骨性安氏Ⅱ类错(牙合)经外科——正畸联合治疗后颜面软组织侧貌的变化

目的:探讨骨性安氏Ⅱ类错患者采用外科-正畸联合治疗后颜面软组织侧貌在矢状和垂直方向上的变化.方法:选用华西医科大学口腔医院正畸科连续收治的骨性安氏Ⅱ类错患者22例,男7例,女15例,年龄20～30岁.在术前及术后6～12个月摄取X线头侧位片,对16个软硬组织标志点的变化进行矢状、垂直向的分析.结果:在矢状向上,上唇沟点、上唇缘点、上唇下点后退均大于2mm(P<0.01);与上切牙点后移量之比为0.59:1～0.64:l;颏唇沟软、硬组织点前移量之比为0.83:1,软组织颏前点与硬组织颏前点前移量之比为0.95:1.在垂直向上,鼻尖点、鼻底点、上唇缘点平均向上移动量均小于1mm(P>0.05);但软组织颏前点、颏唇沟、下唇缘点、下唇上点向上移动量均大于2mm(P<0.05),与相应的硬组织移动量之比为1.07:l～1.34:1.结论:骨性安氏Ⅱ类错患者经外科-正畸联合治疗后颜面软组织侧貌改善明显.在矢状方向,上下颌软组织改变量均小于硬组织;但在垂直方向,下颌软组织的改变却比硬组织更明显.     

骨性安氏Ⅱ类错经外科—正畸联合治疗后颜面软组织侧貌的变化

目的 :探讨骨性安氏Ⅱ类错患者采用外科—正畸联合治疗后颜面软组织侧貌在矢状和垂直方向上的变化。方法 :选用华西医科大学口腔医院正畸科连续收治的骨性安氏Ⅱ类错患者 2 2例 ,男 7例 ,女 15例 ,年龄 2 0～30岁。在术前及术后 6～ 12个月摄取X线头侧位片 ,对 16个软硬组织标志点的变化进行矢状、垂直向的分析。结果 :在矢状向上 ,上唇沟点、上唇缘点、上唇下点后退均大于 2mm(P <0 0 1) ;与上切牙点后移量之比为 0 5 9∶1～0 6 4∶1;颏唇沟软、硬组织点前移量之比为 0 83∶1,软组织颏前点与硬组织颏前点前移量之比为 0 95∶1。在垂直向上 ,鼻尖点、鼻底点、上唇缘点平均向上移动量均小于 1mm(P >0 0 5 ) ;但软组织颏前点、颏唇沟、下唇缘点、下唇上点向上移动量均大于 2mm(P <0 0 5 ) ,与相应的硬组织移动量之比为 1 0 7∶1～ 1 34∶1。结论 :骨性安氏Ⅱ类错患者经外科—正畸联合治疗后颜面软组织侧貌改善明显。在矢状方向 ,上下颌软组织改变量均小于硬组织 ;但在垂直方向 ,下颌软组织的改变却比硬组织更明显     

Ⅱ类1分类错正畸治疗前后牙齿移动与软组织侧貌变化的线性相关分析

目的通过对Ⅱ类1分类错患者正畸治疗前后的头影测量指标进行相关性分析,探讨影响面部软组织侧貌变化的相关因素。方法选取2012年6月至2017年11月于上海交通大学医学院附属第九人民医院口腔颅颌面科就诊的42例已完成正畸治疗的Ⅱ类1分类错患者[男性10例,女性32例,年龄(23.8±6.3)岁,平均矫治时间1.9年],拔除4颗第一前磨牙或2颗上颌第一前磨牙后进行正畸治疗纠正磨牙关系,测量矫治前后硬组织及软组织相关头影测量指标30个,包括上下唇突点、颏唇沟点、软硬组织颏前点及颏顶点的矢状向及垂直向距离、鼻唇角及颏唇角等。对矫治前后各指标变化量进行线性回归分析,根据标准化回归系数(Beta)分析影响上下唇、鼻唇角、颏唇角等面部软组织的主要相关因素。结果 30个头影测量指标中18个矫治前后差异均有统计学意义(P<0.05),与矫治前相比,矫治后上中切牙点矢状向距离[(63.87±7.14) mm]、上唇突点矢状向距离[(77.73±7.60) mm]显著减小(P<0.05)。14对头影测量指标变化量间存在线性关系,其中上唇突点矢状向变化量与上中切牙点矢状向变化量强正相关(r=0.64...     

