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Teeth arrangement in balanced occlusion
The document provides detailed guidelines for the arrangement and placement of teeth in balanced dentures, emphasizing alignment with facial features and anatomical considerations. Key factors include the positioning of maxillary and mandibular teeth to ensure aesthetic harmony and proper occlusion, as well as specific instructions for various types of teeth. It also discusses the importance of compensating curves in achieving balanced articulation during movements.
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Teeth arrangement in balanced occlusion
- 1. TEETH ARRANGEMENT IN BALANCEDDENTURES NAMITHA.AP SECOND MDS DEPT.OF PROSTHODONTICS
- 2. Guidelines for toothplacement and arrangement 1. Parallel to interpupillary line 2. Incisal edge of maxillary incisors 1 to 2 mm below maxillary lip at rest 3. No bulging should be evident under the nostrils 4. Philtrum should be restored, if possible 5. Full vermilion border of lip should be seen 6. “Smile line” (maxillary incisal edges) should follow the line of the lower lip in smiling Frontal view - Anterior teeth
- 3. FRONTAL VIEW POSTERIORTEETH 1. Maxillary posteriors (premolars) should be placed buccally enough so as to avoid too large a dark buccal corridor upon smiling, but not to eliminate it 2. The occlusogingival length of the maxillary first premolar tooth should be long enough so that denture base material is not obvious on smiling 3. The occlusal surface of the mandibular first bicuspid should never be superior to the corner of the mouth when the mouth is open only sufficiently to receive food 4. Posterior plane of occlusion should not “drop down” posteriorly, or maxillary posterior teeth will show too much during smiling
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- 5. The incisive papilla- valuable guide to anterior tooth placement A line marking the center of the incisive papilla on the wax rim can be extended forward onto the landing area of the cast
- 6. relationship to the reflectionof soft tissues under the lip or as recorded in the maxillary impression The anteroposterior position of the dental arch should be governed chiefly by consideration of the orbicularis oris muscle and its attaching muscles and by the tone of the skin of the lips. The labial surfaces and incisal edges of the teeth are anterior to the tissues at the reflection, where the denture borders would be placed position and expression of the lips
- 7. Arranging ANTERIOR TEETH Setting teeth over the maxillary anterior ridge may undermine the esthetic result Greatest harm is done when the maxillary anterior teeth are set too far back on the ridge or under the ridge (tooth’s direction is upward and backward) In the resorbed situation, the crest of the ridge is considerably more posterior than it is in a patient with recent extractions. If the rule of setting teeth over the ridge is followed after the residual ridge has resorbed, a prematurely aged appearance will result. Remove the maxillary wax occlusal rim on one side from the midline around the arch for a distance of approximately 1 inch (about 25 mm). A longer tooth clinically will provide a better esthetic result. Short, stubby teeth are not natural in appearance. set both central incisors and thus establish the midline before setting the lateral and canine
- 8. MAXILLARY CENTRAL INCISOR Make certain that the long axis of the tooth is perpendicular to the horizontal, with the incisal edge 0.5 mm below the wax occlusal rim. it establishes the midline and the esthetic support of the patient’s lip. The proper arrangement of the maxillary and mandibular anterior and posterior teeth relies on the setting of the maxillary central incisors.
- 9. MAXILLARY LATERAL INCISOR neck slightly depressed incisal edge symmetry with the central incisor and with the remaining anterior occlusal rim. (even with the remaining maxillary wax occlusal rim) slightly elevated from the central incisor. parallel with the mandibular wax occlusal rim.
- 10. MAXILLARY CANINE anteriorone half of the incisal edge is in symmetry with the lateral and central incisors as it curves around the labial contour of the wax occlusal rim. Neck of the tooth must be prominent and the tooth tilted slightly to the distal. incisal tip of the canine must be 0.5 mm below the maxillary wax occlusal rim.
- 11. Mandibular Central Incisor Position the central incisor next to the midline and tip it slightly to the labial. Direct the long axis of the tooth toward the residual ridge. Necks of the teeth are depressed so that they are in from the edge of the record base. Incisal edges of these teeth must be at the height of the mandibular wax occlusal rim.
- 12. MANDIBULAR LATERAL INCISOR long axis of the tooth directed toward the residual ridge. incisal edge should be at the height of the wax occlusal rim. 1 to 2 mm of horizontal overlap between the maxillary and mandibular anterior teeth should be continued.
