Teeth selection / orthodontics courses


Published on

Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.

Published in: Education
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Teeth selection / orthodontics courses

  1. 1. TEETH SELECTION AND TOOTH ARRANGEMENT INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Introduction A knowledge and understanding of a number of physical and biological factors directly related to the patient are required to appropriately select artificial teeth to rehabilitate the occlusion. The goals for this phase of therapy are to construct complete dentures that (1) function well, (2) allow the patient to speak normally, (3) are esthetically pleasing, and (4) will not abuse the tissues over residual ridges. The prosthodontist is the best person to accumulate, correlate, and evaluate the biomechanical information so that the artificial teeth selected will meet the individual needs of the patient. The selection and arrangement of artificial teeth is a relatively simple non-time consuming procedure, but it requires the development of experience and confidence. www.indiandentalacademy.com
  3. 3. ANTERIOR TOOTH SELECTION • Pre extraction guide • Post-extraction record • Size of anterior teeth • Form of anterior teeth • Color of teeth www.indiandentalacademy.com
  4. 4. www.indiandentalacademy.com
  5. 5. ANTERIOR TEETH SELECTION Clinical judgment and experience still remain the final criteria in selection of the proper width and mold, The following are among the most widely used and suggested methods for anterior tooth selection. A. Patient pre extraction records: 1. Diagnostic casts of the patient's natural or restored teeth prior to extraction of the remaining teeth. 2. Request the most recent photographs of the patient before loss of his teeth. 3. Measurements may also be made from radiographs of the teeth, making allowances for lengthening or foreshortening . 4. The use of facial photographs is usually of far more help to the dentist in determining the placement of anterior teeth, arch form, and lip support than for the actual size of the mold of an artificial tooth. 5Teeth of close relative – This method is usually followed only if other records are not available. www.indiandentalacademy.com
  6. 6. B. Postextraction examination— if the patient is edentulous and wearing complete dentures, examine the patient with the dentures he presently wears, paying attention to the following: 1. Do the teeth appear lost in the face (too small or set too far in)? . 2. Do the teeth appear too small, regular, and set like a picket fence? 3. Are the teeth set too high, and are they almost lost from view during speaking and smiling? 4. Are the teeth overbearing, too large, but of proportion in their length and breadth to the size and dimensions of the face and head? 5. Do the maxillary teeth show in smiling, and the mandibular teeth during speech? All of these observations should be used in arriving at a determination of which teeth should be selected for the trial denture. On the basis of the teeth the patient is wearing, determine whether to choose teeth that are larger or smaller, longer or shorter, wider or narrower, flatter or having a more curved labial surface. www.indiandentalacademy.com
  7. 7. SIZE OF THE ANTERIOR TEETH • Size of the face • Size Of Maxillary Arch • Incisive papilla and the canine eminence • Maxillo-Mandibular Relation • Contour of the residual ridge • Vertical distance between the ridges • Lips www.indiandentalacademy.com
  8. 8. SIZE OF THE ANTERIOR TEETH Anatomic entities used as a guide for anterior teeth size: Size of the face: Width of the central incisor = one sixteenth of the bi- zygomatic width of the face. Combined width of the six anterior teeth = slightly less than one third of the bizygomatic breadth of the face. www.indiandentalacademy.com
  9. 9. Size Of Maxillary Arch The mold be used to make measurements of the maxillary cast. Accurately contoured occlusal rims are required. Make the measurements from the crest of incisal papilla to the hamular notches and from one hamular notch to the opposite notch. The combined length of the triangle in millimeters is used on the selector. The circular slide rule indicates the tooth sizes, anterior and posterior, for both arches. LIMITATION These criteria’s will not be usable in situations like spacing, rotating and overlapping. The excessive or unusual loss of bone may also influence the size of anterior teeth (length) When the discrepancy between the size and related arch exist the selection of anterior teeth is more governed by face size than the arch size www.indiandentalacademy.com
  10. 10. • Incisive papilla and the canine eminence – the combined width of the six anterior teeth is equal to the length of a line drawn on the cast at the distal termination of one canine eminence to the other. • Intra-orally, the patient is requested to relax with the lips touching. A mark is made at the corners of the lips. The distance between the two marks on either side is equal to the combined width of all the anterior teeth. www.indiandentalacademy.com
  11. 11. • . Maxillo-Mandibular Relation – Any disproportion in the size between the maxillary and mandibular arches influences the length, width and position of the teeth. If mandible is protruded; anterior teeth are larger, if mandible is retruded; anterior teeth are smaller. • . Contour of the residual ridge – teeth should be placed in relation to follow the contour of the residual ridges that existed when natual teeth were present. www.indiandentalacademy.com
  12. 12. • Vertical distance between the ridges – according to the available inter-arch space length of the teeth can be selected. Minimal of the denture base should be visible in the final prosthesis. • . Lips – During relaxed state the labial surface of the maxillary anterior teeth support the upper lip. When the teeth are together the incisal edge of the maxillary incisors supports the superior border of the lower lip www.indiandentalacademy.com
  13. 13. • FORM OF THE ANTERIOR TEETH • Factors governing the form of the anterior teeth: • Form and contour of the face: from the frontal aspect the shape of the face can be classified as – – Square – Square tapering – Tapering – Ovoid www.indiandentalacademy.com
  14. 14. Shapes of the artificial teeth chosen to be in harmony with the size of the patient’s face www.indiandentalacademy.com
  15. 15. • From the lateral aspect the facial profile can be classified as: – Straight – Concave – Convex – Form of the artificial anterior teeth should conform to the form of the face. • The labioincisal contour of the teeth usually conforms to the profile of the individual www.indiandentalacademy.com
  16. 16. www.indiandentalacademy.com
  17. 17. The geometric figures-square, tapering, ovoid, and combinations there of serve as a starting point in selecting the tooth form as it is viewed from the frontal aspect . www.indiandentalacademy.com
  18. 18. Trubyte indicator The indicator may be used in one of two ways to establish the facial outline Place the tooth indicator on the patient's face, allowing the nose to come through the center triangle. Center the pupils of the eye in the eye slots and hold the indicator with its center line coinciding with the median line of the face. The form of the face will be best observed by noting the particular characteristic of each form as it appears in comparison with the vertical lines of the indicator www.indiandentalacademy.com
  19. 19. • In the square form the sides' of the face will approximately follow the vertical lines of the indicator. In the square tapering form, the upper third of the lower two thirds will taper inward. In tapering faces, the side of the face from the forehead to the angle of the jaw will taper at an inward diagonal. www.indiandentalacademy.com
  20. 20. www.indiandentalacademy.com
  21. 21. • Ovoid faces will be best determined by examination of the curved outline of the face against the straight vertical of the face against the straight vertical of the tooth indicator • To determine the facial profile, observe the relative straightness or curvature of the profile. Check three points: the forehead, the base of the nose, and the point of the chin. If these three points are in line, the profile is straight. If the points of the forehead and of the chin are recessive, the profile is curved www.indiandentalacademy.com
  22. 22. • 2. Sex: Curved features are associated with feminity and square features are associated with masculanity. Teeth selected for females are more ovoid or tapering; whereas for males are more squarish, and sharp edged. • 3. Age: Aging process affects the entire masticatory apparatus in general including the teeth. Teeth wear at the incisal edges, labial surface becomes more flatter and outline appears more squarish. www.indiandentalacademy.com
  23. 23. COLOR OR SHADE OF ANTERIOR TEETH Color is the sensation resulting from stimulation of the retina of the eye by light waves of certain lengths. Shade is the degree of darkness of a color with reference to its mixture with black. When a tooth is viewed for the purpose of determining its color, two principal colors yellow and gray are evident. The yellow is more prominent in the gingival third, and the gray is more prominent in the incisal third. The principal modifications are termed hue. The degree of intensity of the hue, as measured by its freedom from mixture with white, is saturation. Hue of the tooth is actually the quality that the prosthodontist attempts to duplicate. One other slight modification appears in teeth with thin incisal edges. The yellow disappears, and the edge appears blue gray. This is the only place that blue appears in a tooth. www.indiandentalacademy.com