成人安氏Ⅱ类1分类错牙合患者正畸前后唇部软组织测量和评估

目的 测量和评估成人安氏Ⅱ类1分类错牙合患者正畸前后的唇部软组织形态. 方法 选择30例已经完成正畸治疗的安氏Ⅱ类1分类错牙合成年患者,术后模型及头影测量的数据均在正常范围内. 对其正畸前后正面像和头颅侧位片唇红的矢状向厚度和垂直向厚度进行测量. 结果 正畸后上唇垂直向厚度有变小的趋势,下唇垂直向厚度有变大的趋势,差异有统计学意义(P<0. 05). 上唇矢状向唇红部组织厚度术后有增大的趋势,下唇矢状向唇红部组织厚度矫正后有减少的趋势,且有统计学意义(P<0. 05). 上颌上中切牙(U1C)矢状向内收量与上唇红(TUL)的内收呈显著正相关,下唇红(TLL)矢状向位置的变化与下颌切牙突点(L1C)位置变化存在正相关,下唇红(TLL)矢状向位置的变化与上颌切牙突点(U1C)位置变化存在正相关. 结论 安氏Ⅱ类1分类错牙合成人患者拔牙矫治后,可以通过切牙回收量较好地预测其唇部软组织正畸前后的矢状向厚度和垂直向厚度变化.     

Ⅱ类1分类错[牙合]正畸治疗前后牙齿移动与软组织侧貌变化的线性相关分析

目的通过对Ⅱ类1分类错[牙合]患者正畸治疗前后的头影测量指标进行相关性分析,探讨影响面部软组织侧貌变化的相关因素。方法选取2012年6月至2017年11月于上海交通大学医学院附属第九人民医院口腔颅颌面科就诊的42例已完成正畸治疗的Ⅱ类1分类错[牙合]患者[男性10例,女性32例,年龄(23.8±6.3)岁,平均矫治时间1.9年],拔除4颗第一前磨牙或2颗上颌第一前磨牙后进行正畸治疗纠正磨牙关系,测量矫治前后硬组织及软组织相关头影测量指标30个,包括上下唇突点、颏唇沟点、软硬组织颏前点及颏顶点的矢状向及垂直向距离、鼻唇角及颏唇角等。对矫治前后各指标变化量进行线性回归分析,根据标准化回归系数(Beta)分析影响上下唇、鼻唇角、颏唇角等面部软组织的主要相关因素。结果30个头影测量指标中18个矫治前后差异均有统计学意义(P<0.05),与矫治前相比,矫治后上中切牙点矢状向距离[(63.87±7.14)mm]、上唇突点矢状向距离[(77.73±7.60)mm]显著减小(P<0.05)。14对头影测量指标变化量间存在线性关系,其中上唇突点矢状向变化量与上中切牙点矢状向变化量强正相关(r=0.649,P<0.01),上唇突点垂直向变化量与上中切牙点垂直向变化量中度正相关(r=0.544,P<0.01),软组织颏顶点矢状向变化量与Y轴角变化量中度负相关(r=0.537,P<0.01)。多元逐步后退回归分析显示,上唇突点内收量与上中切牙点内收量、平面角增大量以及上中切牙角增大量均相关,且与上中切牙点内收量相关性最大(Beta=0.79);上唇突点下移量与上中切牙点下移量、上中切牙角减小量、上颌第一磨牙面中点到腭平面距离减小量以及平面角增大量相关,且与上中切牙点下移量及平面角增大量的相关性最大(Beta均为0.59);下唇突点下移量与上、下中切牙点下移量相关,且与上中切牙点下移量相关性更大(Beta=0.36)。结论Ⅱ类1分类错[牙合]矫治后鼻唇颏关系得到一定改善,切牙的矢状向变化对唇突度的影响最大,且下唇矢状向与垂直向移动与上中切牙的位置关系更密切,牙齿移动对颏部的影响有限。     

