Clinical facial analysis for orthodontist and surgeon by almuzian

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Clinical facial analysis for orthodontist and surgeon by almuzian

  1. 1. UNIVERSITY OF GLASGOW Clinical Facial Analysis (CFA) For Orthodontists & Maxillofacial Surgeons 2013 Mohammed Al-Muzian
  2. 2. Mohammed Almuzian, University of Glasgow, 20131 Mind map for Clinical Facial Analysis Frontal View Facial type Vertical heights Lip assessment Symmetry assessment Skeletal base assessment Smile analysis Dental factors Profile View Total profile analysis Angle of convexity Powell analysis Analysis of the high midface Soft tissue glabella Orbital rim Cheek bone contour Analysis of the maxillary area Nasal base Nasal projection AP lip position Relationship of upper lip to nose Analysis of the mandible area AP lip position Relationship of lower lip to chin AP chin position Relationship of chin to submental plane
  3. 3. Mohammed Almuzian, University of Glasgow, 20132 Frontal View Facial type Facial index 1.3:1 Bizygomatic facial width 70% of TFH Bitemporal width 60 % of TFH Bigonial width 50% of TFH Vertical heights TFH (190-210mm) is one- tenth of standing height upper third from hairline (trichion) to glabella, Equal (62-70 mm for each) middle third from glabella to subnasale, lower third from subnasale to soft tissue gnathion Upper lip 19-22mm Lower lip and chin 42-48mm Interlabial gap 1-5mm Symmetry assessment Facial midline Middle of philtrum of upper lip (Cupid’s bow) and glabella centre of the nasal bridge to Middle of philtrum of upper lip vertical perpendicular from glabella ‘Rule of fifths’. Each fifth =width of an eye= 34mm Mouth width=distance between the medial iris
  4. 4. Mohammed Almuzian, University of Glasgow, 20133 margins=65mm Alar base width=intercanthal distance= one fifth=34mm Skeletal base assessment Mandibular assessment Chin-Jawline parallel to interpupillary line Mid face and Maxillary assessment sclera show Paranasal hollowing/flatness Lip assessment Vertical lip lines level Lower lip cover incisal third of U1. U1 exposure at rest 2–4 mm Lip activity Normal Lip morphology Vermilion show of lower lip 12mm, upper lip 9mm. Lip position competent incompetence Potentially competent Rolled blind upper lip postured mandible Dentoalveolar assessment Overbite 3mm or 1/3-1/2 of the Li height Occlusal plane (Upper, lower, anterior posterior) parallel to interpupillary line
  5. 5. Mohammed Almuzian, University of Glasgow, 20134 Maxillary dental midline Coincident with FML and LML Mandibular dental midline Coincident with FML, midpoint of the chin and UML Smile analysis The smile arc Ui slightly touch vermilion border of L lip Width of smile Visible U4 Posed smile 70-100% exposure of incisors 7-8mm Maximum smile 100% exposure of incisors 9-11mm +4mm gingival show
  6. 6. Mohammed Almuzian, University of Glasgow, 20135 Profile View Total profile analysis 1. Soft tissue nasion to FH  (Sandler 2006)  Maxilla should be approximately 2-3 mm in front, and the soft tissue pogonion should lie 2 mm behind this facial plane. 2. Steiner_Kole technique 3.  It is used to determine the convexity of the dentofacial complex by using SN-MP angle which is 32 degree.  The face can be classified into divergent, convergent or normal Angle of convexity (facial convexity or facial angle) Glabella-subnasale-pog 11-30 degree Powell analysis Nasofrontal angle 160 degree Nasofacial angle 40 degree Nasomental angle (Total facial angle)160 degree Mentocervical angle 100 degree Analysis of the high midface Soft tissue glabella 2mm ahead of the soft tissue nasion Orbital rim 2mm posterior to the eye globe Check bone contour. smoothly convex from the outer canthus of the eye through the sub-pupil area to end in
