Evaluation of effects of brackets and orthodontic wires on intraoral scans: A prospective in-vivo study.

OBJECTIVE: To evaluate any distortion produced by multibracket fixed orthodontic appliances on digital models obtained from intraoral scans (IOS), considering the presence of both brackets only and brackets/archwire combination. SETTING/SAMPLE: The IOS data of the arches of 20 patients (12 females and 8 males; mean age = 15.55 ± 2.84 years) were acquired using the CS3600 intraoral scanner (Carestream Dental, Atlanta, USA), without any appliances (model A), with vestibular brackets alone (model B) and then with brackets and orthodontic archwire fitted (model C). MATERIALS AND METHODS: Data were acquired between the months of January and October 2021 at the moment of indirect bonding phase. On each model, five intra-arch linear measurements were obtained (inter-canine, inter-premolar 1 and 2, inter-molar and arch depth), and after digital matching between model A and B (match 1) and A and C (match 2), the linear discrepancies were evaluated at 20 points (10 occlusal and 10 gingivolingual) previous identified on the reference model A. All measurements were performed using Geomagic Control X software (3D Systems, Morrisville, USA), and any dimensional variations and distortions were evaluated by the linear regression analysis and two-sample t-test (P ≤ .05). RESULTS: The results show an almost perfect correlation between both models B and C and the reference model A, both as regards the intra-arch linear measurements and the linear discrepancies found at the 20 identified points. CONCLUSIONS: Multibracket fixed orthodontic appliances do not produce any relevant distortions in digital models obtained via intraoral scanning. Therefore, the removal of archwire is not mandatory before IOS.

G-Block: Posterior anchorage device tads-supported after molar distalization with aligners: An adult case report.

INTRODUCTION: Temporary anchorage devices represent a fundamental tool to reliably manage orthodontic anchorage in several conditions. One of the most recent application is represented by the combination of aligners with TADs to simplify specific movements such as posterior intrusion, anterior intrusion, molars distalization. The objective of this case report is to show a novel technique called "G-block" to manage posterior anchorage with a hybrid approach combining aligners and TADs. MATERIALS AND METHODS: This case report shows a Class II malocclusions (end to end relationship) with increased overjet and incisors proclination treated with aligners and maxillary distalization approach. To manage the posterior anchorage after second molar distalization and to avoid the use of Class II elastics, TADs (Spider Pin 1.3mm×10mm) were inserted into the interradicular space between the maxillary first and second molars following second molar distalization. The mini screws were used to provide both direct and indirect anchorage. The second molars were connected to the TAD by means of a 0.18 SS wire embedded in the attachment and blocked to the head of the mini-screw for indirect anchorage, while an elastic chain connecting the TADs to the buttons bonded to the first molars and premolars provided direct anchorage during first molar and premolar distalization. RESULTS: A solid bilateral Class I occlusion was achieved with a normal overjet and overbite. The dental arches were well aligned and leveled with good intra-arch symmetry and regular arch forms. Final cephalometric analysis showed a significant change in upper incisor proclination (15̊ reduction) while maintaining correct torque control and a significant change in molar relationship. The aesthetic analysis showed an improvement in lip competence and incisor exposure. CONCLUSION: The use of TADs for posterior anchorage after maxillary molar distalization with aligners, could represent an effective solution to easily manage the posterior anchorage reducing the need for patient's compliance in using elastics and in particular simplifying the posterior teeth movements by coupling the force expressed from the aligners with the force expressed by the auxiliary system.

Class II extraction treatment with aligners: a reliable approach / Traitement de la classe II avec extraction par aligneurs : une approche fiable

Aim: Class II extraction approach by means of maxillary first premolars represents a common treatment strategy in order to reduce the overjet and create a stable Class I canine relationship and Class II molar relationship. The objective of this paper is to describe digital planning protocol and complete clinical phases of space closure in Class II malocclusion treatment in adult patient. Materials and Methods: The accuracy of movements and correction of dental parameters has improved exponentially in recent years, as a result of continuous research performed in aligner orthodontics. However, the most complex movement to realize with aligners is the apical movement, but the application of the G6 protocol for managing extractive cases allows to obtain the final parallelism of the roots with a control of the tipping managed on the digital plan as an overcorrection (overtipping) of the roots adjacent to the extraction site. Through the description of two cases, this article will present the application of the specific protocol for first premolars extraction in order to manage anchorage and closure of extraction spaces. Results: All patients finished with proper OVJ and OVB with a Class II molar relationship and Class I canine relationship respecting face balance and smile arc. Discussion: The Invisalign G6 protocol through the use of SmartStage™ technology combined with SmartForce™ features provides vertical control during anterior sector retraction and teeth body movement maintaining maximum posterior anchorage.

