveIn order to improve patient’s facial profile by orthodontic treatment, we analyzed and compared cranio-facial hard and soft tissue characteristics in patients with class I, class II and class III skeletal pattern, who were divided into aesthetic and unaesthetic facial profile groups.MethodFrom year2005to2011, more than1800patients were screened, of which427patients met the inclusion criteria. Lateral cephalograms of these427patients were analyzed. According to the cephalometric ANB value, they were divided into Class I, Class II and Class III skeletal pattern respectively. The patients who satisfied both the aesthetic standards of E-line and H angle constituted the aesthetic soft tissue facial profile group, rest of them made up for the reference group.33commonly used hard tissue indicators and9soft tissue indicators were used to conduct the cephalometric analysis, t-Test was performed for the aesthetic soft tissue facial group; Class I compared with Class II and Class I compared with Class III skeletal pattern. Paired t test was performed between aesthetic and unaesthetic soft tissue facial profile groups for all the three skeletal pattern bases. Results1、 The distribution of aesthetic appearing soft tissue facial profile group had statistical significant difference (P<0.01). The highest proportion constituted the Class I skeletal pattern, followed by Class III and Class II made up for the least.2、 The result of pleasant soft tissue facial profile analysis in different skeletal pattern-(1)5cephalometric measurements of Class II skeletal pattern were larger than Class I. They were Pog-NB, Wits value, Ar-Go-Me, N-Go-Me, Ns-Sn-Pog’.6cephalometric measurements were smaller than Class I. They were OP/MP, U1-NA, U1/SN, U1/FH, U1/APo, and L1/APo. In all,11measurements were statistically significant.(2)8cephalometric measurements of Class III skeletal pattern were larger than Class I skeletal pattern. They were SNB, Go-Me, S-N/Go-Me, U1-NA, FMIA, soft tissue thickness at Point A, Z angle and Ns-Sn-Pog’.6cephalometric measurements were smaller than Class I; they were Wits value, L1-NB, L1-NPog, Over Jet, U1-NPog, H angle. In all,14measurements were statistically significant.3、The ANB value of aesthetic Class III skeletal pattern, was smaller than their reference group (P<0.05). 4、 Result obtained from the analysis on similar skeletal pattern bases between the aesthetic soft tissue facial profile group and their reference peers-(1) In Class I skeletal pattern, the aesthetic group had12measurements smaller and4measurements larger than the reference group.The12measurements were Wits value, U1-NA, L1-NB, U1-SN, U1-FH, L1/MP, U1-NPog, L1-NPog, U1-APo, L1-APo, IMPA, and Over Jet.The4measurements were-Inter-incisal angle, FMIA, naso-labial angle, Z angle. In all16measurements were statistically significant.(2) In Class II skeletal pattern, the aesthetic soft tissue facial profile group had5measurements smaller and3measurements larger than the reference group.The5measurements were SN/MP, Ul-NPog, L1-NPog, L1-NB, and L1-APo.The3measurements were S-N/Go-Me, Pog-NB and Z angle.In all,8measurements were statistically significant.(3) In Class III skeletal pattern, the aesthetic soft tissue facial profile group had6measurements smaller and1measurement larger than the reference group.The6measurements were Ar-Go-Me, N-Go-Me; SN/MP, FH/MP, FMA, L1-NPog and1measurement were Over Bite. In all,7measurements were statistically significant.Conclusion1、 The characteristic features of aesthetic facial profile adolescent patients with Class I skeletal pattern base were-facial convexity and upper lip protrusion were less, upper and lower anterior teeth were close to the APo line, the axial inclination and the degree of protrusion of upper and lower anterior teeth were small and the over jet was increased. The distribution of aesthetic appearing soft tissue facial profile group had statistical significant difference. The highest proportion constituted the Class I skeletal pattern, followed by Class III and Class II made up for the least.2、 The characteristics features of aesthetic facial profile adolescent patients with Class II skeletal pattern base were-protruded bony chin, upper anterior teeth were less protruded and more upright, lower anterior teeth were close to the APo line, mandible exhibited counter-clockwise rotation.3、 The characteristic features of aesthetic facial profile adolescent patients with Class III skeletal pattern base were-protruded upper anterior teeth and retruded lower anterior teeth, there was increase in upper lip thickness, presence of deep overbite and mandible exhibited counter-clockwise rotation. In Class III skeletal pattern base, the hard tissue abnormality in sagittal relationship was, to a lesser extent in aesthetic facial profile group when compared to their reference peers.