  7. 7. Mohammed Almuzian, University of Glasgow, 20136 the alar base Analysis of the maxillary area Nasal base Subnasale is on 0 degree Meridian line Nasal projection Distance from tip of the nose to TVL 22m AP lip position The upper lip normally touch the True Vertical Line TVL The upper lip should be 4 mm behind E line The lips should touch S line H line should touch U lip & bisect the nose. Relationship of upper lip to nose Naso-labial angle 85–120 Analysis of the mandibular area AP lip position The lower lip 0.5mm-2mm behind TVL The lower lip 2 mm behind E line The lower lip should touch or 1mm ahead of S line Relationship of lower lip to chin Labiomental angle AP chin position Bass aesthetic line touch ST Pog Soft tissue pog should be 0 ± 2 mm to Zero Meridian Holdaway angle (n-pog-ls) 15 degree Z angle (FH-pog-ls or li) 71-89 degree Relationship of chin to submental plane Lip-chin-submental plane angle: average 90– 110 Submental plane length 40mm
  8. 8. Mohammed Almuzian, University of Glasgow, 20137 Clinical Facial Analysis (CFA) For Orthodontists & Maxillofacial Surgeons Key articles (Arnnett 1993) Introduction Clinical facial analysis (CFA) is a method utilized by clinician for evaluating and judging the patient‘s face; to define its proportions, volume, appearance, symmetry, and visible deformities (Biondi, 2005) Is CFA parameters are standard? One of the aims of CFA is to assess the facial esthetic of the patient. Facial esthetic considered a term used to describe the quality of beauty and acceptance. There are many factors affect the values and the slandered used during CFA steps which involve: 1. Racial background 2. Cultural difference 3. Gender 4. Personal preference 5. Clinician philosophy Importance of CFA McLaughline and Arnnet in their textbook ‘’ Facial and Dental Planning for Orthodontist & Oral Surgeon’’ in 2004 simply classify the dentofacial deformities in adult patient into 3 groups:  G1 which can be addressed comprehensively by routine orthodontics  G2 which represent a deformity with mild to moderate skeletal discrepancies but can be well treated by some dental compensation to achieve a camoflagable results
  9. 9. Mohammed Almuzian, University of Glasgow, 20138  G3 represent cases with moderate to severe facial imbalance and malocclusion which should be treated by combined surgery and orthodontics. It is inappropriate to provide the treatment modalities of G3 to G2 and vice versa. So, differentiation between these two groups considered one of the main criteria for treatment success. The way of differentiating between the two groups mainly depends on the evaluation and assessment of the diagnostic records among this is the clinical facial analysis (CFA). To sum up, the main objectives of CFA are: 1. To diagnose and classify the deformities especially for border line cases. 2. To plan the treatment approach that addresses the patient concerns and complaints. 3. To predict the treatment outcomes & prognosis. To whom CFA might be beneficial? 1. Plastic surgeons, 2. Maxillofacial surgeons, 3. Ophthalmic plastic surgeons, 4. ENT surgeon, 5. Orthodontists, 6. Rehabilitative dentists, 7. Dermatologists 8. For many nonmedical professionals, such as hairdressers, eyeglasses designers and make-up artists. When CFA should be performed? (Biondi, 2005) 1. Initial CFA usually starts
  10. 10. Mohammed Almuzian, University of Glasgow, 20139  During observation stage: From the time of patient entrance to the clinical practice.  During questionnaire stage. The clinician should have the skill of interpretating and understanding the body language. 2. During clinical examination stage and should precedes the intraoral examination Methods of CFA 1. Direct clinical examination 2. Clinical photographs 3. Non Radiographical 3D imaging methods (with or without the use of metal marker) 4. Conventional & 3D x-ray imaging. Steps in CFA Before commencing any clinical examination the patient should be in: 1. Natural Head Position (NHP)  History: It was developed by Moores, 1958  Technique: Described clearly by Solow and Tallgren in 1971 (walking in the room for few minutes to relax then looking at 5 feet distance located mirror while shaking head until a more comfortable position is achieved)  Reproducibility: It has 2 degree reproducibility (Cook, 1988 & Lundstrom, 1992). 2. Centric relation 3. Relaxed lip position, BOWB (Bite Opening Wax Bite) indicated in case of vertical deficiency that resulted in soft tissue deformity during CO. 4. First tooth contact  Sometime the use of precentric wax bite is essential when there is more than 1mm incoincednce between the RCP and the ICP.