  24. 24. The position of the patient and the source of light are very important in color selection. The patient should be in an upright position. The dentist should be in a position so that the teeth are viewed in a plane perpendicular to the dentist's plane of vision. The teeth should be observed from different angles to make certain that the shadows do not influence the color. The patient's mouth should not be opened too wide but should remain a dark cavity as in ordinary conditions. White light is considered suitable. White light may be secured from artificial sources if provided with the proper filters. Eyes fatigue to color perception very rapidly and for this reason they should not be focused on a tooth for more than a few seconds www.indiandentalacademy.com
  25. 25. • If the proper shade is hard to establish the tooth and the shade guide should be viewed from a distance of 6 or 8 feet. • The color of the teeth, like the form, must be in harmony with the surrounding environment if they are to appear pleasing. Harmony should exist between the color of the teeth and the color of the skin, hair, and eyes. The color of the skin is a more reliable guide. • A female patient’s cosmetics must be considered in harmonizing with the complexion. www.indiandentalacademy.com
  26. 26. • Selecting The Color Of Artificial Teeth • Observations of the shade guide teeth should be made in three positions: outside the mouth along the side of the nose, will establish the basic hue, brilliance, and saturation www.indiandentalacademy.com
  27. 27. 2) under the lips with only the incisal edge exposed, will reveal the effect of the color of the teeth when the patient's mouth is relaxed 3) under the lips with only the cervical end covered and the mouth open, will simulate exposure of the teeth as in a smile. www.indiandentalacademy.com
  28. 28. Basic considerations are the harmony of tooth color with the color of the patient's face and the inconspicuousness of the teeth. The color selected should be so inconspicuous that it will not attract attention to the teeth. The color of the teeth should be observed on a bright day when possible, with the patient located close to natural light. The teeth should also be observed in artificial light, since denture patients are often seen in this environment. www.indiandentalacademy.com
  29. 29. The "squint test" may be helpful in evaluating colors of teeth with the complexion of the face. With the eyelids partially closed to reduce light, the dentist compares prospective colors of artificial teeth held along the face of the patient. The color that fades from view first is the one that is least conspicuous in comparison to the color of the face. www.indiandentalacademy.com
  30. 30. • Although some person’s natural teeth become darker with age, there are many exceptions to this; it is therefore incorrect to establish a rule that prescribes light teeth for young patients and darker teeth for older ones. • Tooth color must be in harmony with the facial coloring at the time the dentures are made. Color of a tooth changes immediately when it is removed from the mouth and becomes non vital; it blanches further as the tooth dries out. • Thus, extracted teeth are valuable for size and form selection but should not be used for color selection. www.indiandentalacademy.com
  31. 31. Posterior Teeth Selection The selection of posterior teeth likewise involves shade, size, number, and form SHADE OF POSTERIOR TEETH The shade of the posterior teeth should harmonize with the shade of the anterior teeth. As noted previously, the maxillary premolars are sometimes used more for esthetic than for functional purposes. Bulk influences the shade of teeth, and for this reason it is advisable to select a slightly lighter shade for the premolars if they are to be arranged for esthetics. www.indiandentalacademy.com
  32. 32. • Buccolingual Width of Posterior Teeth The buccolingual widths of artificial teeth should be less than the widths of the natural teeth they replace. Artificial posterior teeth that are narrow enhance the development of the correct form of the polished surfaces of the denture by allowing the buccal and lingual denture flanges. to slope away from their occlusal surfaces. These narrower forms, especially in the lower denture, assist the cheeks and tongue in maintaining the dentures on the residual ridge. www.indiandentalacademy.com
  33. 33. Mesiodistal Length Of Posterior Teeth The length of the mandibular residual ridge from the distal of the canine to the beginning of the retromolar pad is usually available for artificial posterior teeth. If the residual ridge anterior to this point slopes upward, smaller or fewer teeth must be used to avoid having a tooth over a pronounced incline at the distal end of the ridge. This shortened occlusal table will often prevent the lower denture from sliding forward when pressure is applied on the molars. www.indiandentalacademy.com
  34. 34. www.indiandentalacademy.com
  35. 35. • The total mesiodistal width in millimeters of the four posterior teeth is often used as a mold number. For example, mold 32L signifies that the four posterior teeth have a total mesiodistal dimension of 32 mm and a long occluso-cervical length. • The posterior teeth should not extend too close to the posterior border of the maxillary denture because of the danger of cheekbiting. However, if the posterior teeth do not extend far enough posteriorly, the forces of mastication will place a heavier load on the anterior part of the residual ridges. www.indiandentalacademy.com
  36. 36. Posterior teeth are not arranged over the retromolar pad, because: • the pad is too soft and too easily displaced, has glandular tissue which is hurt • Putting teeth over it will allow the denture to tip during mastication. • Tendon of Tempolaris is inserted in the retromolar region tends to displace the denture www.indiandentalacademy.com
  37. 37. Vertical Height of the Facial Surfaces of Posterior Teeth It is best to select posterior teeth corresponding to the interarch space and to the height of the anterior teeth. Artificial posterior teeth are manufactured in varying occlusal cervical heights. The height of the maxillary first premolar should be comparable with that of the maxillary canines to have the proper esthetic effect. Without this relationship, the denture base material will appear unnatural distal to the canines. Ridge lapping the posterior teeth can be done without sacrificing leverage or esthetics. The form of the dental arch should copy, as nearly as possible, the arch form of the natural teeth they replace. www.indiandentalacademy.com
  38. 38. Types of Posterior Teeth According to Materials For many years, porcelain was the favorite tooth material because of the rapid wear of acrylic resin. However, with the tendency for porcelain to chip and fracture, acrylic resin teeth have gained in popularity. Improved acrylic resin teeth and newer composite resin teeth are more wear resistant, and they have supplanted porcelain during the past two decades Acrylic resin or composite resin posterior teeth are specifically called for when they oppose natural teeth or teeth whose occlusal surfaces have been restored with gold. These resin teeth reduce the possibility that the artificial teeth will cause unnecessary abrasion and destruction of the natural or metallic occlusal surfaces of the opposing teeth www.indiandentalacademy.com
  39. 39. SELECTION OF MATERIAL FOR ARTIFICIAL TEETH Porcelain Teeth Wear is clinically insignificant over a long period of time. No significant loss of vertical dimension. Can be ground and polished and will hold shape for years. Allow for total rebasing procedures. Maintain comminuting efficiency for years. Difficult to grind and fit into close inter ridge space without fracturing or loss of retention in the base. www.indiandentalacademy.com
  40. 40. Cause dangerous abrasion to opposing gold crowns and natural teeth. Have a sharp impact sound. Ground surfaces must be highly polished to reduce friction and prevent chipping. Will not bond to the base material. Potential for marginal staining due to capillary leakage . Acrylic Resin Teeth Wear is clinically significant. Loss of occlusal vertical dimension due to wear. Occlusal surface altered by wear is such that in five to seven years they are inefficient and usually worn to a reverse curve. Loss of comminuting efficiency. Do not chip, and have softer impact sounds. Self adjusting and self- polishing. Easy to grind into close inter ridge space. Potential for bond to base material. www.indiandentalacademy.com
  41. 41. Types of Posterior Teeth According to Cusp Inclines Posterior artificial teeth are manufactured with cusp inclines that vary from steep to flat. Selecting the tooth to be used is based on the concept of occlusion to be developed, the philosophy of occlusion to be fulfilled, and the accomplishment of both of these goals with the least complicated approach . i- teeth to be balanced in centric and eccentric positions – cusp teeth ii- posterior teeth to disocclude in eccentric jaw movement – cusp or monoplane teeth iii – posterior teeth to be arranged in flat plane and balanced in centric occlusion position only- monoplane teeth www.indiandentalacademy.com
  42. 42. ARRANGMENT OF TEETH The four principal factors that govern the positions of the teeth for complete dentures are (1) the horizontal relations to the residual ridges, (2) the vertical positions of the occlusal surfaces and incisal edges between the residual ridges, (3) the esthetic requirements, and (4) the inclinations for occlusion www.indiandentalacademy.com
  43. 43. HORIZONTAL POSITIONS to provide stability to the denture bases. to direct the masticatory forces along the long axis. to support lips and cheek for esthetics to be compatible with functions of the surrounding tissues for functions of masticaiton, speech, swallowing and phonetics. www.indiandentalacademy.com
  44. 44. • Forces directed at right angles to the supporting tissues are more stabilizing than forces directed at an inclined plane. • The artificial teeth must be placed in suitable horizontal positions to allow the muscle activity to occur naturally www.indiandentalacademy.com