影响双颌前突青少年患者唇部内收因素的研究

目的 探讨影响双颌前突青少年患者正畸治疗后唇部内收的因素.方法 对满足纳入标准的37例双颌前突青少年患者进行治疗前后的X线头影测量分析.测量治疗前软组织、硬组织、牙体组织项目及治疗后软硬组织变化项目共27项,应用多元线性回归（后退法）筛选影响唇部变化的敏感因素.结果 治疗后上中切牙颈缘点矢状向变化,治疗前年龄,上唇缘点至E线距离和颏部厚度影响上唇缘点矢状向内收变化,回归方程相关系数为0.875;治疗后下中切牙切缘矢状向变化,治疗前下唇缘点至E线距离,下唇紧张度,颏唇角和颏部厚度影响下唇缘点矢状向变化,回归方程相关系数为0.887.结论 治疗前生长潜力、骨性、牙性、软组织特点,及治疗后牙性变化影响双颌前突患者唇部内收变化.     

骨性Ⅱ类错 正畸正颌联合治疗前后软硬组织侧貌变化的线性相关分析

目的:通过对骨性Ⅱ类错 畸形患者正畸正颌联合治疗前后头颅定位侧位片指标的测量分析,探讨影响软组织侧貌的因素及贡献。 方法:选取40例骨性Ⅱ类错 畸形女性患者,对其正畸正颌联合治疗前后头颅定位侧位片进行测量分析,采用SPSS 24.0对治疗前后软硬组织的变化量进行线性回归分析。 结果:发现21组指标变化量间存在线性关系,其中软硬组织颏前点矢状向变化量呈极强相关性( r＝0.862, P<0.001),比率为0.935∶1;多元逐步后退回归分析显示上、下唇突点内收量分别与上、下中切牙内收量相关性更大等。 结论:骨性Ⅱ类错 畸形在正畸正颌联合治疗前后软组织移动量与硬组织移动量间存在着一定的线性比例关系,临床可根据患者诉求进行硬组织移动量的设计。     

正畸正颌联合治疗骨性Ⅲ类错(牙合)畸形侧貌软硬组织变化及相关性分析

目的:测量骨性Ⅲ类错(牙合)畸形正畸正颌联合治疗前后侧貌软硬组织变化及相关性分析,评估正畸正颌联合治疗的美学效果,为更好地预测术后美学性数值提供研究支持。方法:选择32例严重的骨性Ⅲ类错(牙合)畸形患者,并在正畸治疗前、后拍摄CBCT。通过CBCT获得精确的头影侧位片,选择头影测量标记点,测量侧貌相关的角度、厚度、距离。对侧貌相关的角度、软组织厚度进行配对t检验,并对软硬组织的矢状面距离变化进行Pearson相关分析。结果:鼻唇角、颏唇角、下颌平面与SN前下交角、下中切牙长轴与SN后下交角差异显著(P<0.05),上中切牙长轴与SN后下交角差异无统计学意义(P>0.05)。LL’处软组织厚度、Bs处软组织厚度增加,差异有统计学意义(P<0.05),Sn处软组织厚度、UL’处软组织厚度、Pos处软组织厚度差异无统计学意义(P>0.05)。软/硬组织对应点:鼻下点/A点、上唇缘点/上中切牙点、下唇缘点/下中切牙点、颏唇沟点/B点、软组织颏前点/颏前点、软组织颏顶点/颏顶点的矢状向距离变化显著相关,相关系数分别为0.69、0.59、0.73、0.85、0.90、0.97。结论:骨性Ⅲ类错(牙合)畸形患者正畸正颌手术治疗后,侧貌美观明显改善。相关性分析显示,术后颏部位置预测性佳,唇位置预测性差,下颌比上颌更具有可预测性。     