  11. 11. Mohammed Almuzian, University of Glasgow, 201310  If the wax bite cannot be obtained with the condyle in the RCP due to adaptive changes, it is recommended to us deprogramming splint for 3-6 months. (Arnnet & McLughlin, 2004) 5. Then the CFA can be started which involve: A. Frontal view analysis, this should not be underemphasized since the major concern of the patient viewed frontally. B. Profile view analysis C. 45 degree view analysis (to deeply investigate some feature that cannot be fully assessed by 2 or 3. D. Other view analysis including face base (bird view), face down or worm view (submental), nasal base view (subnasal). Unattractive features of facial appearance The flowing features of facial appearance are generally rated as unattractive: 1. Little show of vermilion border 2. A very high or very low smile line 3. An upper lip that slopes backwards 4. An everted lower lip 5. Extreme bilabial protrusion 6. Lack of a well-defined labiomental fold 7. Severe class 2 or class 3 malocclusions So it should be carefully spotted and analyzed. Frontal facial analysis Facial type  The facial height (Tr-Me) to width ratio (Zy-Zy)= (Facial index). This gives the overall facial type, such as ‘long’ or ‘short’ or ‘square’ face. The proportionate facial height to width ratio is 1.35:1 for males and 1.3:1 for females. (Naini 2008)
  12. 12. Mohammed Almuzian, University of Glasgow, 201311  Bizygomatic facial width, measured from the most lateral point of the soft tissue overlying each zygomatic arch (zygion), is approximately 70% of vertical facial height.  Bitemporal width, measured from the most lateral point on each side of the forehead, is 60 % of vertical facial height.  Bigonial width, measured from the soft tissue overlying the most lateral point of each mandibular angle (soft tissue gonion), is usually 50% of vertical facial height. Vertical heights 1. It is important to consider the vertical facial proportions and their balance in relation to the patient's general build and personality. 2. Facial thirds described by Bell et al 1980, Fish and Epker 1981: upper third from hairline (trichion) to glabella or midbrow, middle third from glabella to subnasale, lower third from subnasale to soft tissue menton (62-75 mm). 3. Ricketts et al 1979 divided the face use the middle and lower facial heights only. 4. However the underlying cephalometric proportions of the middle to the lower facial height are 45:55. This is because the N, ANS and Me points in cephalometric are used instead of Glasbella, soft tissue nasion and soft tissue menton in soft tiusse analysis. This might increase the UFH in clinical analysis. 5. Lower anterior facial third is further subdivided into: (Farkus 1984) a. Upper lip, Subnasale to stomodion superioris  19-22mm  Male>female  Decreased with aging b. Lower lip and chin, stomodion inferioris to soft tissue soft tissue menton  42-48mm  Increased with age due to submental fat accumulation  It can be subdivided equally into lower lip (stomodion inferioris to soft tissue B) and the chin area (from soft tissue B to soft tissue soft tissue menton)
  13. 13. Mohammed Almuzian, University of Glasgow, 201312 c. Interlabial gap  Stomodion inferioris-to stomodion superioris  1-5mm,  Female>male because male have longer upper lip. An increased anterior lower facial height may be due to: 1. Vertical maxillary excess (VME), resulting from excessive inferior development of the maxilla. This is often accompanied by excessive gingival display at rest and on smiling, referred to as a ‘gummy smile’. Usually it cause increase in AFH by posterior rotation of the mandible. 2. Increased vertical chin length. 3. Posterior mandibular rotation. 4. Over eruption of the posterior teeth causing posterior mandibular rotation Transverse analysis of frontal view I. Facial midline:  Perpendicular line from glabella to interpupillary line or to true horizontal line if the pupils are not leveled.  Middle of philtrum of upper lip (Cupid’s bow) and glabella (Naini and Gill 2008) or centre of the nasal bridge (Arnett and McLaughlin 2004) used to construct facial midline. If the nasal deviation is significant, the philitrum might be deviated and the use of vertical perpendicular from Glabella might be used as alternative. (Sheen, 1978).  Postural camouflage can be a problem with the asymmetrical face. The patient with a marked occlusal Cant habitually tilted the head to level the lip line giving the impression of orbital dystopia. This was corrected by bimaxillary levelling of the occlusal plane. II. ‘Rule of fifths’. Each fifth is approximately the width of an eye.
