ARRANGEMENT OF ANTERIORARTIFICIAL TEETH DR TALIB AMIN
TABLE OF CONTENTSINTRODUCTIONOBJECTIVESRESORPTION PATTERN IN MAXILLA AND MANDIBLEBASIC FACTORS INVOLVED IN POSITIONING OFANTERIOR TEETHINDIVIDUAL ARRANGEMENT OF ANTERIOR TEETHTOOTH ARRANGEMENT IN DIFFERENT ARCH FORMSARRANGEMENT OF TEETH INFLUENCED BY AGE, SEX ,PERSONALITY, COSMRTIC FACTOR & CHARACTERIZATIONREFERENCES
INTRODUCTION Anterior teeth arrangement is an area of Prosthodontics where Art dominates science, where esthetics is the major concern, and where knowledge must be applied to create a pleasing appearance while simultaneously maintaining oral function.
Objectives• Anterior artificial teeth are arranged primarily for esthetics.• Proper lip support.• Permit satisfactory phonetics.• Function.
Studies conforming importance of esthetics in complete denturesBrewer, Reibel and Nassif JPD 1967 _ 12 patients received 7 sets of dentures each made by 7 dentists. _ Each patient preferred the best looking dentures.Straus et al. JPD 1977 – 64 patients were asked how their new complete dentures improved their self image. – Nearly all the patients responded that the new dentures improved their appearance, increased self confidence, and provided an overall sense of well being.
Technically, the anterior teeth are composed of6 maxillary and 6 mandibular teeth.Exceptions: Sometimes maxillary first premolar is considered more for esthetics than for masticatory function. Sometimes in Class 2 situations maxillary cuspids assume a functional role by addition of lingual centric stops.
Payne states “set the teeth in place wherethey grow.” Payne SH MEDCOM Inc , 1973Ridge resorption have a major effect on the position ofanterior teethMandibular ridge is used to determine arch form dueto resorption of maxillary ridge.
• In maxilla, resorption is centripetal. It occurs on the labial and buccal areas• Consequently, the residual ridge is usually palatal to the original location of natural teeth.• Hence teeth should be arranged labial to the resorbed maxillary arch
The facial surface of the central incisors should be 8-10 mm anterior to the center of the incisive papilla.Schiffman :Relation of maxillary canines tothe incisive papilla JPD 1964;14:469-472Watt and Like man states “the distal surface caninesshould be located in a coronal plane passing through theposterior border of the papilla” 8 to 10mmThe tips of the canines are frequently +_1mm related to centre ofpapilla.The incisive papilla can also be used to help locate themidline of dental arc ZARB - BOLENDER
The use of phonetics can also be used as a guide in theplacement of maxillary anteriors
• In mandible resorption is centrifugal. It occurs anteriorly on the labial side and posteriorly on the lingual side. In the premolar region it occurs equally labially and lingually.• Hence teeth should be arranged anteriorly labial to the resorbed mandibular ridge• Functional recording of neutral zone for the arc form can be done in advanced cases of resorption
5 factors are involved in positioning anterior teeth.Anterior slope - Labial inclination.Mesiodistal inclination - Mesial or distal tilt.Inferior-superior positioning - to a horizontal plane - Above/below plane of occlusion.Rotation on a long axis - Turning tooth on its center axis.Antero-posterior positioning - How far labially or lingually (in or out) the anterior or posterior teeth are located.
Maxillary central incisors The maxillary central incisor is the most difficult tooth to set because1. Establishes the midline2. Esthetic support of the patients lip3. Proper arrangement of maxillary and mandibular anterior and posterior teeth relies on the setting of the maxillary central incisor ZARB-BOLENDER 12TH EDITION Pg311
1.Mesiodistal inclination Its long axisslopes towards the vertical axis 2.Inferior-superior positioning Theincisal edge should touch themandibular occlusion rim 3.Labial inclination Slopes labiallyabout 15 degrees when viewed from theside. FENN The contact point should coincide withthe midline of the face
Maxillary lateral incisors 1. The long axis should incline slightlydistally in the cervical area2. The cervical portion of the tooth shouldincline slightly lingually (neck is slightlydepressed) 3. The incisal edge of the lateral should beraised approximately 0.5 to 1mm from themandibular occlusion rim. 4.Inclined labially about 20 degrees whenviewed from the side FENN
Maxillary canines• In nature, the position of the canine teeth plays an important part in the esthetic appearance of the dentition.• In a denture they play an equally important role.• They have esthetic and functional influence on both the anterior and posterior tooth arrangements
1. The incisal edge of the canine should touch the mandibular occlusion rim. 2. The long axis should be perpendicular to the occlusal plane. 3.Canines are arranged on the line drawn perpendicular to the midline of the palate, through the centre of incisive papillaSheldon Winkler 2nd edition pg 203
• Viewed from the anterior, the mesiolabial surface of the canine is prominent, and the gingival one-third is positioned more facially than the incisal one-third. Prominent neck
• Profile or side view emphasizes the almost vertical long axis and position of the canine.
