Dental Movement Research Articles

External apical root resorption after molar space closure with miniscrew as anchorage: a tomographic evaluation

Objective: The purpose of this retrospective study was to evaluate and quantify external apical root resorption (EARR) in molars after masialization into atrophic alveolar ridge area. Materials and Methods: The sample consisted of 11 patients, five women and six men, and a total of 16 molars, both superior and inferior (seven in the maxilla and nine in the mandible). The age range was 19 to 55 years at the beginning of treatment (initial mean age of 36 years and 5 months), with an average treatment time of 23 months. Tooth movement was performed with mini-implant anchorage using NiTi springs, using a mean force of 300 grams. The sample was evaluated using cone-beam CT scans (CBCT) in two periods, at the beginning of the treatment (T1) and after 4 mm of movement (T2). Root resorption was measured by the difference in root lengths (T2-T1). Using the distance from the floor of the pulp chamber to the root apex as a reference. Root length was measured using specific software (OnDemand3Ddental) and was analyzed using the paired t-test, adopting a significance level of 5%. Results: There was statistically significant resorption only in the mesial and distal roots, with a mean reduction of 0.69 mm in the mesial root (-6.2%) and 0.83 mm in the distal root (-7.4%). Conclusion: Space closure after dental movement in an atrophic alveolar ridge was identified as a risk factor for ARR. However, the amount of ARR could be considered clinically irrelevant.

Evaluation of Palatal Rugae Following Orthopedic Treatment Using Rapid Maxillary Expander and Facemask

The purpose of this study was to determine whether the palatal rugae could be used as an appropriate reference area for serial model superimposition following Rapid maxillary expansion(RME) and facemask treatment.<br/>A total of 52 pediatric patients who had undergone RME and facemask treatment were selected. Palate and palatal rugae in the pre- and post- treatment casts from the patients were measured.<br/>In spite of dentoalveolar changes occurred by RME and facemask, anteroposterior changes in palate and palatal rugae were not significant. Anatomical changes of palate and palatal rugae were mostly shown in the transverse dimension. The soft tissue of the palatal rugae stretches in adaptation to hard tissue movement. Among the evaluated landmarks, the medial point of the third palatal rugae seemed to be the most stable.<br/>The observed alterations in the palatal rugae demonstrated the potential of medial points of third palatal rugae as a reference point in model superimpositions to evaluate dental movement within the maxillary arch following RME and facemask treatment.

Management of an Elderly Patient with Orthostatic Hypotension in Endodontic Retreatment: A Case Report

Orthostatic hypotension occurs when cardiovascular adaptive mechanisms fail to compensate the reduction in venous return that normally occurs on the upright position. A patient with orthostatic hypotension can be a challenging case for a dentist. A 78-year-old male came with idiopatic orthostatic hypotension and felt uncomfortable with his old crown restoration and discoloration on his upper teeth. Management of orthostatic hypotension can be handled by manipulating the dental chair interval movement position.

Mini implants osseointegration, molar intrusion and root resorption in Sinclair minipigs

The use of mini implants to create a passive intraoral anchorage point has been mainly tested in clinical trials. In this study, an experimental integrated approach evaluated mini implant loading protocols (immediate vs. delayed loading) on bone remodelling and mini implant stability and the consequent degree of dental intrusion and apical root resorption. A total of 40 Absoanchor® mini implants with 1.2mm diameter and 8mm length were placed in a total of 5 minipigs, 8 per animal, 2 in each hemiarch. Each implant was attached through a lingual button to the vestibular side of the second and fourth premolars with a nitinol coil spring of 150g force. The analysis of morphological aspects included the degree of dental movement, mini implant stability, and new bone formation over the mini implant heads. Bone mini-implant interface and modifications of dental root in response to intrusion were studied by light and electron microscopy. The rate of mini implant success was>98%, mainly in those subjected to immediate loading. This loading protocol promoted a high degree of osseointegration along with a high degree of intrusive dental movement, particularly of the second premolars. However, the radiological and histological studies showed a low degree of root resorption. Associated with the high intrusive movement, the penetration of the root apexes produced an inner cortical surface deformation of the maxillary sinus floor by remodeling and bone growth. In minipigs immediate loading of smooth mini implants promoted a high degree of intrusive movement particularly of the second premolars, stimulated bone growth and osseointegration, but extensive root resorption was not observed.