  45. 45. • The positions of the teeth influence the phonetics as exemplified by the J, ch, and sh sounds. • When the maxillary anterior teeth are placed too far posteriorly as related to the lower lip, the J sound may be muffled. • It may be necessary to arrange the mandibular anterior teeth with more labial version to aid in the correct enunciations of the ch and sh sounds • www.indiandentalacademy.com
  46. 46. • In mastication, the tip of the tongue reaches into the buccal and labial vestibules, gathers the food, and places it on the occlusal surfaces. • When the teeth are placed too far in a lateral or anterior direction, the vestibular spaces are obstructed to the tongue. • When the teeth are placed too far in a medial or posterior direction, the tongue will dislodge the mandibular denture in an attempt to reach over the teethwww.indiandentalacademy.com
  47. 47. The crests of the residual ridges are aids in positioning the artificial teeth if the natural teeth were recently extracted and the cortical plates of bone remain intact. Unfortunately, the crests of the residual ridges do not remain in the same anteroposterior or mediolateral positions. www.indiandentalacademy.com
  48. 48. As resorption of alveolar ridge progresses, the maxillary arch becomes narrower and the mandibular arch becomes broader. www.indiandentalacademy.com
  49. 49. LIMITS TO PLACING POSTERIOR TEETH • The mandibular arch determines the posterior limit for placing posterior teeth • Mucosa considered capable of bearing stress terminates at the retromolar papilla • Medial extension of the mylohyoid ridge determines the medial limit in placing mandibular posterior teeth- if placed more lingually than it, elevating the tongue may dislodge the denture • Actions of tongue and cheek, alongwith esthetics determine the lateral limits of mandibular posterior teeth www.indiandentalacademy.com
  50. 50. • • LIMITS TO PLACING ANTERIOR TEETH. • Involves placing the teeth in an anteroposterior and mediolateral position in harmony with the action of the lips and the tongue. • Establish horizontal overlap sufficient to prevent the anterior teeth from contacting when the posterior teeth are in centric occlusion . www.indiandentalacademy.com
  51. 51. • • POSITIONING OF THE TEETH ACCORDING TO THE HORIZONTAL RELATION OF THE JAWS . • Maxillary arch is broader Using larger teeth buccolingually may than the mandibular arch be required. • Maxillary arch is smaller The buccolingual relations of the teeth • than the mandibular arch are reversed • Place the buccal cusps of the mandibular teeth lateral to the buccal cusps of the maxillary teeth • www.indiandentalacademy.com
  52. 52. • The mediolateral and anteroposterior positions of the anterior teeth influence sounds in speech. • f – incisal edges of maxillary centrals should barely contact the vermillion border of the lower lip. • s- mandibular anterior teeth affect the s sound . • • th – the tip of the tongue should make contact with the palatal surface of maxillary anterior teeth www.indiandentalacademy.com
  53. 53. • The artificial maxillary central incisors should be placed anterior to the incisal papilla regardless of the relation of the papilla to the existing residual ridge • When natural teeth are present, the inclinations of the anterior teeth, as related to the crest of the alveolar ridge, are downward and forward. Usually this relationship is accentuated as resorption takes place. www.indiandentalacademy.com
  54. 54. • The upper lip is supported in the area of the philtrum by labial surfaces of the maxillary anterior teeth and at the corners of the mouth by the canines. • In normally related jaws, the border of the lower lip is supported by the labial incisal third of the maxillary anterior teeth. www.indiandentalacademy.com
  55. 55. • Reteromolar fossae- triangle formed by external oblique line and mylohyoid line. This triangle is slightly posterior and lateral to the position of the molar teeth. • Reteromolar papilla – small pear-shaped area of gingival tissue situated at the base of reteromolar pad limits the position of artificial teeth. • Reteromolar pad- pear shaped pad of tissue located at the distal end of the mandibular ridge. • Mandibular canine – turning point of the mandibular arch, distal part is rotated posteriorly. www.indiandentalacademy.com
  56. 56. • Definite anatomic landmarks to be used as guides in arranging the anterior teeth are • the incisal papilla • the midsagittal suture, and • the canine lines. • By locating these landmarks and recording their positions on the cast, one establishes points of reference indispensable to the correct arrangingof the teeth www.indiandentalacademy.com
  57. 57. • In the absence of other more definite information, the arch form is used as a guide for the initial arrangement of the teeth • The anterior teeth for the tapered arch places the central incisors farther forward than the canines . • The anterior teeth for the square arch places the central incisors nearly horizontal with the canines. • The anterior teeth for the ovoid arch places the six anterior teeth in gentle curve. www.indiandentalacademy.com
  58. 58. A-SQUARE , B- TAPERING, C- OVOIDwww.indiandentalacademy.com
  59. 59. • The size and shape of the head are reliable factors in determining arch form. • Round heads are associated with square arches and a broad flat arrangement of the anterior teeth. The labial surfaces of the central incisors are in full view, and the canines are prominent. • Long narrow heads are associated with long narrow, palates, tapered arches, and a tapered anterior tooth arrangement. www.indiandentalacademy.com
  60. 60. VERTICAL POSITIONS Correct vertical position of the teeth should provide- Denture stability Favorable forces Support to lips and cheek Compatibility www.indiandentalacademy.com
  61. 61. Vertical postion of the mandibular teeth – The occlusal surface of the last mandibular molar is on a place approximately at the bottom of the upper third of the retermolar pad. Vertical position of the maxillary teeth - is usually determined by the esthetics, phonetics. www.indiandentalacademy.com
  62. 62. • The occlusal groove, on the inner surface of the cheek, is located opposite the occlusal plane of the natural mandibular posterior teeth. • When this groove is present, it is a reliable guide to the position occupied by the occlusal surfaces of the natural mandibular posterior teeth and can be used as a guide to positioning the posterior artificial teeth in a vertical direction . www.indiandentalacademy.com
  63. 63. VERTICAL POSITIONS OF MAXILLARY ANTERIOR TEETH. Esthetics and phonetics are used to establish the vertical position of the incisal edges of the maxillary anterior teeth. The following are aids to establishing the vertical positions of the artificial teeth by using occlusion rims: 1. Attach hard wax occlusion rims to accurate, stable record bases. 2. Properly contour the occlusion rims in an anteroposterior and mediolateral direction. www.indiandentalacademy.com
  64. 64. • 3. Instruct the patient to say "fifty-five" and establish the vertical length of the occlusion rims in the anterior section of the maxillary arch. • 4. Reduce the posterior occlusal surfaces until the surface is parallel to a line drawn from the ala of the nose to the tragus of the ear . • 5. Make a face-bow transfer and a centric relation record and attach the casts to the articulator. • 6. Record the top of the retromolar pad on the cast. • 7. Alter the occlusion rims so the posterior vertical positions of the mandibular rim are on a plane at the same level as the top of the retromolar pads and the anterior vertical position is in contact with the maxillary occlusion rims.www.indiandentalacademy.com
  65. 65. • Remember that the use of the ala – tragus line is an expediency and is not a reliable indication for the occlusal surfaces of the teeth. • The plane is not used unless it coincides with the other guiding factors. • Establish the plane , using the retromolar pad for the posterior and the incisal edge or low lip line for the anterior points of reference. www.indiandentalacademy.com
  66. 66. Arrangement of teeth for esthetics Influenced by: Age Sex Personality Cosmetic factor www.indiandentalacademy.com
  67. 67. Influences of age: Muscle tonus decreases with age, cheek sag- horizontal overlap of posterior teeth increased to prevent cheek biting. Interincisal distance increases with age: therefore more of the incisal portion of the mandibular teeth is visible. Teeth abrade with age. Central and lateral incisor lie at same horizontal levels. Smile of older individuals is more curved than sharp as in for young individuals. www.indiandentalacademy.com
  68. 68. Influences of sex: Square features are associated with males, and rounded or oval with females. Incisal edge of maxillary anterior teeth follows the curve of the lower lip for females. Distal surface of the maxillary central incisor is rotated posteriorly for females. The mesial portion of the lateral incisor usually overlaps the central incisor in case of females. In males the central incisor’s distal half overlaps the lateral incisor. Distal surface of female canines are rotated distally making only mesial half visible. In males even the distal surface is visible when viewed from fronatalwww.indiandentalacademy.com
  69. 69. Personality of the patient: Habitual patterns and qualities of behaviour. Profession and public appearance of the patient. Cosmetic Factor Patients personal interest in grooming. Teeth for an otherwise neat, well groomed patient can expected to be similar. www.indiandentalacademy.com
  70. 70. ARRANGING TEETH FOR COMPLETE DENTURE OCCLUSION Maxillary Central Incisor: The long axis of the tooth is perpendicular to the horizontal (labiolingual inclination) Its long axis slopes towards the vertical axis ( mesiodistal inclination) Slopes labially about 15 degrees when viewed from the side. Incisal edge is in contact with the occlusal plane. www.indiandentalacademy.com