• 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. ZARB-BOLENDER 12TH EDITION Pg311
Mandibular central incisors• 1. The long axis of the mandibular central incisor should be set perpendicular to the occlusal plane.• 2.It slopes slightly labially when viewed from the side 3. The contact point of mandibular incisors should coincide with the midline of the maxillary teeth.
ZARB-BOLENDER 12TH EDITION Pg312Set the mandibular central incisors so that themaxillary incisors cover them, 0.5mm verticallyand there is 1-2mm horizontal overlap. This willcreate a low incisal guidance ideal for the patient
Mandibular lateral incisors• 1. The long axis of the mandibular incisor should be slightly inclined distally at the cervical portion of the tooth.• 2. The occlusal height should be the same at the central incisors.• 3. there is no labial inclination when viewed from the side
Mandibular canines1. The long axis of the mandibular canine isnearly perpendicular with a slight lingual anddistal inclination to the occlusal plane2. The tip of the canine should be at the sameocclusal height as the mandibular central andlateral incisor
Tooth Arrangement in the Square Arch• The two centrals are usually set to an almost straight line across the front of the arch.• The laterals are also positioned with a nearly full labial aspect and exhibit very little rotation. This give prominence to the canines.• The teeth also tend to be straight up and down, rather than sloping
Tooth Arrangement in the Tapering Arch• Rotation of the centrals on their long axis inward at the distal, which sets the two teeth at an angle.• Rotation and lapping of teeth is often observed , and crowding is a result.• This often reduces the amount of labial surface visible.
Tooth Arrangement in the Square Tapering Arch• The Square Tapering arrangement combines characteristics of the Square and Tapering forms, modifying both.
Tooth Arrangement in the Ovoid Arch• The Ovoid arrangement exhibits definite curvature; rotation is seldom observed.• The central incisors in the Ovoid anterior arch are often set well forward of the canines.• A typical Ovoid alignment shows a fullness of labial surface from canine to canine.
Arrangement of teeth is influenced by• Age• Sex• Personality• Cosmetic factor• Artistic reflection Heartwell 5th edition Pg 339
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• Middle age – incisal wear, mild staining slight spacing due to drifting, which can be incorporated in the dentures.• Old age – long axis is not in alignment, gum recession, erosion natural staining, occlusal and incisal wear caused by habit.
• The displayed amount of anterior teeth is determined by muscle position that varies from one person to another, and with age Tjan AH, Miller GD, Some esthetic factors in a smile J PD 1984 Jan;51(1):24-8• The lips and cheeks are supported by teeth, not by denture borders
Display of maxillary central incisors decreases with age and is concurrently accompanied by a gradual increase in the display of mandibular central incisors Reason :With age muscle tone decreases as a result lower lip sags and upper lip dropsThe Journal of Contemporary Dental Practice, Volume 5, No. 1, February 15, 2004
• Teeth abrade with age• The centrals and laterals abrade in a straight line• Canines abrade in a curve• The abrasion of the incisal edges of anterior teeth flattens the arch
Gingival tissues recede with age,recession can be reproduced by: Long tooth Contouring the wax, and then staining it a bit
• For complete denture patients, a guideline was suggested to adjust the vertical length of the maxillary occlusion rim in the anterior region by extending it approximately 2 mm below the relaxed lip• Conversely, reduction in the amount of maxillary anterior teeth visibility contributes to the early perception of aging of individuals in their 40s
• Femininity is expressed by roundness, smoothness and softness• Distal surface of central incisors are rotated in posterior direction
Squareness denotes masculanityNo distal rotations in males
“Smile Line” (maxillary incisal edges) shouldfollow the line of the lower lip in smiling infemales Sheldon Winkler 2nd edition pg203
• In males central incisors are on a horizontal plane parallel with the lip, laterals are above the plane and canines are on the plane. Sheldon Winkler 2nd edition pg 343
• With the lips at rest, females display more maxillary central incisors than males. Vig RG, Brundo GC. The kinetics of anterior tooth display. J P D 1978 May;39(5):502-4.
