Effect of clear aligner type on maxillary full-arch intrusion: 3D analysis using finite element method.

BACKGROUND: Vertical maxillary excess (VME) is one of the most common reasons for seeking orthodontic treatment. Total intrusion with aligners is a promising alternative to surgery in some cases. Considering the elastic deformation of aligners, this study aimed to evaluate the possible desirable and undesirable teeth displacements during full maxillary arch intrusion using clear aligners and temporary anchorage devices (TADs). METHODS: The maxillary arch and clear aligners were modeled in SolidWorks. Four aligner brands including Leon, Duran, Duran Plus, and Essix Plus were selected based on their material properties. Anterior and posterior intrusion forces of 80 and 300 g were applied from attachments between the canines and first premolars and between the first and second molars, respectively. Vertical and anteroposterior tooth displacements were determined. RESULTS: The greatest intrusion was recorded at the buccal of the second molar, followed by the first molar. The lowest value was measured at the palatal of the molars with all aligners except Duran, which indicated minimal intrusion in the central incisor. All teeth were mesially displaced at the incisal/occlusal except incisors that moved distally. All apices showed distal movement. CONCLUSIONS: Total intrusion using clear aligners may be accompanied by other tooth movements, including buccal tipping and mesial-in rotation of the molars, retrusion of incisors, and mesial movement of other teeth.

Orthodontic correction of anterior open bite using skeletal anchorage: systematic review and meta-analysis.

The purpose of this study was to investigate the scientific evidence on the short- and long-term effects of orthodontic correction of anterior open bite (AOB) using skeletal anchorage (SA). Clinical studies on the use of SA for AOB in patients with permanent dentition, or at least 12 years of age, were searched. Short- and long-term (≥2 years) outcomes were collected. Mean differences were calculated from pooled data. Twenty-four eligible articles with a total of 362 subjects were selected for inclusion in the meta-analysis. There was a significant increase in overbite (3.88 mm, P < 0.001) and maxillary molar intrusion (-2.15 mm, P < 0.001). The mandible showed counterclockwise rotation with anterosuperior chin movement (all P < 0.001). Long term, the decrease in overbite was 19.9% and decrease in molar intrusion was 22.9%. The decrease in the mandibular projection was 14.6% for ANB (A-point-nasion-B-point angle) and 46.2% for mandibular anteroposterior position. The overall risk of bias in the included studies was rated as moderate to high, and publication bias existed for several key variables. SA for maxillary molar intrusion effectively improved dental and skeletal outcomes, but there was a long-term decrease in overbite and maxillary molar position. The variable data quality, heterogeneity, and publication bias in investigated outcomes are limitations in interpreting the findings.

Analysis on Mandibular Anterior Tooth Intrusion with Clear Aligners / 医用生物力学

国家自然科学基金项目(11932012、81400536),上海申康医院发展中心临床创新三年行动计划(SHDC2020CR3009A),上海交通大学医工(理)交叉基金(JYJC202130)

Regenerative Endodontic Procedure in an Immature Permanent Incisor with Internal Root Resorption: a Case Report.

This report describes a regenerative endodontic procedure of an immature permanent incisor with internal root resorption (IRR) and 4-years follow-up. A healthy 8-year-old man was referred for treatment of tooth #9 after a traumatic intrusion. The periapical radiograph showed an IRR and an open apex with periradicular lesion. A diagnosis of pulp necrosis and chronic apical abscess was achieved. In the first appointment, under local anesthesia and rubber dam isolation, an access cavity was designed and the root canal was chemically cleaned under irrigation with 10 mL 1.5% sodium hypochlorite (NaOCl). The root canal was then dried and calcium hydroxide paste was placed. During the second appointment, the root canal was irrigated with 5 mL of 17% ethylenediaminetetraacetic acid (EDTA) for 5 minutes and dried. The blood clot was established in a time of 3 minutes after the bleeding from the periapical tissue was trigged. White mineral trioxide aggregate (MTA) was placed up to the amelocemental junction and the final restoration of the access cavity was carried out. During periodic clinical and radiographic follow-up, the patient remained symptom free, the periapical region was completely healed, inhibition of the root resorption process achieved, and formation of the new periodontal ligament as well as tooth widening development observed, meeting functional expectations after 48 months. The regenerative endodontic procedures are an available option to treat IRR in severely immature teeth. The available literature on the regenerative endodontic procedures applied to IRR treatment is limited, and more research is needed in this field.