骨性Ⅱ类错 正畸正颌联合治疗前后软硬组织侧貌变化的线性相关分析

目的:通过对骨性Ⅱ类错 畸形患者正畸正颌联合治疗前后头颅定位侧位片指标的测量分析,探讨影响软组织侧貌的因素及贡献。 方法:选取40例骨性Ⅱ类错 畸形女性患者,对其正畸正颌联合治疗前后头颅定位侧位片进行测量分析,采用SPSS 24.0对治疗前后软硬组织的变化量进行线性回归分析。 结果:发现21组指标变化量间存在线性关系,其中软硬组织颏前点矢状向变化量呈极强相关性( r＝0.862, P<0.001),比率为0.935∶1;多元逐步后退回归分析显示上、下唇突点内收量分别与上、下中切牙内收量相关性更大等。 结论:骨性Ⅱ类错 畸形在正畸正颌联合治疗前后软组织移动量与硬组织移动量间存在着一定的线性比例关系,临床可根据患者诉求进行硬组织移动量的设计。     

骨性安氏Ⅲ类错下颌单颌手术后软硬组织的变化

目的:探讨正畸-正颌联合治疗成人骨性安氏Ⅲ类错,上、下颌软、硬组织的变化及其变化的相关性。方法:选取骨性安氏Ⅲ类错患者20例,手术前、后拍摄X线头颅侧位片,手术方式为双侧下颌骨矢状劈开截骨术(BSSRO)。采用SPSS13.0软件包对数据进行配对t检验。结果:治疗后SNB、B点和Pog点到Y轴的距离变小,ANB变大;软组织颏唇角、TLL点、SB点和TC点到Y轴的距离均变小,且均有显著差异(P<0.01)。SB点到Y轴的距离与B点到Y轴的距离存在线性关系,比值为1∶1,决定系数R2=0.96;TC点到Y轴的距离与Pog点到Y轴的距离比为0.84,决定系数R2=0.97。结论:单纯下颌前突患者经正畸和BSSRO治疗后,上颌软组织无明显变化,上、下唇长度不受影响。颏前点软组织与骨组织变化比值为0.84,颏唇沟点为1:1,相关强度均在0.9以上。     

Soft tissue profile changes after autogenous iliac crest onlay grafting for the extremely atrophic maxilla.

PURPOSE: The aim of this study was to evaluate profile changes in the hard and soft tissues after onlay grafting in the extremely atrophic maxilla. PATIENTS AND METHODS: Onlay grafting using autogenous iliac crest bone grafts was performed in 49 patients (42 females and 7 males) with extreme atrophy of the edentulous maxilla (vertical amount of bone: <6 mm, transverse amount of bone: <5 mm). For the assessment of the changes to the hard and soft tissues, the preoperative and postoperative cephalograms were traced and the cephalometric measuring points (44 skeletal and 25 soft tissue points) were digitalized with the aid of the Dentofacial Planner System. Evaluation of a relationship between soft tissue and hard tissue profile changes was performed by comparing the movement of the skeletal points Sub-ANS and A-point with the shift of the soft tissue point SLS. To determine significant hard tissue and soft tissue changes, the measured values were evaluated using the SPSS program system and examined for statistical significance by use of the Wilcoxon test. RESULTS: An advancement of the bony maxilla profile in the sagittal direction by an average of 2.4 mm (P < .01) was found. The soft tissue profile of the upper lip was moved forward on average by 2.3 mm (P = .0039) at the superior labial sulcus point and by 2.7 mm (P = .0018) at the labrale superius point. The ratio of the soft tissue change to hard tissue change was 0.7:1 (superior labial sulcus: skeletal point sub-ANS) or 0.9:1 (superior labial sulcus: A point). CONCLUSIONS: When planning onlay graft operations, consideration should be given to the functional and aesthetic effects of the profile changes on the upper lip.     

