Smile esthetics in othodontics. /certified fixed orthodontic courses by Indian dental academy


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Smile esthetics in othodontics. /certified fixed orthodontic courses by Indian dental academy

  1. 1. Smile esthetics in orthodontics INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2.  Introduction  Historical aspects  The esthetic paradigm  Records in treatment of the smile  Tooth-lip relationships  The social smile and the enjoyment smile.  Analysis of the smile in 4 dimensions. (Frontal, Sagittal, Oblique, Time-specific.)
  3. 3.  Influence of extractions on smile esthetics  Tooth shape and smile esthetics  Principles of cosmetic dentistry in smile esthetics.  Maxillary midline diastema.  Conclusion
  4. 4. Introduction  The importance of beauty and attractiveness in today’s society has been well established.  Physically attractive people are perceived to be more kind, sensitive, interesting, strong, poised, modest, sociable, outgoing, exciting, and responsive. (Dion et al 1972)  It is also believed that attractive people are more likely to obtain better jobs,have more successful marriages, and experience happier,more fulfilling lives.  These societal biases begin early in life and impact a person’s future for a lifetime.
  5. 5.  Dentofacial attractiveness is particularly important to a person’s psychosocial well being.  People with a normal dental appearance are judged more socially attractive over many personal characteristics than those with malocclusions. (Shaw et al AJO 1985)  Those with poor dental esthetics have been linked to lack of self-confidence and are thought to be disadvantaged in social, educational, and occupational
  6. 6.  During interpersonal interactions, the eyes primarily scan other people’s eyes and mouths, with little time spent on other features. (Miller, 1970)  Thus it is not surprising that the general public considers the smile to rank second only to the eyes when considering features most important to facial esthetics. (Goldstein, 1969)  Tatarunaite et al (AJODO 2005) reported that smiling and youthful facial appearance make women look more attractive
  7. 7.  Esthetics, which is derived from the Greek word for perception, deals with beauty and the beautiful.  It may be divided into two dimensions: objective (admirable) and subjective (enjoyable ) beauty.  Objective beauty implies that the object possesses properties that make it unmistakably praiseworthy.  Subjective beauty is value laden, and is related to the tastes of the person contemplating it.
  8. 8.  Contemporary techniques in orthodontics should lend objective esthetics to the entire orofacial complex involving unity, form, color, function and display of the dentition.  In addition, the creation of subjective beauty according to the orthodontist‟s own preferences may enhance the cosmetic value of treatment given to each patient.
  9. 9. Esthetics in orthodontics has been defined mainly in terms of profile enhancement, but if you ask lay people what an orthodontist does, their answers will usually include something about creating beautiful smiles.
  10. 10. Historical aspects  The study of frontal facial form dates back to the Egyptians, who depicted ideal facial esthetics as the ―golden proportion.‖ This concept has been described extensively in classical art and orthodontic literature.
  11. 11. In the latter part of the 19th century, Norman Kingsley, the leading orthodontist of the era, emphasized the esthetic objectives of orthodontic treatment. In the Kingsley paradigm, the articulation of the teeth was clearly secondary to facial appearances.
  12. 12. Edward Angle‟s emphasis on occlusion led him to teach that optimal facial esthetics always coincided with ideal occlusion and that esthetics could essentially be disregarded because it took care of itself.  Classification schemes were based on static morphologic features, such as molar relationships and the extent of facial divergence.  Also, the early concepts of esthetics revolved largely around the patient’s profile, and it was believed that, once the ―ideal‖ tooth–jaw positions were achieved, then the soft tissues would fall in line. 
  13. 13.  This focus on the profile was because the lateral cephalogram has long been the lynchpin of orthodontic treatment planning.  As a result, orthodontics tended to drift away from clinical examination of the patient and the art of physical diagnosis.  There is little debate about the many advancements that Angle made in orthodontics, most notably his system of classifying malocclusion.  But perhaps more attention should be paid to his inclusion of art in the orthodontic search for quantifying facial beauty.
  14. 14.  Art instruction by Prof Wuerpel was an integral part of the Angle curriculum, but it has gradually disappeared from the modern residency program.  When orthognathic surgery developed in the 1970s and growth modification treatment reappeared for children, the goal was to obtain better occlusion more than better facial proportions.  In the 1980s, the introduction of new esthetic materials in restorative dentistry led to the widespread adoption of “esthetic dentistry.”  At about the same time, it became clearer to all involved that orthognathic surgical goal setting was esthetically driven.
  15. 15. The esthetic paradigm  Although ideal occlusion remained the primary functional goal, it was acknowledged that the esthetic outcome was critical for patient satisfaction.  This has led to the emergence of the esthetic paradigm in orthodontic treatment.  A paradigm can be thought of as “ a set of shared beliefs and assumptions that represent the conceptual foundation for an area of science or clinical practice.
  16. 16.  Today’s ―art of the smile‖ is being driven by the orthodontist’s ability to clinically examine the patient in 3 dimensions and use the latest technology (computer databasing of the clinical examination and digital videography) to document, define, and communicate the treatment strategy to patients and colleagues involved in interdisciplinary care.
  17. 17.  The contemporary orthodontist no longer evaluates patients in terms of only the profile, but also frontally and vertically, to complete the 3 spatial dimensions, and statically and dynamically.  Also, the orthodontist must now add a fourth dimension: Time
  18. 18.
