Teeth Setting PDF

Tooth arrangement General Considerations for the Arrangement of the Anterior Teeth 1. The...

Tooth arrangement General Considerations for the Arrangement of the Anterior Teeth 1. The midline of the teeth should coincide with the facial midline 2. For most patients, the position of the incisal edge of the maxillary anterior teeth provides esthetics and phonetics, while the position of the cervical portion, or necks, of the teeth and the fullness of the maxillary denture base determines lip support (fullness of the lips) Tooth arrangement 3. The labial surfaces of the maxillary anterior teeth should generally be placed slightly labial to the surface of the labial flange. When viewed from the tissue side of the denture, a small but consistent amount of tooth should be present beyond the denture flange 4. A vertical overlap of the anterior teeth is not indicated unless specifically determined by the clinician. Marketing Department Mon. Feb. 21. 2018 Tooth arrangement Tooth arrangement Position of teeth 2- Lip Horizontal positions Anterior teeth 1-Incisive papilla Aid in determining the mid line Labial surfaces of the central incisors are usually 6- 8 mm anterior to the middle of incisive papilla 3- Crest of the ridge Upper anterior teeth anterior to the crest of the upper ridge Lower anterior teeth over the crest of the lower ridge Tooth arrangement Tooth arrangement Over bite: the vertical distance between the When arranging the mandibular anterior incisal edges of maxillary teeth, it is generally desirable to have some and mandibular teeth. horizontal and/or vertical separation of the opposing anterior teeth while in centric Over jet: the occlusion. This arrangement will minimize horizontal distance premature contact of the anterior teeth, between the incisal eliminating potentially excessive forces on the edges of maxillary and weaker anterior residual ridges. mandibular teeth. Tooth arrangement Tooth arrangement Vertical overlap is generally indicated for esthetic, phonetic, or functional The teeth should not be arranged with such a steep incisal guidance that the posterior teeth disclude in excursive movements. Christensen’sphenomena, the space that occurs between opposing occlusal surfaces during excursive movements, is not acceptable for complete denture patients. Tooth arrangement The occlusal rims contoured to hold the lips in proper position. The teeth properly set in the wax to maintain desired labial fullness. Factors governing the position of teeth: I. Anterior Teeth: Antero-posterior positioning of anterior teeth is important for esthetics and phonetics because of the support that teeth give to lips, cheeks and other tissues of the oral cavity. Therefore it is important to place anterior artificial teeth in the same position or in a position as close as possible to that occupied by natural teeth to maintain proper support of these tissues and natural patient appearance. Tooth arrangement Tooth arrangement The crest of the residual ridges aids in positioning the artificial teeth if the natural teeth are recently extracted. As resorption progresses, the crests of the residual ridges do not remain in their relative position, due to the pattern of alveolar bone resorption. The loss of bone structure is usually greater on the buccolabial aspect of the maxillary ridge than on the palatal aspect. This causes the crest of the residual ridge becomes more palatal than it was prior to extraction of the teeth. For this reason the incisive papilla is used as a useful anatomic guide in determining the anteroposterior and mediolateral position of maxillary anterior teeth, because of its constant relationship to the natural teeth. Tooth arrangement Tooth arrangement A line drawn on the cast anteroposteriorly bisecting the midsagital suture, incisive papilla and the labial frenum coincide with the midline of the upper dental arch. Mediolaterally, the central incisors are set on either side of this line. Anteroposteriorly, the central incisors are positioned so that the distance from the center of the incisive papilla to the labial surface of the central incisors is about 6-8 mm anterior to the middle of incisive papilla Tooth arrangement Tooth arrangement Note that, generally, a small but consistent amount of tooth should extend beyond the denture flange when viewed from the tissue side of the denture Tooth arrangement Tooth arrangement Arrangement of upper anterior Factors considered in the arrangement of teeth teeth pattern of bone resorption Esthetics and phonetics Occlusal plane 1 Harmony with contour of the ridge Contacts the incisal plane. Slightly deviated distally Slightly depressed neck Same contour with the arch  Tooth arrangement Tooth arrangement 2 1mm away from the inscisal plane The 2 central inscisors are usually set, Deviated distally followed by the lateral inscisor and cuspid on depressed neck one side& then the lateral incisor and the Same contour with the arch cuspid on the other side 3 Contacts the incisal plane Slightly deviated distally or perpendicular Prominent neck Same contour with the arch & ends at the canine line Tooth arrangement The incisal edges of the mandibular teeth should not be placed forward of a plane perpendicular to the center of the labial vestibule, and under no circumstances should they be positioned over the anterior land area of the cast Because of potential undesirable cantilever forces, the incisal edges of the mandibular anterior teeth should not be arranged beyond the center of the vestibule.These teeth are in excellent position. To minimize a significant horizontal overlap of the opposing anterior teeth, the incisal edges may occasionally be positioned over the land area. However, position of the teeth in this manner is a compromise. Arrangement of lower anterior teeth Tooth arrangement Canine 1 Contacts the incisal plane Even with the occlusal plane nearly perpendicular with slight distal inclination Perpendicular to the occlusal plane Prominent neck Slightly depressed neck inclination Same contour with the arch Same contour with the arch The maxillary canines are generally positioned so that the incisal cusp tip is at the same level as the central incisors. The long axis of the maxillary canine should 2 be vertical or inclined distally, with the cervical portion Even with the occlusal plane appearing prominent because of its labial position in relation to the lateral incisor. For