- 13. MANDIBULAR CANINE Placethe mandibular canine with the anterior one half of the incisal edge in symmetry with the lateral and central incisors. Place the incisal tip at the same level as the lateral and central incisors. neck of the tooth is slightly prominent and tilted to the distal.
- 14. Arrangement of posteriorteeth and posterior arch form Anteriorly by the position of the canine Posteriorly by the shape of the basal seat and the location of the retromolar pads. The curvature of the arch of anterior teeth should flow pleasingly toward the posterior teeth. The posterior teeth are positioned in such a way that they are properly related to the bone that supports them and to the soft tissues that contact their facial and lingual surfaces.
- 15. Setting maxillary teethfirst 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. The mandibular cusps tips are designed to engage the embrasures of the opposing maxillary teeth.
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- 18. MAXILLARY FIRST MOLAR Thedistolabial surface of the canine, the buccal surfaces of the premolars and the mesiobuccal surface of the 1st molar should follow a straight line.
- 19. MAXILLARY SECOND MOLAR Thedistobuccal surface of the 1st molar and buccal surfaces of the 2nd molar are slightly inwards and are placed so that all buccal surfaces of the 1st and 2nd molars follow a straight line.
- 20. MANDIBULAR FIRST MOLAR Whenthe mandibular first molar is placed in position without adjoining teeth, it is possible to determine its correct anteroposterior position more easily. intercuspation is very exacting, it is best done by placing the mandibular first molar in position first.
- 21. MANDIBULAR SECOND MOLAR Mandibular2nd molar is placed with the mesiobuccal cusp should engage between the maxillary 1st and 2nd molars and contact with their marginal ridges. The second mandibular molar is placed after the positioning of the first molar, thereby assuring its antero posterior correctness.
- 22. MANDIBULAR SECOND PREMOLAR The long axis of the tooth slopes slightly lingually when viewed from the front. The long axis of the tooth is parallel to the vertical axis when viewed from the side. Both the cusps are 2 mm above the level of the occlusal plane The buccal cusp of the 2nd premolar should occlude with the adjacent marginal ridges of the maxillary 1st and 2nd premolars. The mandibular second premolar is next placed, after another block of wax has been cut away from the occlusal rim.
- 23. MANDIBULAR FIRST PREMOLAR The Mandibular 2nd Molar The mandibular 2nd molar is placed with the mesiobuccal cusp should engage between the maxillary 1st and 2nd molars and contact with their marginal ridges. If the mandibular first premolar is positioned first, the inconstant vertical overlap might crowd the tooth into difficult intercuspation with the maxillary teeth, and this would be continued throughout all the mandibular posterior teeth. placement of the mandibular first premolar is left until last to take up all the variation in vertical and horizontal overlap of the anterior teeth. The first premolar is then ground to fit the remaining space
- 24. Setting the mandibularteeth first follow the form of the residual ridge. facial surface - perpendicular to the occlusal rim, slightly facial to the canine( never farther facially than the buccal flange.) long axis of the tooth - cusp tips are level with the remaining mandibular wax occlusal rim. The second premolar is set in a similar manner set into maximum intercuspation with the two lower premolars POSITIONING MANDIBULAR PREMOLARS MAXILLARY FIRST PREMOLAR If a space develops between the maxillary canine and first premolar, the maxillary first premolar is aligned with the canine, and the maxillary second premolar is positioned in the upper arch.
- 25. Positioning of mandibularand maxillary first molar central groove is placed on the canine to retromolar pad reference line. vertical height of the tooth is adjusted by positioning the cusp tips on the occlusal plane. Articulated with the mandibular first molar. Articulator is closed so that the mandibular tooth will assist in seating the maxillary tooth into maximum intercuspation. This will develop the desired lingual cusp contact of the maxillary molar in the central fossa of the mandibular antagonist. MANDIBULAR FIRST MOLAR MAXILLARY FIRST MOLAR Same procedure is used for setting the remaining maxillary teeth. The teeth on the opposite side of the dental arches are arranged in a similar manner.
- 26. Arranging Non anatomicalMandibular Posterior Teeth to Balanced Articulation The arrangement of nonanatomical posterior teeth with both anteroposterior and mediolateral compensating curves permits the establishment of a balanced articulation. mandibular teeth usually are arranged first followed by the maxillary teeth. The contours established in the wax occlusal rim and 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.