  19. 19.  Orthodontists are the first in line in a decision-making process that ultimately affects a patient’s appearance for the rest of his or her life.  The orthodontist must understand not only dentoskeletal growth and development, but also soft tissue growth, maturation, and aging.
  20. 20.  The orthodontist must work with 2 dynamics. A. Soft tissue repose and animation assessed at the patient’s examination including how the lips animate on smile, gingival display, crown length, and other attributes of the smile. B. Facial change throughout a patient’s lifetime: the impact of skeletal and soft tissue maturational and aging characteristics, which are well documented.
  21. 21. Records in the treatment of the smile 3 categories of orthodontic records  Static records (Photographs)  Dynamic records (Video)  Direct biometric measurements
  22. 22. Photographs:  In addition to the standard frontal at rest, frontal smile and profile at rest images, Sarver and Ackerman (AJO DO 2003) recommend 4 additional views:  Profile smile  Oblique smile  Frontal smile closeup  Oblique smile closeup
  23. 23.
  24. 24.  Dynamic recording is accomplished with digital videography  Digital video and computer technology enables the clinician to record anterior tooth display during speech and smiling at the equivalent of 30 frames per second.  5 seconds of video for each patient may be taken, yielding 150 frames for comparison.  One segment of video is taken in the frontal dimension and one from the oblique view.
  25. 25.
  26. 26. Direct measurement as a biometric tool  Quantification of resting and dynamic liptooth relationships is critical to smile visualization.  Direct measurement also has application in research efforts relative to time related changes and the repeatability of the social smile.
  27. 27. Tooth-lip relationships Systematic measurement of resting tooth–lip relationships virtually leads the clinician to a quantified treatment plan. The following frontal measurements should be performed :  Philtrum and commissure height,  Interlabial gap,  Incisor show at rest and smile,  Crown height, Gingival display,  Smile arc.
  28. 28. Philtrum height is measured in millimeters from subspinale (the base of the nose at the midline) to the most inferior portion of the upper lip on the vermilion tip beneath the philtral columns.
  29. 29.  Commissure height is measured from a line constructed from the alar bases through subspinale, and then from the commissures perpendicular to this line.  Interlabial gap is the distance in millimeters between the upper and lower lips when lip incompetence is present.
  30. 30.  The absolute linear measurement of philtrum height is not particularly important, but its relationship to the upper incisor and the commissures of the mouth is significant.  In the adolescent, the philtrum height is often shorter than the commissure height, and the difference can be explained in the differential in lip growth with maturation.
  31. 31. A short philtrum in adults results in an unesthetic maxillary lip line which makes resting posture resemble a frown.
  32. 32. Incisor show at Rest and Smile  The amount of maxillary incisor show at rest is a critical parameter esthetically, because it is an inevitable characteristic of aging  As a general guideline, in adolescents 3-4 mm of the maxillary incisor should be displayed at rest, and the entire clinical crown with some gingiva should be seen on smiling.  Generally, males show less upper incisors and more of lower incisors, while females show more of upper incisors and less of lower incisors.
  33. 33.  Peck et al (AJODO 1992) showed that the normal display of maxillary incisors with relaxed lips at 15 years age is 4.7 + 2 mm for boys and 5.3 + 1.8 mm for girls. This sexual dimorphism is evident at all ages.  Also, Whites show more of upper incisor but less lower incisor at rest than do Asians or Africans.
  34. 34.  Excessive tooth display is judged better at rest than on smile, because lip elevation on smiling is quite variable.  If exposure at rest is normal, even if a considerable amount of gingival display occurs on smiling, this should be considered normal for that individual.
  35. 35. A gummy smile can be esthetic !
  36. 36.  In 1992, Peck et al described how orthodontists and surgeons are conditioned to see high gingival smile lines as undesirable and concluded that the gingival smile line is not influenced by upper lip length, incisor crown height, mandibular plane angle, or palatal plane angle.
  37. 37.  They noted that the biological mechanisms of the gingival smile line are influenced by anterior vertical maxillary excess, greater muscular capacity to raise the lip, and supplemental factors, such as excessive overjet and overbite.  They also noted that the location of the gingival smile line largely depended on the subject’s sex. On average, the smile line in women is 1.5 mm higher than in men.
  38. 38.  Dong et al (Int J Prosthod 1999) compared the age changes in maxillary and mandibular incisor display at rest and when smiling and found that aging (from 30 years to 60 years) was associated with a steady decrease in maxillary incisor display and a concomitant increase in mandibular incisor display.  This is associated with sagging of the perioral soft tissue partly due to the natural flattening, stretching and decreasing elasticity of the skin with age.
  39. 39.
  40. 40.  The importance of proper planning for vertical incisal positioning in orthodontics and orthognathic surgery cannot be overemphasized.  It may make all the difference between a youthful and an elderly smile at end of treatment.
  41. 41. Crown height  The percentage of incisor display, when combined with crown height, helps the clinician decide how much tooth movement is required to improve the smile index.  Crown height is the vertical height of the maxillary central incisors; in adults, crown height is normally between 9 and 12 mm, with an average of 10.6 mm in men and 9.6 mm in women.  The age of the patient is a factor in crown height because of the rate of apical migration in the adolescent.
