Incisal Display Research Articles

Smile analysis: A comparison between photographic and videographic methods

Objectives: To evaluate and compare the differences between the spontaneous smile captured by conventional photography and the video clip method. Methods: A digital video camera was used to capture smiles in 100 subjects using the static and videographic methods. Results: Measurements of the anterior and posterior height of the smile, interlabial gap, lower incisal display and eye wink on photographs obtained by the two methods showed considerable differences. Except for the anterior and posterior height of the smile in girls, these differences were statistically significant ( P Conclusions: In orthodontic treatment planning, certain treatment modalities (in particular intrusion and expansion) are based on an analysis of the full spontaneous smile. Since the videographic method is better able to capture this smile, it may be a preferred method of obtaining pretreatment facial photographs.

Incisor display during speech and smile: Age and gender correlations.

To evaluate age- and gender-related changes in the soft tissues, incisors, and gingival display during rest, speech, and posed smile. A total of 265 participants (122 men, 143 women) ranging in age from 19 years to 60 years were recruited for this study. Participants were divided into one of the following four age groups: 19 to 24 years, 25 to 34 years, 35 to 44 years, and 45 to 60 years. Image capture was performed using standardized videographic methods. Each video produced pictures where measurements were performed: rest, speech, and smile positions. A statistically significant gender dimorphism was apparent in most of the variables. There was a significant increase in the upper lip length and lip commissures height with aging and more markedly in men. A greater exposure of mandibular incisor with increasing age was a feature in both genders. With increasing age there was a significant decrease in maxillary incisor display, especially for men. After 25 years of age there is significant difference in the aging process between men and women. Gingival and maxillary incisor display during speech and smile is a youthful and feminine characteristic.

Influence of aesthetic dental and facial measurements on patient satisfaction between genders in Indian patients

PurposeThe purpose of the present study was to investigate patients satisfaction and correlate the variability of aesthetic dental and facial measurements by the maxillary anterior teeth appearance in different gender group among Indian patients. Materials and methodsThe dental and facial measurements were made on 80 Indian subjects: Central incisor width/length ratio, gingival zenith displacements, the upper lip height, intercommisural width, maximum maxillary central incisal at rest and smile were measured. All the patients rated their satisfaction with the dental appearance on the visual-analogue scale. All the parameters have been analyzed with respect to gender. ResultsThe great majority of the participants were completely satisfied with their dental appearance (p > 0.05). In the men, maximum maxillary central incisal display at rest and intercommisural width during smile showed statistical significant difference. In women, the combination of central incisor width/length ratio, intercommissural width at rest and smile, and maximum maxillary incisal display measurements were statistically significant. ConclusionsWithin the population tested, the results suggest that the use of aesthetic dental and facial measurement may serve as an aesthetic guideline. The gingival architecture should be considered in aesthetic anterior oral rehabilitation.

Esthetic factors of smile in vertical dimensions: A comparative evaluation

Introduction: The variations in aesthetic perception among the professionals and the laypersons were compared, to understand the association of various skeletal and dental factors in vertical dimension, which alter the soft-tissue characteristics during posed/social smile, among young adults. Methods: Images of the posed smile were captured with a digital camera from the 60 nonorthodontic treated young adults (30 girls, 30 boys). Determinants of the pleasing smile were identified from the results of a Visual Analog Scale. Quantitative measurements of the soft- and hard-tissue were made by using the smile images and cephalometric radiographs. The esthetics of the smile was correlated with specific skeletal, dental, and soft-tissue structures in the anteroposterior and vertical dimensions. Results: Three factors formed significant components of a pleasant smile, for orthodontists (incisogingival display, upper lip, and buccal corridor) and three for laypersons (upper lip, lower lip, and smile arc). A strong positive correlation was seen among skeletal and dental vertical dimensions and incisor show. The vertical thickness of the upper lip had a significant positive correlation with the position of the maxillary incisor. Conclusion: Incisogingival display, upper lip, lower lip and buccal corridor proved to be the most influential variables in smile esthetics. The significant relationship of incisor protrusion with the vertical thickness of the vermilion border of the upper lip shows that skeletal and dental vertical dimensions for incisal display must be considered when planning orthodontic treatment.

The distraction osteogenesis in midfacial hypoplasia.