Ethnic differences in upper lip response to incisor retraction

INTRODUCTION: The purpose of this retrospective longitudinal study was to investigate the response of the upper lip to incisor retraction and to ascertain the effect of ethnicity on this response. METHODS: Pretreatment and posttreatment lateral cephalograms of 88 postpubertal female patients (44 black and 44 white; mean age, 18.45 years) were evaluated. The groups were matched by age and the amount of incisor retraction at incisor superius. RESULTS: Although significant pretreatment differences existed between the groups in some cephalometric measurements, analysis of the treatment changes demonstrated significant differences only in incisor inclination. Hard and soft tissue changes of the black group were more downward, whereas changes in the white group were more backward. Multivariate regression analysis showed that the horizontal response of the upper lip to hard tissue changes at subnasale and superior labial sulcus was different in whites than in blacks. At subnasale, stepwise multivariate regression analysis showed that ethnicity contributed to the upper lip response to incisor retraction and was significantly greater in the white group. CONCLUSIONS: The hard and soft tissue treatment changes of the black group were more downward, and those of the white group were more backward. Ethnic differences exist in the soft tissue response to hard tissue changes in the upper lip, and at subnasale and the superior labial sulcus; however, these response differences at superior labial sulcus can be explained by the ethnic differences in initial lip thickness and incisor inclination; they are not due in and of themselves to ethnicity. The change at prosthion was significantly correlated with the response of the upper lip at labrale superius to incisor retraction. Ethnicity added no increase to the predictability of the response. When incisor retraction was performed, the final horizontal upper lip position could be accurately and reliably predicted.     

外科矫治上颌前突畸形颜面软组织侧貌改变及其预测的研究

对１５例上颌前部骨切开后退术患者的手术前后Ｘ线头影测量进行研究,结果显示软组织鼻底点Ｓｎ,上唇凹点Ａ＇分别以上齿槽座点Ａ的３７％和６３％向后移动,上唇突点Ｌｓ以上中切牙切缘点Ｉｓ的７５％向后移动。同时还分析求得了施行该术式后软硬组织变化的相关关系和回归方程。     

Use of artificial intelligence to predict outcomes of nonextraction treatment of Class II malocclusions

Maxillary molar distalization is a standard option for nonextraction treatment of Class II malocclusions. The purpose of this study was to develop an automated, artificial intelligence (AI) system to predict the dental, skeletal, and soft tissue changes after nonextraction treatment. Retrospective data and images were obtained for 284 patients who had had nonextraction treatment using modified C-palatal plates. Pre and posttreatment cephalograms were superimposed using the sella and the nasion as reference points. Cephalometric changes as a result of treatment were used for learning using convolutional neural networks (CNN). From the results, heatmaps were generated in the form of lateral cephalograms, representing the predicted amount of change for each landmark as a result of treatment. Six landmarks had a prediction error of < 1.0 mm: the A point, anterior nasal spine, subnasale, soft tissue A, pronasale, and columella. Ten landmarks, including the upper lip, labrale superius, and stomion superius, showed errors of 1.0–2.0 mm. Eleven landmarks, including the lower lip, soft tissue B, and stomion inferius, had errors of 2.0–3.0 mm. Only the soft tissue pogonion and menton landmarks had errors > 3.0 mm. Our AI model based on CNN architecture shows that it is possible to predict the cephalometric changes resulting from nonextraction treatment. The predicted changes expressed in the form of lateral cephalometric images may be useful visual guides for clinicians as well as patients when considering nonextraction treatment.     

Soft tissue changes of the upper lip associated with maxillary advancement in obstructive sleep apnea patients.

