Orthodontic Traction Research Articles

Surgical uprighting of mandibular second molars: A single-group retrospective cohort study

The management of impacted, unerupted, or malpositioned mandibular secondmolars with orthodontic therapy requires special attention in order to achieve normal anatomic positioning within the dental arch. We present a surgical approach to managing these teeth combining exposure and surgically-assisted forced eruption. This retrospective single-group cohort study followed 260 impacted mandibular secondmolars. The molars were exposed and surgically uprighted. An orthodontic bracket was bonded to aid in orthodontic traction, and the wound was packed to prevent soft tissue growth over the crown of the exposed molar. Patients were followed for a minimum of 6months after uprighting, during which the following outcomes were measured: the degree of success of the eruption one the basis of the clinical occlusal relationship to the opposing dentition, radiographic evidence of bone fill, the periodontal status of the teeth involved, and tooth vitality. A total of 260 mandibular secondmolars were uprighted in 177 patients (83 female, 94 male) with an average age of 14.8years. Outcomes showed that 255molars (98.1%; 95% confidence interval, 96.3-99.8) were successfully uprighted. Complications included infection/abscess in 3molars and fractured root requiring extraction in 2molars. All remaining 255 teeth tested vital, 17 teeth had periodontal pocketing of more than 5mm, and 235 of the teeth had occlusal contact after healing. Surgically-assisted forced eruption with or without orthodontic forced eruption is a safe, successful, and viable approach to managing unerupted or malpositioned mandibular secondmolars in the adolescent population.

A Custom-Made Orthodontic Mini-Implant-Effect of Insertion Angle and Cortical Bone Thickness on Stress Distribution with a Complex In Vitro and In Vivo Biosafety Profile.

Background: Orthodontic mini-implant failure is a debatable subject in clinical practice. However, the most important parameter to evaluate the success rate of mini-implant is the primary stability, which is mainly influenced by cortical bone thickness (CBT) and insertion angle. Materials and methods: Three-dimensional finite element models of the maxilla were created and a custom-made, self-drilling, tapered mini-implant was designed. For the pull-out test, 12 simulations were performed, sequentially increasing the thickness of the cortical bone (1, 1.5 and 2 mm) and the insertion angle (30°, 60°, 90°, 120°). For the force analysis, 24 simulations were performed using an experimental orthodontic traction force of 2 N both in the horizontal and vertical axis. Results: Insertion angle and CBT have significant impact on force reaction values (p < 0.05). Cortical bone stress had the lowest value when the mini-implant had a 30° insertion angle and the highest value when the implant had a 120° insertion angle, while the CBT was 1 mm. Cortical bone stress had the lowest value with an insertion angle of 90° and the highest value when the implant was inserted at an angle of 30°, while the CBT was 2 mm independent of the force direction. Regarding the biosafety profile of the mini-implant alloy, the present results reveal that the custom-made mini-implant presents good biocompatibility. Conclusions: When the CBT is reduced, we recommend inclined insertion while, when the CBT is appropriate, perpendicular insertion is advised.

Digital workflow of orthodontic and prosthetic treatment for subgingival residual root preservation guided by target restoration space

The use of orthodontic traction to preserve healthy subgingival residual root is a classical method combining the treatment of restoration and orthodontics. Based on the target restoration space (TRS), by establishing a TRS digital model, the final traction position of the subgingival residual root can be preset. After evaluating the key parameters such as crown-to-root ratio and minimum crown height, clinicians can estimate the treatment time and exclude cases with bad preset position. The time of traction treatment can be effectively reduced, and the efficiency and efficacy of the entire treatment can also be improved.

Placing Dental Implants through Impacted Teeth to Support a Fixed Partial Denture in a Geriatric Patient as an Alternative to Invasive Extraction Surgeries.

