Clinical follow-up of corticotomy-accelerated Invisalign orthodontic treatment with Dental Monitoring

The demand for fast and invisible treatment options for adults has grown. Treatment protocols involving clear aligners in association with alveolar corticotomy have been developed in response to this demand. Alveolar corticotomy surgery can accelerate orthodontic tooth movement, but good clinical follow-up is crucial and can become cumbersome as the frequency of aligner changes accelerates. Clinical monitoring with patient-managed software can be of assistance in such cases. We present the ortho-surgical treatment of a healthy 21-year-old woman with Class III malocclusion who was treated with corticotomy-accelerated presurgical decompensation and clear aligners, followed by mandibular sagittal split osteotomy. Alveolar corticotomy surgery was performed and the aligners were changed every 4 days. Clinical follow-up of aligner-mediated tooth movement was managed with a patient-managed smartphone application, allowing early interception and correction of minute orthodontic movement errors. Such errors would have been difficult to detect considering the rapidity of aligner change when accelerated by alveolar corticotomy. Clinical follow-up with a patient-managed smartphone application could thus allow for better and easier management of corticotomy-accelerated clear aligner orthodontic treatment.

Highlights

  • Alveolar corticotomy can allow faster more secure orthodontic treatment in adults.

  • Clear aligner orthodontic movements can be facilitated by alveolar corticotomy.

  • Patient-managed software is essential to intercept aligner errors in such cases.

Adult orthodontic patients often demand fast, esthetic, and comfortable treatment. Several treatment modalities have been developed to answer such demands, including the increasingly popular clear aligners such as Invisalign (Align Technology, San Jose, Calif). This bracketless treatment option involves a series of custom-made clear aligners tailored to the planned orthodontic tooth movements. The aligners are generally changed every 10 to 15 days with little discomfort. ,

Adult orthodontic treatment carries its own specific risks, including dental caries, root resorption, and periodontal lesions. Such risks are linked to total treatment duration and can be reduced significantly by using an orthodontic tooth movement acceleration and modulation surgical technique such as alveolar corticotomy. , By creating a surgical lesion of the alveolar cortical plate, rapid remodeling of the underlying bone ensues (namely the “regional acceleration phenomenon” ) which results in transient localized osteopenia and facilitated orthodontic tooth movement. Such surgically-accelerated tooth movement has been shown to faster (up to 2 to 4 times the conventional tooth displacement speed ) and to offer greater total tooth movement , with less iatrogenic root resorption. Several authors even suggest the possibility of an osteogenic effect of alveolar corticotomy.

Modulating and accelerating the orthodontic tooth movement resulting from clear aligner treatment with alveolar corticotomy has been described in the literature but little attention has been given to the clinical follow-up of such accelerated treatment. Indeed, as the aligners are changed at a faster pace (as a result of the transient osteopenia and corticotomy-facilitated tooth movement) the risk of movement errors increases and the need for closer monitoring arises. In that regard, resorting to patient-managed software for clinical follow-up can be of valuable assistance for the orthodontist. For instance, Dental Monitoring (Dental Monitoring SAS, Paris, France), a smartphone application, allows the orthodontist to remotely monitor the orthodontic treatment via videos sent directly by the patient at preplanned specific time points.

We present a case of ortho-surgical management of a Class III malocclusion in a healthy 21-year-old woman, treated with corticotomy-accelerated-presurgical decompensation with Invisalign clear aligners followed by mandibular sagittal split osteotomy. Clinical follow-up of the aligner-mediated tooth movement was managed using Dental Monitoring software. Such follow-up allowed early interception and correction of minute orthodontic movement errors, which would have been difficult to detect considering the rapidity of aligner change in the present case.

Methods

A 21-year-old healthy melanoderm woman consulted our department of orthodontics and dental orthopedics because of an esthetic concern regarding her chin that she regarded as too prominent. She reported having previously undergone an orthodontic treatment with extraction of the maxillary second premolars and mandibular first premolars to compensate for the Class III malocclusion. Her main demands regarding any new treatment were that it be as short as possible (with treatment completion before traveling abroad for her job in 8 months) and with minimal visibility of the orthodontic appliances.