  42. 42. The Smile Arc  The smile arc from the frontal view is the relationship of the curvature of the incisal edges of the maxillary incisors and canines to the curvature of the lower lip in the posed social smile.  In an ideal smile arc, the curvature of the maxillary incisal edge is parallel to the curvature of the lower lip upon smile; the term consonant describes this parallel relationship.  In a nonconsonant or flat smile, the maxillary incisal curvature is flatter than the curvature of the lower lip on smile.
  43. 43.
  44. 44.  Tjan et al (J Prosthet Dent 1984) in a survey of young Los Angeles adults, found that a great majority (85%) had a maxillary incisal smile curve parallel to the inner contour of the lower lip, 14% showed a straight rather than a curved line, and only 1% had a reverse smile curve.
  45. 45. The Social Smile and the Enjoyment Smile.  The social smile is a voluntary smile a person uses in social settings or when posing for a photograph. When you are introduced to someone, your smile indicates that you are friendly and “pleased to meet” that person.  The enjoyment smile (or Duchenne smile) is an involuntary smile and represents the emotion you are experiencing at that moment. It is natural in that it represents authentic emotion and dynamic in that it bursts forward and but is not sustained.
  46. 46.
  47. 47.  What differenciates the social smile from the enjoyment smile is not the activity of the orbicularis oris musculature, but instead the participation of the orbicularis oculi.  In the enjoyment smile there is a crinkling around the eyes that cannot be duplicated with a social smile.  According to both Darwin and Duchenne, we “smile with our eyes.”
  48. 48.    1. 2. 3. Tarantili, Halozonetis and Spyropoulos (AJODO 2005) recorded and analyzed spontaneous smiles in fifteen children, average age of 10.5 years, using a hidden camera while they watched a funny cartoon. The spontaneous smile was found to develop in a staged fashion. Three stages were identified: An initial attack period from relaxed neutral position to full smile. (500 milliseconds) A sustaining period (Variable time period) A fadeout or decay period back to relaxed posture.
  49. 49.  The smiles were accompanied by display of teeth and mouth opening, though not consistently.  On average, facial measurements showed that the upper lip elevated by 28% and the mouth increased in width by 27%, while the corners of the mouth moved laterally and superiorly at an angle of approximately 45 degrees.
  50. 50.  The smile extended over the whole face including wrinkling around the eyes and contraction of the orbicularis oculi muscles, confirming that the smile was genuine.  The frequency and extent of smiling were enhanced in the presence of other children, showing that smiling is a social activity that people like to share.  This study emphasizes the point that conventional photographic records of the smile might involve errors related to capturing a time-evolving event at a single instant.  Video recordings may provide more comprehensive information for assessment of facial esthetics.
  51. 51.  In treating the smile, the social smile generally represents a repeatable smile. Sarver and Ackerman (AJODO 2003) chose the social smile as the representation in order to analyze the smile in 4 dimensions: frontal, oblique, sagittal, and time-specific.
  52. 52. FRONTAL DIMENSION  To visualize and quantify the frontal smile, Ackerman and Ackerman (1998), developed a ratio, called the smile index, that describes the area framed by the vermilion borders of the lips during the social smile.  The smile index is determined by dividing the intercommissure width by the interlabial gap during smile. This ratio is helpful for comparing smiles among different patients or across time in 1 patient.
  53. 53. This patient has small smile index value with substantial incisor display on smile.
  54. 54.  Frontally, we can visualize and quantify 2 major dimensions of the smile: vertical and transverse characteristics.  The vertical characteristics of the smile are broadly categorized into 2 main features: those pertaining to incisor display and those pertaining to gingival display.  If, for example, the patient shows less than 75% of the central incisor crowns at smile, tooth display is considered inadequate. (Morley and Eubank, JADA 2001.)
  55. 55. Inadequate incisor display can be due to:  Vertical maxillary deficiency  Limited smile area (a large smile index),  Short clinical crown height. Short clinical crown height could be due to  Lack of tooth eruption (treated with observation),  Gingival encroachment (treated with cosmetic periodontics),  Short incisors secondary to attrition (treated with cosmetic dentistry).
  56. 56.  Other vertical smile characteristics are the relationships between the incisal edges of the maxillary incisors and the lower lip, and between the gingival margins of the maxillary incisors and the upper lip.  The gingival margins of the canines should be coincident with the upper lip and the lateral incisors positioned slightly inferior to the adjacent teeth.  It is generally accepted that the gingival margins should be coincident with the upper lip in the social smile. However, this is very much a function of age, because children show more tooth at rest and have more gingival display on smile than do adults.
  57. 57.  1. 2. 3. Tjan and Miller (1984) described three types of smiles acording to lip coverage of maxillary incisors in full smile: The average smile, that reveals 75-100% of the upper incisors (most frequent). The low smile which displays < 75% of the maxillary incisors (found in 20% of population.) High/ gummy smile, revealing the complete cervicoincisal length of the upper incisors and a contiguous band of gingiva.(10% of the population)
  58. 58. Clinical implications for Deep Overbite correction Average and low smile types  Correction of deep anterior overbite can be made with various combinations of incisor intrusion and molar extrusion.  In the past, active intrusion of maxillary incisors with intrusion arches, utility arches and other approaches has been considered a cornerstone of deep bite correction.  However, over-intrusion of upper incisors tends to hide them behind the upper lip when the patient is speaking.  With increasing age of the patient and drooping of upper lip, this would predictably worsen over time.