Intrusion of Maxillary Posterior Teeth by Skeletal Anchorage: A Systematic Review and Case Report with Thin Alveolar Biotype.

This study aimed to review the literature related to the intrusion of maxillary posterior teeth in subjects needing pre-prosthetic restoration or orthodontic treatment due to anterior open bite, and to report a thin alveolar biotype case needing a pre-prosthetic intrusion of maxillary teeth by introducing a novel, personalized method of intrusion measurement. An electronic search was conducted between February 2022 and March 2022 in the following databases: PubMed, Scopus, Embase, Web of Science, and Lilacs; the terms "tooth movement techniques", "orthodontic anchorage procedures", "tooth intrusion", "intrusion", "molar", "premolar", and "human" were surveyed. Eighteen articles were included in this review; the mean amount of intrusion ranged from between 2.1 ± 0.9 mm and 4.57 ± 0.98 mm (being mostly 2-3 mm). The intrusion force varied between 100 and 500 g; 10 articles reported miniscrews (MS), 7 reported zygomatic plates (ZP), and 1 publication reported both anchorage types. The average treatment time was 6.9 months for MS and 7.9 months for ZP. Levelling the occlusal plane by intrusion of the upper posterior teeth can be achieved by skeletal anchorage. The stability of the obtained results, shortening treatment time, and controlling treatment outcome are the main goals for a complex surgical and orthodontic treatment approach.

Massive intrusion of maxillary second molar for prosthodontic purposes through miniscrew-supported biomechanics and fixed partial appliances: A case report.

This clinical case demonstrates how the use of a hybrid approach consisting of aligners, orthodontic miniscrews and partial fixed appliances can be an effective and efficient solution for recovering adequate vertical space for satisfactory implant-prosthetic rehabilitation. Specifically, massive intrusion of an upper second molar (tooth 1.7) was achieved orthodontically with direct TADs support to allow otherwise unpredictable movements and achieve maximum anchorage control for subsequent implant rehabilitation of the fourth quadrant.

Traumatic Displacement of Maxillary Teeth into the Nasal Cavity: A Diagnosis Delayed for 15 Years

ABSTRACT Intrusion is defined as displacement of a tooth into the alveolar bone. In this report, we presented a patient with 15 years of delayed diagnosis of maxillary teeth intrusion into the nasal cavity. A 30-year-old male presented to our clinic with nasal discharge. He had been in a traffic accident 15 years ago. Radiographic examination revealed intrusion of two anterior teeth into the nasal cavity. In patients with maxillofacial trauma, the possibility of having an accompanying dentoalveolar trauma must always be kept in mind. While a computerized tomography (CT) scan is useful in diagnosis of such traumas, it must be performed in all patients with maxillofacial trauma to avoid misdiagnosis.

Vestibular Incision Subperiosteal Tunnel Access (VISTA) for Surgically Facilitated Orthodontic Therapy (SFOT).

Surgically Facilitated Orthodontic Therapy (SFOT) in combination with bone augmentation and the placement of anchorage devices installed into bone have been used to accelerate and facilitate orthodontic treatment. This is usually performed after flap surgery, which is associated with moderate morbidity, as well as possible negative sequale such as gingival recession. The present case report illustrates the clinical benefits of vestibular incision subperiosteal tunnel access (VISTA) for SFOT, and tissue augmentation to facilitate orthodontic therapy. VISTA entails making vertical incision(s) in the vestibule followed by subperiosteal elevation of tunnels to provide direct access to the facial alveolar bone. Unlike previously reported vestibular access surgical procedures, VISTA allows for wider elevation of an access tunnel for clear visual and surgical access to perform careful inter-radicular corticotomy. The present report describes VISTA for corticotomy surgery (anterior mandible and maxillary teeth) in combination with the placement of titanium fixation devices and bone augmentation to facilitate orthodontic treatment of an adult female with borderline Class II Division 1 malocclusion, with excessive overjet and deepbite. In view of the fact that VISTA does not require surface incisions in the gingival margins or papillae, it potentially minimizes gingival recession that sometimes accompanies flap surgery.