Objectif: Le traitement de la classe II par extraction des premières prémolaires maxillaires représente une stratégie de traitement répandue dont le but est de réduire le surplomb horizontal (overjet) et de créer une classe I canine stable avec une classe II molaire thérapeutique. L'objectif de cet article était de décrire le protocole digital et les différentes phases cliniques de fermeture des espaces dans les cas de malocclusion de classe II chez les patients adultes. Matériels et méthodes: La précision des mouvements et de la correction des paramètres dentaires s'est améliorée de façon exponentielle ces dernières années, grâce à la recherche continue effectuée dans le domaine de l'orthodontie par aligneurs. Cependant, le mouvement le plus complexe à réaliser avec les aligneurs est le déplacement apical, mais l'application du protocole G6 pour la gestion des cas d'extraction permet d'obtenir le parallélisme final des racines avec un contrôle du tipping géré sur le plan numérique comme une surcorrection (overtipping) des racines adjacentes au site d'extraction. À travers la description de deux cas, cet article présentera l'application du protocole spécifique pour la première extraction des prémolaires afin de gérer l'ancrage et la fermeture des espaces d'extraction. Résultats: Tous les patients ont terminé avec un surplomb vertical et horizontal correct avec une relation molaire de classe II et une relation canine de classe I respectant l'équilibre du visage et l'arc du sourire. Discussion: Le protocole Invisalign G6, grâce à l'utilisation de la technologie SmartStage™ combinée aux fonctionnalités SmartForce™, permet un contrôle vertical pendant la rétraction du secteur antérieur et le mouvement des dents, en maintenant un ancrage postérieur maximal.

Precision bite ramps and aligners: An elective choice for deep bite treatment.

OBJECTIVE: To review a series of clinical studies demonstrating the clinical efficiency of aligners with bite ramps in the treatment of severe deep bite. MATERIALS AND METHODS: In order to predictably manage the correction of deep bite with aligners, precision bite ramps on maxillary incisors have been used while posterior extrusion and anterior intrusion in the lower jaw with lateral attachments and proper levelling of the curve of Spee have been planned. Transverse correction and controlled upper and lower incisors proclination completed the treatment plan. RESULTS: Full deep bite correction with normal overbite was obtained in nine months of treatment by a combination of anterior intrusion and posterior torque correction, distal tipping and relative extrusion. CONCLUSION: The use of bite ramps represents a valid option for the successful treatment of deep bite with aligners creating proper space for lateral sector extrusion and supporting lower anterior intrusion and controlled proclination.

Bidimensional system for space closure treatment of missing lateral incisors: 10 years follow-up.

INTRODUCTION: Missing lateral incisors represent a common condition that normally requires specific anchorage conditions to be treated with space closure mechanics to protract upper teeth creating a proper occlusal relationship. CASE PRESENTATION: Two cases showing Class II malocclusion with missing lateral incisors in developing age are presented, both treated with the same approach of maximum anterior anchorage applied using the Bidimensional Technique system. Long-term follow-up of 10 years is shown. MANAGEMENT AND OUTCOME: Bidimensional technique is a modified edgewise technique that uses sliding mechanics for protraction of the posterior segments by placing vertically slotted brackets of different sizes on the anterior (.018" x 0.025") and posterior teeth (.022" x 0.028"). When a .018" x .022" wire is inserted in the .018" x .025" brackets slot on the incisors, third-order control is created in the incisor segment while the wire is undersized in the rest of the arch. Lateral brackets have been positioned on the canines, while the canine brackets have been positioned on the first premolars respecting a differential bonding height able to produce canine extrusion and first premolars intrusion and proper torque expression. Full Class II molar relationship and Class I substituted canine relationship has been reached in both cases and kept stable in the long-term follow-up (10 years). DISCUSSION: The described approach provided anterior anchorage with more simple mechanics expressing the anterior torque with a full engagement concept and adding few auxiliaries (uprighting springs) which do not require compliance.

Simplifying the approach of open bite treatment with aligners and selective micro-osteoperforations: An adult case report.

INTRODUCTION: Open bite treatment represents one of the most challenging malocclusions because it has a multifactorial aetiology and in particular because its dental correction strongly depends on the possibility to manage the posterior intrusion with a reliable system controlling the vertical position of upper and lower molars. Clear Aligner system proved to be an efficient way to control the hyper divergent patients performing posterior intrusion and managing the counterclockwise rotation of the mandible. This technique has shown to be predictable for molar intrusion up to 1mm. METHODS: This case report shows a successful open bite orthodontic treatment in which the molar intrusion effect has been amplified in the digital setup and facilitated by means of micro-osteo perforations (MOPs) performed selectively only in the molar areas in order to stimulate the bone in a specific movement direction. The digital setup was set to create molar intrusion in upper and lower molars up to 3mm and thus favouring a counterclockwise mandible rotation, supported and controlled by elastics. The posterior intrusion was combined with an anterior extrusion following smile arc exposure and the treatment was completed in 16 months overall. RESULTS: The final cephalometric analysis showed a significant reduction of SN/Go-Gn angle of 4° with consequent counterclockwise rotation of the mandible. The mandibular superimposition showed a 2.5mm molar intrusion without root resorption and with a controlled incisor proclination. A solid Class I bilateral occlusion was achieved with normal overjet and overbite, the dental arches were well aligned and levelled with good intra-arch symmetry and regular arch form. The frontal aesthetic analysis showed an improvement of the dental exposure with a normalized smile arc due to a combination of relative and pure extrusion. CONCLUSION: The present alternative approach to treat severe open bite combining selective MOPs in the posterior and lateral sectors and clear aligners could predictably control molar vertical position avoiding the use of auxiliary and eliminating the risk of root resorption. Arch development, molar intrusion, and overbite correction with counterclockwise mandible rotation could be predictably achieved respecting digital setup and creating proper Class I bilateral occlusion.