  71. 71. Maxillary Lateral Incisor: Long axis slopes rather more towards the midline Inclined labially about 20 degrees when viewed from the side The neck is slightly depressed The incisal edge is about 1mm short of the occlusal plane. www.indiandentalacademy.com
  72. 72. Maxillary Canine : Its long axis is parallel to the vertical axis when viewed from both the front and side or it may be slightly to the distal. The bulbous cervical half of the tooth provides its prominence. Its cusp is in contact with the horizontal plane. . The neck of the tooth must be prominent www.indiandentalacademy.com
  73. 73. Remaining maxillary teeth are arranged on the other side of the arch to complete the anterior set up. To maintain the set teeth in position, the wax supporting the teeth must be heated and sealed both to the teeth and to the record base. www.indiandentalacademy.com
  74. 74. First premolar: • Long axis is parallel to the vertical axis when viewed from the front or the side. • Its palatal cusp is about 1mm short of, and its buccal cusp in contact with, the occlusal plane. www.indiandentalacademy.com
  75. 75. Second premolar: • Its long axis is parallel with the vertical axis when viewed from the front or the side. • Both buccal and palatal cusps are in contact with the occlusal plane. www.indiandentalacademy.com
  76. 76. First molar: • Long axis slopes buccally when viewed from the front, and distally when viewed from the side. • Only mesiopalatal cusp is in contact with the occlusal plane.www.indiandentalacademy.com
  77. 77. Second molar: • Long axis slopes buccally more steeply than the first molar when viewed from the front, and distally more steeply when viewed from the side. • All four cusps are clear of the occlusal plane, but the mesiopalatal cusp is nearest to it. www.indiandentalacademy.com
  78. 78. Arranging the Mandibular Teeth Mandibular central incisor: • Long axis slopes slightly towards the vertical axis when viewed from the front. • Slopes labially when viewed from the side. • Incisal edge is about 2mm above occlusal plane www.indiandentalacademy.com
  79. 79. Mandibular lateral incisor: • Long axis inclines to vertical axis when viewed from the front • Slopes labially when viewed from side but not so steeply as the central incisor. • Incisal edge is about 2mm above occlusal planewww.indiandentalacademy.com
  80. 80. Mandibular canine: • Long axis leans very slightly towards the midline when viewed from the front. • Leans very slightly lingually when viewed from the side • Neck is slightly prominent and the tooth is tilted to the distal • Tip at same level as incisors. www.indiandentalacademy.com
  81. 81. First premolar: • Long axis is parallel to the vertical plane when viewed from the front and the side. • Its lingual cusp is below the horizontal plane • Its buccal cusp about 2mm above it as it contacts the mesial marginal ridge of the upper first premolar. www.indiandentalacademy.com
  82. 82. Second premolar: • Long axis is parallel to the vertical plane when viewed from both the front and the side. • Both cusps are about 2mm above the occlusal plane. • The buccal cusp contacts the fossa between the two upper premolars. www.indiandentalacademy.com
  83. 83. First molar: • Long axis leans lingually when viewed from the front and mesially when viewed from the side. • All cusps are at a higher level above the occlusal plane than those of the second premolar. • The buccal and distal cusps are higher than the mesial and lingual. • The mesiobuccal cusp occludes in the fossa between upper second premolar and first molar. www.indiandentalacademy.com
  84. 84. Second molar: • Lingual and mesial inclination of the long axis is more pronounced than in the case of the first molar. • All the cusps are at a higher level above the occlusal plane than those of the first molar, the distal and buccal cusps more so than the mesial and lingual. • The mesiobuccal cusp contacts the fossa between the two upper molars. www.indiandentalacademy.com
  85. 85. Arranging the Posterior Teeth . The anatomical guides most often used in developing the anterior plane of occlusion are the corners 0f the mouth. The posterior plane of occlusion is an extension of this anterior plane level with the junction between the middle and upper third of the retromolar pads bilaterally. The height of the occlusal plane is not simply a matter of dividing the maxillomandibular denture space equally. This space is governed by the relative amount of bone lost from the two ridges. More bone may have been lost from the maxilla than from the mandible and the occlusal plane should not be placed an equal distance between the two ridges. It also should not be at a level that would favor the weaker of the two ridges (basal seats). The most reliable guides are esthetics or anterior tooth placement and the retromolar pads www.indiandentalacademy.com
  86. 86. .The solution to the problem is to position the teeth along a line extending from the tip of the canine to the middle of the retromolar pad this arbitary line should pass through the central fossa of the mandibular premolars and molars The basic principle for the buccolingual positioning of posterior teeth is that they should positioned over the residual ridge. The canine retromolar pad should provide guides for arrangement. www.indiandentalacademy.com
  87. 87. Anterior teeth arrangement according to Dentogenic concept of dental esthetic: SPA factor It is the interpretation of three main factor which every patient posses, sex, personality and age. To construct a dentogenic restoration effectively is a matter of interpreting the sex, personality and age of the patient properly in the denture. This is done through detailed consideration of the three equally important parts of the denture – the tooth, its position and the matrix. The quality of femininity, masculinity, personality and the various physiologic ages will be revealed in the smile as a result of way we do our interpretation. A dentogenic dentures gives the denture wearer an inner sense of well being, the veneer perceives fulfillment of the denture wearer’s personality in his smile and the dentist who fabricated the denture feels deeply rewarded. www.indiandentalacademy.com
  88. 88. Interpretation of sex factor in Dentogenic restoration, sex identity in dentures is a symbol of progress in prosthetic dentistry, on artistic challenge to all of us, which is met with the application of dentogenics The expression of feminine characteristics Femininity is expressed by roundness, smoothness and softness that is typical of women. Therefore the selection of basic shape which has the soft lines expression of the feminine form, together with effective personality characteristics is particularly helpful. The expression of Masculine characteristic A typical masculine form is described as (cuboidal) hard muscular, vigorous appearance beyond the evaluation of physical appearance. A basic tooth form, which expresses masculine characteristic show big or, boldness and hardness. Thus sex identity becomes an automatic part of our esthetic procedures . www.indiandentalacademy.com
  89. 89. SEX INTERPRETATION OF TOOTH POSITIONING Positioning of the teeth is necessary in further conveying sex characteristics to a denture. However, definite positions cannot be assigned to one sex or the other, as other factors other than sex must be taken into consideration. The anterior teeth should be arranged in a lively position. Central incisor can be arranged in four different harmonious lively positions. The incisal edge of one upper central incisor can be brought anteriorly to create on effect of hardness. If one of the central incisor is moved out at the base but leaving the incisal edge together – softness is important to the anterior teeth. www.indiandentalacademy.com
  90. 90. A more vigorous look can be given by one of the central incisor bodily anterior to the other, yet another position for incisors is a combined rotation of the two centrol incisor with their distal surface forward having one incisor depressed at the cervical and the other depressed incisally. These 4 positions can be treated either softly or more vigorously as it is for men or women Their placement controls I) midline ii) speaking line iii) smile line iv) lip support v) labioverison www.indiandentalacademy.com
  91. 91. Lateral Incisors: (Right/left lateral incisor should have asymmetric long axis) This tooth is referred to as the sex tooth or it imparts effect of hardness or softness to anterior tooth by its position. Lateral incisor rotated to shape its mesial surface, slightly over lapping the central incisor imparts softness and youth fullness to smile . If lateral incisor is rotated mesially. The effect of the smile is hardened which is best for vigorous man. www.indiandentalacademy.com
  92. 92. The soft position (S) of the lateral incisor is produced by rotating it’s mesial surface outward and inward rotation produces hard position (H) www.indiandentalacademy.com
  93. 93. • Canines: (Rotated to show mesial surface, controls, the buccal corridor). • A prominence in the canine tooth imparts great importance and thereby gives the smile a vigorous look, which is more suitable to the male sex. www.indiandentalacademy.com
  94. 94. General, we will adopt for the cuspid conjointly the three following positions: (1) out at the cervical end, as seen from the front (2) rotated to show the mesial face (3) almost vertical as seen from the side www.indiandentalacademy.com
  95. 95. THE THIRD DIMENSION-DEPTH GRINDING The "denture look" is due mostly to the flat appearance of the artificial upper anterior teeth, their lack of depth, or of "body." The depth grinding is done on the mesial surface of the central incisor only. Central incisors are the widest, almost always the longest, and therefore, the most noticeable of the six anterior teeth. It is necessary to develop the desired effect in the depth grinding by consideration of these main factors: www.indiandentalacademy.com