- 27. Number of posteriorteeth number of posterior teeth used in balanced articulation with nonanatomical teeth will be limited to three. It is more convenient to drop the first premolar and place the second premolar and the first and second molars into the available space. With the elimination of the first premolar and with the use of only three posterior teeth, it often is necessary to position the two molars slightly to the facial.
- 28. Anteroposterior compensating curves The amount of curvature developed is dependent on the steepness of the condylar guidance, but it rarely requires more than a combined 20-degree elevation of the occlusal surfaces of the posterior teeth from the horizontal plane of orientation established by the anterior and posterior reference points. The anteroposterior curve is developed to provide the needed tooth structure for balancing contacts in the protrusive movement.
- 29. Mediolateral compensating curves 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 guidances. The curve usually does not exceed 5 to 10 degrees from the horizontal plane of orientation when viewed in the frontal plane
- 30. First premolar Theposition of the first mandibular replacement tooth (second premolar) will be dictated by the position of the lower anterior teeth. The second premolar should be positioned immediately next to the canine, with no space allowed to detract from pleasing esthetics. 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.
- 31. First molar Positionthe 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 elevated. Distal of the first molar should be elevated approximately 1 mm above the occlusal plane (established by the anterior and posterior reference points.) The amount of elevation may need to be increased or decreased, depending on the mechanical equivalent recorded for the horizontal condylar guidance central fossa of the first molar should be slightly to the facial in relation to the reference line from the canine to the retromolar pad. frontal plane -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. High condylar guidance greater compensating curve long axis directed anteriorly. anteroposterior compensating curve begins with this tooth. avoid possible crowding of the tongue.
- 32. Second molar positionedwith the mesial marginal ridge at the same level as the distal marginal ridge of the first 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. long axis of this tooth also will be anteriorly directed. central fossa of the second molar also will be positioned slightly to the facial of the reference line. facial cusps of both the first and second molars should be in a straight line when viewed from the occlusal surface. The teeth should not be positioned “around” the remaining residual ridge. The mediolateral compensating curve should be continued as viewed in the frontal plane.
- 33. Remaining Mandibular PosteriorTeeth The mandibular posterior teeth are arranged for the other side of the arch with the same criteria and procedures as just outlined. As the remaining teeth are positioned, they should be evaluated in relation to the teeth on the opposite side of the arch. This is extremely important, especially in trying to maintain (1) the appropriate level of the occlusal plane (2) the same degree of anteroposterior and mediolateral compensating curves for both sides of the mandibular arch.
- 34. Arranging Non anatomicalMaxillary Posterior Teeth to Balanced Articulation 1st premolar For most patients, only three maxillary posterior teeth will be used. maxillary first premolar – longer occlusal cervical height (more esthetic 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. 1 to 2 mm of horizontal overlap of the maxillary facial cusp in relation to the mandibular facial cusp. prevent cheek biting will contribute to the attainment of a balanced articulation.
- 35. 1st molar 2ndmolar Position the maxillary first molar tooth alongside the premolar, aligning their marginal ridges and facial surfaces. Carefully close the articulator and establish contact between the maxillary occlusal surface and the central fossa or marginal ridges of the mandibular antagonist. Maintain maximum contact between the maxillary occlusal surface with the central fossa of the lower tooth and the 1 to 2 mm of horizontal overlap of the maxillary facial cusp in relation to the mandibular facial cusps. View the tooth-to-tooth relationships from the lingual by turning the instrument around and looking through the tongue space. Position the maxillary second molar tooth with a small cone of pink wax. Again, carefully close the articulator and establish the tooth contacts as you did with the first molar. Seal the tooth to the record base.
