Detailed three-dimensional orthodontic tooth repositioning to improve restorative outcome:: A case report

The case describes the interdisciplinary treatment of a 23-year-old woman with a Class III malocclusion, missing an upper right lateral incisor, abrasion of the maxillary incisal edges, anterior gingival margin discrepancies, and gingival recession. Initially, the patient was treated with fixed appliances combined with orthognathic surgery. The extraction of the upper left lateral incisor and bilateral canine substitution plan was chosen. At the end of the surgical and orthodontic treatment, the restorative treatment with six veneers was accomplished to improve smile esthetics. Despite the missing lateral incisors, the patient showed a natural, good-looking final result. A symmetric incisal plane was established, a functional occlusion with average vertical and horizontal overlap was set, and the bone scallop and consequently the gingival margins were leveled. The interdisciplinary approach hid all of the initial esthetic defects of the case. The result highlights how to obtain a remarkable improvement of the smile outcome with a well-functioning masticatory system.     

Morphological features of smile attractiveness and related factors influence perception and gingival aesthetic parameters

IntroductionIn addition to understanding the basic standards of a smile and patient's opinion, dentists should take into account smile aesthetics, an essential factor for optimal outcomes. This study aimed to evaluate the factors that affect the perception of an aesthetic smile and determine its morphological characteristics and measure the gingival aesthetic parameters.MethodsIn all, 200 Vietnamese aged 18-35 years were recruited to have their spontaneous smiles captured. These smile images were assessed by 50 laypersons and 50 dentists using a visual analogue scale measurement. The images were analysed to evaluate perceptions of evaluators, determine smile attractiveness, and measure gingival aesthetics.ResultsThe difference in the judgements of laypersons and dentists, males and females, and laypersons aged 18-25 and 26-35 years were nonsignificant. High or average anterior smile line, parallel smile arc, upward upper lip curvature, second premolars as the posterior-most teeth displayed, smile index of 5.23-5.63, and dynamic smile symmetry of 1 were scored highly on smile attractiveness. The following maxillary gingival aesthetic parameters were preferred: gingival zenith (GZ) of the canine 0.72-0.75 mm apical to the GZ of the central incisor; GZ of the lateral incisor 0.66 mm coronal to the gingival line; gingival line angle of ～87°; for the central incisor, lateral incisor, and canines, distance from the GZ to the long axis of 1, 0.4, and 0 mm, respectively; interdental papilla height of 4.25, 3.60, and 3.85 mm, respectively; ratio of the distance from the GZ and the interdental papilla tip to the incisal edge of ～1.74-1.77 mm.ConclusionsFactors including profession, gender, and age of evaluators had almost no impact on their perception of aesthetics. Smile attractiveness characteristics and gingival aesthetic parameters have clinical applicability for patient care.     

Smile microesthetics as perceived by dental professionals and laypersons

ObjectivesTo evaluate and compare the perception of different dental professionals and laypersons toward altered gingival characteristics (microesthetics) and to identify those characteristics that are most negatively and positively rated.Materials and MethodsA smiling photograph of a female dental student was selected and digitally manipulated to create changes in different microesthetic parameters. These altered images were rated by the following five groups: 120 orthodontists, 45 periodontists, 49 prosthodontists, 130 general dentists, and 172 laypersons. Smile esthetics scores were calculated, and comparisons between groups were performed using the univariate general linear model.ResultsThe presence of black triangles between the upper incisors was the most negatively rated, and the ideal smile was the most positively rated. Significant differences were detected in the rating scores among the different study groups (P < .05). Orthodontists, prosthodontists, and general dentists scored the presence of a black triangle in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons.ConclusionsThe ideal smile and that with black triangles between the upper incisors were rated as the most and the least attractive smiles, respectively. Orthodontists, prosthodontists, and general dentists scored the presence of black triangles in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive smiles, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons.     