  96. 96. • a flat thin narrow tooth is delicate looking and fits delicate women ( little depth grinding) • a thick bony big sized tooth heavily carved on it’s labial surface is vigorous and to be used exclusively for men ( severe depth grinding) • For the average patient the depth grinding will be an average between delicate and vigorous • Depth grinding reduces the width of the central incisor according to the severity of grinding to be accomplished.www.indiandentalacademy.com
  97. 97. www.indiandentalacademy.com
  98. 98. www.indiandentalacademy.com
  99. 99. Grinding of teeth for age abrasion effect Of early youth: Teeth prominent, bulbous gums, no abrasion short stuffy tooth, spacing between lateral, cuspid developmental groove early middle age – incisal wear, mild staining slight spacing due to drifting, which can be incorporated in the dentures. Middle age – More incisal wear on C, L, canine, mild staining recession of gum Old age – long axis is not in alignment, gum recession, erosion natural staining, occlusal and incisal wear caused by habit. www.indiandentalacademy.com
  100. 100. Interpretation of personality factor in dentogenic restoration For a dentogenic restoration the human personalities can be grouped into three categories. The vigorous- Hard, aggressive, muscular type The medium type- Normal, robust, healthy The delicate type fragile, frail appearance. Personality of denture depends on the selection of tooth molds, tooth colors tooth position, and the matrix of the teeth (denture base) When we incorporate the personality factor in esthetics we do so keeping in mind the influence of the sex and age factors as we proceed. www.indiandentalacademy.com
  101. 101. Interpretation of age factor in dentogenic restoration As age progress in human individual there will be visible changes in the appearance of his teeth as in other living tissues. It is an artistic challenge to the prosthodontist to maintain a favorable relationship between his chronologic life and his physiologic mouth condition. Age in artificial tooth Is established by mold refinement by grinding of the teeth and its matrix (gum). Gives the denture a individual look and eliminates an artificial look diastema is a common condition seen in the mouth of the adult because of the drifting of teeth resulting from premature loss of teeth. Again matrix interdental papilla loses its stippled appearance, receding gum line will suggest recession. www.indiandentalacademy.com
  102. 102. DENTOGENIC CONCEPT Dynesthetic theory Term Dynesthetic is derived from the Greek word ‘dynamis’ meaning power. It supports in working factors of the dentogentic concept. The technique of dynesthetic is an auxiliary stimulus in the creation ot a dentogenic restoration. It is secondary to sex personality and age factors. These are rules, which concern the three important division of denture fabrication. 1) The tooth 2) its position and 3) its matrix and should not be confused with dentogenic procedure. The skilled technicians ability allows the dentist to further refine the dynesthetic rules according to own perception at the try in appointment. www.indiandentalacademy.com
  103. 103. Consideration in dynesthetics The following are the dynesthetic consideration, which are necessary for the production of dentogenic restoration. Mold- The selection of an acceptable personality mold, involves its subsequent treatment for abrasion, erosion, dept grinding, masculinity or femininity, shaping and polishing. Lip support- This is the bodily anterior, posterior positioning of the teeth, which adequately support the upper lip in natural and pleasing manner. The pleasing lip support is achieved by the anterior teeth and matrix. The border of the lip support is carried chiefly by the central incisor. www.indiandentalacademy.com
  104. 104. Mid line- The features of face usually start one way or another and its is rather difficult to see a true midline in a dentition. It is usually more eccentric than is noticed. Therefore an eccentric midline in a denture if not to exaggerated, is acceptable and may lead to the elusion ot the natural dentition. The mid axis is important to general composition and should be vertical to the incisal and occlusal plane. Labioversion- The most pleasing effect is obtained when the long axis of the central incisors are either vertical or with a slight labial inclination. Speaking line- It is the incisal length or the vertical composition of the anterior teeth. It is spoken of, as the speaking line because the final evolution of the incisal length is made when the patient is speaking seriously, the lip of the lateral incisors should be seen. www.indiandentalacademy.com
  105. 105. Smiling line- The smiling line is a curve whose path follows the incisal edges of the central incisors up and backs to the incisal edges of the lateral incisors and then to the lips of the cuspids. It is determined by the age of the patient and decreases, as the patient gets older. Central incisor position: The central incisors are the corner stones of tooth position, if their positions are correct, then the position of all of the other teeth will be more nearly correct and their placement controls. a) The midline b) Speaking line c) the lip support d) Labiovesion e) Smiling line compositions. www.indiandentalacademy.com
  106. 106. The canine position: It supports the anterior arch forms in its widest part and controls the size of the buccal corridor. It should be carefully positioned so as to dominate the lateral incisor and to complete the desired upward curve of the smiling line. It should be abraded to copy the physiologic age of the patient. The three basic requirement of the canine position are a) Tooth should be rotated to show its mesial surface b) The cervical end should be out and c) When observed from the right, the long axis of the cuspid should be vertical Space: Spacing in the anterior or posterior teeth are extremely effective but their size and positions must be artistically and hygienically formed. www.indiandentalacademy.com
  107. 107. The rules which must be observed are a) All spaces must be shaped to shed food. b) A diastema below the central incisor is unsightly and should be avoided. c) Diastema should be asymmetrically placed on either side of the dental arch. d) The width of the diastemas should be controlled so as not to appear unsightly. Embrasures- Represent a divergence of the proximal surface of the anterior teeth from the contact point. Buccal corridor- is created between the buccal surface of the posterior teeth and the corner of the lips when the patient smiles- the buccal corridor begins at the cuspid and its size and shape are controlled by the position and stand of the cuspid. The use of the buccal corridor prevents the sixty-tooth smile, or the molar-to-molar smile, which is often characteristic of a denture. www.indiandentalacademy.com
  108. 108. Long axis- upon close examination of the position of the natural teeth, it will be noticed that their long axis very even though these variance is sometimes in minute degrees. It is there and should be exaggerated in a dentogenic restoration as an artistic device. Gumline- at the cervical ends of the teeth should vary in height. The generally accepted rule for this are that the gumline should be formed. a) Slightly below the high lip line at the central incisor. b) Lower than the CI gum line of the later incisors. c) Higher than the CT or LI gumline at the cuspid end. d) Slightly lower than at the cuspid, at the bicuspid. www.indiandentalacademy.com
  109. 109. Inter dental papilla- in a dentogenic restoration the esthetic consideration ot the denture base lies in the matrix of the tooth. The general rule for papilla a) The papilla must extent to the point of tooth contact. b) The papilla must be of various lengths c) Interdental papilla must be convex in all direction d) Papilla must be shaped to the age e) The papilla must, end near the labial face of the tooth Labial and buccal denture base contour The denture base contours beyond the matrix should provide self cleaning surfaces and therefore should not be over accentuated with depressions grooves, folds of any shape which would defect the smooth cleaning act on of the cheeks and lip. www.indiandentalacademy.com
  110. 110. OCCLUSAL SCHEMES FOR COMPLETE DENTURE OCCLUSION The occlusal scheme or the tooth molds selected occlusal rehabilitation will depend on the concept of occlusion that has been selected to satisfy the needs of the patient. The posterior teeth, arrangement according to the occlusal concept selected, should fulfill the dentist's philosophy of occlusion as which appear esthetically pleasing. Prosthetic tooth anatomy seems to be more important to dentists than to the patients who use the teeth. In the absence of clear evidence of the benefits of one tooth anatomy compared with others, dentists should use the least complicated procedures and tooth forms that will satisfy their concepts of occlusion and articulation of a mucosal supported dentition www.indiandentalacademy.com
  111. 111. . There are several schools of thought on the choice of occlusal forms of posterior teeth for the three concepts of occlusion most often selected, namely, (1) bilateral balance, (2) monoplane or nonanatomical, and (3) lingualized articulations. Anatomical molds usually are selected for bilateral balanced articulation; however, nonanatomical teeth can be used in a balanced concept with the use of compensating curves. Nonanatomical or cusp less teeth are generally the choice for monoplane although teeth with cusps also can be used. For the lingualized occlusal concept, a combination of upper anatomical and lower non-anatomical molds has been introduced by several tooth manufacturers . www.indiandentalacademy.com