Optimizing function and esthetics in an adult patient with a complete crossbite

AbstractThis case report describes the treatment of a 32-year-old woman with anterior and bilateral posterior crossbite, skeletal Class II and dental Class III relationship, with the removal of widely decayed teeth. Treatment options included orthognathic surgery, rapid maxillary expansion (RME), and orthodontic treatment associated with implant and prosthesis. The patient opted for nonsurgical treatment, without RME, extraction of the affected teeth by extensive caries lesions, closure of the remaining spaces by dental movement, and single-crown implant prosthesis.

Uso de analgésicos antiinflamatorios no esteroidales en ortodoncia: Revisión bibliográfica

Un 90% de los pacientes con tratamiento de ortodoncia relatan presentar dolor postoperatorio a la aplicación de fuerzas mecánicas, alcanzando el máximo disconfort a las 24 horas. Estudios sugieren como método de elección el uso de analgésicos antiinflamatorios no esteroidales (AINES) para el control y manejo del dolor. El objetivo de la presente revisión fue evaluar literatura existente sobre AINES utilizados en pacientes sometidos a tratamientos ortodóncicos y su relación con el proceso inflamatorio, revisar alternativas farmacológicas y sugerir el medicamento más apropiado para el manejo y control del dolor. Para llevar a cabo este estudio se utilizaron bases de datos como Pubmed, Scielo, ScienceDirect, EBSCOhost, y Google Académico, teniendo como límites de búsqueda documentos publicados entre los años 2006 y 2018, a excepción de dos estudios, uno del año 1996 y otro del 2000, los cuáles proporcionaron información de suma relevancia. Se consideraron artículos como revisiones sistemáticas, estudios prospectivos y retrospectivos. Se concluyó que es importante manejar el dolor involucrado en los tratamientos ortodóncicos sin interferir en el proceso inflamatorio que lo acompaña. Al analizar diferentes AINES no se observaron diferencias significativas en cuanto a la reducción del dolor, a excepción del Paracetamol, el cual se considera el más apropiado, debido a que este concentra su acción a nivel del SNC, no alterando la síntesis de prostaglandinas y permitiendo el movimiento dental. Se sugiere que se hagan estudios sobre medicamentos como Indometacina, Diclofenaco, Flurbiprofeno y Etoricoxib, debido a que existe escaza evidencia al respecto.

Alveolar corticotomies for accelerated orthodontics: A new mini-invasive technique

Orthodontic and surgical techniques are constantly evolving and practitioners are facing an increasing demand for shorter treatments, with an expectation of results equivalent to conventional treatments. Corticotomies have made it possible to partly meet this need by facilitating dental movement in adult orthodontic care. Many surgical corticotomy techniques were proposed in the past presenting advantages but also a certain number of disadvantages. After retracing the various surgical techniques proposed and explaining the biological principles, we will introduce a new minimally invasive technique, without mucoperiosteal flap and without piezosurgery. This technique can be performed in the dental chair under local anaesthesia or sedation. It is simple and reproducible. This type of treatment combines comfort, speed and periodontal protection. Our objective is to provide more patients and practitioners with corticotomies while controlling the benefit/risk ratio.

Molecular evaluation of tissue proteins in vivo during controlled orthodontic movement.