Distraction osteogenesis (DO) can generate new bone in a gap between 2 vascularized bone surfaces in response to application of graduated tensile stress across the bone gap. The authors present the clinical result in a cleft patient with severe maxillary deficiency treated by a rigid external distraction (RED) device. A boy complained of both masticatory and psychological problems because of cleft with severe midfacial retrusion. The treatment aimed to create a well-balanced facial profile, increase maxillary incisal display, create proper overjet and overbite, and align his dentition. By the RED system, the traction is applied to the maxilla through the dentition by an intraoral splint. A complete Le Fort I osteotomy was performed, including pterygomaxillary and septal disjunction, with mobilization. Once osteotomy was completed, the halo portion of the RED device was adjusted for the width of the neurocranium and was rigidly fixed around the head with 2 scalp screws on each side. A well-balanced facial profile and a good alignment of the dentition were obtained. The patients had considerable improvement in his self-esteem. Clinical reports have suggested that maxillary advancements achieved by distraction are more stable than those achieved with orthognathic surgery with a minimal influence on velopharyngeal competence.

Orthosurgical Management of a Severe Class III Malocclusion

Success in the management of a skeletal Class III malocclusion depends on proper diagnosis and treatment planning. In adults with a severe discrepancy, combined orthosurgical approach is the only way to achieve acceptable results. This case report describes the orthosurgical management of an adult male patient with a severe Class III malocclusion displaying a combination of maxillary deficiency and mandibular excess. The patient had a reverse overjet of 5 mm and an open bite of 7 mm. Incisal display both at rest as well as on smiling was decreased and he presented with a wide buccal corridor. A combination of Arnett’s clinical and cephalometric examination was used to diagnose and plan treatment for facial changes. Double jaw surgery including a 4 mm maxillary advancement and 4 mm rotation of the palatal plane downward anteriorly with a 6 mm mandibular setback was planned. The palatal plane was rotated downward to aid in closure of the open bite thereby taking care of the decreased incisal show. Ideal overjet, overbite, satisfactory facial balance and stomato gnathic function could be achieved because of a com­ bined orthosurgical approach.

A dynamic analysis of the display of the dentition during speech

The aim of this prospective study was to quantify the display of the dentition through the soft tissue frame during speech using videography for different age groups. Two hundred and sixty-one subjects were initially screened and were divided into five groups: group 1 (G1) (15-19 years), G2 (20-29 years), G3 (30-39 years), G4 (40-49 years), and G5 (≥ 50 years). Groups were also made on the basis of gender and history of orthodontic treatment. Video equipment was used to capture video and each frame was analysed out of which two frames that best represented the maximal display of maxillary incisors (MDMI) during speech and the widest transverse display of dentition (WTDD) during speech were selected. The data obtained was analysed using one-way analyses of variance with Fisher's least significant difference post hoc test. MDMI and WTDD were found to be highly significant during speech across all age groups (P < 0.05). G1-G3 displayed approximately similar levels of maxillary incisor (P > 0.05) but was greater (P < 0.05) than G4 and G5. The buccal corridor showed significant differences as a function of age (P < 0.05). Orthodontic treatment had a significant impact on the display of the maxillary incisors (P < 0.05) but not on the buccal corridors (P > 0.05). Mandibular incisor display was relatively stable across G1-G3, increasing only for G4 and G5. It appears that the maximum display of maxillary incisors decreases with age and the decline is particularly rapid with increasing age. Females tend to display more teeth both in the transverse and vertical directions.

Establishing the Customized Occlusal Plane in Systemized Surgical Treatment Objectives of Class III

The purpose of this study was to present a new approach for establishing the customized occlusal plane for an individual patient in systemized surgical treatment objective of class III cases. After the correction of incisor inclination to occlusal planes (U1-MxOP and L1-MnOP), the intermaxillary relationship can be established with normal overbite/overjet and maximum intercuspation. The anterior limits of the maxilla and the mandible can be positioned according to A to N perpendicular, Frankfort horizontal (FH) to AB plane angle, and upper incisor display. The vertical level of the upper first molar can then be determined in relation to the Y plane (an imaginary arch drawn using the distance between the lower incisor edge point and the rotation center point of the condylar head as a radius) and a triangle projected by the upper and lower limits of the FH to the occlusal plane (FH-OP triangle). Soft-tissue facial balance can be checked with the lip/chin projection in relation to the true vertical line at subnasale and the lower third facial height ratio. Appropriate superior impaction of the posterior part of the maxilla in relation to the Y plane and FH-OP triangle in case 1 produced significant improvement of the facial profile and occlusion. However, case 2 showed that the amount of superior impaction of the posterior part of the maxilla was not enough to produce a significant setback of the mandible and retraction of the lip and chin. The systemized surgical treatment objective flowchart that could set the customized occlusal plane for an individual patient might provide a useful guideline for obtaining optimal aesthetics and functional occlusion in class III cases.

