Tooth Arrangement - Presentation PDF

Tooth arrangement Marketing Department Mon. Feb. 21. 2018 Tooth arrangement Tooth arrangement Tooth arrangement Objectives How to arrange the anterior artificial teeth. Importance of vertical and horizontal overlap. Tooth arrangement General Considerations for the Arrangement of...

Tooth arrangement Marketing Department Mon. Feb. 21. 2018 Tooth arrangement Tooth arrangement Tooth arrangement Objectives How to arrange the anterior artificial teeth. Importance of vertical and horizontal overlap. 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) 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. Tooth arrangement Position of teeth 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 Tooth arrangement 2- Lip 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 Over bite: the vertical distance between the incisal edges of maxillary and mandibular teeth. Over jet: the horizontal distance between the incisal edges of maxillary and mandibular teeth. Tooth arrangement When arranging the mandibular anterior teeth, it is generally desirable to have some horizontal and/or vertical separation of the opposing anterior teeth while in centric occlusion. This arrangement will minimize premature contact of the anterior teeth, eliminating potentially excessive forces on the weaker anterior residual ridges. 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 The teeth properly set in the wax to hold the lips in proper position. maintain desired labial fullness. Tooth arrangement 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 understand 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 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 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 of previous summary Factors considered in the arrangement of teeth pattern of bone resorption Esthetics and phonetics Occlusal plane Harmony with contour of the ridge Tooth arrangement Arrangement of upper anterior teeth centrals upper lover must cover 1 Centrals vertical Overlap Contacts the incisal plane. Slightly deviated distally Mesial incline of canine is upper Slightly depressed neck with Distal incline Same contour with the arch of Lowercanine  Tooth arrangement 2 1mm away from the inscisal plane Deviated distally depressed neck Same contour with the arch 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 2 central inscisors are usually set, followed by the lateral inscisor and cuspid on one side& then the lateral incisor and the cuspid on the other side  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  Tooth arrangement 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 1 Even with the occlusal plane Perpendicular to the occlusal plane Slightly depressed neck inclination Same contour with the arch 2 Even with the occlusal plane Slightly deviated distally Same contour with the arch Tooth arrangement Canine Contacts the incisal plane nearly perpendicular with slight distal inclination Prominent neck 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 be vertical or inclined distally, with the cervical portion appearing prominent because of its labial position in relation to the lateral incisor. For esthetic purposes, the canine should be rotated so that the distal half of 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 Setting Mandibular Anteriors Tooth arrangement Setting Mandibular Anteriors Incisal edges are placed at the same level Even with the occlusal plane  Bucco-Lingual Tilt Maxillary Anterior Teeth Neck of central is slightly depressed I Neck of lateral is depressed Neck of canine is prominent Central Canine Tooth arrangement Bucco-Lingual Tilt Mandibular Anterior Teeth Central is proclined Lateral is more upright Canine has a prominent neck Central Canine Tooth arrangement Anterior Tooth Setup jump Anterior teeth don’t contact in centric position Overbite = 0mm Overjet = 2mm Tooth arrangement in No Anterior Insufficient Contact in Centric Excessive Correct Tooth arrangement Central & lateral incisors must begin to turn along the curvature of the arch 2Canines same at level Tooth arrangement Circumference Follows Arch Shape Tooth arrangement Tooth arrangement understand 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 Thank You