  14. 14. Mohammed Almuzian, University of Glasgow, 201313  Mouth width equal to the distance between the medial iris margins 65mm  Alar base width equal to the intercanthal distance 34mm. Skeletal base assessment in frontal view Mandibular assessment  Chin-Jaw line: It is a line under the surface of the chin at maximum tissue contact.  This plane should be parallel to inter-pupillary line in the absence of vertical orbital dystopia otherwise they described as cant. Mid face and Maxillary assessment  Increased sclera show above the lower eyelid and below the iris is a sign of midface deficiency.  Paranasal hollowing/flatness is a sign of maxillary hypoplasia. This may be observed in frontal and profile examination of the face. Signs of midface deficiency 1. Increased sclera show above the lower eyelid, normally assessed in the frontal facial examination, is also a sign of midface deficiency 2. Paranasal hollowing is a sign of midface deficiency, 3. Flattened upper lip 4. An obtuse nasolabial angle. 5. Class III problem 6. Upper arch narrow with cross bite and crowding 7. Wide Buccal corridor
  15. 15. Mohammed Almuzian, University of Glasgow, 201314 Lip assessment (LAMP=line, activity, morphology and position) mini-aesthetic analysis a. Vertical lip lines level 1. Lower lip should cover incisal third of maxillary incisors. 2. Maxillary incisor exposure at rest: 2–4 mm at rest. 3. Depends on:  Anterior maxillary height,  Upper lip length,  Clinical crown length,  Vertical maxillary incisor inclination  Lip activity during facial animation.  Combinations. Where the upper lip length is very short then the patient would expect to show more of the upper incisors. Any attempt to reduce the incisor exposure in relation to a short upper lip will lead to an unaesthetic reduced middle face height. Similarly, with a long upper lip, the patient would be expected to show less or no upper incisor, both at rest and during facial animation. b. Lip activity  A strap-like lower lip often retroclines incisors (commonly occurs in Class II division 2 malocclusions). (Mossy 1981)  Flaccid lips are less likely to significantly alter position with anteroposterior dental movement. c. Lip morphology  Vermilion show of lower lip 12mm, upper lip 9mm. (Fish & Epker 1981)  Full lips are less likely to significantly alter position with anteroposterior dental movement.  Thin lips are more likely to ‘flatten’ with incisor retraction.