  59. 59.  The optimal vertical reference position for the maxillary incisal edge in orthodontic treatment planning is with relaxed lips.  For young adults (20-30 years): At least 3 mm of maxillary incisor show.  For adults 30-40 years: About 1.5 mm of maxillary incisor show.  Adults 40-50 years: About 1mm .  In patients 50-60 years: No maxillary incisor show at rest.
  60. 60. Prior to treatment, each patient‟s tooth display should be carefully analyzed at rest and speech, before deciding whether maxillary intrusion mechanics are indicated.  From the esthetic point of view, the best strategy in the majority of cases of deep overbite is active intrusion of mandibular incisors.  This is especially when the curve of Spee is marked, and the six anterior teeth are above the functional occlusal plane.  Achieved using overlay base arches or segmented arch mechanics. 
  61. 61. Reduced anterior overbite and high erupting canines  Use of a continuous leveling wire may overintrude the incisors into functionally and esthetically unacceptable positions. This should be avoided.  In such cases the first molars should be connected with a TPA to yield reliable posterior anchorage, and a cantilever wire from the extra tube used to bring down the canines.
  62. 62. Treatment of gummy smiles  The biologic mechanism of gummy smiles appears to involve anterior vertical excess, increased muscular ability to raise the upper lip on smiling, excessive interlabial gap at rest and excess overbite and overjet.  Different treatment strategies are needed for patients with high smile line, involving various combinations of orthodontic, periodontal and surgical therapy.  Both the incisor show at rest and gingival show on smiling should be considered.
  63. 63.  If maxillary incisor show at rest is optimal, active upper incisor intrusion should not be initiated. Instead surgical crown lengthening with removal of crestal alveolar bone should be made.  Especially desirable in case of excess marginal gingiva and short clinical crowns.
  64. 64. Treatment of most severe gummy smiles may require maxillary superior repositioning surgery (Le Fort I osteotomy) along with reduction of the associated vertical maxillary excess.
  65. 65. Gummy smile treated with combination of maxillary impaction surgery and crown lengthening
  66. 66.  Gummy smiles can also be treated using plastic surgery to correct the hyperfunction of upper lip muscles, especially by resection of the levator labii superioris.  However Ellenbogen (Plastic Reconstr Surg 1984) reported that resection of the levator labii superioris is short-lived, with the gummy smile returning within 6 months.  He advocated placing a spacer, either nasal cartilage or prosthetic material, between the stumps to prevent the muscles from being reunited and again hyperelevating the lip.
  67. 67. Use of Botox for treatment of gummy smiles.  Botulinum toxin has been under clinical investigation since the late 1970s for the treatment of several conditions associated with excessive muscle contraction or pain.  Botulinum toxin is produced by the anaerobic bacterium Clostridium Botulinum.  Type A (BTX-A), marketed as Botox, is the most potent and the most commonly used clinically.
  68. 68.  BTX-A weakens skeletal muscles by cleaving the synaptosome-associated protein SNAP25, thus blocking the release of acetylcholine from the motor neuron and enabling the repolarization of the postsynaptic terminal.  As a result, the muscular contraction is blocked. The production of acetylcholine is not affected by this blockade of the neuromuscular transmission.
  69. 69.  Polo M (AJODO 2005) described a nonsurgical alternative for reducing excessive gingival display caused by muscle hyperfunction, using Botox.  Five subjects with excessive gingival display due to hyperfunctional upper lip elevator muscles were treated with BTX-A injections in the levator muscles.  This treatment modality was effective, producing esthetically acceptable smiles in these patients.  The improvements lasted 3 to 6 months.
  70. 70.
  71. 71.
  72. 72. Injection with BTX-A provides effective, minimally invasive, temporary improvement of gummy smiles for patients with hyperfunctional upper lip elevator muscles.
  73. 73. Flattening of the Smile Arc  Undesirable flattening of the smile arc is greatly underestimated in orthodontics.  Hulsey (AJO 1970) assessed standardized photographs of 40 subjects, 20 treated orthodontically and 20 considered to have normal occlusion. He noted that the curvature of the incisal edges of the maxillary anterior teeth was flatter in those who were treated orthodontically.  Ackerman et al (1998) reported that the smile arc of as many as 32% of their patients was flattened during treatment.
  74. 74.  Normal orthodontic alignment of the maxillary and mandibular arches may result in a loss of the curvature of the maxillary incisors relative to the lower lip curvature.  It is important to assess and visualize the incisor-smile arc relationships and place brackets so as to extrude the maxillary incisors in flat smiles and to maintain the smile arc where it is appropriate.
  75. 75.  If all patients routinely have their maxillary central incisors placed 4.5 mm above the incisal edge, their lateral incisors at 4 mm, and their canines at 5 mm, without the clinician taking into account the relationship of the incisal edges to the lower lip curvature in each individual case, the positioning may or may not fit the esthetic criteria required.
  76. 76.  Bracket placement, with emphasis on the goal of attaining canine guidance may create relative intrusion of the maxillary incisors while extruding the maxillary canines.  This could lead to non-consonant smile.
