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The present adult patient case report shows the correction of a crossbite malocclusion and severe tooth rotations treated with the Invisalign system. A 27-year-old female with a dental crossbite (24, 34), severe rotations of two lower incisors (more than 40 degrees) and malalignment of the upper and lower arches is described. The Invisalign system was treatment planned to correct the malocclusion. The treatment goals of crossbite, rotation and malalignment correction were achieved after 12 months of active aligner therapy. The overbite improved (2.5 mm before treatment, 1 mm at the end); the dental crossbite, the crowding and the severe tooth rotations (with a mean of 2 degrees of improvement per aligner) were corrected. After treatment, the dental alignment was considered excellent. The presented case indicates that the Invisalign system can be a useful appliance to correct a dental malocclusion involving severe rotations.
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Australian Orthodontic Journal Volume 28 No. 2 November 2012
15
© Australian Society of Orthodontists Inc. 2012
Background: The present adult patient case report shows the correction of a cross bite malocclusion and severe tooth rotations
treated with the Invisalign system.
Methods: A 27-year-old female with a dental crossbite (24, 34), severe rotations of two lower incisors (more than 40°)
and malalignment of the upper and lower arches is described. The Invisalign system was treatment planned to correct the
malocclusion.
Results: The treatment goals of crossbite, rotation and malalignment correction were achieved after 12 months of active aligner
therapy. The overbite improved (2.5 mm before treatment, 1 mm at the end); the dental crossbite, the crowding and the severe
tooth rotations (with a mean of 2° of improvement per aligner) were corrected.
Conclusions: After treatment, the dental alignment was considered excellent. The presented case indicates that the Invisalign
system can be a useful appliance to correct a dental malocclusion involving severe rotations.
(Aust Orthod J 2012; 28: XXX)
Received for publication: September 2011
Accepted: July 2012
Correction of severe tooth rotations using clear
aligners: a case report
Gianluigi Frongia and Tommaso Castroflorio
Private practice, Turin, Italy
Introduction
In recent years, increasing numbers of adult patients
have sought orthodontic treatment
1
and expressed
a desire for aesthetic alternatives to conventional
fixed appliances.
2
The possibility of using clear
overlay appliances to achieve an orthodontic result
was introduced in 1946, when Kesling
3
devised
the concept of using a series of thermoplastic tooth
positioners to progressively move malaligned teeth to
impoved positions.
In 1997, Align Technology (Santa Clara, CA, USA)
adapted and incorporated modern technologies to
introduce the Invisalign system which made Keslings
concept a feasible, efficent and effective orthodontic
treatment option. In 2000, Boyd et al.
4
published
the first case report on the use of clear aligners and
indicated that the primary benefit of the Invisalign
appliance was the superior aesthetics during treatment,
compared with metal braces.
The Invisalign system
5,6
is based on a clear sequential
appliance (aligners) made from a translucent
thermoplastic material, which is worn for at least
20 hours per day. According to current protocols,
the appliances are replaced on a bi-weekly regimen
which incorporates a progressive alignment of up to
0.25 mm translation or up to 2 degrees of rotation per
tooth per aligner.
Malocclusions treated with the Invisalign system
initially involved only mild crowding of 3-6
millimetres.
7
Recent data has expanded the use of
this appliance to incorporate molar distalisation,
8
extraction cases,
9
the treatment of open bites,
10
crossbites,
7
deep bites,
11
Class II
8
and Class III
corrections
12
and orthodontic-periodontic problems.
13
Rotation is an orthodontic movement reported to be
difficult to achieve and control with the Invisalign
system. Previous studies
14,15
have demonstrated
that aligners were not able to control the rotation
of canines requiring rotational movements greater
Gianluigi Frongia: gianluigi_frongia@msn.com; Tommaso Castroflorio: tcastroflorio@libero.it
Australian Orthodontic Journal Volume 28 No. 2 November 2012
16
FRONGIA AND CASTROFLORIO
Figure 1. Intra-oral photos at the beginning of the treatment.
Figure 2. Teleradiography and superimposition of the latero-lateral
cephalometry. Dark grey represents the Bolton Standard chart and light
grey represents the cephalometry of the patient.
than 15 degrees, which underlined the fact that the
effectiveness of canine derotation was questionable.
Recently, many new biomechanical features have
been promoted by Align Technology to improve
the predictability of aligner treatment. In particular,
the G3 and G4 platforms introduced a collection of
newly engineered attachments to improve control of
desired tooth movements, including dental rotation
and root tipping. The present case report describes an
adult patient in whom the correction of a crossbite
malocclusion with severe tooth rotations was
successfully achieved with the Invisalign system.