  16. 16. Mohammed Almuzian, University of Glasgow, 201315 d. Lip posture Lip competency help to know the etiology of malocclusion and the possible treatment stability. Types of lip relationships are: 1. Competent: Lips held together at rest. 2. Lips habitually competent which are held apart at rest by more than 3–4 mm but the patient tries to posture his/her haw forward to achieve anterior lip seal like in CLII D1 cases. 3. Potentially competent (lips are unable to be held together due to increased inter- labial space) and the patient exert muscle effort to close them which can be seen in a form of active mentalis. The features of this condition are puckering of the chin area and flattening of the LMA. 4. Rolled blind upper lip, means the lip retract on smiling to show more gum. Lip incompetency is due to:  With aging the lip incompetency is reduced  Short lip  Increased LAFH due to VME  Increased LAFH due posterior growth rotation,  Over-eruption of BS,  AP skeletal malrelationships.  Proclined ULS or LLS Dental factors 1. Overbite (3mm or 1/3 of the lower incial crown height) 2. Occlusal plane A. Upper Occlusal plane which subdivided into anterior and posterior (Profitt et al 1980) B. Lower Occlusal plane which subdivided into anterior and posterior
  17. 17. Mohammed Almuzian, University of Glasgow, 201316  The posterior Cant represent skeletal problem while anterior represent dental or it might be secondary to posterior cant.  All these plane should be assessed using fox bite or wooden tongue depressor and should be parallel to interpupillary line in the absence of vertical orbital dystopia otherwise they described as cant.  In the presence of orbital dystopia, the true horizontal showed be used. In this case a direct evaluation is difficult and it is better to take a photograph with the patient biting on the wooden plate and then assess it. 3. Maxillary dental midline Assessed in relation to middle of philtrum of upper lip (Cupid’s bow) and to facial midline. 4. Mandibular dental midline Assessed in relation to midpoint of chin and to the facial midline and in relation to maxillary dental midline. Smile analysis The components of the smile analysis are: 1. The smile arc is defined as the contour of the incisal edges of the maxillary anterior teeth relative to the curvature of the lower lip during a social smile. For best appearance, the contour of these teeth should match that of the lower lip. If the lip and dental contours match, they are said to be consonant. 2. 100% of incisors show (9-11mm at social smile) and 4mm gingival show (There are two types of smiles: the posed or social smile, and the emotional smile. The social smile is reproducible, and is the one that is presented to the world routinely. The emotional smile varies with the emotion being displayed (for instance, the smile when you're introduced to a new colleague differs from the smile when your team just won in the year's biggest upset) 3. Width of smile show premolar and narrow Dark ‘buccal corridors’ on Smiling. 4. Upper and lower dental midline in relation to the facial midline, to the chin and to each other.
  18. 18. Mohammed Almuzian, University of Glasgow, 201317 Dark ‘buccal corridors’ might increase due to:  Palatally inclined maxillary posterior teeth;  Transverse maxillary deficiency;  Anteroposterior maxillary deficiency.  Wide commissure. The lip incisor relationship in determining smile line depends on a number of factors including: 1. Soft tissue problems  Upper lip length.  The ‘smile curtain’, defined as the muscular capacity to raise the upper lip. If the position of the maxilla and maxillary incisors in relation to the face is correct, yet the patient presents with a ‘gummy smile’ owing to vertical hypermobilility of the upper lip, the option of ‘Botox’ injections to the levator muscles of the upper lip is available. Alternatively, the situation may be accepted. 2. Skeletal problems:  The vertical position of the anterior maxilla. The more inferior the position of the anterior maxilla, the greater the exposure of the maxillary incisors, and vice versa.  The anteroposterior position of the anterior maxilla. 3. Dental problems  The vertical position of the incisor teeth.  The anteroposterior position of the incisor teeth.  The inclination of the maxillary incisor teeth. Retroclination of proclined maxillary incisors towards the correct inclination increases the incisor exposure,  Maxillary incisor crown length, including the presence of incisal wear. 4. Gingival problem  The vertical level of the gingival margins on the labial surface of the maxillary incisor crowns.