PURPOSE: This retrospective study evaluated the horizontal and vertical soft tissue changes that occur with maxillary advancement surgery with a Le Fort I osteotomy with concomitant anatomic reorientation of the nasolabial musculature. SUBJECTS AND METHODS: Fifteen OSA patients who underwent maxillary advancement with a Le Fort I osteotomy without adjunctive nasal soft tissue procedures were studied after a minimum of 8 months of follow-up. The V-Y technique was used to close the maxillary vestibular incision. Only cases with minimal vertical movement (< 3.5 mm) in which no orthodontics were used were included. The average maxillary advancement was 8.0 +/- 2.5 mm, measured at the upper incisor (UPI) and the average vertical movement was 0.7 +/- 1.8 mm. The horizontal and vertical soft tissue change in subnasale (SN), labrale superiorus (LS), superior stomion (SS), nasal tip (NT), nasolabial angle (NLA), and lip length were measured in each patient and correlated with hard tissue measurements at anterior nasal spine (ANS) and UPI. The effect of lip thickness on these soft tissue changes also was evaluated. RESULTS: Using mean data, the horizontal soft-to-hard-tissue ratio for LS to UPI was 0.80:1, with a concomitant vertical (superior) soft tissue change to hard tissue advancement of 0.16:1. Lip length did not change significantly. All patients except 1 showed a slight decrease in nasolabial angle. The average decrease was 5 (range, -10 to +7 ). There was no statistically significant correlation between the degree of change in NLA and the amount of maxillary advancement. CONCLUSION: This study showed that advancement of the maxilla when controlling vertical movement resulted in the a hard-to-soft-tissue ratio of LS:UPI of 0.80:1. NLA did not change significantly.     

骨种植钉前牵引对骨性Ⅲ类错患者软硬组织侧貌的影响

目的研究采用骨种植钉前牵引对骨性Ⅲ类错患者软、硬组织侧貌的改变。方法选取18例需行前牵引矫治的生长发育期骨性Ⅲ类错患者,采用双侧上颌颧牙槽嵴植入骨种植钉配合面框式前牵引,平均治疗时间为9个月,力值为（3.5±0.1）N。治疗前后头影测量采用Legan&Burstone软组织分析法以及相关硬组织测量,分析比较患者治疗前后软、硬组织变化情况。结果所有患者Ⅲ类错均得到改善,鼻底趋于丰满,颏部顺时针旋转,侧貌由凹面型变为直面型,下唇突度减小,软组织上下面高比、鼻唇角、上唇突度及颏唇沟深度无明显变化。上前牙无明显变化,下前牙舌倾,上颌骨向前生长,A点前移,SNA、ANB增大;SNB减小,下颌骨顺时针旋转。结论骨种植钉前牵引可促进上颌生长,使面中份丰满,且对上颌前牙轴倾度无影响,从而纠正骨性Ⅲ类错。     

Predicting upper lip response to 4-piece maxillary LeFort I osteotomy.

The purpose of this retrospective study was to understand and predict the multidimensional changes in upper lip morphologic features after segmental (4-piece) maxillary Le Fort I advancement/impaction with VY closure and alar base cinch sutures. The study evaluated longitudinal lateral cephalograms of 57 patients (42 women, 15 men) 27.5 +/- 11.2 years of age before surgery. Lateral cephalograms with teeth in occlusion and lips in repose were taken 2 weeks before surgery and at least 6 months after the operation. Mean postsurgical duration was 15.5 months. The upper lip predictably moved anteriorly in a graduated fashion, from 50% (subnasale) to 90% (labrale superius) the amount of the underlying osseous anterior movement, and showed a slight lengthening (0.73 +/- 1.9 mm) from subnasale to upper lip stomion. The upper lip surface contour was also straightened as a result of the surgical movement. Multiple regression models showed that the anterior changes in the landmarks prosthion and facial surface of the upper incisor were the most important variables in predicting upper lip response. The prediction equations for horizontal movements explained 86% to 94% of the variation, with errors of the estimates that range between 1.27 mm and 1.65 mm. The models, when applied to an independent validation sample of 14 subjects, explained between 86% and 94% of the total variation. The conclusion is that upper lip response after 4-piece Le Fort I advancement/impaction (VY closure and alar base cinch suture) can be accurately predicted.     