Intrusion of the extruded maxillary central incisor using skeletal anchorage system and unilateral segmental intrusion arch

Patients who have a moderate periodontitis with pathologic tooth migration of maxillary incisors, it is necessary not only periodontal treatment for reduce periodontal inflammation, but also orthodontic treatment to teeth repositioning. For orthodontic treatment, it is necessary to apply less force and careful considerations of the center of resistance of the tooth and optimal force of tooth movement. At this time, the segmental arch applied only to the target teeth, is more effective and predictable, because applied force and direction can be controlled. In addition, to design the orthodontic appliance that can prevent the unwanted tooth movement that used as an anchorage is important. In recent years, various types of skeletal anchorage system have been used for preventing loss of the anchorage. We reported the patient who had extruded maxillary central incisor due to pathologic tooth migration, treated by a successful periodontal-orthodontic multidisciplinary treatment using an orthodontic appliance designed to apply less traumatic force and reduce an anchorage loss.

Profile of intrusive luxation and healing complications in deciduous and permanent teeth - a retrospective study.

OBJECTIVE: This retrospective study analyse the profile of intrusion in deciduous (DT) and permanent teeth (PT), the occurrence of healing complications (HC), type of treatments and predisposing factors. METHODS: The records of patients attended from 2005 to 2011 were analysed. Records of patients who had one or more intruded DT or PT were included in the study. Data collected from dental records included age, gender, attendance (immediate/mediate), healing complications and type of treatment. A Chi-square test and Logistic regression (p ≤ .05) were performed to evaluate the associations between the type of teeth and presence of HC, as well as to explore the interactions between predisposing factors. RESULTS: The intrusion prevalence was 9.98% in DT and 2.45% in PT. Partial intrusion (57.3%) with palatal direction of the crown (61.8%) was most prevalent in DT, while complete intrusion (56.7%) with buccal direction of the crown (58.1%) was predominant for PT. Mobility was the most common HC in DT compared to root resorption in PT. Minimally invasive treatments were the most common therapy for DT compared to invasive treatments for PT. PT demonstrated increased HC when compared to DT (p = .004). A logistic regression illustrated that the level of intrusion and crown direction during the trauma did not influence the occurrence of HC (p > .05). CONCLUSION: Intrusion's profile in DT and PT are different. PT showed more HC than DT, however the level of intrusion and crown direction were not associated with the presence of HC.

Intrusion of upper molars with mini-implants for open bite correction is effective? A systematic review / A intrusão de molares superiores com mini-implantes para correção da mordida aberta é eficaz? Revisão sistemática

Introduction: The open bite is a malocclusion defined by the absence of a positive vertical overlap of the upper incisors over the lower ones. It is believed that the correction of this malocclusion with mini-implants is as effective as another technique. Objective: To verify by scientific evidence the effectiveness of upper molar intrusion with mini-implants for correction of open bite. Material and Methods: This systematic review was conducted according to the PRISMA guidelines. Cochrane Handbook for Systematic Reviews of Interventions (version 5.3) was used to assess the methodological quality and risk of bias of the included studies. Results: During the selection and evaluation process, 795 of the 1297 papers were eligible for research in their titles and abstracts. Repeated articles were removed and as a result, 21 articles were retrieved and read completely. Those who did not meet the inclusion criteria were excluded, resulting in only 6 articles that were included. Conclusion: The intrusion of the upper molars with the use of mini-implants as a skeletal anchor is effective for open bite correction. When the technique of upper molar intrusion with mini-implants was compared with the technique of posterior high pull and incisor extrusion, the first one was more effective for the correction of open bite. The recurrence of molar intrusion does not invalidate mini-implant treatment for open bite correction because the benefits achieved outweigh the small dental relapse. (AU)