  112. 112. Arranging Anatomical Teeth to a Balanced Articulation The anterior teeth are set with a minimal vertical overlap of 0.5 to 1 mm and 1 to 2 mm of horizontal overlap to establish a low incisal guidance . In the arrangement of the posterior teeth, most clinicians set the mandibular teeth before the maxillary because this provides better control of the orientation of the plane of occlusion both mediolaterally and superoinferiorly www.indiandentalacademy.com
  113. 113. Setting the Mandibular Teeth First The primary consideration in positioning the premolars is that they follow the form of the residual ridge. The facial surface of the premolars should be perpendicular to the occlusal rim, and yet slightly facial to the canine, but never farther facially than the buccal flange. In the ideal situation, the mandibular first and second premolars, with their central grooves, are positioned on a line from the canine tip to 1 to 2 mm below the top of the retromolar pad www.indiandentalacademy.com
  114. 114. . The second premolar is set in a similar manner. When these lower teeth have been arranged, a segment of the maxillary occlusal rim is removed to accommodate the first maxillary premolar, which is set into maximum intercuspation with the two lower premolars. . In the positioning of the mandibular first molar, the central groove is placed on the canine to retromolar pad reference line. The vertical height of the tooth is adjusted by positioning the cusp tips on the occlusal plane. After these adjustments are completed, the maxillary first molar is articulated with the mandibular first molar. After the maxillary first molar is positioned, the articulator is closed so that the mandibular tooth will assist in seating the maxillary tooth into maximum intercuspation The index finger is used to hold the cervical neck of the maxillary tooth in place while the articulator is closed www.indiandentalacademy.com
  115. 115. . Setting the Maxillary Teeth First In arranging the maxillary posterior teeth first, start with the maxillary first premolar and continue the arrangement of the teeth through to the second molar. During the positioning of these teeth, the maxillary lingual cusps are aligned with the reference line that has been scribed on the mandibular wax occlusal rim from the mandibular canine tip to the middle of the retromolar pad. Positioning the maxillary teeth with a slight opening of the contact points between these teeth allows the mandibular teeth to better assume their correct mesiodistal position as they are interdigitated with the maxillary posterior teeth. www.indiandentalacademy.com
  116. 116. 2 Arranging nonanatomical mandibular Posterior Teeth to Balanced Articulation anteroposterior and mediolateral compensating curves permits the establishment of a balanced articulation. In such arrangements, the mandibular teeth usually are arranged first followed by the maxillary teeth. the use of the several reference lines and guides developed for the anatomical arrangement also are used with the nonanatomical teeth. The major difference is in the positioning of the mandibular posterior teeth to develop the compensating curves.www.indiandentalacademy.com
  117. 117. Anteroposterior Compensating Curve The anteroposterior compensating curve begins at the distal marginal ridge of the first posterior replacement tooth (which is usually the second premolar) and continues through the second molar .most often the number of poseriot teeth used in balanced articulation with nonanatomical teeth will be limited to three.eliminating the first premolar is a logical choice because this tooth has less occlusal surface for the mastication. Mediolateral Compensating Curve A mediolateral compensating curve also is needed to provide the needed tooth structure to achieve balanced articulation during lateral movements. This curve also is initiated with the first replacement tooth and continues through the second molar , the degree to which the facial cusps are elevated in relation to the lingual cusps to establish this curve will vary with the condylar and incisal guidance www.indiandentalacademy.com
  118. 118. . FIRST PREMOLAR The central fossa of the mandibular premolar tooth is aligned with the reference line from the tip of the canine to the middle of the retromolar pad. The long axis of the tooth is perpendicular to the occlusal plane, and the facial cusp is slightly elevated above the lingual cusp. www.indiandentalacademy.com
  119. 119. First Molar Position the mandibular first molar next to the premolar with the mesial marginal ridge at the same level as the distal marginal ridge of the premolar and its distal marginal ridge slightly ele-vated. . The distal of the first molar should be elevated approximately I mm above the occlusal plane that was established by the anterior and posterior reference points. When viewed in the frontal plane, the mediolateral compensating curve, initiated with the setting of the premolar, should be maintained by a slight elevation of the facial cusp above the lingual cusp.. www.indiandentalacademy.com
  120. 120. Second Molar The anteroposterior compensating curve is continued posteriorly by elevating the distal of this second molar tooth approximately 2 mm above the occlusal plane established by the reference points. Posterior Teeth The mandibular posterior teeth are arranged for the other side of the arch with the same criteria an procedures as just outlined. www.indiandentalacademy.com
  121. 121. Arranging Nonanatomical Maxillary PosteriorMaxillary Posterior Teeth to Balanced Articulation After some of the wax occlusal rim distal to the canine is removed, the first premolar is set. Place a small portion of soft, pink wax on the neck of the maxillary premolar and attach the tooth to the record base. Carefully close the articulator and establish contact between the occlusal surface of the maxillary tooth and the central fossa or marginal ridges of the mandibular antagonist. There should be approximately I to 2 mm of horizontal overlap of the maxillary facial cusp in relation to the mandibular facial cusp. www.indiandentalacademy.com
  122. 122. First Molar Aligning their marginal ridges and facial surfaces. Establish contact between the maxillary occlusal surface and the central fossa or marginal ridges of the mandibular antagonist.. Second Molar Position the maxillary second molar tooth. Again, carefully close the articulator and establish the tooth contacts as you did with the first molar. Remaining Maxillary Posterior Teeth The maxillary posterior teeth are arranged for the other side of the arch with the same criteria and procedures as previously outlined for maxillary posterior teeth. www.indiandentalacademy.com
  123. 123. 3 Arranging Nonanatomical Teeth to Monoplane Articulation With this concept of occlusion, there is no attempt to eliminate deflective occlusal contacts in lateral or protrusive excursions. The dentist's desire to achieve an optimal esthetic result will require some vertical overlap of the anterior teeth. However, this can generally be accommodated for with sufficient horizontal overlap to permit a range of anterior and lateral movements without anterior tooth contacts. Basically, the patient can clench and grind in and around maximum intercuspation during both functional and nonfunctional activities. However, some deflective occlusal contacts of the posterior teeth will be experiencedwww.indiandentalacademy.com
  124. 124. The condylar inclinations on the articulator are set at 0 degrees. The articulator is reduced to a simple hinge articulator. With the mandibular wax occlusion rim positioned on its cast on the articulator small segment of the rim is removed from the posterior tooth area. The maxillary posterior teeth positioned one at a time with the mandibular occlusal rim and its references and guides for the placement. The maxillary teeth are positioned occlude with the flat surface of the mandibular occlusion rim . www.indiandentalacademy.com
  125. 125. There should be approximate l to 2 mm of horizontal overlap of the maxilla facial cusp in relation to the mandibular occlusal rim When completed, the occlusal surfaces of the maxillary posterior teeth should be flat against the mandibular wax occlusal rim. The mandibular teeth are arranged so they maximally contact the upper teeth. The anteroposterior relation of the upper and lower teeth is not critical because of the absence cusps. www.indiandentalacademy.com
  126. 126. Arranging Mandibular Posterior Teeth to Lingualized Articulation Lingualized articulation has been advocated many practitioners over the past 70 years, and most instances these clinicians have done so with a variety of tooth molds. However, what has been lacking for the practitioner are tooth molds design specifically for this concept. Myerson Lingualized, Integration (MLI) molds represent an occlusion scheme designed for this concept. It has been suggested that these molds will provide maximum intercuspation, an absence of deflective occlusion contacts, adequate cusp height for selective occlusal reshaping, and a natural and pleasing appearance . www.indiandentalacademy.com
  127. 127. The MLI teeth are available in two posterior tooth molds: (1) controlled contact (CC) and (2) maximum contact MC molds . The primary difference in the two molds is the maxillary posterior teeth The mandibular teeth are the same for both molds. The mandibular teeth were designed with lower cusp heights and multiple occlusal spill­ways to assist in mastication. The selection of one or the other mold (CC or MC) is dependent on the patient's ability to consistently reproduce their centric jaw relation position. For those patients in whom uncertainty exists in the registration and reproducibility of the centric jaw relation position, the CC mold is suggested because it provides for greater freedom of movement around maximum intercuspation. www.indiandentalacademy.com