Soft Tissue Changes in Cleft Lip and Palate Patients: Anterior Maxillary Distraction versus Conventional Le-Fort I Osteotomy

The purpose of the study was to compare the soft tissue changes after maxillary advancement in patients with maxillary deficiency associated with cleft lip and palate (CLP) by two approaches—anterior maxillary distraction (AMD) and advancement LeFort I osteotomy (ALO). Twenty patients with maxillary hypoplasia associated with cleft lip and palate who had undergone either LeFort I osteotomy or distraction osteogenesis with maxillary advancement were included in this study. Lateral cephalogram taken at various intervals of time were used to evaluate soft tissue and hard tissue changes over time. In both groups, vertical as well as horizontal changes in pronasale was well observed. A substantial increase in nasal parameters was noted in case of AMD group in comparison to ALO. Though maxillary advancement was evident in both the groups, a significant and consistent change was observed in AMD. Significant vertical and horizontal changes were seen with respect to subnasale and labrale superius in AMD group. Soft tissue as well as hard tissue relapse was greater in ALO group than AMD group. Significant soft tissue and hard tissue changes were clearly observed in both the groups, but the treatment results were more consistent in cases treated with AMD. Hence AMD could be considered as a better treatment of choice in cases of maxillary hypoplasia associated with cleft lip and palate.     

Measurement of three-dimensional perioral soft tissue changes in dentoalveolar protrusion patients after orthodontic treatment using a structured light scanner

Objective:To evaluate the three-dimensional (3D) perioral soft tissue changes after orthodontic treatment in patients with dentoalveolar protrusion using structured light–based scanners.Materials and Methods:Forty-four Korean adults (19 men and 25 women, 21.4 ± 3.4 years) with dentoalveolar protrusion treated by extraction of all four first premolars and then en masse retraction with maximum anchorage were evaluated. Lateral cephalograms and 3D facial scans were obtained before treatment (T1) and immediately after debonding (T2). Superimposition was performed, and 27 perioral landmarks were identified. The 3D changes in the landmarks and ratio of movement of the soft tissue relative to the horizontal incisal tip were evaluated. A paired t-test and one-way analysis of variance were performed.Results:The upper incisors were retracted 5.76 mm and the lower incisors were retracted 4.62 mm (P < .001). The upper lip moved inferoposteriorly, and the lower lip moved superoposteriorly. In the lower lip, upward movement was greater than backward movement (P < .001). The most prominent changes appeared at the greatest bulge area. The relative ratios were 42%–53% in the upper lip area and 22%–82% in the lower lip area. The lip corners moved superoposteriorly (P < .001). Subnasale moved downward (P < .05) and posteriorly (P < .001), while the landmarks under the nostrils moved upward and posteriorly (P < .001).Conclusion:Facial scans from white structured light scanners efficiently evaluated 3D perioral soft tissue in dentoalveolar protrusion patients. Backward movement and significant vertical movement of the lip were observed. The nasal and lip angle areas showed considerable changes.     

The Influence of the Upper Incisor Position on Soft Tissue Facial Profile

Abstract

Facial proportions are important from an aesthetic point of view in that to be harmonious the upper, middle and lower face need to be of approximately equal size.

The object of this study is to determine changes in hard and soft tissue profile which occur in patients having a Class II, Division 1 type incisor relationship as a result of overjet reduction.

Thirty-three patients were studied cephalometrically there being an average overjet of 6·99 mm at commencement of treatment which reduced to an average of 3·5 mm on final analysis.

Clinical appraisal suggests that there was an improvement of facial appearance following treatment. Cephalometric analysis shows that subnasale, labrale superius and labrale inferius moved nearer to the facial Plane as a result of re-modelling of the hard tissues resulting from orthodontic treatment.

The female patients showed a relationship between retraction of the upper incisors and reduction in prominence of the lower lip and in those having a Class I dental base relationship, prominence of the upper lip. The male patients showed no correlation between upper incisor position and lip position. Continuing mandibular growth in the male could have a bearing on these findings.