Influence of Esthetic Dental and Facial Measurements on the Caucasian Patients' Satisfaction

The purpose of the present study was to investigate how some esthetic dental and facial measurements may correlate the variability of patients' ratings of their satisfaction with the maxillary anterior teeth appearance in different gender groups. The following measurements were made on 78 Caucasian subjects: width and length of each maxillary anterior tooth, their distal gingival zenith displacements, the upper lip height, intercommisural width, maximum maxillary central incisal, and gingival display at rest and smile. All the patients rated their satisfaction with the dental appearance on the visual-analogue scale (0 meaning absolute dissatisfaction, whereas 4 indicated complete satisfaction). All the parameters have been analyzed with respect to gender. The majority of the esthetic dental and facial measurements were larger in men (p<0.05). The great majority of the participants were completely satisfied with their dental appearance (75% of men and 89% of women; p>0.05). In the men, the two factors of maximal maxillary incisal display at rest and intercommisural width at smile paralleled the variability of the patients' satisfaction with dental appearance by 99% (p>0.05). In women, the combination of central incisor width/length ratio, intercommisural width at rest, central incisor gingival zenith displacement, intercommisural width at smile, upper lip height, and maximum maxillary incisal display at rest paralleled the variability of the patients' satisfaction with dental appearance by 99% (p>0.05). Within the population tested, the results suggest that the use of esthetic dental and facial measurements may serve as an esthetic guideline and should be considered in esthetic anterior oral rehabilitation. The information presented in this article may be useful in helping to create dental restorations with an acceptable esthetic appearance to the patient. Prior to the treatment the dentist should consider not only the size of maxillary anterior teeth but also their gingival architecture and the soft tissue surrounding the teeth.

Lip - tooth relationships during smiling and speech: an evaluation of different malocclusion types

Abstract Background Few studies have focused on the impact of malocclusion on lip – tooth relationships during smiling and speech. Aim To evaluate the impact of different malocclusions on lip – tooth relationships during smiling and speech, using video images. Methods One hundred and three subjects with Class I (N = 31), Class II division 1 (N = 26), Class II division 2 (N = 16) and Class III malocclusions (N = 30) were asked to repeat the same sentence and then smile in front of a video camera. Nine frames were extracted from each subject’s video clip: at rest, posed smile, unposed smile and during the pronunciation of the sounds: ‘che’, ‘fa’, ‘se’, ‘chee’, ‘tee’ and ‘mee’. On each frame, up to 10 parameters describing the lip – tooth relationships were measured. Results In all frames, there were no statistically significant differences in the upper central incisor display ratios among the malocclusion groups (p &gt; 0.05). The buccal corridor ratio in the posed and unposed smiles did not differ significantly among the malocclusions (p &gt; 0.05). The most frequently visible last maxillary tooth was the first premolar in the posed smile, and the second premolar in the unposed smile. In each malocclusion group, the upper central incisor display ratio varied significantly among the nine frames and the buccal corridor ratio during the unposed smile was less than the ratio during the posed smile; although this was only significant in the Class II division 2 subjects. The smile arc was similar in all malocclusions. Conclusions In each malocclusion the upper central incisor display ratio varied significantly among the nine frames. In each group, the buccal corridor ratio during the unposed smile was less than that during the posed smile, but only the Class II division 2 group was significantly different. The smile arc did not differ among the malocclusions.

Display of the incisors as functions of age and gender

Abstract Background Older subjects usually show less of their upper incisors and more of their lower incisors than younger subjects. Objectives To determine how much of the upper and lower central incisor crowns are visible in Brazilian subjects with their lips at rest. Methods The subjects were 240 white Brazilian subjects divided into four age groups: Group 1, 12 to 15 years of age; Group 2, 20 to 30 years of age; Group 3, 31 to 50 years of age and Group 4, 51 years of age and older. Each group contained 30 males and 30 females. The vertical display of the incisors was measured in millimetres from the midpoints of the incisal edges of the upper and lower central incisors to the borders of the upper and lower lips. Results In females, the mean upper central incisor display reduced from 4.45 mm in Group 1 to 1.32 mm in Group 4, and in males it reduced from 3.35 mm in Group 1 to 0.57 mm in Group 4. Less of the lower central incisor crowns were displayed in Group 1 females (Mean: 0.47 mm) than in Group 4 females (Mean: 2.22 mm), and in Group 1 males (Mean: 0.61 mm) than in Group 4 males (Mean: 3.05 mm). Brazilian women showed significantly more of their upper incisor crowns than Brazilian men in Groups 1, 2 and 4, whereas Brazilian men showed significantly more of their lower central incisors than Brazilian women in Group 4. Conclusions With the lips at rest, older Brazilians display less of their upper central incisors and more of their lower central incisors than young Brazilians. Women show more of their upper incisors than men, while men display more of their lower central incisors than women.