  128. 128. For those patients in whom muscle control is not a problem and jaw relation records are easily repeated, the MC mold may be the tooth selection of choice. In the MC mold, the maxillary teeth are more anatomical in appearance with greater cusp heights. This form demands some minor reshaping and refinement of the occlusal fossae and marginal ridges of the mandibular teeth during the arrangement of the teeth to accept the lingual cusps of the maxillary teeth. With the MC mold, a more exacting occlusion can be attained in maximum intercuspation, and bilateral balanced articulation can be developed over a greater range of movement both anteroposteriorly and mediolaterally. Lingualized integration is based on the maxillary lingual cusp functioning as the main supporting cusp in harmony with the occlusal surfaces of the lower teeth.. www.indiandentalacademy.com
  129. 129. The maxillary cusp heights in the CC mold are lower and permit greater flexibility around maximum intercuspation. The tooth contacts in eccentric positions remain as bilateral balanced articulation, even though the range of contact is less because of the reduced height to the maxillary lingual cusps. However, a greater range of contact is probably not necessary for most edentulous patients, and the bilateral balanced articulation achieved with the CC mold is very acceptable. In the arrangement of the teeth for lingualized articulation, the mandibular teeth are set first to establish the occlusal plane. www.indiandentalacademy.com
  130. 130. The MLI tooth scheme calls for anteroposterior and mediolateral compensating curves arranged in the mandibular arch, thereby permitting balanced articulation between the maxillary lingual cusps and the mandibular teeth during various jaw movements. 1 Anterior and Posterior Reference Points 2 Buccolingual Positioning of the Teeth 3 Anteroposterior Compensating curve 4 Mediolateral Compensating Curve www.indiandentalacademy.com
  131. 131. Premolar The first premolar tooth is positioned in contact with the canine and with its long axis perpendicular to the occlusal plane. The occlusal surface is positioned on the occlusal plane; however, the facial cusp is elevated slightly above the lingual cusp to establish the mediolateral com­ pensating curve. The second premolar is eliminated from the arrangement. First Molar. The distal marginal ridge of this tooth is elevated slightly above the mesial marginal ridge to create the anteroposterior compensating curve. The mediolateral compensating curve is maintained by elevating the facial cusp of the molar slightly above the lingual cusp. The central fossa of the first molar is positioned slightly to the facial of the reference line connecting the canine with the middle of the retromolar pad www.indiandentalacademy.com
  132. 132. Second Molar The anteroposterior compensating curve is continued by elevating the distal marginal ridge of this tooth. the retromolar pad.. The mediolateral compensating curve is continued by elevating the facial cusps above the lingual cusps. Remaining Mandibular Posterior Teeth The mandibular posterior teeth are arranged for the other side of the arch with the same criteria and procedures, as previously outlined. www.indiandentalacademy.com
  133. 133. Arranging Maxillary Posterior Teeth to Lingualized Articulation Premolar The first tooth arranged in the maxillary arch is the first premolar. This tooth is selected because of its cusp tip to cervical margin height.. The lingual cusp is positioned to contact the marginal ridge or occlusal fossa of its mandibular antagonist. No attempt is made at this time to balance the facial or lingual cusps in lateral or protrusive movements. Maximum interdigitation of the lingual cusp against the occlusal surface of the mandibular tooth is the primary consideration www.indiandentalacademy.com
  134. 134. First Molar Often, a Class I molar relationship will not be present. Such a relationship is not necessary, and positioning of the teeth to establish such a relationship is discouraged. Integration of the lingual cusps with the marginal ridge or fossa of the mandibular antagonist is the primary consideration. Second Molar The anteroposterior compensating curve is continued when the tooth is closed into contact with the mandibular tooth. Again, maximum intercuspation is essential, as is the maintenance of the mediolateral compensating curve. www.indiandentalacademy.com
  135. 135. Arranging the Maximum Contact Mold In the arrangement ofthe MC mold, the maxillary teeth are positioned with the incisal pin slightly open when the lingual cusps are in contact with their mandibular antagonists. The prominence of the maxillary lingual cusps will require some occlusal reshaping of the central fossae and marginal ridges of the lower teeth to establish maximum intercuspation. After each maxillary tooth is positioned, a thin sheet of articulating paper is interposed between the tooth and its mandibular antagonist. The articulator is closed, marking the first contact point. The contact point on the occlusal surface of the mandibular tooth is enlarged by grinding with a round bur to permit the lingual cusp to obtain positive seating with the lower tooth. This process is continued until maximum interdigitation is achieved and the incisal pin is in contact with the incisal table. www.indiandentalacademy.com
  136. 136. POSTERIOR TEETH ARRANGEMENT FOR CLASS II RELATION SHIP The lower ridge is small and markedly inside the upper ridge .The anterior teeth exhibit a pronounced horizontal overlap when they are arranged properly for esthetics . The vertical overlap should be kept as small as esthetics and phonetics will allow in order to establish an incisal guidance as shallow as possible . In most of these cases, the horizontal overlap is great enough to accommodate for mastication without the anterior teeth interfering during the function of mastication on the posterior teeth. www.indiandentalacademy.com
  137. 137. The small arch of the lower ridge retruded to a position inside the upper makes it impossible to obtain the correct upper and lower canine relationship. The lower canine is inside the upper arch of teeth and is more distal in its relationship to the upper canine than in class I .This gives a tooth­on­tooth vertical relationship to the posterior teeth that can be articulated to establish a stable centric and eccentric occlusion after special grinding procedures www.indiandentalacademy.com
  138. 138. Setting the Mandibular Posterior Teeth • The same criteria described for setting lower teeth are applied to this case. The lower anteriors were set for lip support and the first premolar follows the arch contour established by them so that the modiolus is supported. Any attempt to set the lower anterior or posterior teeth to an exaggerated labial or buccal position in relation to the lower ridge is contraindicated because it will create an unfavorable lever action on the lower denture base during function. www.indiandentalacademy.com
  139. 139. Either anatomic, modified anatomic, or non­anatomic teeth can be used for these retrusive cases. The selection of the occlusal form is based on the same factors of ridge strength, form, and interridge space as for the normal ridge relation. Because the lower ridge in these patients is usually small and weak in relation to the upper, the buccolingual inclines are modified to a shallow angulation, or nonanatomic teeth are selected. After the lower premolars are initially set, the upper first premolar is temporarily set to evaluate its position. It will have a marked buccal overlap with the upper lingual cusp usually opposing the lower buccal cusp. www.indiandentalacademy.com
  140. 140. The initial grinding follows the same basic concepts that modified the buccolingual inclines and eliminated the mesiodistal interlocking cusp heights and transverse ridges . A special grinding procedure is then necessary to establish a stable centric occlusal contact for the premolars. The buccal tips of the lower premolars are flattened to a horizontal table . Usually, the molar teeth do not need this additional grinding procedure on their buccal cusps because the lower ridge crest in the molars region is under the upper ridge. This permits the upper molar lingual cusps to be set in the modified central fossa of the lower molars .www.indiandentalacademy.com
  141. 141. Grinding Modifications for Upper Posterior Teeth The upper anatomic or modified anatomic teeth are initially ground to eliminate all mesiodistal interlocking transverse ridges and cusp heights. The buccal cusps are shortened progressively from the premolars to the molars The maxillary premolars need additional special grinding on the lingual cusp to create a flat stable platform for centric occlusal contact with the lower premolars Setting the Upper Posterior Teeth Before the upper posterior teeth are set the incisal guide pin must be checked for the proper occluding vertical dimension. The condylar locks are opened so that eccentric excursions can be made into right lateral, left lateral, and protrusive positions. The incisal guidance should be set for most patients so that the anterior teeth just clear during these excursions. www.indiandentalacademy.com
  142. 142. Anterior interference, evident by extensive excursions on the articulator, cannot be eliminated when patients have a deep vertical overlap. This interference will not be traumatic to the foundation tissues if it occurs outside of the normal masticatory cycle. Fortunately, this holds true for most orthognathic patients because there is ample compensating horizontal overlap . 1. The upper first premolar is set so that its flattened lingual cusp occludes with the flattened buccal cusp of the lower first premolar . The amount of buccal overlap of this tooth will vary in each case because of the difference in ridge relationships in orthognatic patients. In severe retrusions, the first premolars may be out of contact in centric occlusion. 2. The upper second premolar is set with its flattened lingual cusp occluding with the flattened buccal cusp of the lower second premolar. There is less buccal overlap and a larger area of contact is possible between these teeth .www.indiandentalacademy.com