Orthodontic tooth movement determines a biological response of all the tissues surrounding the teeth to which force is applied. The aim of this study is to evaluate which ideal orthodontic force, at the biological level, arouses an acute inflammatory response on periodontal tissues, and the duration of the force in order to establish an ideal experimental model of dental movement. The periodontal ligament and the alveolar bone change abruptly due to the biochemical adaptive response, resulting in a re-organization of the intracellular and the extracellular matrix. There is a modification of the local vascularization which stimulates a cascade production, synthesis and the release of arachidonic acid, metabolites, proteins, such as cytokines, and growth factors. Every dentist can control and should know the above-mentioned mechanism. Moreover, the production of proteins by modulating the direction and the intensity of the force can be changed but, above all, the duration.

Influence of Hyrax screw position on dental movement and cortical bone: A study of finite elements.

BackgroundRapid maxillary expansion (RME) has effects on the dental and periodontal structures of the parts involved, which vary according to the design and position of the expansion screw. The purpose of the study was to determine the optimal three-dimensional position of the Hyrax screw to obtain precise control of the dental movement and effect on the bone cortex using the finite element method (FEM).Material and MethodsRME was performed from the patient whom two Cone-Beam computerized tomography scans (CBCT) were obtained: T1 before expansion, and T2 three months after stabilization of RME. The FEM model was designed with T1 and of Hyrax photographs. FEM was obtained by comparing the simulation, T2, and clinical results. Three sagittal screw positions (anterior-middle-posterior) and vertical (upper-medium-low) were evaluated.ResultsA coronal- buccal displacement of premolars and first molars was found which decreased in the occlusal-apical direction, presenting different types of dental movement in the screw positions; besides, a tendency of translational movement in the posterior-high location was observed. In the posterior-high position a higher concentration of efforts and homogeneous deformations in the periodontal ligament and vestibular cortex of the cervical area of first molars, first and second premolars were observed, with variations according to the screw position and the distribution of stresses.ConclusionsThe ideal location of the expansion screw for controlling dental movement and periodontal side effects was the high-posterior position. Key words:Maxillary expansion, dental movement, finite element analysis, orthodontic appliances.

Superimposition of 3D maxillary digital models using open-source software.

Historically, whether for research purposes or clinical monitoring, orthodontic evaluation of dental movements has been done using plaster study models and two dimensional (2D) radiographs. However, new frontiers for the diagnosis, planning and outcome assessment of orthodontic treatments have arisen, due to the revolutionary digital tools which enable a three dimensional (3D) computerized analysis of dental movements by means of digital models. However, the software for 3D analysis are often costly, resulting in limited access to orthodontists. The present study aims to describe, through a clinical case presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics, a method for the superimposition of maxillary digital models using an open-source software to evaluate dental movements.

Biomechanics of extra-alveolar mini-implants.

ABSTRACTIt is undeniable that extra-alveolar mini-implants anchorage has revolutionized Orthodontics. Correspondingly, the proper understanding of mini-implants biomechanics allowed to broaden the range of dental movements as never seen before in clinical practice. However, in order to produce better treatments, especially regarding the effects in occlusal plane, it is important to be aware of the numerous possibilities of applying force systems based on skeletal anchorage. Thus, this paper aims to address, by means of clinical cases, the application of biomechanics concepts that are extremely relevant to the proper employment of extra-alveolar mini-implants.

A systematic review of the accuracy and efficiency of dental movements with Invisalign®.

We are currently living in an era where the use of computer-aided design/computer-aided manufacturing has allowed individualized orthodontic treatments, but has also incorporated enhanced digitalized technology that does not permit improvisation. The purpose of this systematic review was to analyze publications that assessed the accuracy and efficiency of the Invisalign® system. A systematic review was performed using a search strategy to identify articles that referenced Invisalign®, which were published between August 2007 and August 2017, and listed in the following databases: MEDLINE, Embase, Cochrane Library, Web of Knowledge, Google Scholar, and LILACS. Additionally, a manual search of clinical trials was performed in scientific journals and other databases. To rate the methodological quality of the articles, a grading system described by the Swedish Council on Technology Assessment in Health Care was used, in combination with the Cochrane tool for risk of bias assessment. We selected 20 articles that met the inclusion criteria and excluded 5 due to excess biases. The level of evidence was high. Although it is possible to treat malocclusions with plastic systems, the results are not as accurate as those achieved by treatment with fixed appliances.

