The smile line, a literature search

Beautiful teeth, visible when smiling, are in line with the present ideal of beauty. The display of teeth when smiling is determined by the smile line: the projection of the lower border of the upper lip on the maxillary teeth when smiling. On the basis of a literature search the determining methods of the smile line are discussed, demographic data of the position of the smile line are given, and factors of influence are examined. There is no unequivocal method for determining the position of the smile line. A rough distinction can be made between qualitative and (semi)-quantitative methods. The (semi)-quantitative methods have clear advantages for research purposes, but their reliability is unknown. It was demonstrated that among minimally 40% of subjects the maxillary gingiva was not visible when smiling. The mandibular gingiva was not visible when smiling among more than 90% of subjects. Furthermore, it appeared that among women the smile line was on average higher situated than among men and that it has not yet been proven that the smile line will be situated lower when growing older.     

P-ASA block injection: a new palatal technique to anesthetize maxillary anterior teeth.

This technique article presents a new local anesthetic injection that is reported to produce anesthesia of the six maxillary anterior teeth, the anterior third of the palate, and the facial gingiva from a single-site injection. The injection is referred to as the palatal approach anterior superior alveolar (P-ASA) nerve block. The 0.9 to 1.4 mL dosage recommendation for this block injection is significantly less than for a traditional supraperiosteal approach. The primary advantage of this injection is that it allows the dentist to anesthetize the teeth and gingiva without collateral anesthesia to the lips, face, or muscles of facial expression. Therefore, the smile line is not distorted during the operative phase of an appointment, and the patient is more comfortable postoperatively. CLINICAL SIGNIFICANCE: The P-ASA is a new block injection technique that provides anesthesia of the maxillary anterior teeth from a single injection without numbness of the face, lips, and muscles of facial expression. This injection technique prevents distortion of the smile line and enhances restorative procedures that use the lip line as an esthetic reference element.     

美学区牙冠延长术联合树脂修复改善露龈笑并关闭牙间隙的初步探索

上颌前牙美学区作为微笑过程关注的重点，区域内任何粉白美学的缺陷都可能损害整体的微笑美学，对于高位笑线伴有被动萌出不足的患者，微笑时显露牙龈过多是常见的美学问题之一。而美学区牙冠延长术通过对牙周软硬组织的切除和成形，可有效重建协调、美观的龈缘位置和曲线，增加被动萌出不足的临床冠高度，同时改善牙冠宽长比等相关白色美学缺陷。文章完整展示了1例针对因被动萌出不足所致露龈笑且存在上中切牙牙间隙的美学治疗过程，包括美学分析、治疗计划的制定、临床实施过程和随访效果观察，详细介绍了美学区牙冠延长术的手术过程，并采用美学树脂直接修复关闭窄牙间隙，为此类患者的临床诊治积累经验。     

140名山西籍青年人微笑美学定性指标初步分析

目的:分析山西籍青年人姿势微笑位美学定性指标,探讨性别对微笑特征的影响,为前牙美学区域修复治疗提供参考依据。方法:选取20~30岁个别正常140例受试者,男68例,女72例,平均年龄25.6岁。采用视频录像的方式记录姿势微笑位的整个过程,使用计算机软件获取姿势微笑位图像。对微笑线、微笑弧、上唇曲度、上颌前牙与下唇的关系、微笑宽度进行定性分析。使用Pearson chi-square检验分析性别组间微笑指标,微笑定性指标之间采用Spearman相关分析。结果:在总体样本中,中微笑线(59.3%)、平行微笑弧(71.4%)、笔直上唇曲线(51.4%)、上前牙与下唇不接触(72.9%)以及微笑宽度显示至第二前磨牙(54.3%)较为常见。除了微笑线(P=0.040)和上颌前牙与下唇的接触关系(P=0.039)以外,其它定性指标在性别间无统计学差异。微笑线和上前牙与下唇的接触关系相关、微笑宽度和上前牙与下唇的接触关系相关(P<0.05)。结论:中微笑线、平行微笑弧、笔直上唇曲度、上前牙与下唇不接触以及微笑宽度显示至第二前磨牙的微笑特征在受试者中占比较高。微笑线和上颌前牙与下唇的接触关系差异在性别组间有统计学意义,女性较男性显示更高的微笑线,易出现下唇覆盖上颌前牙的唇齿关系。笑线越高,上前牙与下唇的接触关系越易出现覆盖关系;笑线越低,上前牙与下唇的接触关系越易出现不接触关系。微笑时牙齿显露数量少,上前牙与下唇的接触关系越易出现覆盖关系;微笑时牙齿显露数量多,上前牙与下唇的接触关系越易出现不接触关系。     

