| Skeletal Class Ⅲ malocclusion is one of the common clinical skeletal malocclusion, hard and soft tissue abnormalities involving the entire craniofacial unit, its presence not only affects the patient’s occlusal and physiological function but also psychological health. For adults with skeletal class Ⅲ patients, orthodontic- orthognathic treatment can provide best therapeutic effect. The maxilla-mandibular position and their relationship after treatment are predictability because it depends on surgical procedures and moving distances which is decided before surgery. While, patients are often pay attention to facial appearance, which is difficult to predict because there are so many factors that effect the soft tissue changes. Measuring the amount of hard and soft tissue change, knowing the changes’ law, will help the doctor’s diagnosis and treatment, and also conducive to communication.ObjectiveIn this study, through cephalometric measurements preoperative and postoperative, to evaluate the lips soft tissue morphology changes of different severity of skeletal malocclusion and different surgery pattern, understand the correlation of hard and soft tissues in adult patients with skeletal class Ⅲ, predict clinical program development.MethodsExperiment 1: Patients met the inclusion criteria of selection has been completed skeletal class Ⅲ orthodontic- orthognathic treatment,included 94 patients(46 male, 48 female), according to malocclusion severity(mild:-5 ° <ANB <0 °, severe: ANB ≤-5 °) and sex were grouped for each patients before and after surgery lips soft tissue thickness, length, angle and distance to the reference plane to be measured, and all the measurements analyses by SPSS18.0, performed by the Independent-Samples t-test. Experiment 2: The patients included in this experiment are divided into groups according to the surgical approach(maxillary surgery, jaw surgery, double jaw surgery) group, then before and after surgery lips soft tissue thickness, length, angle and distance to the reference plane to be measured,, use SPSS18.0 software for Paired-Samples t-test. Experiment 3: The patients included in this experiment are divided into groups according to the surgical approach(maxillary surgery, jaw surgery, double jaw surgery) group, and then overlap the cephalometric before and after surgery through different reference respectively, measure the changes of soft and hard tissue from both horizontal and vertical, use SPSS18.0 software for Pearson correlation test.Result1. Skeletal Class Ⅲ patients’ lips soft tissue study before surgery show that: 1) 1)The difference of soft tissue between women and men is mainly reflected in the position of the soft tissue landmarks vertically, rather morphological differences no matter mild and severe malocclusion; 2) severe malocclusion patients have thicker lip and shorter upper lip than mild malocclusion patients have and also have deeper nasolabial fold, the lower lip and chin are flatter, present obviously concave profile,and the difference exist in the position of the soft tissue landmarks horizontally. 2. Skeletal Class Ⅲ malocclusion study the postoperative lip chin soft tissue morphology changes show that: 1) after maxillary surgery, the thickness of the upper lip are reduced, the length increased, nasolabial depth decreased, the inclination of the upper lip lower lip inclination were increased, the level of the upper lip are all signs point to move forward, lower lip and chin portion of the soft tissue down; 2)after jaw surgery, lip thickness increases, but no change in the thickness of the chin, lips and mentolabial deepened, lower lip angle increases, mentolabial angle decreases, the side surface type appearance can be improved, lower lip and chin soft tissue levels were moved back;3) after double jaw surgery, the thickness of the upper lip is reduced,while lower lip thickness is thicker, upper lip increasing and lower lip shortening,mentolabial fold depth deepened, upper lip inclination angle increases lower lip, mentolabial angle decreases, in addition to UL, Stms, Stmi, the remaining soft tissue landmarks have changed, the maxillary move forward, while mandibular move back. Vertically soft tissue move down. 3. The correlation of hard and soft tissue change of skeletal Class Ⅲ patients study show: 1) after maxillary surgery, the hard tissue at ANS, A corresponding soft tissue(Sn, A ’, UL) are highly correlated, horizontally and vertically,but the scale have a large differences; 2)after jaw surgery, the jaw hard tissue and soft tissue were associated with corresponding levels are highly correlated to the change, but only moderate or low vertical.Correlation to changes in soft lips and hard tissue changes in the proportion varied greatly, while chin soft tissue and hard tissue changes correspond substantially 1: 1;3)after double jaw surgery, soft and hard tissue correlation are just like the correlation of the maxillary, mandibular surgery only, but the change in the proportion exist a big difference, especially in the upper jaw.ConclusionThis study of different surgical patterns and different severity of skeletal Ⅲmalocclusion preoperative and postoperative lip soft tissue morphology were compared, the lip and soft tissue characteristics between men and women showed little difference, while between mild and severe malocclusion is quiet different and soft tissues changes after differerent surgery have difference. In terms of the hard and soft tissue surgery-related changes, the manibular jaw show relatively high correlation, and the horizontal direction correlation are more high than the vertical correlation.Select a specific surgical approach should depends on the patient’s condition, for the poor shape of the upper lip patients should choose maxillary or double jaw surgery, which can better improve the shape of the upper lip; while for preoperative patient who’s upper lip profile is still good, better choose simple jaw back surgery, thus reducing trauma. Surgery program developed at this stage, mostly based on the establishment of good hard tissue morphology and occlusion position, the profile appearance had been taken into consideration, but it can not be accurately estimated, so the recovery of ideal lip soft tissue will be designed in orthognathic surgery as key elements to consider. |
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