- 36. Remaining maxillary posteriorteeth 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. As the remaining teeth are positioned, they should be evaluated for the required contacts between the maxillary occlusal surfaces and the central fossae and marginal ridges of the mandibular antagonists. When all teeth have been properly positioned, they are sealed to the record base with pink wax and evaluated. Bilateral balanced articulation between the maxillary and mandibular teeth will be developed and refined after the dentures are processed with the selective occlusal reshaping procedures
- 37. WHICH IS FIRST? MAXILLARYOR MANDIBULAR most clinicians - mandibular teeth (provides better control of the orientation of the plane of occlusion both mediolaterally and superoinferiorly.) DECISION ON NUMBER OF TEETH available space for posterior teeth from the distal of the canine to the retromolar pad. If only three teeth are to be arranged, it is more convenient to drop the first premolar (less occlusal surface for the mastication of food.) REQUIREMENTS OF OCCLUSAL UNITS WORKING SIDE BALANCING SIDE efficient in cutting and grinding. They should contact on the second molars when the incising units contact in function.decreased buccal-lingual width should function as a group They should contact at the end of the chewing cycle when the working units contact. over the ridge crest in thf masticating area for lever balance surface to receive and transmit the force of occlusion essentially vertically. They should have smooth gliding contacts for lateral and protrusive excursions. center the work load near the anteroposterior center of the denture. plane of occlusion as parallel as possible to the mean foundation plane.
- 38. FACTORS OF TOOTH ARRANGEMENTVERTICAL DIMENSION CUSP HEIGHT COMPANSATING CURVES INCISAL GUIDANCE PLANE OF ORIENTATION CONDYLAR GUIDANCE
- 39. ARRANGEMENT OF ANTERIORTEETH The six upper and six lower teeth are set up in the arrangement dictated by the patient’s esthetic and phonetic requirements. Lock the Articulator into centric. The occlusal rims are then seated onto their casts at the established vertical and centric relation. Lower the Incisal Pin into contact with the “zero” horizontal Incisal Guide, the chisel end of the Pin resting crosswise on the center table and lock in position by the Thumbscrew. Verify or correct at this time, the alignment of the Incisal Pin chisel end with the “zero” indicating line on the Lateral Wings.
- 40. ANTERIOR GUIDE ONARTICULATOR It is a mechanical device which, together with the anterior pin, may be utilized to maintain the established occluding'vertical dimension and as a substitute for dental arch guidances which are to be established or which are already present. The guide itself should permit both anteroposterior and lateral adjustments. Very seldom is it a true copy of the actual incisal guidance represented by the occlusions of the anterior teeth, either present or to be arranged.
- 41. Incisal guidance Incisalguidance is the guiding influence which results from the positional relationships of the upper and lower anterior teeth when the mandible is moved into eccentric relations to the maxillae while the anterior teeth remain in contact. It is the guidance which results from the occlusions of the anterior teeth themselves and should not be confused with the inclines of the anterior guide of the articulator. Incisal guidance may or may not be one of the factors to be considered when arranging artificial teeth into balanced occlusion It depends upon which of two generally accepted methods of tooth arrangement is being used:
- 42. Method 1 Bythis method the upper and lower anterior teeth are arranged and tried in the patient's mouth. They are arranged to produce the best possible esthetic values for the individual patient. The resulting ineisal guidance is accepted as being a fixed factor and is used for adjusting the anterior guide on the articulator. geometric problem to be solved with posterior occlusal surface form and arrangement has been established for the individual patient.
- 43. Method 2 Sixupper anterior teeth and the upper posterior teeth are arranged on one side only. The lower first molar on the same side is positioned and, with its upper opponents, is arranged into the best possible centric, lateral, and protrusive occlusions, without grinding. The occlusions of this lower first molar with its opponents are then used for adjusting the anterior guide of the articulator. incisal guidance is the resultant of posterior tooth arrangement and is not a factor fixed in advance of posterior tooth arrangement All remaining posterior teeth are then arranged into balanced occlusion, and then the lower anterior teeth are arranged The amount of horizontal overjet (horizontal overlap) is established in the anterior tooth arrangement.
- 44. The maxillaryand mandibular anterior teeth should not make contact when the jaws are closed in centric relation. There should be not less than 2 mm of horizontal overjet in dentures for patients with normal ridge relations. Upper anterior teeth – esthetics Lower anterior teeth - over the crest of the remaining ridge, or at least within the labial border of the lower denture.
- 45. This completes adjustment ofthe anteroposterior portion of the anterior guide. ADJUSTMENT OF INCISAL GUIDE Gently guide the upper cast into a straight protrusion. The lingual edges of the upper central incisors are brought into contact with the incisal edges of the lower incisors The Incisal Guide is then rotated antero posteriorly to make contact with the Incisal Pin, tightening the small Locknut to maintain the angulation.