  77. 77.
  78. 78.  In patients in whom excessive gingival display on smile is noted, and for whom one of the treatment objectives is to reduce the gumminess of the smile, maxillary incisor intrusion may improve the gingival display on smile.  However, if the smile arc relationship has not been noted and evaluated, unwanted flattening of the smile arc may result.  Maxillary intrusion arches or maxillary archwires with accentuated curve could result in a flattening of the smile arc.
  79. 79. Midline considerations  When viewing dentitions, many clinicians use the maxillary central incisors as their esthetic baseline  However, considering the importance of the facial midline, there remains confusion regarding techniques for reliably locating it.  Careful photographic analysis of patients’ faces shows that prominent facial anatomy— including the eyes, nose and chin—can be deceptive in locating the midline.
  80. 80. A practical approach to locating the facial midline references two anatomical landmarks. The first is a point between the brows known as the nasion  The second is the base of the philtrum, also referred to as the cupid’s bow in the center of the upper lip.  A line drawn between these landmarks not only locates the position of the facial midline but also determines the direction of the midline .
  81. 81.
  82. 82.  Whenever possible, the midline between the maxillary central incisors should be coincidental with the facial midline.  In cases in which this is not possible, the midline between the central incisors should be parallel to the facial midline.  If the visual junction of maxillary central incisors is at an angle to the facial midline, it is referred to as a canted midline.  Canting is a major design flaw in any natural or restored dentition.
  83. 83.  According to Kokich, as long as the maxillary midline deviation is parallel to the facial midline, even a 4mm maxillary midline deviation was not noticed by dentists and laypeople.  However, even a 2 mm deviation in incisor angulation was noticeably unattractive.
  84. 84. Transverse characteristics  The transverse characteristics of the smile in the frontal dimension are  Arch form,  Labiolingual crown-inclinations of teeth,  Buccal corridor and  Transverse cant of the maxillary occlusal plane.
  85. 85.  Arch form plays a pivotal role in the transverse dimension of the smile. Recently, much attention has been focused on the use of broad, square arch forms in orthodontic treatment.  When the arch form is narrow or collapsed, the smile may also appear narrow and therefore present inadequate transverse smile characteristics.
  86. 86.  An important consideration in widening a narrow arch form, particularly in adults, is the axial inclination of the buccal segments.  Patients whose posterior teeth are already flared laterally are not good candidates for dental expansion. Patients with upright premolars and molars have more capacity for transverse expansion;  This is true in adolescents, but it is particularly important in adults because sutural expansion is less likely.
  87. 87. Orthodontic expansion and widening of a collapsed arch form can dramatically improve the smile by decreasing the size of the buccal corridors and improving the transverse smile dimension
  88. 88. Labiolingual crown inclinations:  Generally 90% of people show the 1st or 2nd premolar as the last tooth when smiling.  To create the illusion of smile fullness, the last premolar should be positioned relatively upright.  Torque prescriptions for most preadjusted appliance systems tend to create too much lingual crown inclination, which may not be optimal from the esthetic perspective.  Crown inclination symmetry of contralateral teeth contribute to to an optimally esthetic appearance., and necessary archwire correction bends should be made to achieve this.
  89. 89.
  90. 90.
  91. 91. Buccal corridors  The transverse smile dimension is also related to the lateral projection of the premolars and the molars into the buccal corridors.  The buccal corridor may be defined as “ The distance from the posterior teeth to the corners of the lips ”(Frush and Fisher, 1958)  Frush and Fisher considered the buccal corridor to be a normal feature of a dentition that prevents the “Sixty tooth Smile” that is often characteristic of a denture.
  92. 92.  They stated that the size and shape of the buccal corridors were not important, as long as the buccal corridors were noticed.  The wider the arch form in the premolar area, the greater the portion of the buccal corridor that is filled.
  93. 93.  Only a few studies have determined the esthetic value of the buccal corridor space.  In 1995, Johnson and Smith found that extraction of teeth during orthodontic treatment had no effect on the buccal corridors.  Similar findings were reported by Gianelly (AJODO 2003) who found no differences in arch width in extraction and nonextraction patients.  Hulsey (AJO 1970) also reported that there was no relation between buccal corridors and smile scores.  However, Hulsey measured the buccal corridor from the canine to the corner of the mouth.
  94. 94. In adolescents, it is often desirable to increase arch width with rapid maxillary expansion to create space for non-extraction treatment.
  95. 95.  Arch expansion might fill out the transverse dimension of the smile, but 2 undesirable side effects could result, and careful observation is needed to avoid these, if possible. 1. The buccal corridor can be obliterated, resulting in a denture-like smile.
  96. 96. 2. When the anterior sweep of the maxillary arch is broadened, the smile arc may be flattened  This is particularly important today because of the trend toward broader arch forms.
  97. 97.  Although it may not be possible to avoid these undesirable aspects of expansion, the clinician must make a judgment in concert with the patient as to what tradeoffs are acceptable in the pursuit of the ideal smile.
  98. 98.  According to Moore et al (AJODO Feb 2005) the esthetic values of today may differ from those of 50 years ago.  People now keep their teeth longer, and there has been a shift away from complete denture prosthodontics.  Thus, a full smile might no longer be perceived as a denture smile.