计算机图像处理技术在前牙美学修复中的应用

目的探讨用计算机图像处理技术为患者制作美观的、符合个性特征的前牙修复体的过程。方法对13例需行前牙美学修复的患者拍摄修复治疗前及治疗中前牙图像，获取患者牙齿与周围软组织的美学信息，包括天然牙的形态、颜色、半透明度、个性特征，以及下颌息止位时和微笑时牙齿的切缘位置、龈缘位置等。分析美学信息资料后行美学修复设计，应用Photoshop 8.0软件制作修复预期效果图，指导技师制作修复体。结果完成13例患者的前牙美学修复，临床美学修复效果良好。结论将计算机图像处理技术应用于前牙美学修复设计，有助于医师和技师为患者制作美观的、符合个性特征的修复体。     

Esthetics and Anterior Tooth Position: An Orthodontic Perspective Part II: Vertical Position

This article discusses the vertical position of the maxillary incisors and its relationship to esthetics. Two situations are discussed. The first, a discrepancy between the incisal plane and the interpupillary line, is corrected by maxillary surgery, orthodontic intrusion/extrusion, or orthodontics and restorative dentistry. The correct decision depends on the interrelationship of the posterior occlusal plane, incisal plane, interpupillary line, and the crown length of the incisors.
The second discrepancy in the vertical position of the maxillary incisors is the "gummy" smile. This problem, due to either overdevelopment of the entire maxilla or over-eruption of the maxillary incisors, is solved by maxillary surgery, orthodontic intrusion of the over-erupted teeth, or orthodontics and restorative dentistry. The proper choice of treatment depends on the interrelationship of the posterior occlusal plane, incisal plane, crown length of the maxillary incisors, and the level of the gingival margins of the maxillary anterior teeth.     

Influence of facial type on attractiveness of vertical canine position from the perspective of orthodontists and laypeople

ObjectivesTo evaluate the attractiveness of changes in vertical position of maxillary canines in frontal smiles of different facial types, and to evaluate the esthetic perceptions of orthodontists and laypeople, and the influence of facial type on these perceptions.Materials and MethodsThree adult female volunteers were selected as individuals with normal, vertical, and horizontal growth patterns. Frontal posed smile photographs were digitally altered by adjusting vertical positions of the maxillary canines above, below, or coincident with the incisal line in increments of 0.5 mm within a range of 1 mm of extrusion and intrusion. For assessment, a web-based survey was formed with 18 images (six images for each model). A scale was present underneath each image, graded from 0 to 10 (0: unattractive; 10: the most attractive). Images were rated by 233 participants (105 orthodontists; 128 laypeople).ResultsOrthodontists scored 0-mm images significantly as the highest in all groups. Laypeople scored significantly higher for −0.5 mm images regardless of facial type. The lowest scored images were −1 mm (except for horizontal pattern) and +1 mm images. Mean values of scores given by men were higher (P < .05).ConclusionsOrthodontists favored ideal dental alignment and preferred the incisal edges of central and canine teeth to be at the same level. Laypeople preferred a smoother smile arc than orthodontists and found harmony with the soft tissue more attractive. Facial type affected perceptions of the vertical changes of maxillary canines.     

Alteration of gingival exposure and its aesthetic effect

This study analyzed the computerized variations of gingival exposure (GE) in unattractive smiles and evaluate the aesthetic effect to determine the acceptable range of GE for attractiveness. Images of the frontal posed smile of 50 juvenile women were evaluated in terms of attractiveness by doctors and laypersons separately to select the most unaesthetic one. And the most unaesthetic smile was modified with Photoshop in 2 ways-lowering upper lip and lifting lower lip-and the same evaluators were asked to reevaluate the changed images. We found that the smile with the most significant GE was selected as the most unaesthetic one. The attractiveness ratings were significantly lower in the doctors' group than in the laypersons' group (P < 0.05). The acceptable range of GE in the doctors' group was 0.54 to 2.23 mm, and in the laypersons' group, it was 0.09 to 2.35 mm. Among the many contributors to an attractive smile, GE alteration is the principal one, but not the only, and although 0- to 2.3-mm GE is just an acceptable range; there is an attractive GE degree or point for every individual. Gingival exposure alteration must be balanced against the others in clinical treatment, especially in maxillofacial surgery for the gummy smile.     

62名中国汉族青年笑线水平的测量研究

目的 评估中国汉族健康人群上颌美学区域牙齿及软组织等解剖形态对容貌美观和义齿修复美学的影响,为临床牙科美学修复提供客观依据.方法 对平均年龄为28.5岁的62名旅德中国汉族青年志愿者进行面部拍照记录.依据标准的试验条件对所有志愿者大笑时上颌牙齿及其牙龈和牙龈乳头进行测量分析.统计分析采用Mann-Whitney-U检验和双因子重复测量分析.结果 所有志愿者在上唇大笑运动时81％的上颌中切牙至上颌前磨牙的牙龈形态均有不同程度显露.上颌中切牙平均显露高度为10 mm,性别间差异无统计学意义(P＞0.05).所有志愿者平均牙龈显露高度为1.3mm,平均显露牙龈乳头高度为3.4mm,男女间差异无统计学意义(P＞0.05).31％( 19/62)的志愿者为高笑线类型,50％ (31/62)的志愿者为中度笑线类型,19％ (12/62)的志愿者为低笑线类型.结论 中国汉族青年人群高笑线者比例高于西方研究人群比例,其中100％汉族青年志愿者在大笑时前牙区的牙龈乳头显露.     