Macro H2A.1 immunohistochemical expression in an “in vivo” model of orthodontic dental movement

Macro H2A.1 immunohistochemical expression in an “in vivo” model of orthodontic dental movement

Long-term side effects of sleep apnea treatment with oral appliances: nature, magnitude and predictors of long-term changes

ObjectivesOral appliances for the treatment of obstructive sleep apnea (OSA) reduce upper airway collapse by advancing the mandible (OAm) and associated soft tissues. OAm are well tolerated but have side effects, mainly dental movement. It is not yet clear whether there are irreversible skeletal changes associated with treatment. As oral appliance treatment for OSA is a life-long therapy, careful and extended follow-up of patients is required. The objectives of this study were to evaluate the magnitude and progression of the dental and skeletal changes associated with long-term treatment, in addition to determining the predictors of the changes. MethodsLateral cephalograms of adults treated for primary snoring or mild to severe OSA with a custom-made titratable OAm for a minimum of eight years were retrospectively studied. The magnitude and rate of progression of any changes over time was determined and initial patient and dental characteristics were investigated as possible predictors of the observed side effects. ResultsRecords of 62 patients with an average treatment time of 12.6 years (range:8–21 years) were included. Cephalometric analysis revealed significant (p < 0.001) maxillary incisor retroclination (mean of ≈6°) and mandibular incisor proclination (mean of ≈8°) over the observation period. Maxillary incisors demonstrated a constant rate of retroclination –0.5°/year, the rate of mandibular incisors proclination was variable. The number of treatment years was significantly associated with these variables (p < 0.001). A greater body mass index (BMI) and Subspinale, Nasion, Supramentale angle (ANB) were associated with more maxillary and mandibular incisor proclination respectively. Although statistically significant (p < 0.001) skeletal changes were noted over this extended observation period, the difference in the Sella, Nasion, Supramentale point B (SNB) and mandibular plane angles were approximately 1° and were deemed not clinically significant. ConclusionsThis study represents the longest observation period to date examining OAm side effects with up to 21 years of follow up for some patients. It confirms that there are significant and progressive dental changes with prolonged OAm use. Conversely, over the same time period skeletal or postural changes were negligible. Additionally, treatment duration was the predictor consistently associated with the magnitude of the observed side effects.

The use of four different lasers in a “surgery first” case, for orthodontic movement acceleration, paresthesia, aphthous ulcer, edema, and pain control

Photobiomodulation is an important resource during an orthodontic treatment. It is useful to control post archwire activation pain, reduce orthodontic treatment time, and achieve faster-wound healing. The aim of this report is to present an ortho-surgical case treated with four different laser wavelengths applied during all stages of the treatment to achieve different results in the benefit of the patient. A severe class II 52-year-old female patient with muscular pain and temporomandibular disorders. The patient was treated with a surgery-first protocol and passive self-ligating brackets to achieve dental movement acceleration and pain control; the patient was irradiated using 808 nm wavelength, 100 mW, ED 80 J/cm2, E 2.2 J, 22 s along the vestibular and palatal surface performing a scanning movement. After surgery, the patient has irradiated 6 sessions for edema and inflammation control, with a 940 nm, in continuous mode, 2.5 W, 120 s, 85.71 J/cm2, over the right and left side. After 2 weeks, the patient reports paresthesia in her left lower lip. A paresthesia protocol was started with a 650 nm wavelength laser, using the following parameters: 100 mW, PD 0.2 W/cm2, E 6 J, 60 s, one session every 2 days for 3 weeks. When the patient reported one aphthous ulcer in her left lower lip, the affected surface was irradiated with a wavelength of the 660 nm laser, 25 J/cm2, 100 mW, for 14 s, applying laser by scanning the lesion 1 mm away. Only one laser application per aphthous lesion was made. The patient finished all the ortho-surgical treatment in 4 and a half months. Four successful wavelengths, but also two laser protocols were applied during the treatment, not only to accelerate orthodontic movement but also to reduce edema after orthognathic surgery, paresthesia, and aphthous ulcer as well.