Age-related changes of the dental aesthetic zone at rest and during spontaneous smiling and speech

The aims of this study were to analyse lip line heights and age effects in an adult male population during spontaneous smiling, speech, and tooth display in the natural rest position and to determine whether lip line height follows a consistent pattern during these different functions. The sample consisted of 122 randomly selected male participants from three age cohorts (20-25 years, 35-40 years, and 50-55 years). Lip line heights were measured with a digital videographic method for smile analysis, which had previously been tested and found reliable. Statistical analysis of the data was carried out using correlation analysis, analysis of variance, and Tukey's post hoc tests. Maxillary lip line heights during spontaneous smiling were generally higher in the premolar area than at the anterior teeth. The aesthetic zone in 75 per cent of the participants included all maxillary teeth up to the first molar. Coherence in lip line heights during spontaneous smiling, speech, and tooth display in the natural rest position was confirmed by significant correlations. In older subjects, maxillary lip line heights decreased significantly in all situations. Lip line heights during spontaneous smiling were reduced by approximately 2 mm. In older participants, the mandibular lip line heights also changed significantly and teeth were displayed less during spontaneous smiling. Mandibular tooth display in the rest position increased significantly. Upper lip length increased significantly by almost 4 mm in older subjects, whereas upper lip elevation did not change significantly. The significant increasing lip coverage of the maxillary teeth indicates that the effects of age should be included in orthodontic treatment planning.     

The gingival smile line.

A comparative study was performed to examine the nature of the gingival smile line (GSL), a specific dentolabial configuration characterized by the exposure of maxillary anterior gingiva during a full smile. Five soft-tissue, three dental and three skeletal variables were selected, measured and reported for a GSL sample (n = 27) and a reference sample (n = 88), both consisting of North American white orthodontic patients with a median age of 14.4 years. The results indicated that the capacity to project a gingival smile was related to: anterior vertical maxillary excess and the muscular ability to raise the upper lip significantly higher than average when smiling. Other variables significantly associated with GSL were greater overjet, greater interlabial gap at rest, and greater overbite. Factors that did not appear associated with the GSL phenomenon were upper-lip length, incisor clinical crown height, mandibular plane angle, and palatal plane angle. Clinical aspects of GSL were discussed.     

A combined prosthodontic and orthodontic treatment approach in a case of growth inhibition induced by dental implants: a case report

Functional and esthetic results can improve significantly when a combined prosthodontic-orthodontic treatment approach is employed in cases requiring extensive oral rehabilitation. The patient presented in this case report was treated in his late teens with dental implants as a replacement for his maxillary incisors. Ten years later, the entire maxillary anterior segment was in infraocclusion compared to the rest of the dentition and lip line. Since prosthodontic follow-up treatment alone could not achieve an optimal functional and esthetic outcome, the patient was treated orthodontically prior to renewing the restoration. A fixed appliance was used to intrude the mandibular anterior teeth as well as vertically align the infrapositioned maxillary lateral incisors.     

Maxillary anterior papilla display during smiling: a clinical study of the interdental smile line

The purpose of this research was to quantify the visual display (presence) or lack of display (absence) of interdental papillae during maximum smiling in a patient population aged 10 to 89 years. Four hundred twenty digital single-lens reflex photographs of patients were taken and examined for the visual display of interdental papillae between the maxillary anterior teeth during maximum smiling. Three digital photographs were taken per patient from the frontal, right frontal-lateral, and left frontal-lateral views. The data set of photographs was examined by two examiners for the presence or absence of the visual display of papillae. The visual display of interdental papillae during maximum smiling occurred in 380 of the 420 patients examined in this study, equivalent to a 91% occurrence rate. Eighty-seven percent of all patients categorized as having a low gingival smile line (n = 303) were found to display the interdental papillae upon smiling. Differences were noted for individual age groups according to the decade of life as well as a trend toward decreasing papillary display with increasing age. The importance of interdental papillae display during dynamic smiling should not be left undiagnosed since it is visible in over 91% of older patients and in 87% of patients with a low gingival smile line, representing a common and important esthetic element that needs to be assessed during smile analysis of the patient.     