Differential Diagnosis for Inappropriate Upper Incisal Display During Posed Smile

The amount of upper incisor display (UID) during smile and conversation is one of the most decisive components in aesthetic judgment. The purpose of this study was to find which soft tissue and underlying hard tissue factors contributed to the amount of UID during posed smile (PS) and at rest posture (RP). The subjects consisted of 76 young adults (33 men and 43 women; mean [SD] age, 24.79 [2.29] y) with skeletal and dental class I relationship, normal overbite/overjet, and minor crowding (<2 mm). After checking reproducibility of the amounts of UID during PS and at RP in lateral cephalograms with facial photographs, 15 hard and soft tissue variables were measured, and statistical analysis was done. There was no significant sex difference in the amount of UID during PS and at RP. The amount of UID during PS significantly increased when anterior maxillary height was longer, lower gonial angle was larger, occlusal plane to sella-to-nasion plane angle was steeper, interlabial gap at RP was larger, upper lip length at RP was shorter and upper lip elevation during PS was larger. Multiple linear regression analysis to predict the degree of UID during PS generated a 4-variable model (adjusted R = 0.607): upper lip elevation (the dynamic soft tissue variable), interlabial gap and upper lip length (the static soft tissue ones), and anterior maxillary height (the hard tissue one). The diverse causes of inappropriate UID according to the soft and hard tissue factors need different treatment approaches such as orthodontic treatment, periodontal treatment, orthognathic surgery, botulinum toxin, or myectomy. The clinician can use these variables as a guideline for differential diagnosis of inappropriate UID.

Dynamic smile analysis: Changes with age

The objective of this study was to define age-related changes in the smile. The areas of interest were upper lip length at smile and repose, upper lip thickness at smile and repose, maxillary incisal display at smile, interlabial gap height at smile, smile index, percentage of buccal corridors, intercommissural width at rest, smile height, and smile arc. A secondary objective was to study the perioral changes from rest to smile and compare them on the basis of age. Video equipment was used to capture images of 261 subjects, who were divided into 5 groups by age. Two frames for each subject were selected, 1 frame representing the lips at rest and the other representing the widest smile. After 40 subjects were excluded, the data for the remaining 221 were analyzed by using 1-way analysis of variance (ANOVA) with the Fisher LSD post-hoc test. There was a decrease of 1.5 to 2 mm in maxillary incisor display during smile with increasing age, but the smile index showed a significant increase. In accordance with some other studies, most subjects (78%) had average smile height. No subject in the 50 and over age group had a high smile, and no subject in the 15-to-19 year group had a low smile. All dynamic measurements indicated a pattern of decreasing change from rest to smile, especially evident after ages 30 to 39 years. This study helps to establish age-related dynamic norms. As a person ages, the smile gets narrower vertically and wider transversely. The dynamic measures indicate that the muscles' ability to create a smile decreases with increasing age.

Editor's Summary and Q&A: Dynamic smile analysis: Changes with age

Introduction The objective of this study was to define age-related changes in the smile. The areas of interest were upper lip length at smile and repose, upper lip thickness at smile and repose, maxillary incisal display at smile, interlabial gap height at smile, smile index, percentage of buccal corridors, intercommissural width at rest, smile height, and smile arc. A secondary objective was to study the perioral changes from rest to smile and compare them on the basis of age. Methods Video equipment was used to capture images of 261 subjects, who were divided into 5 groups by age. Two frames for each subject were selected, 1 frame representing the lips at rest and the other representing the widest smile. After 40 subjects were excluded, the data for the remaining 221 were analyzed by using 1-way analysis of variance (ANOVA) with the Fisher LSD post-hoc test. Results There was a decrease of 1.5 to 2 mm in maxillary incisor display during smile with increasing age, but the smile index showed a significant increase. In accordance with some other studies, most subjects (78%) had average smile height. No subject in the 50 and over age group had a high smile, and no subject in the 15-to-19 year group had a low smile. All dynamic measurements indicated a pattern of decreasing change from rest to smile, especially evident after ages 30 to 39 years. Conclusions This study helps to establish age-related dynamic norms. As a person ages, the smile gets narrower vertically and wider transversely. The dynamic measures indicate that the muscles' ability to create a smile decreases with increasing age.

