Evidenced Based Dentistry Spring 2006 Group 4 Kevin Hancock Jess Havron Bayne Heersink Alec Helms Nathan Johnson

Is Invisalign ® orthodontics better for most young adult patients? What are the pros and cons of this method versus conventional orthodontics?

Is Invisalign ® orthodontics better for most young adult patients?

What are the pros and cons of this method versus conventional orthodontics?

What is Invisalign ® ? A series of clear plastic aligners Made of thin, see-through plastic Fit over the buccal, lingual, and occlusal surfaces of teeth Photo: Invisalign.com

A series of clear plastic aligners

Made of thin, see-through plastic

Fit over the buccal, lingual, and occlusal surfaces of teeth

What is Invisalign ® ? Bite impressions are made. 3-D computer imaging technology is used to transform the bite impressions into a custom-made series of clear and removable aligners. Photo: Invisalign.com

Bite impressions are made.

3-D computer imaging technology is used to transform the bite impressions into a custom-made series of clear and removable aligners.

What is Invisalign ® ? Worn for a minimum of 20 hours per day (removed for eating, brushing, and flossing) Aligners changed every two weeks Photo: Invisalign.com

Worn for a minimum of 20 hours per day (removed for eating, brushing, and flossing)

Aligners changed every two weeks

What is Invisalign ® ? Each tray moves a tooth or group of teeth 0.25 – 0.30 mm. Average treatment time is approximately one year. Photos: Invisalign.com

Each tray moves a tooth or group of teeth 0.25 – 0.30 mm.

Average treatment time is approximately one year.

Is Invisalign ® orthodontics better for most young adult patients? What are the pros and cons of this method versus conventional orthodontics?

Is Invisalign ® orthodontics better for most young adult patients?

What are the pros and cons of this method versus conventional orthodontics?

Treatment Arches with multiple missing teeth Teeth with short clinical crowns Severely tipped teeth (more than 45 degrees) Extrusion of teeth Open bites (anterior and posterior) Severely rotated teeth (more than 20 degrees) Narrow arches that can be expanded without tipping the teeth too much Centric relation and centric occlusion discrepancies Deep overbite problems (Class II, div. 2 malocclusions) Skeletal anterio-posterior discrepancies of more than 2 mm Spacing problems (1-5mm) Crowding and spacing over 5 mm Mildly crowded and malaligned problems (1-5mm) Difficult to Treat with Invisalign ® Possible to Treat with Invisalign ®

Advantages of Invisalign ® Ideal asthetics Ease of use for the patient Comfort of wear Simplicity of care and better oral hygiene Potential metal allergy reactions associated with conventional fixed appliances are avoided

Ideal asthetics

Ease of use for the patient

Comfort of wear

Simplicity of care and better oral hygiene

Potential metal allergy reactions associated with conventional fixed appliances are avoided

Advantages (continued) Elimination of treatment options in detail before beginning treatment Evaluation of treatment options in detail before beginning treatment The virtual treatment model can serve as a motivation tool for the patient

Elimination of treatment options in detail before beginning treatment

Evaluation of treatment options in detail before beginning treatment

The virtual treatment model can serve as a motivation tool for the patient

Disadvantages of Invisalign ® Limited control over movement Limited intermaxillary correction Lack of operator control Additional time and documentation required if changes have to be made once the treatment has started Slight intrusion (.25-.5 mm) of posterior teeth may occur

Limited control over movement

Limited intermaxillary correction

Lack of operator control

Additional time and documentation required if changes have to be made once the treatment has started

Slight intrusion (.25-.5 mm) of posterior teeth may occur

Study of 54 Invisalign ® patients after 3-6 months treatment (12 questions) 78% female 44% ages 20-30 35% no pain; 54% mild pain (lasting 2-3 days after placement of new aligner) 93% said it did not alter normal speech patterns 0% reported TMJ pain 89% were satisfied with treatment

Study of 54 Invisalign ® patients after 3-6 months treatment (12 questions)

78% female

44% ages 20-30

35% no pain; 54% mild pain (lasting 2-3 days after placement of new aligner)

93% said it did not alter normal speech patterns

0% reported TMJ pain

89% were satisfied with treatment

Invisalign ® Systematic Review of available literature Purpose “ To determine the magnitude of the reported treatment effects of Invisalign ® ” “ To help determine which Invisalign ® treatment indications are supported by the evidence”

Systematic Review of available literature

Purpose

“ To determine the magnitude of the reported treatment effects of Invisalign ® ”

“ To help determine which Invisalign ® treatment indications are supported by the evidence”

Invisalign ® Computerized search of online databases (PubMed, Medline, etc.) 1 st Search: “Invisalign ” 2 nd Search: “Invisalign treatment effects” “ Humans” “ Clinical Trials”

Computerized search of online databases (PubMed, Medline, etc.)

