Invisalign System as a Treatment of a Skeletal Open Bite: A Case Report With a 5-Year Follow-up

Background: Orthodontic treatments of skeletal open bite are among the most challenging and at high relapse. Available therapies vary from behaviour-modifying appliances in growing patients to surgical approach in adults. Recently, clear aligners, such as Invisalign®, have also been proposed as a treatment modality, to be used alone or in combination with temporary anchorage devices. Case report: A 19-year-old female presented with 3-mm anterior open bite, peg-shaped upper lateral incisors, incorrect tongue posture at rest and during function. Due to aesthetic request, an orthodontic camouflage with Invisalign® was carried out for 17½ months, along with myofunctional therapy and composite veneers on upper lateral incisors. During the first months of retention, intermaxillary vertical elastics were maintained at night-time as positive feedback to the tongue. A 5-year follow-up confirmed stability of the results. Conclusions: A system of clear aligners in combination with myofunctional therapy was effective in the treatment of a skeletal open bite malocclusion, with stability at 5 years. The closure of the anterior open bite was obtained through a combination of lower molar intrusion, incisor extrusion and counterclockwise rotation of the mandible. In selected cases of optimal compliance, Invisalign® may constitute a feasible treatment option in management of open bite in non-growing patients.

Optimization of Loading Condition for Maxillary Molar Intrusion with Midpalatal Miniscrews by Using Finite Element Analysis

An anterior open bite is one of the most difficult malocclusions in orthodontic treatment. For such malocclusion, orthodontic miniscrew insertion into both buccal and palatal alveolar regions has been indicated for molar intrusion, but it involves a risk of tooth root injury. To solve the problem, a midpalatal miniscrew-attached extension arm (MMEA) is adopted. However, this method causes palatal tipping of the molar because intrusive loads were applied only from the palatal side. Currently, a transpalatal arch is added to avoi0d tipping movement, but it induces the patient’s discomfort. Hence, the objective of this study was to evaluate the loading conditions for maxillary molar intrusion without tipping movement, only by MMEA through finite element (FE) analysis. FE models of maxillary right first molar and surrounding tissues were created. Three hook positions of MMEA were set at 6.0 mm perpendicular intervals in the occluso-apical direction along the mucosal contour. An intrusive unit load was applied from the palatal side of the molar, and various counter loads were applied from the buccal side. An optimal counter load for molar intrusion without palatal tipping was observed in each hook position. In conclusion, an ideal maxillary molar intrusion can be achieved only by MMEA with an optimal counter load.

Outcomes and Stability of Anterior Open Bite Treatment with Skeletal Anchorage in Non-Growing Patients and Adults Compared to the Results of Orthognathic Surgery Procedures: A Systematic Review

The objective of this review is to evaluate, on the basis of the available literature, if anterior open bite (AOB) can be successfully treated with the intrusion of molar teeth using skeletal anchorage in non-growing patients and adults and if this treatment modality provides comparable results to those obtained by orthognathic surgery procedures. Methods: A systematic review of published data in major databases from 2000 to 2021 was performed. Results: In total, 92 articles were included in title and abstract screening, and only 16 articles (11 concerning AOB correction by molar intrusion with skeletal anchorage, and five considering AOB treatment by orthognathic surgical intervention) qualified for thorough data extraction and analysis. Conclusions: On the basis of this review, it seems to be possible to obtain successful results for AOB treatment in non-growing patients and adults by means of the intrusion of molar teeth with skeletal anchorage. However, due to the different methods of assessing treatment outcomes used by different authors, it is not possible to state conclusively whether the treatment of AOB by means of molar intrusion with skeletal anchorage provides long-term results that are comparable to orthognathic surgery procedures.

Treatment Option Criteria for Open Bite with Receiver Operating Characteristic Analysis—A Retrospective Study

Temporary anchorage devices (TADs) allow molar intrusion as an additional treatment option to conventional treatment for open bite cases. We investigated the treatment option criteria for open bite treatment. A total of 33 patients with skeletal Class I to Class II open bite who had stable occlusion one year after treatment were enrolled in the study, including 15 patients who had undergone surgical orthodontic treatment, 8 patients who had undergone treatment with molar intrusion, and 10 patients who had undergone treatment with anterior teeth extrusion. Pre-treatment cephalometric analysis of these patients was used for comparison. Furthermore, receiver operating characteristic (ROC) curve analysis was employed to examine the measurement parameters that would be valid as treatment criteria. In the results, FMA showed that patients treated with molar intrusion had a moderately high angle, while those treated with surgical orthodontic treatment had a severe high angle. The area under the curve (AUC) of the ROC curve indicated that FMA is the most appropriate parameter for treatment option criteria. In addition, the cutoff value indicated that the borderline between molar intrusion and surgical orthodontic treatment was 37.5° for FMA. In this study, we suggested criteria for the treatment of open bite with molar intrusion.

Occlusal Splint Therapy Followed by Orthodontic Molar Intrusion as an Effective Treatment Method to Treat Patients with Temporomandibular Disorder: A Retrospective Study

Our goal is to show that temporomandibular disorder (TMD) patients with orthopaedic instability can be effectively treated by the combination of occlusal splint therapy and molar intrusion. Diagnostic records of 18 patients reporting previous TMD and treated with splint therapy were evaluated. Postsplint anterior open bite was treated by skeletally anchored molar intrusion. Changes in overjet (OJ), overbite (OB) were measured on articulator mounted models: initially in maximal intercuspidation(MI), centric „de jour”, postsplint centric relation (CR) and postintrusion CR. Changes in ANB (A point-Nasion-B point) angle, mandibular plane–palatal plane angle and facial axis angle were assessed on lateral cephalograms. Morphological changes of the condyle were detected on pre-and posttreatment CBCT images. When compared screening mountings to MI models, significant differences were found in OJ and OB. Following splint wear, there was a significant increase in lower facial height and significant decrease in facial axis angle, which in turn increased ANB angle. OB and OJ showed a significant change on the postsplint mountings when compared to MI. After intrusion, mandible exhibited counterclockwise rotation, which decreased lower facial height, increased OB and facial axis angle and decreased ANB and OJ. Posttreatment CBCTs confirmed improved condylar morphology.Occlusal splint therapy followed by orthodontic molar intrusion provides MI-CR harmony, therefore, it seems to be an effective method for treating TMD patients.