Impact of Gingival Margin Asymmetries on the Smile Esthetic Perception of Dental Specialists,Doctors of Dental Medicine,Students, and Laypeople: a Comparative Pilot Study

ObjectiveTo evaluate the perceptions of altered incisor gingival position among dental specialists, dentists, dental students, and laypeople.Materials and methodsFour digital smile photographs with altered gingival margin position of the right maxillary incisor (0, 1, 2, and 3 mm) were presented to a sample of 232 respondents (71.1% female; 28.9% male): 42 dental specialists, 63 dentists, 33 dental students (1^st to 3^rd year), 38 dental students (4^th to 6^th year) and 56 laypeople. The questionnaire consisted of four randomly displayed photographs, administered via Google Form, and respondents were asked to rate the images on a scale from 1 to 5, from the least attractive to the most attractive. A statistical analysis was performed using the TIBCO Statistica program (v. 13.3. 0, TIBCO Software Inc., Palo Alto, CA, USA; 2017). According to the Shapiro- Wilk''s test, the data were not distributed normally. The Kruskal-Wallis test with post hoc multiple comparisons with the Bonferroni adjustment were used to compare group esthetic scores and to determine the threshold levels of deviation at which each group was discriminated between esthetic and non-esthetic situations.ResultsMedian values of esthetic scores decreased in all groups as the gingival asymmetries increased. Dental professionals were significantly more critical of esthetics than laypeople in all levels of asymmetry. The greatest difference was found for 2 mm of gingival asymmetry (p=0.002).ConclusionFrom the results of our study, we can conclude that the perception of gingival asymmetries in the esthetic zone of smile differs among dental specialists, doctors, students, and laypeople. Dental specialists, doctors, and clinical students were more critical of these asymmetries, while preclinical students and laypeople noticed only 2 mm or more of gingival asymmetry of central incisors.     

福建地区汉族人群对微笑美学参数喜好度的研究

目的    探讨微笑美学参数的改变对微笑美的影响,并研究福建地区汉族人群对微笑美学参数的喜好度,为临床诊疗提供参考。方法　选取1张美观协调的志愿者（福建医科大学口腔医学院本科生）微笑图像作为模板图像,通过调整颊隙率、侧切牙与中切牙宽度比值、上中切牙宽长比例和牙龈暴露量等微笑美学参数对模板图像进行修改,获得24张微笑图像,作为调查资料。选择2019年3—9月于福建医科大学附属口腔医院就诊的成年患者158例［男75例、女83例,年龄（29.8 ± 5.5）岁］作为调查对象,对24张微笑图像进行视觉模拟评分（visual analogue scale,VAS）,并对所获VAS评分进行Kruskal-Wallis检验和Mann-Whitney检验。结果　颊隙率为0 ~ 15%、侧切牙与中切牙宽度比值为62% ~ 87%、上中切牙宽长比例为80% ~ 95%,以及牙龈暴露量为-1 ~ 1 mm时,其VAS评分在相应微笑美学参数中相对较高（均P < 0.05）。结论    颊隙率、侧切牙与中切牙宽度比值、上中切牙宽长比例以及牙龈暴露量均可对微笑美产生显著影响。     

An evaluation of the functional lip posture

The purpose of this study was to evaluate the relationship of the functional lip posture to the anterior teeth and gingiva and at the same time establish an objective esthetic standard in the clinic. The functional lip posture referred here were the smiling lip line and the maximum opening lip line. From an esthetic and clinical point of view, the functional lip posture was described, classified and scored using the relationship of the border of the upper and lower lip to the labial surface of the anterior teeth and gingiva. A device for taking standardized oral photographs with a high degree of reproducibility was used. Tjan, et.al. studied the esthetic factors in a smile. Using their classification the result of this study were as follows: high smile, 32%; average smile, 42%; and low smile, 26%. The difference in the amount of maxillary and mandibular gingival exposure were also determined in this study. The measurement of the maxillary area was used in classifying the smile since the mandibular area showed interproximal gingiva only. In analyzing the maximum opening lip line, it was not possible to apply Tjan's classification since it referred only to the smile line. A scoring system (smile score) was devised, instead, to evaluate the functional lip posture. By this scoring system, the smiling lip line was classified using the maxillary teeth and gingiva only. The classification were as follows: high smile, score was over 4; average smile, from 3-4; and low smile, under 3. Note that the maxilla was used as reference in analyzing the smiling lip line and the mandible for the maximum opening lip line.     