  19. 19. Mohammed Almuzian, University of Glasgow, 201318 Profile analysis Total soft tissue profile analysis 1. Soft tissue nasion to FH  An easy assessment of the relative protrusion of the mid third and mandible can be made by assessing their position relative to the perpendicular to the Frankfort plane passing downwards through the soft tissue nasion.  With normal facial proportions the soft tissue profile of the maxilla should be approximately 2-3 mm in front, and the soft tissue pogonion should lie 2 mm behind this facial plane.  However the face can vary with ethnic norms, giving anterognathic, mesognathic or posterognathic profiles (Sandler 2006) 2. Angle of convexity (facial convexity) or profile angle  Glabella-subnasale-pog  Described by Burstone 1965.  Class I occlusion presents a total facial angle range of 165° to 175°.' Class II angles are less than 165°, and Class III are greater than 175°. Skeletal discrepancies producing Class II angulation 3. Powell analysis (Powell et al 1984) which is made up of: 1. Nasofrontal angle 160, 2. Nasofacial angle 40,
  20. 20. Mohammed Almuzian, University of Glasgow, 201319 3. Nasomental angle 160 4. Mentocervical angle 100, 4. Steiner-Kole technique  It is used to determine the convexity of the dentofacial complex by using SN-MP angle which is 32 degree.  The face can be classified into divergent, convergent or normal. Analysis of the high midface 1. Soft tissue glabella 2mm ahead of the soft tissue nasion 2. Orbital rim 2mm posterior to the eye globe (Fish & Epker 1981) 3. Check bone contour should be smoothly convex from the outer canthus of the eye through the Subpupil area to end in the alar base. (Fish & Epker 1981) 4. Morphology of the ears: if external auditory meati to lie at unequal levels. This creates an asymmetrical facial artefact and difficulties when taking a facebow recording for transfer to the articulator. Analysis of the maxillary area A. Nasal base Can be assessed using: 1. Facial vertical from soft tissue nasion, perpendicular to Frankfort position or maxilla plane (or ideally true horizontal line) with patient in natural head position. 2. Subnasale is on this line (0 degree Meridian line) developed by Gonzales-Ulloa 1966
  21. 21. Mohammed Almuzian, University of Glasgow, 201320 B. Nasal projection Distance from tip of the nose to TVL 22m C. AP lip position 1. The upper lip normally touch the True Vertical Line TVL describer by Arnett 2. Esthetic line (E-line). Joins the nasal tip to soft tissue pogonion. The upper lip should be 4 mm behind this line in adults. This is very dependent on nasal and chin projection. (Ricketts 1979) 3. Steiner line (S-line). Joins soft tissue pogonion to the midpoint (columella) between Subnasale and nasal tip (pronasale). The lips should touch this line. 4. Harmony line (H-lines) as introduced by Holdaway. The H-angle is formed by a line tangent to the chin (pog) and upper lip (Ls) with the soft tissue N-Pog line. Holdaway said the ideal face has an H-angle of 7° to 15°, which is dictated by the patient's skeletal convexity. The ideal position of the lower lip to the H line is 0 to 0.5 mm anterior. D. Relationship of upper lip to nose  Naso-labial angle is formed by the intersection of the upper lip anterior and columella at subnasale.  Average value: 85–120. (Fish & Epker 1981)  It can be divided by true horizontal at subnasale point into two angles (upper one represent nasal angulation 28 degree and lower angle represent upper lip angulation 85 degree.  In general it depends on 1. Columella orientation, 2. Anteroposterior position of maxillary incisors 3. Inclination of ULS 4. Anteroposterior position of the maxilla, 5. The morphology of the upper lip, 6. The vertical position of the nasal tip.
  22. 22. Mohammed Almuzian, University of Glasgow, 201321 Analysis of the mandibular area 1. Anteroposterior lip position  The lower lip normally 0.5mm-2mm behind the True Vertical Line TVL described by Arnett in 1993.  Esthetic line (E-line). Joins the nasal tip to soft tissue pogonion. The lower lip 2 mm behind this line in adults. This is very dependent on nasal and chin projection.  Steiner line (S-line). Joins soft tissue pogonion to the midpoint between subnasale and nasal tip. The lips should touch this line. 2. Relationship of lower lip to chin  Labiomental angle is formed between the lower lip and chin  Average value: 110–130 degree.  It depends on: A. Thickness of lower lip B. Mental fat area C. A prominence of the chin itself D. AP skeletal relationship as in class III in which there is a loss of upper incisor support to lower lip E. The lower incisor inclination F. Anterior lower face height, a reduced lower anterior facial height may lead to an acute labiomental angle due to excessive folding of the lower lip after contacting the upper incisor on occlusion. G. Lower lip to upper incisor relationship. In case of lip trap the LMA is increase . 3. Anteroposterior chin position A. Bass aesthetic analysis (Bass, 2003) uses Subnasale (rather than soft tissue nasion) from which to drop a perpendicular to the true horizontal line with the patient in NHP. This analysis is useful for planning treatment in mandibular retrognathia, where the maxillary position is correct.
