Ananlysis Of The Sotf Tissue Facial Proifle Of Northern Chinese Young Adult Using Of Linear Measurements

Nowadays, the orthodontist and oral surgeon mainly makediagnosis and treatment planning based on the cephalometricanalysis. But young adult patients are more concerned about theimprovement in the soft tissue of the face. They hope to obtain amore balanced appearance as well as stable and harmoniousocclusion. However, many studies have shown that soft tissuesprofile did not always follow the pattern of underlying dentoskeletalstructure, since the possible anomaly in the hard tissue could bemasked or exaggerated by the soft tissue. Therefore, the researchfocused on the soft tissue profile is emphasized by orthodontist andoral surgeon recently, when clinicians realized this discrepancybetween soft tissue and hard tissue after sustained studies on hard tissue for decades.Objective: To construct a database based on the analysis of thesoft tissue profile of a Northern China population of young adults bymeans of linear measurements made on standardizedphotographic records taken in natural head position(NHP), and toprovide an reference for orthodontists and oral surgeons indiagnosis and treatment planning.Experimental methods: Subjects were selected from thestudents enrolled in the Norman Bethune college of medicine, JilinUniversity, because of the accessibility of subjects. The basiccriteria for selection included dental Class I occlusion with normaloverjet and overbite, minimal spacing or crowding, the upper andlower midline on, no history of orthodontic treatment and cosmeticsurgery, and the ancestral home in Northern China areas. Twoexperimenters selected124experimental subjects from nearly 4,000students. Before making the final decision, the photograph ofthe124subject was evaluated and ranked by all10referees(Consist of5professional orthodontists and5ordinary people whonever accept medical education), and the consensus was madewhich subject should participate in the study. The criteria werebased on the visual balance of facial parts, and the quality parts (ie,beautiful eyes) were disregarded. After the evaluation of allphotographs,36individuals were excluded from the study. Asample consisting of88subjects,29males and59females,between18and30years of age with an average age of23yearsold was used in this study. Then the right profile records were takenin NHP, A vertical measurement scale was placed which allowed formeasurements at life size (1:1). A plumb line, held by a thick blackthread to define the vertical plane on the photographs was hungfrom the scale. The vertical line as a reference line which is perpendicular to horizontal ground plane. The photographic recordswere analyzed with the coreldraw software,10vertical and7horizontal linear parameters were used to determine the averagemale and female soft tissue facial profile.Statistical analysis was carried out using the SPSS17.0statistical package. An independent sample t-test was used tomeasure differences between genders, The reproducibility of themeasurements were analyzed by using Dahlberg formula.Result: The maximum,minimun and average of male andfemale soft tissue profile was defined using linear measurements.All the values of facial heights were greater in males, except theheight of the nasal tip. Observing the facial heights, there is asimilarity between the inferior facial third and middle facial third(theratio≈1:1). The superior third and inferior third and facial depthexhibited a large variability of the soft tissue profile features, as shown by the high values of the standard deviation of thesevariables analyzed. This means that there is considerable diversityof the facial profile in patients with normal occlusions andwell-balanced faces. All the values of facial heights showed genderdifferences except the height of the nasal tip and superior third.Only three soft tissue variables presented statistically significantsexual dimorphism in facial prominence. The systematic andcasual errors for most measurements were low. The highest errorswere found in facial superior height mainly due to the difficulty inthe localization of trichion points.Conclusion: Males have larger faces in general. The labial,nasal, and chin areas showed sexual dimorphism in most of theparameters we used. Nearly all the values of facial heights showedgender differences compared to the sagittal facial prominencewhich indicated less gender differences in our study. In clinical diagnosis and treatment, orthodontists and oral surgeons shouldpay attention to gender differences.