Smile attractiveness. Self-perception and influence on personality

OBJECTIVES: To investigate self-perception of smile attractiveness and to determine the role of smile line and other aspects correlated with smile attractiveness and their influence on personality traits. SUBJECTS AND METHODS: Participants judged their smile attractiveness with a patient-specific questionnaire. The questionnaire contained a spontaneous smiling photograph of the participant. Objective smile-line height was measured using a digital videographic method for smile analysis. Personality was assessed with the Dutch Personality Index. RESULTS: Cronbach's alpha for the smile judgment questionnaire was .77. The results showed that size of teeth, visibility of teeth, and upper lip position were critical factors in self-perception of smile attractiveness (social dimension). Color of teeth and gingival display were critical factors in satisfaction with smile appearance (individual dimension). Participants, smiling with teeth entirely displayed and some gingival display (two to four millimeters), perceived their smile line as most esthetic. Smiles with disproportional gingival display were judged negatively and correlated with the personality characteristics of neuroticism and self-esteem. Visibility and position of teeth correlated with dominance. CONCLUSION: The results of this research underpin the psychosocial importance and the dental significance of an attractive smile.     

Treatment planning: implant-supported partial overdentures

When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the implant-supported overdenture has several advantages, some in common with a removable partial denture.     

P-ASA Block Injection: A New Palatal Technique to Anesthetize Maxillary Anterior Teeth

Abstract: This technique article presents a new local anesthetic injection that is reported to produce anesthesia of the six maxillary anterior teeth, the anterior third of the palate, and the facial gingiva from a single-site injection. The injection is referred to as the palatal approach anterior superior alveolar (P-ASA) nerve block. The 0.9 to 1.4 mL dosage recommendation for this block injection is significantly less than for a traditional supraperiosteal approach. The primary advantage of this injection is that it allows the dentist to anesthetize the teeth and gingiva without collateral anesthesia to the lips, face, or muscles of facial expression. Therefore, the smile line is not distorted during the operative phase of an appointment, and the patient is more comfortable postoperatively.     

A systematic approach to recreate a patient's former smile

In this case involving a 29-year-old woman with a history of stomach-acid-related reflux and extensive loss of tooth structure, the patient desired to regain the smile she "used to have." The treatment goals throughout the process were to manage risk, use minimally invasive procedures, and improve the prognosis in each of the four dental categories-periodontal, biomechanical, functional, and dentofacial. The treatment plan utilized a systematic approach to sequentially restore and protect the young woman's dentition. It included esthetic crown lengthening, establishing the ideal esthetic position of maxillary anterior and posterior teeth, addressing the mandibular plane of occlusion, and achieving optimal function.     

四维微笑设计辅助非对称面型前牙超薄瓷贴面修复前牙区散在间隙1例及文献复习

目的探讨以四维微笑设计为主导、以面部流线为参考体系的全程数字化设计在前牙美学修复中的应用效果。方法对1例前牙区散在间隙患者进行四维微笑设计,辅助行超薄瓷贴面数字化美学修复。通过口内和面部扫描获得患者数字化信息,进行四维微笑设计和预测,进行2次美学预告,医患共同确定治疗方案后,进行微创基牙预备,制作超薄瓷贴面,就位后粘接。术后观察美观度、边缘密合度,于修复完成后1年复查。结果超薄瓷贴面边缘密合,颜色过渡自然,红白美学效果好,微笑时面部协调,1年后随访,颜面整体美学佳,基牙、牙周组织健康,患者满意。文献复习结果表明,时序性面部扫描与口内扫描数据拟合可以准确地进行四维微笑美学预测,模拟动态微笑及发音过程的真实状态,结合面部流线,为非对称面型患者设计出自然协调的个性化微笑;然而对于咬合改变、咬合不稳定或颞下颌关节紊乱患者,需增加电子面弓、锥形束CT等数据拟合,更加准确地模拟患者术后的下颌运动。结论以四维微笑设计为主导、以面部流线为参考体系的全程数字化设计,辅助非对称面型前牙超薄瓷贴面的修复前牙散在间隙的效果良好,患者术后微笑协调美观,符合预期效果;患者参与度、满意度高,值得临床推广。     

Display of mandibular and maxillary anterior teeth during smiling and speech: age and sex correlations

This study aimed to measure mandibular and maxillary anterior tooth display during smiling and speech and to evaluate correlation with age and sex. Ninety-four subjects were video recorded when smiling and when saying "ah" or "shesh." Anterior tooth display was measured using individual video frames. Average mandibular and maxillary anterior tooth display showed opposing trends. The former increased with age, had a tendency to be greater in men, and was greater during speech than during smiling. The latter decreased with age, was greater in women than in men, and was greater during smiling than during speech. Anterior dental esthetic evaluation, especially for the mandible, should include observation of speech.     