- 46. Lateral adjustment ofthe anterior guide RIGHT LATERAL The upper cast is then guided into a right lateral cuspid to cuspid guidance relation by thumb pressure at the right side of the upper cast to assure the Bennett Shift The Lateral Wing is then elevated to contact the corner of the Incisal Pin and the Locknut is tightened to maintain this adjustment.
- 47. LEFT LATERAL Apply thumbpressure at the left side of the upper cast and guide it into a left lateral cuspid to cuspid excursion Adjust the remaining Lateral Wing to contact the Incisal Pin and secure the adjustment by tightening the Locknut.
- 48. The properlyadjusted anterior guide now furnishes a hard metallic surface on which the anterior pin may glide without displacing the anterior teeth. The dotted lines illustrate the anterior guide adjustments.
- 49. ARRANGEMENT OF POSTERIORTEETH The remaining teeth are set into centric occlusion and checked in working, balancing and protrusive excursions. The Incisal Pin acts as the vertical stop and must remain in contact with the Incisal Guide surfaces from centric throughout all excursive movements. For minimal occlusal balance, there should be at least three points of contact on the occlusal plane. More the number of contacts, better the balance. Bilateral balanced occlusion can be protrusive or lateral balance.
- 50. Steep cuspsand prominent compensating curves are usually detrimental to complete denture stability because they result in unnecessary horizontal forces being directed onto the denture bases. Condylar guidances must be accepted as recorded Incisal guidance inclinations may and should be kept as fiat as practicable.
- 51. Factors of lateralbalance 1. The inclination of the condylar path on the balancing side 2. The inclination of the incisal guidance and cuspid lift. 3. The inclination of the plane of occlusion on the balancing side and working side. 4. The compensating curve on the balancing side and working side. 5. The buccal cusp heights or inclination of the teeth on the balancing side. 6. The lingual cusp heights or inclination on the working side. 7. The Bennett side shift on the working side.
- 53. PROBLEMS OF OCCLUSIONWHICH MAY OCCUR DURING POSTERIOR TOOTH ARRANGEMENT IN THE ARTICULATOR AND THEIR SOLUTION Premature occlusal contacts are accompanied by a lifting of the anterior pin from the surface of the anterior guide. The anterior pin should remain in contact with the platform of a properly adjusted anterior guide in all cast relations. An absence of desired occlusal contacts while the anterior pin is in contact with the anterior guide should be interpreted as an absence of occlusal contact.
- 54. Absence of contactin the posterior region with the casts in a protrusive relation To correct: 1. Increase the prominence of the anteroposterior compensating curve 2. Increase the cusp height progressively toward the posterior 3. Raise the plane of orientation in the posterior region. Premature contact in the posterior region with the casts in protrusive relation 1. Decrease the prominence of the anteroposterior compensating curve 2. Decrease the cusp height progressively toward the posterior 3. Lower the plane of orientation in the posterior region.
- 55. Absence of contacton the balancing side with the casts in a lateral relation 1. Increase the lateral cusp height on the balancing side, 2. Increase the prominence of the lateral compensating curve on that side 3. Raise the plane of orientation in the posterior region on that side. 1. Decrease the lateral cusp height on the balancing side, 2. Decrease the prominence of the lateral compensating curve on that side 3. If extreme, lower the plane of orientation in the posterior region on that side. Note. Do not decrease the lateral cusp height on the working side, because that would also require decreasing lateral incisal guidance on the working side and this would affect esthetics. Premature contacts on the balancing side with the casts in a lateral relation
- 56. Absence of contacton the working side with the casts in a lateral relation 1. If all other contacts are correct, increase lateral cusp height on the working side 2. If the error is very slight, spot- grind on the balancing side 3. Decrease the prominence of the lateral compensating curve on the working side (except when such procedure would result in this side being out of contact when it becomes the balancing side). Premature contact on the working side with the casts in a lateral relation 1. Increase the prominence of the lateral compensating curve on that side or 2. Grind the teeth on the working side, but first decide whether to do it by decreasing lateral cusp height or by increasing anteroposterior cusp height. First move the casts into protrusive relation to determine the needs of protrusive occlusion.