  99. 99.  The same authors carried out a study in which color slides of 10 smiling subjects were digitally altered to produce narrow, medium narrow, medium, medium broad and broad smiles.
  100. 100.
  101. 101.  Analysis showed that lay persons considered broader smiles to be more attractive as compared to narrow smiles.  They concluded that having minimal buccal corridors is a preferred esthetic feature for both men and women, and large buccal corridors should be included in the problem list during diagnosis and treatment planning
  102. 102.  In another study by Roden-Johnson et al (AJODO March 2005), smiling photographs of 20 women treated by 2 orthodontists were collected: 1 group had narrow tapered or tapered arch forms, and the other had normal to broad arch forms.Photographs of 10 untreated women served as a control sample.  The photographs with Buccal Corridor Space were altered to eliminate the dark triangular areas, and those without it were altered by the addition of dark triangular areas at the lateral aspects of the smile.  Three groups of raters (dentists, orthodontists, and laypeople) used a visual analogue scale to rate the
  103. 103.  There was no significant difference in smile scores related to BCS for all samples and for all viewers.  Dentists rated broader arch forms as more esthetic than untreated arch forms. Orthodontists rated broader arch forms as more esthetic than narrow tapered arch forms and untreated arch forms.  Lay people showed no preference of arch form.  This study demonstrated that the presence of BCS does not influence smile esthetics.  However, there are differences in how dentists, orthodontists, and laypeople
  104. 104. Transverse cant of the maxillary occlusal plane.  Transverse cant can be due to differential eruption and placement of the anterior teeth or skeletal asymmetry of the mandible resulting in a compensatory cant of the maxilla.  Only frontal smile visualization permits the orthodontist to visualize any tooth-related or skeletal asymmetry transversely.  Smile asymmetry may also be due to soft tissue considerations, such as an asymmetric smile curtain.
  105. 105.  In the asymmetric smile curtain, there is a differential elevation of the upper lip during smile, which gives the illusion of a transverse cant to the maxilla.  It is poorly documented in static photographic images and is documented best in digital video clips.
  106. 106. OBLIQUE DIMENSION  The oblique view of the smile shows characteristics of the smile not obtainable on the frontal view or through any cephalometric analysis.  The palatal plane can be canted anteroposteriorly in a number of orientations.  In the most desirable orientation, the occlusal plane is consonant with the curvature of the lower lip on smile.  Deviations from this orientation include a downward cant of the posterior maxilla, upward cant of the anterior maxilla, or variations of both.
  107. 107. It is important to visualize the occlusal plane and its relationship to the lower lip. In preparation for maxillary surgery to close an anterior open bite, whether the posterior maxilla should be impacted or the anterior maxilla should come down depends on the amount of incisor show at rest and on smile and the smile arc relationship.
  108. 108. This is best visualized in the oblique view.
  109. 109.  The visualization of the complete smile arc afforded by the oblique view expands the definition of the smile arc to include the molars and the premolars
  110. 110. SAGITTAL DIMENSION  The 2 characteristics of the smile that are best visualized in the sagittal dimension are overjet and incisor angulation.  Excessive positive overjet is one of the dental traits most recognizable to the lay person.  In many Class II patterns, the smile is esthetic frontally, but the problem is obvious when observed from the side.  In Class III patterns too, the frontal smile looks esthetic but the oblique or sagittal view shows the underlying skeletal pattern and dental compensation.
  111. 111.  Incisor proclination in the sagittal dimension can also have a dramatic effect on incisor display.  In simple terms, flared maxillary incisors tend to reduce incisor display, and upright maxillary incisors tend to increase it
  112. 112. Effect of retraction of incisors following extraction of four premolars.
  113. 113. THE FOURTH DIMENSION: TIME  The growth, maturation, and aging of the perioral soft tissues have a profound effect on the appearance of both the resting and smiling presentations.  In preadolescent patients, the facial soft tissues are still in a growth phase, and treatment decisions pertaining to the relative facial divergence at profile and frontal facial soft tissue topography must take this into account.
  114. 114.  Adolescent patients, or those at the point of pubertal onset, have experienced the maximum velocity in the growth of the skeletal subunits and have roughly achieved their facial soft tissue “look.”  In adults, nuances in the aging of perioral and facial soft tissues become increasingly important.It is known from orthodontic cephalometric research that, on average, profiles flatten over time.
  115. 115.  In a direct measurement study of more than 3500 subjects, Dickens et al (World Journal of Orthodontics, 2002) studied the changes in philtrum height and commissure height in patients from age 6 years to their 40s and the relationship to the smile.  These data demonstrate the lengthening of the philtrum and commissure, with the rate of philtrum lengthening greater than that of the commissures.  This would explain the flattening of the “M” characteristics of the vermilion border of the upper lip in the youthful lip.
  116. 116. 1. 2. 3. 4. 5. The effects of maturation and aging on the soft tissues can be summarized as Lengthening of the resting philtrum and commissure heights. Decrease in turgor (or tissue “fleshiness”) Decrease in incisor display at rest, Decrease in incisor display during smile Decrease in gingival display during smile.