Microcirculation of the healthy human gingiva

 The purpose of this study was to evaluate the microcirculation in healthy human gingiva. Forty-two adult volunteers with clinically healthy gingiva participated. The ages of this research sample ranged from 20 to 30 years. Periodontal conditions were evaluated and assessed by using the qualitative plaque index, gingival index, gingival bleeding index, tooth mobility, and laser Doppler flow-metry (LDF) on 12 maxillary and mandibular anterior teeth. The LDF data were recorded on the facial aspect of the free gingiva, interdental gingiva, attached gingiva, and alveolar mucosa of 12 maxillary and mandibular anterior teeth, utilizing an acrylic stent to stabilize the probe. This technique was then modified to circumvent contamination by saliva and gingival exudate. Blood flow in the maxillary anterior gingiva differed significantly from that in the mandibular anterior gingiva in interdental gingiva, attached gingiva, and alveolar mucosa, at P < 0.01. The maxillary anterior gingiva, at each point on the stent, showed significant differences in the mean LDF, at P < 0.01. For the mandibular anterior gingiva, the difference was significant only in the alveolar mucosa region. Received: November 10, 2000 / Accepted: January 23, 2002     

The quantitative topographic characteristics of the minor salivary glands of the lips

Secretory activity of labial minor salivary glands was examined in 20 normal caries-resistant subjects. The lower lip glands were found to dominate over the upper lip glands in the number of functioning glands, in the density of their location, and in secretion volume. Therefore, the labial mucosa and mandibular vestibular surface of the gingiva and teeth are washed by a higher amount of secretion than the upper lip mucosa and maxillary gingiva and teeth.     

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.     

Three-dimensional esthetic analysis in treatment planning for implant-supported fixed prosthesis in the edentulous maxilla: review of the esthetics literature

Fixed implant-supported prosthesis for the edentulous maxilla has gained tremendous popularity over the years. Multiple prosthetic designs have been introduced in order to accommodate a gamut of clinical situations. Irrespective of the design, it is paramount that the esthetics imparted by the prosthesis be uncompromised. Though esthetics is subjective, a common ground exists where all its fundamental principles converge. This article reviews pertinent dental and facial esthetics literature for application of various esthetic concepts involved in diagnosis and treatment planning for an implant-supported fixed prosthesis in the edentulous maxilla. Three-dimensional esthetic analysis involves assessment of various esthetic parameters in superior-inferior, medial-lateral, and anterior-posterior dimensions. The impact of various esthetic parameters such as facial forms, facial profiles, maxillary teeth positions, maxillary teeth proportions, smile lines, lip support, gingival display, facial midline, dental midline, horizontal cant, and smile width are discussed in detail.     

Treatment of gingival fibromatosis associated with Zimmermann-Laband syndrome

BACKGROUND: Gingival fibromatosis is a rare condition characterized by a generalized enlargement of the buccal and lingual aspects of the attached and marginal gingiva. METHODS: This case report describes the periodontal management of a 13-year-old female patient with gingival fibromatosis associated with Zimmermann-Laband syndrome. The patient presented with gingival enlargement involving the maxillary and the mandibular arches, anterior open bite, and non-erupted teeth. Periodontal treatment included gingivectomy in all four quadrants. RESULTS: Histopathologic evaluation of the excised tissue supported the diagnosis of gingival fibromatosis. A significant improvement in esthetic appearance and eruption of the non-erupted teeth were obtained. The patient was referred for appropriate orthodontic treatment and has been closely followed for the earliest signs of recurrence of gingival enlargement. CONCLUSIONS: The successful therapy for gingival fibromatosis depends on correctly identifying the etiological factors and improving the impaired function and esthetic appearance through surgical intervention and adjunctive orthodontics. Maintaining treatment results depends on preservation of periodontal health.