- 57. If theadjustment of the anterior guide has not been altered, and if the anterior pin remains in contact with it, this is not a premature contact but rather an absence of contact on the balancing side and should be treated as such. If reduction of the buccal cusps of the upper and lingual areas of the lower teeth would destroy the necessary protrusive occlusion contacts, then grind only those surfaces of both the upper and lower teeth which are complementary to the opposing cusps. In other words, deepen the lateral escapement grooves which oppose all cusps and rearrange these teeth. This procedure will relieve the premature contact in working occlusion and accentuate contact in protrusive occlusion and should always be given serious consideration before spot-grinding the occlusion of processed dentures or of natural teeth.
- 58. Premature contact ofthe anterior teeth with the casts in a protrusive relation To correct: I. Rearrange the lower anterior teeth closer to the lower ridge II. Use shorter lower anterior teeth III. Shorten them by grinding. This is a very unlikely error, because the anterior teeth were arranged first and the anterior guide was adjusted to harmonize with the arrangement. Unless the original anterior guide adjustment has been altered, the anterior pin adjustment hasbeen changed, or the anterior tooth arrangement has been altered, this problem is one of absence of contact in the posterior region and not one of premature contact in the anterior region.
Editor's Notes
- #5 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. These posterior references (retromolar pads) will place the overall plane at a level that is familiar to the tongue. If the plane is too low in the anterior region or too high in the posterior region, the maxillary denture will tend to slide forward. plane of occlusion should parallel the mean mandibular residual ridge. The height of the occlusal plane is not simply a matter of dividing the maxillomandibular denture space equally ( governed by the relative amount of bone lost from the two ridges) The most reliable guides are esthetics or anterior tooth placement and the retromolar pads.
- #6 The labial surfaces of the central incisors are usually 8 to 10 mm in front of the papillae vary with the size of the teeth and the labiolingual thickness of the alveolar process carrying the natural teeth, so it is not an absolute relationship. Furthermore, as severe resorption of the residual ridge in a vertical direction occurs, the incisive papilla may be located more posteriorly to the position of the replacement teeth. Thus the distance from the papilla to the labial surface of the teeth may become greater for those patients with excessive bone loss in the maxillary anterior region
- #7 This fact must be kept in mind when placing an artificial incisor in the wax occlusion rim. The root of the natural tooth extends into the alveolar process, with a relatively thin layer of bone over it labially. This means that in some situations the residual ridge can be used as a guide to determine the proper inclination of anterior teeth. However, the accuracy of this guide decreases as resorption of the residual ridge progresses. Clinical judgment is essential in the evaluation and application of these guides.
- #8 For the maxillary anterior teeth to be set with the appropriate labial orientation, it may be necessary to grind the acrylic resin to reduce the thickness of the record base. This is a common occurrence in clinical practice and should always be performed before grinding on the neck of the tooth.
- #9 Seal the tooth into position with pink wax, using the no. 7 spatula. Try to use only the amount of wax needed for securely attaching the teeth to the record base. Excess wax should be removed from the teeth.Place a small portion of soft, pink wax on the neck of the maxillary central incisor and attach the tooth to the record base over the anterior region of the residual ridge
- #10 After this tooth is arranged in the normal position for a lateral incisor, it may be repositioned with spacing, lapping, or rotation to meet the individual esthetic requirements for the patient.
- #11 Again, after initially setting the tooth to these guidelines, any individual changes necessary for the creation of naturalness for the patient should be performed.
- #12 Reducing the horizontal and vertical overlaps of the anterior teeth is necessary to reduce the incisal guide angle. It should be recognized that this reduction may have an impact on esthetics. dangers from a high incisal guidance far exceed the possible impact on esthetics that might be produced when the teeth are set with less horizontal and vertical overlaps. It is not necessary for the anterior teeth to contact in maximum intercuspation. In fact, it is better that they be set just out of contact 0.5-mm vertical overlap with the maxillary central and canine teeth. 1- to 2-mm horizontal overlap must exist between the lingual surface of the maxillary anterior teeth and the labial surface of the mandibular anterior teeth.
- #14 After these teeth are adjusted to this ideal arrangement, they may be altered by rotation, spacing, and tilting the teeth to achieve the naturalness requirement of the patient.
- #15 This is the space resulting from the removal of the posterior teeth and the loss of bone from the residual ridgesposition the teeth along a line extending from the tip of the canine to the middle of the retromolar pad. This arbitrary line should pass through the central fossa of the mandibular premolars and molars
- #23 It frequently needs to be ground because of the minimal space remaining between the second premolar and the canine after these teeth have been arranged in maximum intercuspation. For this reason, the tooth must be ground and shaped to fit the space available. The teeth on both sides of the dental arches are arranged in a similar manner.