  143. 143. The mesiodistal relationship of the upper and lower premolars is not critical because the flattened cusp contacts and the elimination of mesiodistal inclines do not demand a critical tooth position for a stable occlusion. 3. After setting the upper premolars, mark the centric occlusal contacts with articulating paper to analyze for stability and the area of contact. The contacts must not be on deflective and enlarge the area of contact. Readjust the upper premolars to centric occlusion and recheck the contacts. 4. The upper molars can be set with their lingual cusps in the modified central fossa of the lower teeth. Again the contacts must be checked for deflective inclines and corrected by the same grinding procedures described for the premolars. 5. The posteriors now should have a centric occlusion with stable non deflective stops. Only the lingual cusp are the occluding elements on the upper teeth . They contact the buccal cusp of the lower premolars and the central fossa of the lower molars . www.indiandentalacademy.com
  144. 144. POSTERIOR ARRANGEMENT FOR CLASS III RELATIONSHIP The usual approach to the arrangement of the anterior teeth for the class III is to set the upper anteriors as far forward as esthetics requires for the support of the upper lip and to set the lower anteriors as far lingual on the ridge as possible without interfering with the tongue . The patient treated with this basic approach looks less prognathic and the anterior teeth, except for the very pronounced class III relationship, can be set edge­to­edge . This procedure creates no particular problem in establishing the proper relationship between the upper and lower canines. It permits an anatomically normal . vertical interdigitated relationship for the posterior teeth. www.indiandentalacademy.com
  145. 145. The problem is the horizontal relationship of the teeth in the posterior region, where the lower ridge is in an abnormal buccal relation to the upper. This requires an atypical arrangement of the posterior teeth to control the biomechanical forces of the occlusion. The atypical arrangement is commonly called a cross­bite occlusion. In this type of occlusion the upper posterior teeth are crossed over the lower posterior teeth so that the buccal cusp of the upper is in the lower central fossa instead of the lingual cusp. This may occur either unilaterally or bilaterally, depending on the posterior upper and lower ridge relationship . www.indiandentalacademy.com
  146. 146. The crossing point of this occlusion depends on the buccolingual vertical relationship of each case. The crossing over of the upper posterior tooth occurs when a conventional occlusal relationship would position the upper tooth too far to the buccal In this errant position, the tooth would create unfavorable displacing leverage on the upper base during function. It would also impinge on the buccal mucosa, which would result in additional displacing forces acting on the teeth and denture base. Cheek biting is also common with teeth positioned too far to the buccal www.indiandentalacademy.com
  147. 147. Selection of Posterior Teeth The same indications for the selection of the size and the modification of the occlusal form for the conventional case hold for this type of ridge relationship. However, it is the upper ridge that is primarily considered since it is always the smaller and usually the weaker ridge. When the lower ridge is markedly resorbed a nonanatomic teeth is indicated . The buccolingual and mesiodistal relation of the upper and lower posteriors is not as critical with this type of occlusion . www.indiandentalacademy.com
  148. 148. Usual guidelines are followed as it was followed in normal relationship .An attempt to set the lower posterior teeth under the upper ridge so that the upper and lower posterior will have a conventional occlusal relationship will position the lower teeth too far lingual .This will restrict the tongue movements and cause displacement of the lower denture . Grinding Modifications for Lower Posterior Teeth No variations in the grinding procedures are made in the initial modification, which unlocks the mesiodistal interdigitation and reduces the buccolingual inclination. Additional spot grinding is necessary to establish a static centric occlusion when the upper posteriors are set. www.indiandentalacademy.com
  149. 149. Grinding Modifications for Upper Posterior Teeth Each upper posterior tooth is modified before it is set. The transverse ridges are flattened to eliminate the mesiodistal interlocking potential of the anatomic tooth. Special additional individual tooth grinding is necessary as the teeth are set. It depends on the tooth that initiates the crossing over of the occlusion. When this occurs, the upper tooth is flattened both on buccal and lingual cusps to establish a static centric occlusal contact with the lower tooth . The teeth in cross­bite relation need additional modification by grinding on the upper buccal cusps. They must be rounded to occlude in the modified central fossa of the lower. www.indiandentalacademy.com
  150. 150. Setting the Upper Posterior Teeth The upper first premolar can usually be set in conventional relationship to the lower premolars. The upper lingual cusp is set in the common central fossa of the modified lower premolars . It should be in a complimentary esthetic position in relation to the upper canine and should establish a normal arch form. The second premolar usually requires special consideration because it starts the crossover to the cross­bite occlusal relation. The upper buccal and lingual cusps are flattened. When it is properly set in relation to the upper ridge, the articulator is closed to evaluate its occluding position with the lower teeth. The lower teeth must now be flattened on the buccal and lingual cusp inclines so that a stable occlusal contact is established when the articulator is closed to the occluding vertical dimension . www.indiandentalacademy.com
  151. 151. The upper first and second molars are set in a cross­bite relation, which puts the rounded upper buccal cusps in the lower central fossa. This position of the upper molar teeth provides for a compatible arch form of teeth in relation to the maxilla and provides a favorable leverage system during function. The crossing point can vary from case to case, depending on the degree of prognathism and the residual ridge relationship. It may not be bilaterally symmetric. When the basic concepts of acceptable arch form, biomechanical principles, and tooth modification are applied intelligently, any degree of prognathism and aberrant ridge relation can be successfully managed either with modified anatomic or nonanatomic teeth. www.indiandentalacademy.com
  152. 152. REVIEWOF LITERATURE www.indiandentalacademy.com
  153. 153. • Temperament in relation to the teeth..Dent cosmos 1884:26::113­120 . White JW proposed the temperament theory in dentistry to aid tooth selection and improve esthetics . Sex and age were also considered factors that influence dental composition and enhancing the esthetic effect .formulations of tese features determine the suitable tooth forms ,size ,colours,textures and denture base contours for each temperament . www.indiandentalacademy.com
  154. 154. • Dental and facial types . Am syst dent1887,2:1030­1052 . Ivy RS gave description of specefic arch forms,together with complementry palatal conours for each tempearament .for example a flat anterior arch that turned posteriorly to form diverging lines was consistent with bilious temperament .in cross section palatal vault was almost square .The sanguine arch resemble a horesshoe in outline while palatal contour was semicircular . The nervous temperament had an arch that gently curved on either side to form a rounded point anteriorly .likewise the palate had a high vault reminiscent of a gothic arch . An almost semicircular arch typified the lymphatic temperament with a rounded ,shallow palate. www.indiandentalacademy.com
  155. 155. • Is the theory of temperament the foundation to the study of prosthetic art? Dent mag 1905;1:405­413. Berry FA. Found a analogy between face form and tooth form .in his study facial outline was determined by drawing a line midway between the hairline and eyebrows to the zygomas on each side and down to the chin. The inversion of this outline form was purported to represent almost without exception the natural mould of the central incisor . It also sugested that original arch form could be assessed by using the inverted form of the cheeks and chin as an accurate guide .when viewed obliquely the cheek outline revealed the labila countour of the canine. www.indiandentalacademy.com
  156. 156. • Complete denture prosthesis,ed 3.london.saunders,1925:47:915­923. Schlosser RO et al reported a high percentage of edentulous cases having consistency between the face form and arch form .a continous line drawn along the alveolar crest as far as the tuberosities and just posterior to the junction of the hard and soft palte when inverted and superimposed on the onto the face was to correspond with the chin margin,jaw lines,cheek lines and eyebrows .artificial tooth selected to arch form and therefore face form produced esthetically pleasing effect. www.indiandentalacademy.com
  157. 157. CONCLUSION • Selecting anterior teeth for a complete denture can be difficult if no pre­extraction records are available. A review of dental literature shows that several factors has been proposed as an aids for artificial teeth selection,and numerous method has been devised for their evaluation as reliable esthetic factors in determining artificial tooth form To date ,however , no universally reliable method has been found for determining tooth form. www.indiandentalacademy.com
  158. 158. www.indiandentalacademy.com