Tooth shape preferences in an esthetic smile.

INTRODUCTION: The purpose of this study was to evaluate the contributions of tooth shape to the esthetic smile. METHODS: Restorative dentists (120), laypeople (102), and orthodontists (113) evaluated a series of color photographs of men's and women's smiles. The photographs were randomly presented to test the effects of 3 different shapes of maxillary incisors and canines on the same patient. RESULTS: For women, orthodontists preferred round and square-round incisors (P < .01), and restorative dentists preferred round incisors (P < or = .03). Laypeople did not discriminate between incisor shapes. For men, all 3 groups preferred square-round incisors (P < or = .042). There was also a tendency for male judges to rate female images more attractive than did female judges. CONCLUSIONS: Restorative dentists, orthodontists, and laypeople share similarities and display differences when considering esthetic preferences in tooth shape. Although there was no consensus in preference among the laypeople as a group, their preferences differed from those of the dental professionals.     

种植支抗治疗露龈笑过程中切牙牙根吸收的CBCT检测

目的　通过CBCT技术精确测量种植支抗治疗露龈笑过程中所导致的上颌切牙牙根吸收的情况。方法　11例患者全部采用直丝弓矫治技术,在上颌两侧侧切牙和中切牙之间的牙槽骨上,各植入1枚微螺钉,每侧约0.98 N压低上前牙。当龈缘距与微笑线基本平齐时,治疗停止,进入保持阶段。治疗前后拍摄CBCT,在矢状位图像选取牙根长度最长的轴面进行长度测量。结果　所有患者露龈笑均有明显改善,平均减小(2.47±0.64)mm,切牙压入量为(2.81±0.62)mm。CBCT显示,治疗前后切牙牙根有一定程度的吸收,其中中切牙的吸收量大于侧切牙,但没有统计学意义。结论　采用种植支抗治疗露龈笑会导致上颌切牙出现牙根吸收,CBCT能够定量测量根吸收的情况。     

正畸患者对露龈微笑的审美认知

目的：调查成人正畸患者对露龈微笑的审美认知，并探讨医师的专业知识对正畸患者审美认知的影响。方法建立露龈微笑模型，采用电子调查问卷对正畸患者进行问卷调查。结果调查样本共计99例，露龈微笑的审美理想值-1.0 mm，可接受程度为2.0 mm。经医师对患者进行审美干预后可接受程度为2.5 mm。结论露龈微笑的理想值和可接受度可以为临床治疗提供一定的量化标准，正畸患者接受正畸专业知识干预后，对微笑显露牙龈的可接受程度增大。     

Laypeople's preferences regarding frontal dentofacial esthetics: periodontal factors

BackgroundThe authors conducted a review to evaluate the magnitude of esthetic impairment that the general public is able to discern with regard to periodontal factors.MethodsThe authors conducted a systematic computerized search of electronic databases (MEDLINE, PubMed, Embase, Cochrane Library and Web of Science) until May 2010. They scrutinized the abstracts of the retrieved articles and identified, selected and assigned methodological scores to those that investigated periodontal factors affecting anterior dental esthetics from a layperson's perspective.ResultsThirty-two articles met the inclusion criteria. The authors determined laypeople's preferences and sensitivities with regard to midline deviation, gingival display and architecture, smile arc and buccal corridors.ConclusionsThe results of the literature review show that most laypeople could detect dental midline deviations of less than 3.0 millimeters, but when made aware of midlines, they preferred those that are coincident with each other and with the facial midline. There appears to be an esthetic range—from 4.0 mm of incisal coverage to 3.6 mm of gingival display—that the general public tolerates, with a preference for the lip at or near the gingival margins of the maxillary central incisors. They preferred consonant smile arcs in both sexes but tolerated flat smile arcs in men more than they did in women. Laypeople preferred minimal buccal corridor.Clinical ImplicationsLaypeople have varying degrees of sensitivity to certain dental esthetic issues. Thus, clinicians can expect their patients to be more attentive to some dental esthetic factors than they are to others.     