  23. 23. Mohammed Almuzian, University of Glasgow, 201322 B. Zero Meridian line: vertical from soft tissue nasion, perpendicular to true horizontal line with patient in natural head position. Soft tissue pogonion should be 0 ± 2 mm to Meridian line. C. Holdaway angle: angle between the Pog and lip superioris with NPog. 15 degree D. Profile line or Z angle(of Merrifield). A tangent to the chin and vermilion border of most prominent lips should ideally intersect with FH at 80+9. (Merrifield, 1966) E. Kole analysis used two lines. The first from prominent part of upper lip perpendicular to SN. Other from Or perpendicular to SN. The soft tissue Pog should be in the middle between these two line. 4. Relationship of chin to submental plane A. Lip-chin-submental plane angle: average 90–110 degree. It is increased in:  Thick lower lip  Increased submental fat are present. (Moshiri et al, 1982)  Mandibular retrognathia,  Retrogenia,  Lower lip projection due to proclined LLS B. Submental plane length (soft tissue menton to junction of submental plane and vertical plane of the anterior aspect of the neck). If excessively short, this is a contra- indication to mandibular setback, which could result in the formation of a ‘double chin’.
  24. 24. Mohammed Almuzian, University of Glasgow, 201323 Dental Appearance: Micro-Esthetics. A. Tooth Proportions 1. Golden Proportion  The apparent widths of the maxillary anterior teeth on smile, and their actual mesio- distal width, differ because of the curvature of the dental arch.  Particularly, only a portion of the canine crown can be seen in a frontal view.  For best appearance, the apparent width of the lateral incisor (as one would perceive it from a direct frontal examination) should be 62% of the width of the central incisor, the apparent width of the canine should be 62% of that of the lateral incisor, and the apparent width of the first premolar should be 62% of that of the canine 2. Height-Width Relationships: Note that the width of the tooth should be about 80% of its height 3. Gingival Heights, Shape and Contour, Generally, the central incisor has the highest gingival level, the lateral incisor is approximately 0.5 mm lower and the canine gingival margin again is at the level of the central incisor. A discripncy in the gingival height my be due to:  Pd diseases  Teeth attrition  Ankylosis  Canine substitution of lateral  Sever crowding  Delayed maturation of gingivae. B. Connectors  The connector includes the contact point and the areas above it. The normal connector height is greatest between the central incisors, and diminishes from the centrals to the posterior teeth.
  25. 25. Mohammed Almuzian, University of Glasgow, 201324 Embrasures: Black Triangles  The embrasures (the triangular spaces gingival to the contact) ideally are larger in size than the connectors, and the gingival embrasures are filled by the interdental papillae  Short interdental papillae leave an open gingival embrasure and these "black triangles" can detract significantly from the appearance of the teeth on smile.  Current data indicate that lay observers readily detect open gingival embrasures of 3 mm or more and judge them unaesthetic,  Black triangles in adults usually arise from loss of gingival tissue related to periodontal disease, but when crowded and rotated maxillary incisors are corrected orthodontically in adults, the connector moves incisally and black triangles may appear, especially if severe crowding was present. For that reason, both actual and potential black triangles should be noted during the orthodontic examination, and the patient should be prepared for reshaping of the teeth to minimize this esthetic problem Method to treat black triangle  Correct teeth angulation  Relocate contact point by crown contouring or restorative dentistry  Teeth extrusion to relocate alveolar crest more inciso-occlusally Tooth Shade and Color  The color and shade of the teeth changes with increasing age.  The teeth appear lighter and brighter at a younger age, darker and duller as aging progresses. This is related to the formation of secondary dentin as pulp chambers decrease in size and to thinning of the facial enamel, which results in a decrease in its translucency and a greater contribution of the darker underlying dentin to the shade of the tooth.  The maxillary central incisors tend to be the brightest in the smile, the lateral incisors less so, and the canines the least bright. The first and second premolars are lighter and brighter than the canines, more closely matched to the lateral incisors.

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