Submental intubation in orthognathic surgery: initial experience

Submental intubation is a technique for use in maxillofacial trauma, which allows precise assessment of changes to the nasolabial complex, midlines, cants, and incisal display in patients having maxillary orthognathic surgery. We report our initial experience of it used as an adjunct in the management of orthognathic surgery in a series of 44 patients.

Long-term changes of the upper lip position relative to the incisal edge

One result of postadolescent facial growth is elongation of the upper lip and subsequent decrease of incisal display on smiling. The aim of this study was to evaluate the long-term change of upper lip position relative to the incisal edge. Fifty-four subjects with cephalometric x-rays taken at the end (T2) of orthodontic treatment, at least 10 years postretention (T3), and at least 20 years postretention (T4) were selected from the postretention records of the University of Washington, Seattle. On each cephalogram, length of the upper lip, anterior and posterior facial height, and positions of the maxillary and mandibular incisors were registered. From T2 to T3, both upper lip elongation and growth of the facial skeleton were more pronounced in males than in females. The stomion-incision superius distance diminished by 1.3 mm in males, whereas in females this distance increased by 0.3 mm. From T3 to T4, the facial skeleton showed relative stability in both sexes, whereas the upper lip elongated by approximately 2 mm. The stomion-incision superius distance decreased by about 1.2 mm. Elongation of the upper lip continues throughout life. In the second and third decades of life, facial growth balances lip elongation. When late facial growth is minimal, the stomion-incision superius distance steadily decreases.

Overbite Correction and Smile Aesthetics

Achievement of optimum smile aesthetics during orthodontic treatment has recently been the focus of several published articles in the orthodontic literature. Authors speculate that overbite correction, specifically maxillary incisor intrusion, will lead to flattening of the smile arc and consequently reduce smile attractiveness. The purpose of this prospective clinical study was to investigate differences in outcomes from two common procedures used to reduce deep overbite: maxillary incisor intrusion using an intrusion arch and posterior tooth eruption using an anterior bite plate. Pretreatment and postoverbite correction records were gathered from 20 patients who presented with deep overbite malocclusions to the Virginia Commonwealth University orthodontic clinic. Both the intrusion arch and bite plate procedures effectively reduced overbite significantly over a relatively short period of treatment. Intrusion arch patients displayed significant reductions in maxillary incisor display (lip to tooth) accompanying documented incisor intrusion. Half of the patients in both groups experienced flattening of the smile arc in agreement with previous studies showing similar changes in orthodontic patients in general. There was no greater tendency for flattening to occur in either group. Changes in the smile arc are likely due to other factors involved in orthodontic tooth alignment and are not necessarily attributable to the overbite correction method employed during treatment.

Principles of cosmetic dentistry in orthodontics: Part 1. Shape and proportionality of anterior teeth

In the past decade, there has been a remarkable upswing in interdisciplinary collaboration between dentists, orthodontists, and periodontists in smile enhancement, and now an entire field of “cosmetic periodontics” has evolved in collaboration with cosmetic dentistry. Contemporary orthodontic smile analysis is generally defined in terms of (1) vertical placement of the anterior teeth to the upper lip at rest and on smile (adequate incisor display but not too gummy), (2) transverse smile dimension (buccal corridors), (3) smile arc characteristics, and (4) the vertical relationship of gingival margins to each other. Through the interaction with these other disciplines and the knowledge gained, we have expanded our diagnosis of the smile to further refine the finishing of anterior esthetics for our patients. As our interaction with cosmetic dentistry has increased, we have become very aware of what standards guide the dentist who strives for an excellent smile. Through cosmetic bonding and laminate veneers, the dentist can control tooth shape by adding or taking away from the tooth, crown, or laminate. As orthodontists, we have generally limited our toothreshaping efforts to incisal edge “dressing.” The purpose of this article is to examine some cosmetic ideas and present new ways in which we can improve the smiles of our patients. In Part 1, I will define and illustrate how these principles are applied to improve the cosmetics of orthodontic patients. In Part 2, my coauthor and I will review the new laser technology available for reshaping soft tissues, and, in Part 3, we will discuss the clinical use of those lasers.