1 st Search: “Invisalign ”

2 nd Search: “Invisalign treatment effects”

“ Humans”

“ Clinical Trials”

1st Study Vlaskalic and Boyd 38 patients Placed into three groups depending on severity Treatment times (20-32 months) Percentage of patients completing treatment: 61.5 – 90%

Vlaskalic and Boyd

38 patients

Placed into three groups depending on severity

Treatment times (20-32 months)

Percentage of patients completing treatment: 61.5 – 90%

2 nd Study Bollen and colleagues “ Evaluating the effect of activation time and material stiffness in the ability to complete use of a first set of prescribed aligners” 51 subjects Randomization into four groups Conclusions: 15 patients completed study (71% dropout rate!); two week activation, simple cases, no extractions, low PAR index score (more likely to complete initial set of aligners)

Bollen and colleagues

“ Evaluating the effect of activation time and material stiffness in the ability to complete use of a first set of prescribed aligners”

51 subjects

Randomization into four groups

Conclusions: 15 patients completed study (71% dropout rate!); two week activation, simple cases, no extractions, low PAR index score (more likely to complete initial set of aligners)

Conclusions Both studies had flaws 1 st Study: small sample size; not randomized, no specific parameters concerning crowding, etc. 2 nd Study: small sample size, large dropout rate, didn’t follow patients through complete treatment Therefore, no strong conclusions could be made about Invisalign’s indications or limitations Need better and additional clinical trials

Both studies had flaws

1 st Study: small sample size; not randomized, no specific parameters concerning crowding, etc.

2 nd Study: small sample size, large dropout rate, didn’t follow patients through complete treatment

Therefore, no strong conclusions could be made about Invisalign’s indications or limitations

Need better and additional clinical trials

Invisalign ® Outcome assessment of Invisalign ® and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system A retrospective records analysis of non-extraction patients 2 groups, each with 48 patients who were, at the time the study began, the first patients the orthodontist had completed treatment with Invisalign ® , and his other patients he had completed treatment simultaneously with fixed orthodontics Patients had treatment with one system or the other The groups were controlled for case complexity

Outcome assessment of Invisalign ® and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system

A retrospective records analysis of non-extraction patients

2 groups, each with 48 patients who were, at the time the study began, the first patients the orthodontist had completed treatment with Invisalign ® , and his other patients he had completed treatment simultaneously with fixed orthodontics

Patients had treatment with one system or the other

The groups were controlled for case complexity

Pretreatment Patients were evaluated using the Discrepancy Index (DI) to classify patients according to levels of malocclusion DI consists of 10 categories- overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion, lingual posterior crossbite, buccal posterior crossbite, cephalometrics, and “other” This allowed the case complexities to be controlled in the study

Patients were evaluated using the Discrepancy Index (DI) to classify patients according to levels of malocclusion

DI consists of 10 categories- overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion, lingual posterior crossbite, buccal posterior crossbite, cephalometrics, and “other”

This allowed the case complexities to be controlled in the study

Post treatment Each group was measured for 8 different categories using the ABO’s objective grading system (OGS) to determine if satisfactory treatment outcome was achieved Categories are alignment, marginal ridges, buccolingual inclination, occlusal contacts, occlusal relations, overjet, interproximal contacts, and root angulations

Each group was measured for 8 different categories using the ABO’s objective grading system (OGS) to determine if satisfactory treatment outcome was achieved

Categories are alignment, marginal ridges, buccolingual inclination, occlusal contacts, occlusal relations, overjet, interproximal contacts, and root angulations

Statistical tests used in the study Power test- to determine how many patients in each group would yield a study with statistical weight Chi-square tests- to determine any differences in distribution between the two groups with regard to pretreatment malocclusion and post-treatment results Also used Wilcoxon-2 sample tests and Spearman correlation tests to determine if any significant differences were present between individual DI and OGS categories between the two groups, and used to examine differences in treatment time A P-value of 0.05 was used as the level of statistical significance

Power test- to determine how many patients in each group would yield a study with statistical weight

Chi-square tests- to determine any differences in distribution between the two groups with regard to pretreatment malocclusion and post-treatment results