Introdução: A mordida aberta é uma má oclusão definida pela ausência de um trespasse vertical positivo dos incisivos superiores sobre os inferiores. Acredita-se que a correção desta má oclusão com mini-implantes seja tão eficaz quanto outra técnica. Objetivo: Constatar por evidências científicas a eficácia da intrusão dos molares superiores com mini-implantes para correção da mordida aberta. Material e Métodos: Esta revisão sistemática foi conduzida de acordo com as diretrizes PRISMA. Para avaliar a qualidade metodológica e o risco de viés dos estudos incluídos, utilizou-se a Ferramenta Cochrane de Colaboração para avaliação do risco de viés, publicado Cochrane Handbook for Systematic Reviews of Interventions (versão 5.3). Resultados: Durante o processo de seleção e avaliação, 795 dos 1297 artigos mostraram-se elegíveis para a pesquisa em seus títulos e resumos. Os artigos repetidos foram removidos e como resultado, 21 artigos foram recuperados e lidos por completo. Aqueles que não preencheram os critérios de inclusão foram excluídos, resultando em apenas 6 artigos que foram inclusos. Conclusão: A intrusão dos molares superiores com o uso de mini-implantes como ancoragem esquelética é eficaz para correção de mordida aberta. Quando a técnica de intrusão de molares superiores com miniimplantes foi comparada com a técnica de puxada alta posterior e extrusão de incisivos, a primeira foi mais eficaz para correção da mordida aberta. A recidiva da intrusão dos molares não invalida o tratamento com mini-implantes para correção da mordida aberta porque os benefícios alcançados superam a pequena recidiva dentária (AU)

Efficiency of two protocols for maxillary molar intrusion with mini-implants

ABSTRACT Objective: The aim of this study was to compare the efficiency of two protocols for maxillary molar intrusion with two or three mini-implants. Methods: Twenty five maxillary first molars extruded for loss of their antagonists in adult subjects were selected. The sample was divided into two groups, according to the intrusion protocol with two or three mini-implants. Group 1 consisted of 15 molars that were intruded by two mini-implants. Group 2 consisted of 10 molars intruded by three mini-implants. Changes with treatment were analyzed in lateral cephalograms at the beginning and at the end of intrusion of maxillary molars. Results: Results showed that there was no difference in efficiency for the two intrusion protocols. It was concluded that extruded maxillary molars can be intruded with two or three mini-implants with similar efficiency.

RESUMO Objetivo: o objetivo do presente estudo foi comparar a eficiência de dois protocolos de intrusão de molares superiores com dois e três mini-implantes. Métodos: foram selecionados 25 primeiros molares superiores extruídos por perda de seus antagonistas, de pacientes adultos. A amostra foi dividida em dois grupos, de acordo com o protocolo de intrusão, com dois ou três mini-implantes: o Grupo 1 consistiu de 15 molares que sofreram intrusão com dois mini-implantes; o Grupo 2 foi constituído por 10 molares intruídos por três mini-implantes. As alterações com o tratamento foram analisadas em telerradiografias em norma lateral ao início e ao final da intrusão dos molares superiores. Resultados: os resultados mostraram que não houve diferença na eficiência dos dois protocolos de intrusão. Concluiu-se que molares superiores extruídos podem ser intruídos, com eficiência semelhante, por meio de dois ou três mini-implantes.

Primary incisor intruded through the nasal cavity: a case report.

Intrusive luxation may cause complications for the primary tooth and generate adverse sequelae in the permanent successor. Although intrusion is prevalent in the primary dentition, full intrusion is a rare event that requires specialized treatment and a multidisciplinary approach. This article describes the case of a 1-year-old girl who presented with traumatic displacement of the maxillary left central incisor into the nasal cavity. The parents sought treatment 1 month after the child sustained the injury, and the impacted tooth was removed through her left nostril under general anesthesia. Four-year clinical and radiographic follow-up revealed no adverse sequelae.

Orthodontic intrusion of maxillary incisors: a 3D finite element method study

Objective: In orthodontic treatment, intrusion movement of maxillary incisors is often necessary. Therefore, the objective of this investigation is to evaluate the initial distribution patterns and magnitude of compressive stress in the periodontal ligament (PDL) in a simulation of orthodontic intrusion of maxillary incisors, considering the points of force application. Methods: Anatomic 3D models reconstructed from cone-beam computed tomography scans were used to simulate maxillary incisors intrusion loading. The points of force application selected were: centered between central incisors brackets (LOAD 1); bilaterally between the brackets of central and lateral incisors (LOAD 2); bilaterally distal to the brackets of lateral incisors (LOAD 3); bilaterally 7 mm distal to the center of brackets of lateral incisors (LOAD 4). Results and Conclusions: Stress concentrated at the PDL apex region, irrespective of the point of orthodontic force application. The four load models showed distinct contour plots and compressive stress values over the midsagittal reference line. The contour plots of central and lateral incisors were not similar in the same load model. LOAD 3 resulted in more balanced compressive stress distribution.

