arrangement of anterior artificial teeth

ARRANGEMENT OF ANTERIOR ARTIFICIAL TEETH

DR TALIB AMIN

TABLE OF CONTENTS

INTRODUCTION

OBJECTIVES

RESORPTION PATTERN IN MAXILLA AND MANDIBLE

BASIC FACTORS INVOLVED IN POSITIONING OF ANTERIOR TEETH

INDIVIDUAL ARRANGEMENT OF ANTERIOR TEETH

TOOTH ARRANGEMENT IN DIFFERENT ARCH FORMS

ARRANGEMENT OF TEETH INFLUENCED BY AGE, SEX , PERSONALITY, COSMRTIC FACTOR & CHARACTERIZATION

REFERENCES

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.

INTRODUCTION

Objectives

• Anterior artificial teeth are arranged primarily for esthetics.

• Proper lip support.• Permit satisfactory phonetics.• Function.

Studies conforming importance of esthetics in complete dentures

Brewer, 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 of 6 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 where they grow.” Payne SH MEDCOM Inc , 1973

Ridge resorption have a major effect on the position of anterior teeth

Mandibular ridge is used to determine arch form due to 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

8 to 10mm

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 to the incisive papilla JPD 1964;14:469-472

The incisive papilla can also be used to help locate the midline of dental arc ZARB - BOLENDER

Watt and Like man states “the distal surface canines should be located in a coronal plane passing through the posterior border of the papilla”

The tips of the canines are frequently +_1mm related to centre of papilla.

The use of phonetics can also be used as a guide in the placement 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 because

1. Establishes the midline

2. Esthetic support of the patients lip

3. 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 axis slopes towards the vertical axis

2.Inferior-superior positioning The incisal edge should touch the mandibular occlusion rim

3.Labial inclination Slopes labially about 15 degrees when viewed from the side. FENN

The contact point should coincide with the midline of the face

Maxillary lateral incisors

1. The long axis should incline slightly distally in the cervical area 2. The cervical portion of the tooth should incline slightly lingually (neck is slightly depressed)

3. The incisal edge of the lateral should be raised approximately 0.5 to 1mm from the mandibular occlusion rim.

4.Inclined labially about 20 degrees when viewed 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 papilla

Sheldon 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.


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.

Set the mandibular central incisors so that the maxillary incisors cover them, 0.5mm vertically and there is 1-2mm horizontal overlap. This will create 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 canines

1. The long axis of the mandibular canine is nearly perpendicular with a slight lingual and distal inclination to the occlusal plane

2. The tip of the canine should be at the same occlusal height as the mandibular central and lateral incisor

RUDD AND MARROW

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

Age

AGE

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

The Journal of Contemporary Dental Practice,

Volume 5, No. 1, February 15, 2004

Reason :With age muscle tone decreases as a result lower lip sags and upper lip drops

• 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 masculanity

No distal rotations in males

“Smile Line” (maxillary incisal edges) should follow the line of the lower lip in smiling in females


• In males central incisors are on a horizontal plane parallel with the lip, laterals are above the plane and canines are on the plane.


• 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

CONSIDERATIONS

Habitual 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 more maxillary central incisor surface than people with longer upper lips, and those with longer upper lip show more mandibular central incisors

COSMETIC FACTOR

• 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

• 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 of the denture base and teeth to produce a more lifelike/natural appearance

Glossary of prosthodontic terms

It enhance the natural appearance of the individual.

• 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 tootharrangement

Smile 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

References 1. Brewer, Nassif and Reibel JPD 1967

2. Clinical dental prosthetics by FENN 3rd Edition Pg 110-112

3. Frush JP, Fisher RD. How dentogenic restorations interpret the sex factor. J Prosthetic Dent 1956

4. Glossary of Prosthodontic Terms

5. Heartwell CM , Rahn AO. Textbook of complete denture

6. Hardy IR. Problem solving in denture esthetics. DCNA 1960:305-20

7. Martone AL. Effects of complete dentures on facial esthetics. JPD 1964;14(2):231-55.

8. Payne SH MEDCOM Inc , 1973

9. Rudd and Marrow

10. Schiff man :Relation of maxillary canines to the incisive papilla JPD 1964;14:469-472

11. Sheldon Winkler 2nd edition

12. Straus et al. JPD 1977

13. The Journal of Contemporary Dental Practice, Volume 5, No. 1, February 15, 2004

14. Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthetic Dent. 1984 Jan;51(1):24-8

15. 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.

Thank you

arrangement of anterior artificial teeth

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