Facial clinical examination revealed a slight mandibular asymmetry and augmentation of the lower third of the face. Facial profile was ortho-frontal (according to the classification of Simon ) with associated superior retrocheilia and inferior procheilia. Her smile was esthetic with slightly visible lateral buccal corridors ( Fig 1 ). Endobuccal clinical examination showed good dental hygiene and minimal gingival thickness in the mandibular incisor and canine regions. Molar and canine Angle Class III malocclusion was also observed, more pronounced on the right side, with a deviation of the mandibular dental midline (1 mm toward the left) and anterior infraclusion ( Fig 1 ). Remnants of the previous orthodontic treatment could also be observed: dental compensations (maxillary incisors labioversion and mandibular incisors linguoversion), incisor edge-to-edge bite, lack of the previously extracted maxillary second premolars and the mandibular first premolars, and a residual fragment of a previous bonded retention wire (spanning the maxillary right central and lateral incisor and canine). Analysis of the dental casts confirmed the clinical observations. Functional clinical examination revealed oro-nasal ventilation, functional deglutition, and the absence of temporo-mandibular dysfunction.

Fig 1
Pretreatment facial and intraoral photographs.

Orthopantomogram radiography confirmed the absence of the maxillary second premolars and the mandibular first premolars and identified an external apical root resorption on the maxillary right premolar ( Fig 2 ). The lateral cephalogram and Tweed analysis confirmed a Class III skeletal pattern (ANB = −2.2° and AoBo = −4.5 mm) resulting from mandibular prognathism (SNB = 83.7°) on a normodivergent facial pattern (FMA = 25°). Frontal cephalogram showed a moderate mandibular asymmetry with a lower mandibular angle on the left side. Dentoalveolar compensation was confirmed by the labioversion of the maxillary incisor (I/SN = 120°) ( Table ).

Fig 2
Pretreatment cephalograms and orthopantomogram.

Table
Tweed analysis measurements
Measurement Objectives Pretreatment (December 2017) Posttreatment (October 2018)
FMIA, ° 67 ± 3 68 65
FMA, ° 25 ± 3 25 25
IMPA, ° 88 ± 3 87 90
SNA, ° 82 81.5 82.5
SNB, ° 80 83.7 80.3
ANB, ° 2 −2.2 0.5
I/SN, ° 103.5 120 109
AoBo, mm 2 ± 2 −4.5 0.5
Occl Pl/FH, ° 10 7 7
I/I, ° 135 110 125
Z angle, ° 75 ± 5 80 77
Anterior facial height 65 68 69
Posterior facial height 45 50 52
Posterior/anterior index 0.69 0.73 0.75
SN/Frankfort, ° 8 12 12
Upper lip 11 11
Total chin 14 13

After thorough analysis and discussion with the patient, the following treatment objectives were identified: (1) bilateral molar and canine Class I occlusion, (2) correction of the mandibular dental midline deviation, (3) Class I skeletal pattern without any modification of the normodivergent facial pattern, (4) diminution of facial profile concavity and chin setback to comply with the patient’s main esthetic concern, (5) functional and esthetic anterior guidance, and (6) long-term stability.

The following treatment options were proposed to the patient, with detailed information given on the advantages, disadvantages, and risks of each option: (1) no treatment (discarded because of the patient’s demands and motivation); (2) dentoalveolar compensation of the Class III skeletal pattern by intermaxillary elastic traction (discarded because of the preexisting dentoalveolar compensations, limited posttreatment stability and lack of correction of the unesthetic progenia); (3) third molar avulsion and distalization of maxillary and mandibular dental arches requiring absolute posterior anchorage and complex biomechanics (discarded to avoid further tooth avulsions and because of the lack of effect on the skeletal bases and facial profile of the patient); and (4) ortho-surgical treatment with mandibular sagittal split osteotomy to set back and recenter the mandible (after presurgical orthodontic decompensation). This option was favored by both the medical team and the patient.

To comply with the patient’s demands (esthetic concerns and short duration of treatment) and to minimize the periodontal risks related to her periodontal morphotype and planned orthodontic tooth movements (Class III decompensation , ), the presurgical decompensation phase was conducted with Invisalign clear aligners in association with bimaxillary piezoelectric alveolar corticotomy.

The patient gave oral and written consent for this treatment.

The presurgical orthodontic decompensation treatment was conducted by 2 orthodontists (R.H. and E.O.) who used Invisalign clear aligner, alveolar corticotomy surgery, and Dental Monitoring.

Optical scans were made with an Itero optical camera (Align Technology, San Jose, Calif) and using the ClinCheck Pro with 3D Controls software (Align Technology, San Jose, Calif), 29 aligners were designed ( Fig 3 ).

Fig 3
Pretreatment ClinCheck ( blue : initial dental positions; white : planned posttreatment dental positions; yellow : posttreatment dental positions after orthognathic surgery).