Case report
A 27-year-old female patient with a dental crossbite
(24, 34), severe rotations of two lower incisors
(more than 40°) and malalignment of the upper and
lower arches presented for orthodontic treatment
(Figure 1). Informed consent was obtained from
the patient who underwent examination and record
taking. This involved clinical, orthodontic and
temporomandibular disorder (TMD) evaluations,
16
a radiographic assessment (panoramic), lateral
cephalometry (Figure 2), stone casts, intra-oral
(Figure 1) and extra-oral photos, and upper and
lower arch impressions to generate a ClinCheck
®
assessment.
The clinical examination revealed a molar and canine
Class I relationship, an overjet of 1 mm, an overbite
of 2.5 mm, a crossbite between teeth 24 and 34,
upper and lower crowding, and severe rotations of
lower incisors (32 rotated 45° and 42 rotated 44°).
The assessment of the temporomandibular joints
17
revealed no signs and/or symptoms of TMD.
Cephalometric analysis
Cephalometric analysis showed a skeletal Class I-III
relationship according to Steiner
17,18
with an ANB
angle of -1 degree (mean of 2° ± 2°), a hypodivergent
craniofacial form indicated by a SN-GoGn angle of
27 degrees (mean of 32° ± 4°), an interincisal angle of
Australian Orthodontic Journal Volume 28 No. 2 November 2012
17
CORRECTION OF SEVERE TOOTH ROTATIONS USING CLEAR ALIGNERS
Figure 3. Initial stage of the ClinCheck
®
. Figure 4. Final predicted stage of the ClinCheck
®
.
145 degrees (mean of 135° ± 5°), a counterclockwise
growth rotation according to Siriwat and Jarabak,
19
with a PostHt/AntHt ratio of 72% (mean of 60-64%)
and a counterclockwise growth rotation according to
Bjork
21
of 387 degrees (mean of 396° ± 6°).
ClinCheck
®
and aligners
Invisalign treatment was planned to correct the dental
crossbite, the severe rotations of 32 and 42 and the
upper and lower malalignment. The final ClinCheck
®
(version 2.9, Align Technology Inc., Santa Clara,
CA, USA) provided 17 aligners for the upper arch
and 23 aligners for the lower arch (Figures 3 and
4). The duration of therapy was assessed to require
approximately 12 months. Each aligner was to be
worn for two weeks. No inter-proximal reduction
(IPR) was indicated for the correction of the crowding.
Retention attachments were planned on several upper
teeth (13, 14, 23, 24, 26, 27) and on several lower
teeth (32, 33, 34, 36, 42, 43, 44, 45).
Treatment progress was checked every 4 weeks (2
aligners every month) using the ClinCheck
®
analysis
to evaluate changes, patient compliance and bonded
attachment stability. A new aligner was inserted at
each appointment. The precise relationship and
connection between the attachments, the aligner
and the teeth, provided an indication of the positive
progress of treatment. As compliance is critical in all
orthodontic therapy, the patient was instructed to
wear the aligners full time, except for eating and tooth
brushing. The aligners were worn for a minimum of
20 hours per day.
Results and Discussion
A patient with a dental crossbite, severe rotations of
lower incisors and malalignment of the upper and
Figure 5. Intra-oral photos at the end of treatment.
Australian Orthodontic Journal Volume 28 No. 2 November 2012
18
FRONGIA AND CASTROFLORIO
Figure 6. (A) Initial ClinCheck
®
, (B) final ClinCheck
®
and (C)
superimposition of A and B. The ClinCheck
®
simulation shows the
degrees of correction of the rotations. (E) Initial intra-oral photo on
the lower arch, (F) final intra-oral photo on the lower arch and (D)
summary of changes of (E) and (F). The correction of the rotations on the
ClinCheck
®
and on the photos are similar.
Figure 7. (A) Initial and (B) final panoramic x-ray (anterior region only).
No obvious root resorption is present after treatment.
lower arches was treated with the Invisalign appliance.
Patient compliance was high throughout treatment
and excellent oral hygiene was maintained. The molar
and canine Class I relationships were maintained, as
well as the overjet. The overbite improved (2.5 mm
pretreatment, 1 mm post-treatment); the dental
crossbite, the crowding (Figure 5) and the severe tooth
rotations (with a mean of 2° of correction per aligner)
were corrected (Figure 6). No obvious root resorption
was radiographically evident at the end of therapy
(Figure 7). A lower fixed retainer was bonded from the
right first premolar to left first premolar to maintain
lower incisor alignment. Retention in the upper arch
was provided by the last aligner used as a nocturnal
removable retainer.