- #25 Then the two mandibular premolars are repositioned to achieve maximum intercuspation with the maxillary premolars 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 Before the first premolar is positioned, a small section of the mandibular wax occlusal rim is removed to accommodate the first and second premolars. When these lower teeth have been arranged, a segment of the maxillary occlusal rim is removed to accommodate the first maxillary premolar, which is The mandibular first premolar may need to be adjusted mesiodistally to fit into the available space. Reshaping of the tooth by grinding usually will satisfy the space requirements. Maintenance of the occlusal plane by positioning the mandibular teeth at the appropriate height is of paramount importance as is the placement of their central grooves on the reference line from the tip of the canine to the retromolar pad. The first three premolars set (two mandibular and one maxillary) are the key to the relative anteroposterior intercuspation of all the remaining posterior teeth. Once the premolars are set and properly related to each other, positioning of the remaining mandibular posterior teeth is easily accomplished
- #26 The index finger is used to hold the cervical neck of the maxillary tooth in place while the articulator is closed.
- #28 Eliminating the first premolar is a logical choice because this tooth has less occlusal surface for the mastication of food.
- #33 When the arrangement is completed, the tooth is sealed to the record base with the hot no. 7 spatula
- #34 When all teeth have been properly positioned, they are sealed to the record base with pink baseplate wax.
- #35 In such instances, arrangement)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 only one premolar and two molars are the customary teeth selected. T
- #36 Seal the tooth with pink wax.
- #38 and place the second premolar and the first and second molars into the available space. to minimize the work force directed to the denture foundation. simultaneous harmonious contacts at the end of the chewing cycle and during eccentric excursions. Placing teeth on the residual ridge incline as it ascends to the pad should be avoided.
- #41 when properly adjusted its inclines will be concentric with (occasionally parallel with) the condylar guidances Steepest incline furnished by single or multiple inclines anywhere on the occluding dental arches at the occluding vertical dimension. With natural teeth this guidance might be furnished by two or more of the posterior teeth or by the anterior teeth. we should not think of the anterior guide of the articulator as pertaining only to the guidance furnished by the occlusion of the anterior teeth, but rather as the anterior, or third leg guide of the entire "mechanical" dental tripod which we call the articulator. The influence exerted by the inclinations of the incisal guidance upon posterior tooth form and arrangement is much greater than one might expect.
- #43 Although this method usually calls for more reshaping of posterior tooth forms than does the second method, it does offer the opportunity to produce dentures which best harmonize with the facial characteristics of the individual patient and is the method which I prefer.
- #44 While this method is a somewhat arbitrary one, it does require less skill than does the first method. It can be used to advantage by those who are forced to use awho desire to do a minimum of occlusal grinding during tooth arrangement. With this method the preselected posterior tooth form, and also by those
- #45 For some.patients this will result in a very extensive horizontal overjut, but their appearance is improved, and stability of the lower denture is increased over that which results when the upper anterior teeth are set too far lingually and when the lower anterior teeth are set too fa r labially. For several patients a horizontal overjut of at least 0.5 inch has produced most satisfactory results.
- #46 when moving the casts into protrusive relation, it may be noted that the lower end of the anterior pin has been raised from the fiat surface of the anterior guide. Tilt the anterior guide to make contact with the lower end of the anterior pin
- #50 The waxed occlusal rims may then be tried in the patient for esthetics, occlusal function and perhaps correction. The articulation is completed and the gingival and palatal is waxed. Reseat the completed occlusal rims onto their master casts. Seal the rims to the casts to preserve the tissue surface from plaster or stone seepage during the flasking procedure.
- #51 Steep Condylar guidances, steep incisal guidances, and combinations of them suggest prominent compensating curves with steep anteroposterior and lateral cusp height (steep slopes of the cusps).
- #54 Before making any of-the changes which will be suggested, the casts should be moved into all normal relations to each other to ascertain whether or not the suggested change or changes would destroy occlusions which have been satisfactorily established. Also, it should be determined whether the occlusal error is due to a premature (interceptive or deflective) occlusal contact or an absence of contact