A specialist oral surgeon (N.M.) performed multiple interdental alveolar corticotomies on both jaws after mucosal flap retraction to avoid unesthetic scarring (as often reported in melanoderm patients ). Briefly, after local anesthesia (using a 4% articaïne solution with 1/100,000 epinephrine) an envelope flap was reflected extending to the second molars bilaterally to provide adequate visualization of the alveolar bone. Selective alveolar decortications were performed between each dental root using a piezotome with specific piezosurgical inserts (Piezocision; Actéon, Paris, France) under constant irrigation with sterile saline. Piezosurgical decortications were chosen, as they are standard practice in our department and might hold an intrinsic osteogenic potential as a result of the effects of piezoelectric micromovements on bone remodeling. The decortication was started at 3 mm of the interproximal alveolar crest so as to prevent any postoperative bone loss and extended for approximately 10 mm (sparing the apical region of each tooth). Bleeding within the site of corticotomy indicated that the correct depth was obtained. The flap was carefully repositioned and sutured with 4-0 interrupted VICRYL (Ethicon, Johnson & Johnson, New Brunswick, NJ) sutures. Adequate hemostasis was obtained and postoperative information was given before discharging the patient. The postoperative prescription included acetaminophen (4 g/d maximum) with chlorhexidine 0.12% mouthwash. Steroid and nonsteroid antiinflammatory drugs were prescribed, and the patient was recommended to abstain from applying ice after the surgery to avoid interfering with the desired inflammatory bone remodeling.

Based on our experience and the relevant scientific literature , , , we estimated that the rapid pace of aligner change expected after alveolar corticotomy (orthodontic tooth displacement 2 to 4 times faster than the conventional treatment) would render the chairside clinical follow-up difficult to maintain both for the patient and the orthodontist. Therefore we opted for patient-monitored clinical follow-up using Dental Monitoring, a smartphone application that allows for remote follow-up using videos (“scans”) of the patients’ dental arches taken by the patient himself on his phone and sent to the company’s servers where the data are analyzed according to predefined parameters set by the orthodontist for each patient.

An initial 30-minute appointment is dedicated to teaching the patient the correct movement so as to create a video that can be adequately analyzed by the Dental Monitoring software. Most patients master the technique quickly.

The orthodontist then programs the software and sets the frequency of the scans (4, 7, or 14 days). Several notification messages can be programmed to tell the patient when to change the aligners, and the messages can even be personalized by the orthodontist to reinforce the patient’s motivation. ,

The software sends notifications to the patient on the days preprogrammed by the orthodontist. The patient then performs a scan with the aligners in place, a scan without the aligners, in occlusion and, finally, a scan without the aligners but with the mouth slightly open. Once finished the scans are sent to the Dental Monitoring company where they are analyzed, and a new notification is sent to both the patient and orthodontist asking either to validate the change of aligners (go) or not (no go).

We estimated our patient would need an aligner change every 4 days (estimating for a 3-fold to 4-fold increase in orthodontic tooth movement velocity) and programmed such a change rate in the software. The patient learned the correct scanning movement quite rapidly and did not express any difficulty regarding the regular use of the software.

The orthognathic surgery was performed by a specialized maxillofacial surgeon (E.R.) and consisted of mandibular bilateral sagittal split osteotomy for mandible setback and derotation, without genioplasty. Although genioplasty is sometimes required for esthetic and/or functional purposes it was not the case here as there was natural lip occlusion, no vertical excess or insufficiency, and neither residual progenia nor retrogenia after the mandible setback.

After the validation of the treatment plan and optic scans for aligner fabrication, personalized cleats and buttons (for Class II intermaxillary elastics fixation) were installed. Interproximal enamel reduction was also performed during the same appointment. Only the first set of aligners was given to the patient so that she could get used to wearing them for the first 15 days.

After the 15-day adaptation period, alveolar corticotomy were performed ( Fig 4 ). No premedication was given beforehand and the patient was asked not to take any aspirin or other over-the-counter nonsteroidal antiinflammatory drugs. As previously described, after mucosal flap reflection interdental decortications were performed between each tooth from left second premolar to right second premolar on both jaws using a piezosurgical instrument with specific inserts. The flap was then carefully repositioned and sutured and routine postoperative care given. The patient was then informed to change to the second set of aligners 24 hours after the surgery.

Jan 9, 2021 | Posted by in Orthodontics | Comments Off on Clinical follow-up of corticotomy-accelerated Invisalign orthodontic treatment with Dental Monitoring
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