In 2003, Joffe
20
defined the criteria for selecting
Invisalign patients and emphasised that caution should
be taken in specific malocclusions involving severe
tooth rotations (more than 20°). In the presented
case, a correction of 45 degrees and 44 degrees for
teeth 32 and 42 respectively, was achieved with 23
lower aligners, using accepted treatment protocols.
The rotated incisors were derotated approximately 2
degrees per aligner and the final result was achieved
in 12 months. This result may be due to the recent
significant improvement in Invisalign technology
which has allowed the treatment of more difficult
malocclusions over a shorter time. The introduction
of the G3 and G4 platforms with new smart force
features has also potentially allowed more predictable
tooth movement.
Conclusion
The Invisalign system can be a useful therapeutic
tool to correct a dental malocclusion involving severe
rotations. The presented case confirmed that:
1. The correction of a crossbite in an adult patient is
possible with clear aligners.
2. Severe tooth rotations of lower incisors (up to 45°)
can be corrected with clear aligners.
Acknowledgment
The logistical support of Equipe Dentale Srl was
greatly appreciated.
Corresponding author
Dr Gianluigi Frongia
Corso Vittorio Emanuele II, 170,
10138 Torino
Italy
Email: gianluigi_frongia@msn.com
Australian Orthodontic Journal Volume 28 No. 2 November 2012
19
CORRECTION OF SEVERE TOOTH ROTATIONS USING CLEAR ALIGNERS
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... Severe canine rotation more than 15°(clinically discernable amount of malrotation) is an orthodontic movement reported to be difficult to achieve and control with the Invisalign system [10]. When rotations are greater than 15°, the accuracy of the canine is significantly reduced [11]. ...
... Previous studies have reported that significant rotations of teeth particularly in the mandibular canines have not been achieved satisfactorily using the Invisalign system. [12] In this regard Gianluigi and Tommaso who carried out a treatment with Invisalign found that the rotation of mandibular canines only was achieved one third of the expected and the accuracy of canine rotation (more than 20 degrees) [10] was significantly lower than the rotation of the other teeth [9,13]. ...
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Introduction: The Invisalign system has been used in the orthodontic treatment of numerous types of malocclusions. However some clinicians have reported difficulty incorrecting rotations particularly in canines and premolars using the Invisalign appliance system. This case report describes the orthodontic treatment of an adult patient with severe canine rotation (more than 45°) and crowding on upper and lower tooth.Methods: The clinical examination included extra-oral and intra-oral photographs, panoramic radiographic, lateral cephalometric, stone casts, and upper and lower arch analysis obtained from ClinCheck 3.0.The treatment planning was resolved the crowding in both upper and lower arches and the severe rotation of 33 tooth (46°) using Invisalign system as well as the canine and molar relationship, dental verticalization, adequate over jet, overbite and dental midline using the same system. The duration of the treatment was approximately eight months.Results: In Post-treatment extra oralphotographs, no significant changes were observed at the end of the treatment. Intraoral photographs showed an important and notable improved aesthetics. The canine relationship improved slightly and molar Class Irelationship was maintained. An increase in transverse diameter was observed at the level of first premolars, second premolars and first molars. The overbite was improved. The crowding and the severe canine rotation were corrected. No obvious root resorption was radiographically evident and slight cephalometric changes.Conclusion: The treatment with the Invisalign system resolved the complaint of our patient so this system could be considered as an option that offered good results in the treatment of upper and lower crowding of arches involving severe canine rotation.
... Many authors reported that today the clear aligners are able to treat almost every malocclusion in adult patients, from mild to severe [5][6][7], but few authors have reported on the use of sequential clear aligners in mixed dentition [3,4,8]. In 2019, Blevins [3] described three cases with the Invisalign First System ® used to treat dental crowding, class II malocclusion, deepbite and anterior crossbite. ...
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Background One goal of orthodontic treatment in mixed dentition is to expand the maxillary arch to allow proper tooth alignment and a correction of sagittal and vertical malocclusions. However, for most treatment protocols, expected outcome is not really clear to allow for a standardization of phase I orthodontic treatments. This lack of information makes it difficult for clinicians to predict tooth movements, including transverse expansion efficacy with Invisalign® (Align Technology, Santa Clara, CA, USA) in children. Therefore, the aim of the present study was to evaluate the transverse maxillary arch development with the Invisalign First System® in growing subjects.Methods The study group included 23 subjects (9 females, 14 males, mean age 9.4 ± 1.2 years). Patients were treated nonextraction with Invisalign First System® clear aligners with no auxiliaries other than Invisalign® attachments. Transverse interdental widths were measured only in the upper arch on each model at the start (T1) and at the end (T2) of treatment. A paired t‑test was chosen to compare T2–T1 changes. The level of significance was set at 5%.ResultsThe greatest increase of maxillary width was detected at the level of the upper first deciduous molars (+3.7 ± 1.4 mm; P < 0.001), followed by the level of the second deciduous molars (+3.4 ± 1.6 mm; P < 0.001) and by the deciduous canine (+2.6 ± 2.0 mm; P < 0.001). Upper first molars showed a greater expansion in the intermolar mesial width (+3.2 ± 1.2 mm; P < 0.001) than in the intermolar distal (+1.7 ± 1.2 mm; P < 0.001) and transpalatal width (+1.2 ± 1.2 mm; P < 0.01).Conclusions The Invisalign First System® can be considered effective in growing patients who require maxillary arch development. The greatest net increase was detected at the level of upper first deciduous molars, whereas the upper first molars showed a greater expansion in the intermolar mesial width due to a rotation that occurs around its palatal root.