正常牙合人群口周软组织增龄性变化的研究

目的:探讨正常牙合人群口周软组织在休息位与微笑位时随年龄变化特征。方法:选择15~49岁个别正常牙合者240例,进行面像拍摄,应用Smile Measure软件测量其口周软组织。结果:各年龄组间进行两两比较,组间差异有意义的测量项目有休息位上唇长度、微笑位上唇长度、休息位上唇厚度、微笑位上唇厚度、休息位口角宽度、口角宽度变化量、上颌切牙暴露量、上下唇间隙、微笑指数、颊旁间隙(P＜0.05)。同一年龄组不同性别进行两样本t检验,差异有意义的测量项目有休息位上唇长度、微笑位上唇长度、上唇长度变化量、休息位口角宽度(P＜0.05)。微笑高度进行卡方检验, G1、G2、G3、G4组高中低位微笑类型男女性别差异均具有统计学意义(P＜0.05)。结论:随年龄增长,上唇长度变长,嘴唇变薄,微笑时口角变宽,颊旁间隙变大,更趋于低位微笑。相同年龄人群的唇齿关系具有性别差异。     

The variability of the curvature of the labial surface of the upper anterior teeth along the facial axis of the clinical crown

OBJECTIVE: To mathematically assess the curvature of upper anterior teeth along the facial axis of the clinical crown (FACC) line to provide information valuable for assessment of enamel growth. METHODS: Forty upper study models were chosen from the Orthodontic clinic at the Charles Clifford Dental Hospital, Sheffield, UK. The study model incisors and canines were sectioned longitudinally down the FACC line, using a Microslice II cutting machine. Images were captured that showed the proximal view of the tooth curvature from incisal edge/cusp tip to the gingival margin. The images were converted into silhouettes and saved as bitmap files. These were vectorised and converted to an outline of xy data points. The forty xy files were mathematically adjusted so the distance between incisal edge and gingival margin were of equal length. Non Rotational Principal Component Analysis (PCA) was then applied at 20 equal intervals along the curve of each xy file to describe the shape of the teeth. RESULTS: Intra class correlation coefficient for intra-operator repeatability ranged from 0.821-0.998 showing good or excellent levels of reliability. PCA showed variation between tooth types. CONCLUSIONS: The method proved reliable. All tooth types showed that the mid-point region had the greatest rise variable, indicating that the most-prominent point was central or incisal for central and lateral incisors. All were skewed towards the incisal end and had kurtosis at both ends. Central incisors showed least variability. Greater variability was seen within the incisal third than within the gingival third for all tooth types.     

牙冠延长术治疗龈染色的临床效果观察

目的:观察牙冠延长术联合金沉积烤瓷冠修复治疗前牙龈染色的临床效果。方法:对12例共46颗经镍铬合金烤瓷冠修复后出现龈染色的前牙采用牙冠延长术联合金沉积烤瓷冠修复,追踪观察1年。结果:46颗龈染色牙,治疗后未出现牙周组织病变及再次龈染色,美观恢复良好。结论:牙冠延长术联合金沉积烤瓷冠修复是治疗龈染色的有效方法。     

应用3D数字化面部重建评估上颌尖牙垂直位置对微笑美学的影响

目的： 探讨上颌尖牙垂直位置改变对正面观和侧面观微笑美学的影响,寻找能被口腔医师和非专业人士接受的尖牙位置。方法： 选取一名志愿者,通过口内扫描和面部三维扫描,获取牙列和面部软组织图像并进行配准。在计算机辅助设计软件中,将上颌尖牙的垂直位置以0.5 mm为变量,自原始位置向牙合方1 mm和龈方1 mm进行数字化改变,重建三维虚拟数字化微笑面容。选取60名口腔医师和60名非专业人士,采用视觉模拟评分法,分别从正面和右侧45°对5个数字化微笑面容进行评分。将数值输入SPSS 20.0软件包,采用重复测量资料的方差分析比较2组间对数字化微笑面容的评分差异,采用秩和检验分析不同评价角度的评分差异。结果： 尖牙垂直位置改变对笑容评价有显著影响（P<0.05）,口腔医师和非专业人士对上颌尖牙垂直位置改变后微笑面容的美学评价存在显著差异（P<0.05）;评价角度不同,对微笑美学评价的差异无统计学意义（P>0.05）。结论： 尖牙牙尖相对侧切牙切缘于龈方0.5 mm时的笑容最美观,尖牙牙尖超过侧切牙切缘的笑容则不美观。临床上可参照所得数值,进行前牙美学设计。