• The males displayed more of the maxillary lateral, canine, and mandibular anterior teeth than the females Frush JP, Fisher RD. How dentogenic restorations interpret the sex factor. J P D 1956; 6: 160-72
CONSIDERATIONSHabitual patterns and qualities of behavior.Profession and public appearance of the patient
For executives, the teeth should be relatively smaller and more symmetrically arranged
More squarish, large teeth are selected for vigrous people
Vigor• A characteristic of the bold, vigorous face is the dominant size and alignment of the teeth.• larger size of the lateral incisors and canines, and their straight bold arrangement• Vigor and boldness are not necessarily solely masculine characteristics, since strong, bold faces may be found in many female patients.
Softness• Softness in a tooth arrangement is a reduction of the labial surface in terms of its visual appearance.• A rounded form with an ovoid outline is far softer to the eye than a straight line or a flat plane
Individuals with shorter upper lips display moremaxillary central incisor surface than people withlonger upper lips, and those with longer upper lipshow more mandibular central incisors
• Cosmetic factor involves personal grooming.• For a person who dresses neatly, is well groomed, the artificial teeth should complement these efforts.• For a person who dresses unpleasantly , has bushy unkempt eyebrows and hair, if too much strived for refinement in the arrangement ,the teeth would not be in harmony with their settings and would therefore appear more artificial. Heartwell 5th edition Pg 345
• Artistic reflection is the arrangement of teeth to reflect the dentists concept of what appears natural for the patient.• It should be acceptable to the patient• Synonym: characterization
Characterization It is the modification of the form and color ofthe denture base and teeth to produce a morelifelike/natural appearance Glossary of prosthodontic terms It enhance the natural appearance of theindividual.
• Hardy stated that, “To meet the esthetic needs of the denture patient, we should make the (denture) teeth look like (the patient’s) natural teeth” Hardy IR. Problem solving in denture esthetics. DCNA 1960:305-20
• Varying the direction of the long axis of teeth.• Create asymmetry Martone stated that, “The key to esthetics lies in asymmetry.” Martone AL. Effects of complete dentures on facial esthetics. JPD 1964;14(2):231- 55.• Use of eccentric midline
Asymmetry and its influence on tooth arrangementSmile created using only the right side of the natural smile Natural smile showing asymmetry
• Placement of one tooth parallel to midline and slight rotation of contra lateral tooth posteriorly• Slight anterior placement of one central incisor to other central incisor• Place the neck of one maxillary central incisor in a posterior direction and the neck of other central incisor in an anterior direction.• Spacing and diastemas often exist in natural dentition
References1. Brewer, Nassif and Reibel JPD 19672. Clinical dental prosthetics by FENN 3rd Edition Pg 110-1123. Frush JP, Fisher RD. How dentogenic restorations interpret the sex factor. J Prosthetic Dent 19564. Glossary of Prosthodontic Terms5. Heartwell CM , Rahn AO. Textbook of complete denture6. Hardy IR. Problem solving in denture esthetics. DCNA 1960:305-207. Martone AL. Effects of complete dentures on facial esthetics. JPD 1964;14(2):231-55.8. Payne SH MEDCOM Inc , 1973
9. Rudd and Marrow10. Schiff man :Relation of maxillary canines to the incisive papilla JPD 1964;14:469-47211. Sheldon Winkler 2nd edition12. Straus et al. JPD 197713. The Journal of Contemporary Dental Practice, Volume 5, No. 1, February 15, 200414. Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthetic Dent. 1984 Jan;51(1):24-815. Vig RG, Brundo GC. The kinetics of anterior tooth display. J P D 1978 May;39(5):502-4.16. Zarb GA, Bolender CL, Carlsson GE. Boucher’s prosthodontic treatment for edentulous patients.