  117. 117. Influence of extractions on smile esthetics  The recent criticism concerning the detrimental effects of premolar extraction therapy on smile esthetics has added another dimension to the 100year-old extraction vs nonextraction debate.  Presumably, extraction treatment results in narrower dental arches which are associated with a less esthetic smile because the dentition is less full during a smile.  In addition, this arch width reduction creates unaesthetic black triangles at the corners of the mouth and „negative‟ spaces lateral to the buccal segments.
  118. 118.  Documentation of the adverse effects of extraction treatment on smiles is scarce.  Luppanpornlarp and Johnston (Angle Orthod 1993) found that in comparable groups of patients treated with and without extractions, the post-treatment intercanine widths of the maxillary and mandibular arches were the same in both groups.
  119. 119. Johnson and Smith (AJODO‟95) determined that smile esthetics, esthetic scores, and visible dentition during a smile were the same in both extraction and nonextraction patients.  Also, arch width, at least in the intercanine zone, is not necessarily narrower after extraction treatment when compared with nonextraction treatment. 
  120. 120.  Kim and Gianelly (Angle Orthod 2003) studied the dental casts of 30 patients treated with extraction and 30 patients without extraction of four first premolars, (all randomly selected to) determine changes in arch width as a result of treatment.  Standardized frontal photographs of the face taken during smiling of 12 extraction- and 12 nonextraction treated subjects were evaluated by fifty laypersons who judged the esthetics of the smiles.
  121. 121.  Intercanine width increased less than one mm in both groups, and there was no difference between the two groups.  When arch widths of both groups were measured from the most labial surfaces of the teeth at a constant depth, the average arch width of both arches was significantly wider in the extraction sample
  122. 122.  The mean esthetic score and the number of teeth displayed during a smile did not differ between the groups.  The results of this study indicate that constricted arch widths are not a usual outcome of extraction treatment and that neither extraction nor nonextraction treatment has a preferential effect on smile esthetics.
  123. 123.  Isiksal, Hazar and Akyalcin (AJODO 2006) compared smile esthetics among extraction and nonextraction patients and a control group, as judged by orthodontists, plastic surgeons, artists, general dentists, dental professionals, and parents.  The mean esthetic scores for the extraction, nonextraction, and control groups were 3.15, 3.12, and 3.26, on a scale of 5, respectively. (no significant difference )  Visible dentition width relative to the smile width ratio and intercanine distance relative to smile width ratio were significantly different among the groups, with extraction patients showing a slightly wider dental arch relative to the soft tissue.
  124. 124. Importance of tooth shape in smile esthetics  Many notions held today on the esthetics of tooth shape are based on authoritative writings aimed at guiding denture tooth selection.  For example, Williams suggested that tooth shape should be determined by facial form.  However, selecting tooth shape on the basis of facial form has not been supported by the literature. In fact,several studies have found no correlation between facial outline and actual or preferred tooth shape.
  125. 125.  Other popular methods for selecting tooth shapes in the past were based on stereotypes: women should have round, soft, and delicate teeth (tapering/ovoid); men should have square, angular teeth.  Anderson et al (AJODO 2005) conducted a study to evaluate the contributions of tooth shape to the esthetic smile. Three groups of judges were recruited: restorative dentists, laypeople, and orthodontists  The judges each evaluated 18 color photographs of smiles portrayed in either a male or female booklet.
  126. 126.  They were tested for incisor shape preferences while maintaining canine shape, and for canine shape preferences while maintaining incisor shape.  Three shapes based on the incisal line angles of the central and lateral incisors: square, square-round, and round.  Three canine shapes were also compared: pointed, round, and flat.
  127. 127.
  128. 128.  Restorative dentists preferred round incisors for the female images. Orthodontists preferred round and square-round incisors for the female images. Laypeople did not express a preference in female incisor shape.  All 3 groups preferred square-round incisors for the male images.  Canine shape played a less important role than incisor shape in the esthetics of the anterior dentition.  Lay people tended to be less critical than dental professionals. Restorative dentists tended to be more critical than both laypeople and orthodontists.
  129. 129. It would be wise to involve the patient in treatment planning, whether it involves incisal-edge recontouring or complete restoration of the anterior dentition.
  130. 130. Principles of cosmetic dentistry in orthodontics:  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 (2) transverse smile dimension (3) smile arc characteristics, and (4) the vertical relationship of gingival margins to each other.
  131. 131.
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  135. 135.
  136. 136.
  137. 137.
  138. 138.
  139. 139.
  140. 140.
  141. 141.
  142. 142. Use of laser gingivectomy to achieve smile esthetics.
  143. 143.
  144. 144.
  145. 145. Maxillary midline diastema  Sivakumar A and Valiathan A (Kerala Dental Journal, July 2006) emphasized the need to correctly diagnose the underlying etiology of midline diastema, with the help of medical and dental history and radiographic examination to rule out a supernumerary tooth.  Such conditions can sometimes be treated with removable appliances such as finger springs, split labial bow, but better control can be achieved using fixed appliances with artistic positioning bends in the archwire.
  146. 146.  Roots should be allowed to converge together so that relapse could be compensated.  Especially in cases of tooth size arch length discrepancy, it is preferred to carry out veneer bonding to close the space.  In case of very large diastemas, a combination of orthodontic tooth movement and veneering is preferred.
