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Invisalign
1. By-
Dr. Nishat Tasnim Oishi
Intern ID: 818
Bangladesh Medical & Dental College
Supervised by
Dr. Abu Syeed Mohammad Manjurul Karim
BDS, Lecturer (Bangladesh Medical & Dental College)
3. INTRODUCTION
• The first clear aligner was introduced by Kesling in the
early 1940s. Although it didn’t gain much popularity
back then, now a days, with the development of dental
materials and 3D technology, clear aligners became more
popular.
• Invisaligns are an alternative to traditional braces and are
designed to help guide teeth into there proper position by
using a gradual force, but without metal wires or
brackets.
4. • Its made up of a transparent, thin plastic material
formed with CAD-CAM (computer-aided-design and
computer-aided-manufacturing) laboratory techniques.
• Each aligner is planned to move the teeth a maximum
of about 0.25 to 0.3 mm in 2 week.
• For maximum effective treatment , the appliance has to
be worn a minimum of 20-22 hours a day and 400 hours
in total(20 days).
• Invisalign uses less force compared to braces during
teeth straightening.
7. INDICATION
• Malaligned and Mild crowded teeth (1-5 mm)
• Class II div 2 cases (deepbite)
• Class II div 1 cases ( openbite, overejet)
• Class I (rotation, tilting)
• Class III malocclusion (underbite)
Mild to
Moderate cases
8. • Crossbite
• Spacing problems (1-5 mm)
• Narrow arches.
• Tip molar distally
• Lower incisor extraction for severe crowding cases.
11. ADVANTAGES
• The trays are aesthetic as it is clear and also
comfortable as no metal brackets or wires are there
which lead to laceration of mouth
• Clear aligners are invisible and it gives confidence to
patient to smile.
• Better oral hygiene as compared to fixed appliances.
12. • Shorter dental appointments..
• More precised treatment duration than braces
• Less frequent trips to the dental chair by allowing the
patients to replace their aligners on their own every
few weeks.
• Unaltered speech
13. DISADVANTAGES
• Very much costly.
• Removable in nature.
• Patient motivation required.
• It should be worn 22 hours/ day.
• Devices should be removed during meals.
• Missed appointments and deprived oral hygiene
lengthen treatment time and affect quality results.
14. CONTRAINDICATED CASES
• Still having primary teeth present
• Severe malocclusion cases
• Extraction cases
• Having missing teeth, it may not be able to close them
• Using dentures
• Having a dental bridge, because teeth are joined together
• Having gingival disease or periodontal disease.
• Having short, round, pegged shaped teeth.
15. EFFICIENCY, EFFECTIVENESS & TREATMENT
STABILITY ( COMPARED TO CONVENTIONAL METHOD)
Based on different research groups -
• Total treatment time: Conventional group(braces)
was significantly longer than that of the invisalign
group.
• Chair time, appointments & emergency visits:
Conventional groups required more visits, more
emergency visits, more emergency chair time and a
greater total chair time compared to invisalign groups.
16. • Treatment outcomes: According to the OGS
(objective grading system) Invisalign Did not treat
malocclusion as well as conventional braces, basically
it showed lower score for buccolingual inclination,
occlusal contact, occlusal relationships & overjet.
• Stability: The post-retention dental changes in the
invisalign group was significantly larger than that of
the conventional brace group.
17. TOOTH MOVEMENT PREDICTABILITY
Tooth movement Predictability
Crowding or spacing per arch Up to 6mm
Midline discrepancy Up to 2mm
Central incisor rotation Up to 40º
Lateral incisor rotation Up to 30º
Canine and premolar rotation Up to 45º
Molar rotation Up to 20º
Anterior intrusion Up to 2.5mm
Anterior extrusion Up to 0.5mm
Posterior intrusion Up to 0.5mm
Posterior extrusion 0mm
18. INVISALIGN AUXILIARIES
Invisalign is not based on aligners only. It requires the use
of auxiliaries such as-
• Attachments
• Interarch elastics
• Interproximal reduction (IPR)
• Altered aligner geometries (use of pressure points within
the aligner to deliver forces)
These are used to improve grip between aligner and tooth ,
which improves the predictability of orthodontic treatment.
19.
20. CONCLUSION
All in all invisalign is a great alternative to braces,
owing to its comfort level and ease to use. Though its
not very cost effective, we hope in the future newer
technology and materials will make it more affordable.
More research in the field of complex tooth movement
is still needed, but apart from that, invisalign has the
potential to replace conventional orthodontic appliance
in case of mild to moderate maloccusion.