esthetic purposes, Slightly deviated distally the canine should be rotated so that the distal half of Same contour with the arch the facial surface of the tooth is barely visible when viewed from the anterior  Setting Anterior Teeth – Incisal edges of central incisors & canines at level of the occlusal plane – Laterals placed approximately 1mm above the occlusal plane Cervical necks tilt posteriorly from the central incisor to the canine Tooth arrangement Tooth arrangement Setting Mandibular Anteriors Setting Mandibular Anteriors Incisal edges are placed at the same level Even with the occlusal plane Tooth arrangement Bucco-Lingual Tilt Bucco-Lingual Tilt Maxillary Anterior Teeth Mandibular Anterior Teeth Neck of central is slightly Central is proclined depressed Lateral is more Neck of lateral is depressed upright Neck of canine is prominent Canine has a prominent neck Central Canine Central Canine Tooth arrangement Tooth arrangement Anterior Tooth Setup No Anterior Insufficient Anterior teeth don’t Contact in Centric contact in centric position Overbite = 0mm Excessive Overjet = 2mm Correct Tooth arrangement Tooth arrangement Circumference Follows Arch Shape Central & lateral incisors must begin to turn along the curvature of the arch Tooth arrangement Tooth arrangement The alignment of the maxillary lateral incisors can be slightly altered to create a natural-appearing denture. Changes include altering the : (1) inclination of the long axis, usually distally (2) relationship to the incisal edges of the central incisors, (3) tooth width, (4) levels of the gingival margins , (5) tooth shade, and (6) shapes of incisal edges,angles, and proximal surfaces. However, as previously mentioned, most patients do not desire a characterized arrangement of the teeth but prefer a symmetrical arrangement. Tooth arrangement The dental laboratory technician should ensure that the individual tooth orientations combine to make the complete arrangement harmonize with the shape and relative positions of the residual ridges  Teeth Arrangement Order Tooth Arrangement (Posterior) Dr. Malak Bamigdad BDS KAU, Saudi Board in Prosthodontic dentistry General Considerations for the Arrangement of the Posterior Teeth General Considerations for the Arrangement of the Posterior Teeth 1. vertical overlap of the anterior teeth is occasionally indicated due to the esthetic, phonetic, or functional demands of 2. No Teeth on a slop (the retromolar pad) the patient. In case of Insufficient anteroposterior space for all four posterior teeth,(1st premolar or 2nd molar) is eliminated Eliminate 1st premolar for better chewing 3. Nonbalanced occlusion, the mandibular posterior For balance occlusion, posterior teeth arranged in compensating curve teeth are arranged on a flat occlusal plane with the long axes of the posterior teeth arranged perpendicular to the plane of occlusion  The central grooves and centers of the marginal ridges of the teeth should lie in one continuous line, which may be straight or have a slight curvature with the concavity being directed lingually or palatally Lingualized Occlusion Factors Affecting Balanced Occlusion 1. Condylar guidance 2. Compensating curve 3. Incisal guidance 4. Cuspal inclination 5. Plane of occlusion Mandibular Posterior Tooth Arrangement The distal surfaces of the canines are the most anterior position for placement of the first premolars. The distal limit to placement of mandibular molars is the The premolars should be arranged so that the buccal surface of the first premolar aligns beginning of the incline of the retromolar pad with the buccal surface of the canine. In achieving this relationship, the central groove of the first premolar should align with either the contact point between the canine and lateral incisor or the tip of the canine Posteriorly the mandibular molars, A line can be drawn along the crest of the mandibular residual ridges till the land area. particularly the second molar, should be positioned almost directly over the remaining residual ridges A guideline can now be visualized connecting the anterior (canine) to posterior (crest of ridge) guides. The correct alignment of the premolars and molars is indicated when the central grooves are centered on this line and all central grooves align with each other Posteriorly, the plane of occlusion is generally placed at the level of the middle to upper one-third of the retromolar pad and ideally is located midway between the maxillary and mandibular residual ridges and parallel to both ridges When alteration of the vertical height of the occlusal plane become necessary, generally because of a lack of interocclusal clearance, the plane should be lowered whenever possible. Lowering the plane will decrease the height of the denture teeth above the mandibular residual ridges, decrease cantilever forces, and increase the stability of the mandibular denture.  Maxillary Posterior Teeth For a lingualized occlusion, either balanced on nonbalanced, the maxillary For a conventional balanced occlusion, When correctly posterior teeth are arranged so that the buccal cusps of the opposing arranged there is: (1) minimal spacing between the opposing occlusal surfaces in centric teeth are approximately 0.5 mm above the antagonist teeth when the occlusion, (2) anterior and bilateral cross-arch contact in all excursive movements, and articulator is moved into the working position cross-tooth contact on the working side The maxillary posterior teeth, especially second molars, must be arranged to provide adequate buccal overlap to minimize cheek biting Ideally the lingual cusps of the maxillary teeth are centered on the central grooves and marginal ridges of the mandibular teeth ( the buccal surfaces of the maxillary teeth to be more buccally positioned than the buccal surfaces of the mandibular teeth) When the natural teeth have been extracted, the mandibular ridge resorbs downward and outward while the maxillary ridge resorbs upward and inward. Only in the second molar area, while a normal alignment exists in the Because of these resorptive patterns, it may be necessary to create a reverse first premolar area called (a partial reverse articulation) articulation (crossbite) for the posterior teeth. The reverse articulation (crossbite) (crossbite) A balanced occlusion will have both bilateral contacts of the posterior teeth and simultaneous anterior contacts in all excursive movements.