  147. 147.  Contrary to popular belief, a study by Shashua and Artun (Angle Orthod 1999) could find no association between relapse and the presence of an abnormal frenum or an osseous intermaxillary cleft.  Fremitus was the only parameter at followup associated with space reopening.  Retention is the hardest part of treating a midline diastema orthodontically, and invariably requires fixed permanent retention with multistranded stainless steel wires bonded to the lingual surface of the incisors with composite.
  148. 148. Conclusion  Today, well occluding casts and pleasing profiles can no longer be considered to be adequate treatment goals for the orthodontist.  Since most people interact with each other facing each other directly or obliquely, the smile of the patient should be given adequate importance in treatment planning.  In order to correctly diagnose and treat problems associated with the smile, meticulous clinical observation and record taking in the form of photos and videos is warranted, in various dimensions.
  149. 149. A sound knowledge of orthodontic mechanics and growth changes as well as the principles of cosmetic dentistry should help the orthodontist to truly live up to the epithet of “Smile Architect”.
  150. 150.  References: 1. Verma N, Valiathan A. An understanding of facial esthetics and its role in orthodontics. Kerala Dental Journal 2006; 29(3): 27-30. 2. Hulsey CM. An esthetic evaluation of lip-teeth relationships present in the smile. Am J Orthod 1970;57:132-44. 3. Mackley RJ. An evaluation of smiles before and after orthodontic treatment. Angle Orthod 1993;63:183-90. 4. Peck S, Peck L, Kataja M. The gingival smile line. Angle Orthod 1992;62:91-100. 5. Sabri R. The eight components of a balanced smile. Journal of Clinical Orthodontics. 2005; 39: 3: 155-167
  151. 151. 6. Zachrisson BU. Esthetic factors involved in anterior tooth display and the smile: vertical dimension. J Clin Orthod 1998; 32:432-5 7. Ackerman MB, Ackerman J. Smile analysis and design in the digital era. J Clin Orthod 2002;36:221-36. 8. Sarver DM, Ackerman JL. Orthodontics about face: the reemergence of the esthetic paradigm. Am J Orthod Dentofacial Orthop 2000;117:5756. 9. Sarver DM. The importance of incisor positioning in the esthetic smile: the smile arc. Am J Orthod Dentofacial Orthop 2001;120: 98-111.
  152. 152. 10. Morley J, Eubank J. Macroesthetic elements of smile design. J Am Dent Assoc 2001;132:39-45 11. Rubin LR. The anatomy of a smile: its importance in the treatment of facial paralysis. Plast Reconstr Surg 1974;53:384-7. 12. Sarver D, Ackerman M. Dynamic smile visualization and quantification: part 2. Smile analysis and treatment strategies. Am J Orthod Dentofacial Orthop 2003;124:116-27. 13. Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthet Dent 1984;51:24-8. 14. Frush JP, Fisher RD. The dynesthetic interpretation of the dentogenic concept. J Prosthet Dent 1958;8:558-81.
  153. 153. 15. Johnson D, Smith R. Smile esthetics after orthodontic treatmentwith and without extraction of four first premolars. Am J Orthod Dentofacial Orthod 1995;108:162 16. Moore T, Southard K, Casko J, Qian F, and Southard T. Buccal corridors and smile esthetics. Am J Orthod Dentofacial Orthod 2005;127:208-13 17. Sarver D, Ackerman M. Dynamic smile visualization and quantification: Part 1. Evolution of the concept and dynamic records for smile capture (Am J Orthod Dentofacial Orthop 2003;124:4-12)
  154. 154. 18. Polo M. Botulinum toxin type A in the treatment of excessive gingival display Am J Orthod Dentofacial Orthop 2005;127:214-18. 19. Roden-Johnson D, Gallerano R, English J. The effects of buccal corridor spaces and arch form on smile esthetics . Am J Orthod Dentofacial Orthop 2005;127:343-50 20. Kim E, Gianelly A. Extraction vs Nonextraction: Arch Widths and Smile Esthetics. Angle Orthod 2003;73:354–358. 21. Luppanappornlarp S, Johnston LE Jr. The effects of premolar extraction: a long term comparison of outcomes in „„clear-cut‟‟ extraction and non extraction Class II patients. Angle Orthod. 1993; 64:257–272.
  155. 155. 22. Sarver DM. Principles of cosmetic dentistry in orthodontics: part 1. Shape and proportionality of anterior teeth. Am J Orthod Dentofacial Orthop 2004;126:749-53. 23. Sarver DM. Principles of cosmetic dentistry in orthodontics: part 2. Soft tissue laser technology and cosmetic gingival contouring. Am J Orthod Dentofacial Orthop 2005;127:85–90 24. Tarantili V,a Halazonetis D, Spyropoulos M. The spontaneous smile in dynamic motion. Am J Orthod Dentofacial Orthop 2005;128:8-15 25. Anderson K, Behrents R.G, McKinney T, Buschang P Tooth shape preferences in an esthetic smile. Am J Orthod Dentofacial Orthop 2005;128:458-65
  156. 156. 26. Sivakumar A, Valiathan A. Maxillary midline diastema- A closer look. Kerala Dental Journal 2006; 29(3): 25-26. 27. Ravindra Nanda. (Ed): Biomechanical and Esthetic Strategies in Clinical Orthodontics. Philadelphia, W.B. Saunders and Co.2005: 110-130.
  157. 157. Thank you For more details please visit