**Tooth Set-Up Guide – Secrets to a Perfect Smile**

Tooth Set-Up Guide – Secrets to a Perfect Smile

Tooth set-up is an important part of the tooth restoration process, helping you achieve a beautiful smile and good chewing function. When choosing a type of restoration, you need to consider the pros and cons of each type:

Porcelain Teeth:

• Pros:

• High hardness

• Natural color, similar to real teeth

• Does not change color over time

• Good wear resistance

• Does not absorb saliva, limits bacteria that cause bad breath

• Does not age

• Cons:

• Brittle, easy to break

• Too hard, can make opposing teeth brittle

• Difficult to set up, requires high technical skills

• Difficult to adjust the fit when fitting dentures

• There is a clicking sound when chewing if both jaws are made of porcelain

• Poor retention on plastic bases

Plastic Teeth:

• Pros:

• Good retention in plastic bases

• No clicking sound when chewing

• Easy to grind to size for tooth set-up

• Easy to adjust fit when fitting dentures

• Less prone to chipping

• Cons:

• Wear quickly

• Easy to change color over time

• Aesthetics are not as good as porcelain teeth

• Easy to absorb saliva, harder to clean than porcelain teeth

• Age over time

Tooth Shape:

• Williams Tooth Shapes: 3 main types corresponding to the inverted shapes of the face: Square, triangle, oval.

• Nelson’s Triad: The shape of the upper central incisor (the peak is the neck of the tooth) is related to the shape of the arch (the peak is the gap between the two central incisors) and the shape of the face (the peak is the chin).

• Lee Index:

• The width of the upper central incisor is 1/4 of the distance between the two wing of the nose.

• The distance between the two bridges of the nose is equal to the distance between the two sharp peaks of the canine teeth.

• Height of the upper central incisor:

• Upper limit: the neck of the tooth coincides with the smile line.

• Lower limit: when the patient is in a state of relaxed peripheral muscle contraction, the upper incisor protrudes 1.5-2mm.

Tooth Set-Up:

• Set-up of the upper central incisor:

• GX direction (Stage): Straight

• NT direction (Axis tilt): Tilt inwards by 5 degrees

• TD direction (Occlusal plane contact): Occlusal edge touches the occlusal plane

• Set-up of the upper lateral incisor:

• GX direction: Tilt distally by 5 degrees

• NT direction: Tilt inwards by 10 degrees

• TD direction: 1mm away from the occlusal plane

• Set-up of the upper canine tooth:

• GX direction: Tilt distally by 5 degrees

• NT direction: Tilt inwards by 5 degrees

• TD direction: The cusp touches the occlusal plane

• Set-up of the lower central incisor:

• GX direction: Straight

• NT direction: The neck of the tooth tilts slightly inwards

• TD direction: The occlusal edge of the UCI (Central incisor) covers the LLI (Lateral incisor) by 1-2mm

• Set-up of the lower lateral incisor:

• GX direction: Tilt distally by 2 degrees

• NT direction: Vertical

• TD direction: The occlusal edge of the UCI covers the LLI by 1-2mm

• Set-up of the lower canine tooth:

• GX direction: Tilt distally by 5 degrees

• NT direction: Tilt slightly outwards

• TD direction: The mesial surface of the upper canine tooth contacts the distal surface of the lower canine tooth

• The most important role of the anterior tooth set-up: Aesthetics.

• Order of setting up the molars: 4T – 5T – 6T – 7T – 6D – 7D – 5D – 4D

• Angle’s classification of occlusion:

• Class I: The anteroposterior relationship of the upper and lower molars is neutral, the mesiobuccal cusp of the upper molar corresponds to the mesiobuccal groove of the lower molar. Malocclusion occurs in the anterior region.

• Class II: The anteroposterior relationship of the upper and lower molars is distal, the mesiobuccal cusp of the upper 6th molar is anterior to the mesiobuccal groove of the lower 6th molar (overjet).

• Class III: The anteroposterior relationship of the upper and lower molars is mesial, the mesiobuccal cusp of the upper 6th molar is posterior to the mesiobuccal groove of the lower 6th molar (underjet).

• Anterior tooth set-up in the horizontal plane:

• The buccal surfaces of the two upper central incisors are 6-8mm away from the incisal guide, the line passing through the incisal guide also passes through the cusp of the two canine teeth.

• The distance from the palatal peak to the cusp of the canine tooth is 10mm.

• Thielemans’ formula: (Inclination of the condylar path x Inclination of the incisal guide)/(Occlusal plane x Compensatory curve x Cusp height)

• Arrangement of the lower molars: The cusp of the mesial (mesial) of the upper 6th tooth is located in the mesial (mesial) groove of the lower 6th tooth.

Note: Tooth set-up is a complex process that requires precision and experience from the dentist. Please consult a reputable dentist for advice and treatment for safe and effective service.