Objetivo: frequentemente, no tratamento ortodôntico, é necessário o movimento de intrusão dos incisivos superiores. Assim, o objetivo deste estudo é avaliar o padrão de distribuição inicial e magnitude das tensões compressivas no ligamento periodontal (LPD) na simulação da intrusão ortodôntica dos incisivos superiores, considerando os pontos de aplicação da força. Métodos: modelos anatômicos 3D reconstruídos a partir de tomografias computadorizadas de feixe cônico foram utilizados para simular os carregamentos da intrusão dos incisivos superiores. Os pontos eleitos para a aplicação das forças foram: centralizado entre os braquetes dos incisivos centrais (LOAD 1); bilateralmente, entre os braquetes dos incisivos centrais e laterais (LOAD 2); bilateralmente, distal aos braquetes dos incisivos laterais (LOAD 3); bilateralmente, 7mm distal ao centro dos braquetes dos incisivos laterais (LOAD 4). Resultados e Conclusões: as tensões concentraram-se na região apical do LPD, independentemente do ponto de aplicação da força ortodôntica; os quatro modelos de carregamento mostraram distribuição e valores de tensão compressiva distintos na linha mediana sagital de referência; os gráficos de distribuição das tensões não foram similares para os incisivos central e lateral no mesmo modelo de carregamento; o LOAD 3 resultou em uma distribuição mais equilibrada das tensões compressivas.

Periodontal changes following molar intrusion with miniscrews.

BACKGROUND: With the introduction of skeletal anchorage system, recently it is possible to successfully intrude molar teeth. On the other hand, there have been concerns about periodontal changes associated with intrusion and there are few studies on this topic, especially for posterior teeth. MATERIALS AND METHODS: Ten female patients were enrolled in this study. Maxillary molar intrusion was achieved by inserting two miniscrews and a 17 × 25 titanium molybdenum alloy spring. Crestal height changes were evaluated at three intervals including: Baseline (T0), end of active treatment (T1) and 6 months after retention (T2). Other variables including probing depth, gingival recession, attachment level and bleeding on probing were evaluated by clinical measurements in the three above mentioned intervals. One-sample Kolmogrov-Smirnov test ascertained the normality of the data. For all patients, the changes in tooth position and crestal height were evaluated using one-sample t-test. (P < 0.05). RESULTS: Supra-erupted molars were successfully intruded a mean of 2.1 ± 0.9 mm during active treatment (T0-T1). A mean bone resorption of 0.9 ± 0.9 mm in mesial crest and 1 ± 0.8 mm in distal crest had occurred in total treatment (T0-T2). A mean of 0.6 ± 1.4 mm bone was deposited on mesial crest during the retention period (T1-T2) following tooth relapse. On average, 0.8 ± 0.4 mm attachment gain was obtained. Gingival margin coronalized a mean of 0.8 ± 0.6 mm throughout the entire treatment. Probing depth showed no significant change during treatment. CONCLUSION: Within the limitations of this study, these results suggest that not only periodontal status was not negatively affected by intrusion, but also there were signs of periodontal improvement including attachment gain and shortening of clinical crown height.

Conservative management of progressive external inflammatory root resorption after traumatic tooth intrusion.

Intrusive luxation is one of the most severe types of dental trauma. The risk of development of inflammatory or replacement root resorption is high if not timely managed. Endodontic intervention is required soon after the occurrence of trauma, in an attempt to prevent or delay inflammatory root resorption. This case report emphasized timely referral for endodontic management of intruded tooth to prevent inflammatory root resorption.

Intrusive luxation in primary teeth - Review of literature and report of a case.

Luxation injuries such as intrusion are commonly seen in the primary dentition. Intrusion drives the tooth deeper into the alveolar socket, which results in damage to the pulp and peridontium. Difficulty in gaining compliance from a very young child and the risk of damaging the permanent tooth germ makes the management of these injuries challenging. Careful clinical and radiographic examination along with regular follow-up is essential. A case of intrusive luxation to the maxillary central incisor in a 3-year-old patient is reported. Spontaneous reeruption was noted 4 months after injury, but the tooth had developed an abscess and external root resorption. Hence, extraction of the tooth was done and an anterior esthetic fixed space maintainer was placed. Traumatic injuries to the primary dentition should not be ignored by the parents or by the dentist. The paper also includes a literature review of intrusive luxation in the primary dentition.