Does low-frequency vibration have an effect on aligner treatment? A single-centre, randomized controlled trial.

Low-frequency vibrations have been proposed as a means of accelerating tooth movement and reducing orthodontic treatment times. To determine any differences in the accuracy of dental movement in patients treated with a low-frequency vibration aligner protocol and/or by reducing the aligner replacement interval with respect to a conventional protocol. This trial was designed as a single-centre, randomized controlled clinical trial. Participants: Patients (aged 27.1 ± 9.0 years) who required orthodontic treatment with aligners. Randomization: Patients were randomly allocated to three arms as determined by a computer-randomization scheme. Group A were assigned a conventional protocol (aligners replaced every 14 days); group B also used a low-frequency vibration device for 20 minutes per day; group C followed the same vibration protocol but replaced their aligners every 7 days. Blinding: The operator who performed the set-up and the one who analysed the data were blinded to the group of the patients. Outcome: Pre- and post-treatment digital models were analysed using VAM software to identify the accuracy/imprecision of dental movements. One-way analysis of variance (P < 0.05) and the Bonferroni post hoc test were used to identify any statistically significant differences between the three arms in terms of the accuracy of tooth movement versus the prescription. Numbers analysed: A total of 45 patients (15 for group) were analysed (i.e. 2286 dental movements). Outcome: No statistically significant differences emerged between groups A and C in the upper arch, or among groups A, B, and C in the lower. Group B displayed significantly greater accuracy with respect to group A in upper incisor rotation (P = 0.016), and to group C in vestibulolingual (P = 0.007) and mesiodistal tipping (P = 0.029) of the upper canines, and vestibulolingual tipping of the upper molars (P = 0.0001). Harms: No adverse events or side-effects were registered. Considering all tooth and movement types of the 45 participants, the mean total imprecision was 2.1 ± 0.9 degrees, with respect to a mean prescription of 5.7 ± 2.2 degrees. There was no difference in accuracy between replacing the aligners accompanied by low-frequency vibration every 7 days and replacing them every 14 days without vibration. Moreover, low-frequency vibration seemed to improve the accuracy of a conventional protocol in terms of upper incisor rotation. The German Clinical Trials Register (DRK00015613).

Long-term stability of curve of Spee levelled with continuous archwires in subjects with different vertical patterns: a retrospective study.

The aim of the study was to evaluate the curve of Spee (COS) stability in patients treated with continuous archwires with different vertical patterns. The study sample consisted of 60 patients (28 males, 32 females; mean age 19.8 ± 1.4 years) presenting with COS depth of at least2 mm at baseline. For each subject, lateral cephalograms and dental casts were available before treatment (T1), at the end of orthodontic therapy (T2), and 2 years after the end of treatment (T3). All subjects were divided into three groups according to vertical facial patterns. Cephalometric parameters were used to evaluate the dental movements after treatment. COS depth was measured on digital casts. Mean differences between vertical facial subgroups were contrasted by means of analysis of variance test (P < 0.01). In low-angle subjects, COS levelling occurred through advancement and intrusion of lower incisors, whereas in high-angle patients, the COS was flattened through extrusion and uprighting of lower posterior teeth. In the low-angle group, a significant relapse of lower incisors inclination was observed. Differently, the high-angle group exhibited a greater stability of COS obtained by stable extrusion of posterior teeth. The long-term instability of flared incisors determined the relapse of overbite and COS depth in the low-angle group.

Effect of orthodontic force associated with cigarette smoke inhalation in healthy and diseased periodontium. A histometric and immunohistochemistry analysis in rats.

