| Part One:Preliminary Study on the effect of nasal base musculature reposition suture on nasolabial morphology in patients with class ?dentofacial deformitiesObjective:To study the effect of nasal musculature reposition suture on the three-dimensional morphology of nasolabial region in patients with class III dentofacial deformities after Le Fort I osteotomy.Methods:30 patients(11 males and 19 females,with an average age of 23.23± 2.979 years)with skeletal Class III malocclusion underwent orthognathic surgery between August,2019 to November,2019 to have the maxilla advanced no more than 4mm in the department of maxillofacial surgery of Peking University School and Hospital of Stomatology were involved and were randomly divided into test and control groups based on the random number table.There were 15 patients in the test group in which the nasal base musculature was identified and labeled before dissection and reposition sutured after the fixation of maxilla,while the other 15 patients in the control group the nasal musculature was directly sutured and knotted in the midline of nose without prepend labeling.All the patients undergone three-dimensional facial photos preoperatively(TO)and 6 months postoperatively(T1)by using 3dMD face system.On the three dimensional image,soft tissue landmarks of nasolabial region was identified by the same examiner.14 measurements including straight distance,curve distance,angle and ratio were measured.Statistical analysis was done to analyze the difference of each measurement postoperatively and between two groups.Results:The alar width and alar base width of both groups were significantly increased compared with preoperative level(P<0.05).The alar width of the test group increased by an average of 1.00±1.192mm,and the control group increased by 1.23±1.587mm;the alar base width of the test group increased by an average of 0.73± 1.288mm,and the control group increased by 1.44±1.615mm.There were significant differences between the two groups in cutaneous height of upper lip(P=0.023)and in nasal tip protrusion-alar width(P=0.012).The increase rate of cutaneous height of upper lip and the decrease rate of nasal tip protrusion-alar width in control group were significantly higher than test group.The nasolabial angle in control group was significantly higher compared with normal value,while there was no significant difference between test group and normal value.Conclusion:Compared with the conventional suture method,the nasal base musculature reposition suture is more favorable for the postoperative nasal coordination and nasolabial morphology in patients need mild to moderate maxillary advancement,and it has certain advantages in operability and objective accuracy.So that it could become a modified and accurate method of alar base cinch suture and be widely applied in clinical practice.Part Two:Preliminary Study on the effect of nasal base musculature reposition suture on the motor function of nasolabial region in patients with class ? dentofacial deformitiesObjective:To establish a process for the three-dimensional evaluation of the motor function of nasolabial nasal base musculature and to evaluate its feasibility.To study the effect of nasal musculature reposition suture on the motor function of nasolabial region in patients with class III dentofacial deformities after Le Fort I osteotomy.Methods:50 patients(15 males and 35 females,with an average age of 25.0±4.6 years)with skeletal Class III malocclusion underwent orthognathic surgery between November,2019 and January,2020,May,2020 and August,2020 in the department of maxillofacial surgery of Peking University School and Hospital of Stomatology were included.The researcher demonstrated nose-lifting,nose-dragging and maximal smiling expressions.After the patients were proficiently mastered,three facial expressions were performed using 3dMDface Dynamic System on the third day before operation(T0')and the day before operation(TO).After the recording procedure done preoperatively,those patients were randomly divided into test and control groups based on the random number table.There were 25 patients in the test group in which the nasal base musculature was identified and labeled before dissection and reposition sutured after the fixation of maxilla,while the other 25 patients in the control group the nasal musculature was directly sutured and knotted in the midline of nose without prepend labeling.On the sixth month postoperatively(T1),the same researcher demonstrated nose-lifting,nose-dragging and maximal smiling expressions again.After the patients were proficiently mastered,three facial expressions were performed using 3dMDface Dynamic System.Select the rest position frame and the maximum expression frame of each expression,mark a total of 10 landmarks manually in the nasolabial region by using 3dMD Vultus software and obtain the corresponding coordinates automatically,and calculate the cumulative distance of each landmark.Check the consistency of the cumulative distance of each landmark at T0 and T0'and analyze the characteristics of each landmark in those three facial expressions.Analyze the difference of the cumulative distance of each landmark at T0 and T1 in patients of two groups.Results:All the 50 patients completed expression photographs.Except the right crista philtri point in nose-dragging expression,there was no significant difference in the cumulative distance of each landmark in the three facial expression movements between T0 and TO' and there was no significant difference in the cumulative distance between paired landmarks on the left and right sides.In the nose-lifting expression,the cumulative distance of the bilateral alar points was the largest;in the nose-dragging expression,the cumulative distance of the bilateral crista philtri was the largest,followed by the bilateral cheilion and bilateral alar base points;in the maximal smiling expression,the cumulative distance of bilateral cheilion is the largest.16 patients(5 males and 11 females,with an average age of 25.13± 4.07 years)followed up to 6 months postoperatively(Tl)and completed expression photographs.8 of them were in the test group while the other 8 were in the control group.In nose-shifting expression,there were significant decrease in the cumulative distance of bilateral alar points in both groups postoperatively(P<0.05),while there was an another significant decrease in the cumulative distance of alar point on the right side in control group(P=0.043).In nose-dragging expression,there were significant difference in the decrease of cumulative distance of bilateral alar points,alar base points and subnasal point in the control group postoperatively(P<0.05),while that significant decrease only found in the alar point of right side and the subnasal point in the test group(P<0.05).In maximum smile expression,no significant differences were found in the cumulative distance of all landmarks in the test group postoperatively,while in the control group,the alar base point on the left side and bilateral alar points were found significant decrease in the cumulative distance postoperatively(P<0.05).Conclusion:The evaluation process of the motor function of the nasolabial region by using three-dimensional dynamic system was established and its feasibility was verified.Compared with the conventional suture method,the nasal base musculature reposition suture is more favorable for the postoperative nasolabial motor function in patients with class III dentofacial deformities who need mild to moderate maxillary advancement. |
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