... [2] However, several researchers have successfully demonstrated how the present appliances can correct and treat almost all diseases, ranging from mild to severe malocclusion, with better periodontal status. [3][4][5] Despite the known effectiveness of conventional methods practiced across the world, the shortcomings associated with these methods cannot be overlooked. For instance, the conventional methods in dentistry are inconvenient and even painful, often posing difficulty in cleaning. ...
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... Furthermore, analysis of the force direction required for the tooth movement and adjustment of the amount of tooth movement by bonding an attachment to the tooth surface were determined for the correct force loading in an optimal direction 8,9) . Thus, at present, treatment using thermoplastic orthodontic appliances has been expanded from minor tooth movement to whole teeth orthodontic treatment [10][11][12][13] . ...
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... With development of material and computer design of tooth movement, the indication of clear aligners has been greatly enlarged. Many researchers reported successful cases to prove that the clear aligners today have been able to treat almost everything from mild to severe malocclusions [2,3]. Fixed braces have been the conventional and effective orthodontic appliance for over a hundred years. ...
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... These factors sometimes act as deterrents to orthodontic treatment, especially in situation such as minor crowding. Thermoformed appliances are commonly used in various clinical situations [1] to treat the malocclusion. Considering the above, we have developed a new method to correct minor crowding in an esthetic manner using a thermoformed appliance with selective trimming over the study model to achieve desired tooth movement. ...
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Recent developments in software technology have made it possible to create a virtual three-dimensional (3D) model of the dental arches from digitally scanned impressions of a patient's dentition. This model may then be manipulated with software to produce stages of tooth movement from the initial malocclusion to the final desired occlusion. A stereolithographic model is made for each stage of tooth movement which is the basis for construction of a series of clear, thin, overlay appliances. These appliances are worn full time by the patient to move the teeth according to the programmed stages of movement. Malocclusions involving mild to moderate crowding and space closure have been proven to be successfully treated with this appliance. The present study shows orthodontic treatment of patients with more complex orthodontic problems, requiring dental expansion, Class II and Class III correction, extraction treatment and correction of overbite. Experience with this appliance, thus far, has demonstrated excellent patient compliance with less discomfort, and improved esthetics and oral hygiene, when compared with fixed orthodontic appliances. Orthodontic treatment with this appliance is a potentially useful alternative approach to fixed appliances for treatment of a variety of malocclusions in patients with fully erupted permanent teeth.
Article
Three aspects have had a significant impact on orthodontics during the last few decades: the appliances being used, the anchorage being used and finally the distribution of patients being treated. Firstly, the marketing of appliances is increasingly leading the orthodontist to outsource important aspects of treatment such as wirebending and bracket positioning. Brackets and wires are being presented as the solution to all problems and metaphysical terms such as 'intelligent design,' 'working brackets' and 'intelligent wires' are dominating advertising and reducing the impact of evidence-based treatment approaches. Secondly, the introduction of skeletal anchorage has potentially widened the spectrum of orthodontics, allowing for treatments that could not be done with conventional appliances. Biomechanical knowledge is, however, mandatory if we agree that the system should not be abused. Thirdly, the orthodontic population comprises an increasing number of adult patients, many of whom are characterized by a degenerated dentition. The treatment of these patients requires a thorough knowledge not only of biomechanics but also of the reaction of the periodontal tissues to various types of loading. They can be treated only with custom-made appliances adapting the force systems and magnitude to the patient-specific treatment goal. In summary, the orthodontic world is being split between 'appliance-driven fast-food orthodontics' where the results to a large extent are dependent on both growth and function and 'orthodontist-driven' 'slow-food' treatments attempting to push the limits of the possible in relation to complicated problems and reversal of degeneration in adult patients. The latter treatments are performed with individualized appliances adapting the force system to the patient. This paper will attempt to summarize the bearing of these factors on present orthodontics.