Also used Wilcoxon-2 sample tests and Spearman correlation tests to determine if any significant differences were present between individual DI and OGS categories between the two groups, and used to examine differences in treatment time

A P-value of 0.05 was used as the level of statistical significance

Results of the study While the difference in ages of the patients in the two groups was statistically significant, the mean DI scores (for pre-treatment evaluation of the cases) were not significant (P=0.9066) This suggests the two groups were evenly matched in terms of difficulty of the cases The OGS scores (for post-treatment evaluation) were statistically significant (P<0.0001) 4 categories had the greatest discrepancies- buccolingual inclination, occlusal contacts, occlusal relationships, and overjet Only 10 Invisalign ® cases received passing grades, while the fixed orthodontics group received 23 passing grades Invisalign ® patients had a shorter treatment duration than the fixed orthodontics group (1.4 years versus 1.7 years)

While the difference in ages of the patients in the two groups was statistically significant, the mean DI scores (for pre-treatment evaluation of the cases) were not significant (P=0.9066)

This suggests the two groups were evenly matched in terms of difficulty of the cases

The OGS scores (for post-treatment evaluation) were statistically significant (P<0.0001)

4 categories had the greatest discrepancies- buccolingual inclination, occlusal contacts, occlusal relationships, and overjet

Only 10 Invisalign ® cases received passing grades, while the fixed orthodontics group received 23 passing grades

Invisalign ® patients had a shorter treatment duration than the fixed orthodontics group (1.4 years versus 1.7 years)

Discussion Differences in ages between the two groups is mostly due to Invisalign’s contraindication for use on persons with non-erupted teeth Tooth movement in patients should still be similar, regardless of age, and most of the patients in both groups were adults who were finished growing Mean DI scores were similar in each category for both groups, meaning that pre-treatment occlusions for both groups were similar, and thus statistically insignificant Treatment time may be a factor, because even though Invisalign ® can produce faster results, the occlusion may not be as ideal

Differences in ages between the two groups is mostly due to Invisalign’s contraindication for use on persons with non-erupted teeth

Tooth movement in patients should still be similar, regardless of age, and most of the patients in both groups were adults who were finished growing

Mean DI scores were similar in each category for both groups, meaning that pre-treatment occlusions for both groups were similar, and thus statistically insignificant

Treatment time may be a factor, because even though Invisalign ® can produce faster results, the occlusion may not be as ideal

Conclusions Invisalign ® did not score as well on the Objective Grading System as did fixed orthodontics, and was deficient in the categories of occlusal contacts, posterior torque, and especially anterior-posterior discrepancies

Invisalign ® did not score as well on the Objective Grading System as did fixed orthodontics, and was deficient in the categories of occlusal contacts, posterior torque, and especially anterior-posterior discrepancies

Study limitations Because the Invisalign ® patients were the first 48 the orthodontist completed treatment, patients who did not complete Invisalign ® treatment were not included in the study, nor were patients with extractions Since the 48 Invisalign ® patients were the first the orthodontist ever treated using the Invisalign ® system, the operator’s skill is a factor; with time the operator’s technique will improve To be truly fair, the 48 Invisalign ® cases should be compared to the operator’s first 48 fixed orthodontics patients in order to downplay the effect of operator skill on the results

Because the Invisalign ® patients were the first 48 the orthodontist completed treatment, patients who did not complete Invisalign ® treatment were not included in the study, nor were patients with extractions

Since the 48 Invisalign ® patients were the first the orthodontist ever treated using the Invisalign ® system, the operator’s skill is a factor; with time the operator’s technique will improve

To be truly fair, the 48 Invisalign ® cases should be compared to the operator’s first 48 fixed orthodontics patients in order to downplay the effect of operator skill on the results

So… What are the pros and cons of this method versus conventional orthodontics?

So…

What are the pros and cons of this method versus conventional orthodontics?

Is Invisalign ® orthodontics better for most young adult patients?

Is Invisalign ® orthodontics better for most young adult patients?

Before Invisalign ® After Invisalign ®

References Journal of Orofacial Orthopedics, Urban and Vogel, Band 66, Number 2, March 2005, pages 162-173. Lagravere, Manuel C., and Carlos Flores-Mir. &quot;The Treatment Effects of Invisalign Orthodontic Aligners: a Systematic Review.&quot; JADA 136 (2005): 1724-1729. PubMed . Lister Hill Library, Birmingham, AL. Djeu, G., Shelton, C., Maganzini, A. “Outcome assessment of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system.” AJODO 128 (2005): 292-298. Pubmed. Lister Hill Library, Birmingham, AL.