The aim of the present study is to evaluate the effect of orthodontic forces in healthy or diseased periodontium of rats submitted/not submitted to cigarette smoke inhalation. Fifty-six male Wistar rats were allocated into two groups of conditions: smoking and non-smoking. Each group was divided into the following subgroups: control (C), orthodontic tooth movement (OTM), ligature-induced periodontitis (P) and P+OTM (POTM), with n=14 each. Periodontitis was induced in the lower first molar by cotton ligature, and a 4mm closed stainless steel spring was used for orthodontic movement. Animals were exposed to the smoke of 10 cigarettes for 8minutes, 3 times a day for 60days before P induction and OTM. Evaluation parameters were macroscopic analysis of dental movement, bone loss and bone density. In addition, the receptor activator of nuclear factor-kappaB (RANK) immunostaining and RANK ligand/osteoprotegerin ratio in the furcation region were assessed. There was no statistically significant difference between groups, ie, smoking and non-smoking conditions (P=.338). Bone loss intragroup analysis between the P and POTM groups was not significant in smoking (P=1) and non-smoking (P=.5) conditions; both were different from OTM and C in each condition. Regarding bone density, POTM and P were significant to C (P<.05). The POTM group was significant to the P and C (P=.001) regarding dental movement. The RANK ligand/osteoprotegerin ratio in the non-smoking condition was higher in P and POTM compared to C and OTM and to P and POTM in the smoking condition. RANK immunostaining was significant in the smoking condition for the P and POTM groups (P<.05). Within the limitations of the present study, it was concluded that cigarette smoke inhalation had no influence on the evaluated groups, even with the presence of low levels of nicotine, carbon monoxide and tar. The POTM groups did not present greater bone loss compared to P groups, thus periodontal disease is essential for bone loss.

Simulation of a three-dimensional craniofacial structure under the application of orthodontic loads

The aim of this study was to develop a three-dimensional model of a patient’s craniofacial structure to be analysed using the finite element method in order to estimate the forces required to carry out a dental positioning’s correction. The three-dimensional model was composed by several anatomical structures, namely the teeth, the periodontal ligaments, and the trabecular and cortical bones, which were modelled with the aid of computed tomography cone beam images. The tomographic images were analysed and reconstructed using the 3D Slicer software, while the assembly of the anatomical structures modelled, as well as the contact surfaces between contiguous parts, was defined in computer-aided design software. Bone remodelling and the occurrence of tissue’s injuries were considered during the numerical simulations carried out. By imposing displacements to each tooth, it was possible to calculate the orthodontic loads needed to carry out dental correction (reaction forces), as well as the distributions of stresses and deformations inherent to the clinical treatment, allowing to obtain a craniofacial structure capable of simulating the dental movements of upper and lower arches with anatomical realism. In addition, this methodology constitutes a personalised dental medicine that could lead to the development of highly customised orthodontic appliances where different mechanical loads could be applied individually to each tooth to achieve the foreseen dental correction.

What Increases the Risk of Dental Traumatism in Patients with Developmental Disabilities?

This study investigated risk factors for tooth injuries in individuals from a dental clinical reference service for patients with special needs in Belo Horizonte, MG, Brazil. This is a retrospective cohort study that evaluated 493 dental charts of individuals with or without tooth injuries at their first dental appointment. The dependent variable was the time of occurrence of new dental traumatic injuries and was measured in months. Gender, age, International Code of Diseases, mother's education, mouth breathing, hyperkinesis, pacifier use, thumb sucking, psychotropic drug use, tooth injuries at the first dental examination, involuntary movements, open bite, having one or more siblings and reports of seizures were the covariates. The Cox proportional hazards regression model was used to estimate the unadjusted and adjusted hazard ratios and their respective 95% confidence intervals. The average time that individuals remained free of dental traumatism was 170.78 months (95% CI, 157.89-183.66) with median of 216 months. The incidence of new events was 11.88%. The covariate associated with an increased risk of dental traumatism was a history of tooth injuries at the first dental appointment. The increase in dental trauma risk was 3.59 (95% CI, 1.94-6.65). A history of traumatic dental injury was the risk factor for the dental trauma found in this group of individuals with developmental disabilities.