Multiple dental impactions not associated with craniofacial syndromes are a rare condition and present the dentist with a therapeutic challenge when it comes to performing surgical/restorative treatments in adult patients. This case report describes a geriatric patient with multiple impacted teeth restored by means of two different protocols. In the second quadrant, an impacted tooth was extracted followed by regeneration and placement of an implant. In the third quadrant, implants were placed though impacted teeth for restoration with a fixed partial prosthesis. Placing dental implants through impacted teeth may offer a possible therapeutic option for implant-supported restorations in middle-aged or elderly patients, for whom surgery and orthodontic traction are not possible, and/or patients who refuse to undergo more invasive extraction surgery.

ODONTOMA-ASSOCIATED CALCIFYING ODONTOGENIC CYST MIMETIZING DENTAL GERM

An 11-year-old patient, male, was submitted to orthodontic traction of enclosed lower molar. Tomographic examination showed a radiolucent image measuring approximately 1 cm between 46 and suggestive dental germ of the 47. Intraoral examination confirmed absence of the 46. The orthodontic traction was performed and a routine panoramic radiography revealed formation of a delineated radiolucent image with radiopaque foci at the periphery. Thereby, hypothesis of odontogenic lesions with a mixed radiographic appearance was made. A positive aspiration puncture for citrus yellow liquid was performed, followed by excisional biopsy. Microscopic findings revealed a cystic capsule lined by with odontogenic epithelium and numerous phantom cells permeated by areas of calcification. Moreover, the presence of dental tissues pointed to the diagnosis of calcifying odontogenic cyst associated with odontoma. Currently, the patient is in follow-up and radiographic images reveal new bone formation in the region. Financial support: CAPES. An 11-year-old patient, male, was submitted to orthodontic traction of enclosed lower molar. Tomographic examination showed a radiolucent image measuring approximately 1 cm between 46 and suggestive dental germ of the 47. Intraoral examination confirmed absence of the 46. The orthodontic traction was performed and a routine panoramic radiography revealed formation of a delineated radiolucent image with radiopaque foci at the periphery. Thereby, hypothesis of odontogenic lesions with a mixed radiographic appearance was made. A positive aspiration puncture for citrus yellow liquid was performed, followed by excisional biopsy. Microscopic findings revealed a cystic capsule lined by with odontogenic epithelium and numerous phantom cells permeated by areas of calcification. Moreover, the presence of dental tissues pointed to the diagnosis of calcifying odontogenic cyst associated with odontoma. Currently, the patient is in follow-up and radiographic images reveal new bone formation in the region. Financial support: CAPES.

Effect of orthodontic traction on the microstructure of dental enamel

To investigate the effect of orthodontic traction on the microstructure of dental enamel. Forty-eight isolated premolars were randomly divided into 6 groups (n=8), including Group A (blank control group), in which the teeth were bonded with the orthodontic brackets without any loading force; Groups B1, B2, and B3 where the teeth were bonded with the orthodontic brackets using clinical adhesives and loaded with 50 g force for 6 months, 200 g force for 6 months, and 200 g force for 1 month, respectively; and Groups C1 and C2, where the teeth were bonded with straight wire brackets using light curing bonding and chemical curing bonding techniques, respectively. All the teeth were embedded with non-decalcified epoxy resin. Scanning electron microscope (SEM), atomic force microscope (AFM), and energy spectrometer (EDS) were used to analyze interface morphology and elemental composition of the teeth sliced with a hard tissue microtome. Compared with those in Group A, the teeth in the other 5 groups showed increased adhesive residue index with microcracks and void structures on the enamel surface under SEM; AFM revealed microcracks on the enamel surface with angles to the grinding direction. A larger loading force on the bracket resulted in more microcracks on the enamel interface. The interface roughness differed significantly between Groups A and C2, and the peak-to-valley distance differed significantly between Groups A, C, and C2. Orthodontic traction can cause changes in the microstructure of normal dental enamel.

Treatment of 2 impacted molars in a large dentigerous cyst (expansile cystic lesion) with combined orthodontic and surgical therapy

Nonmineralized cysts and cyst-like lesions that frequently occur in the mandible include ameloblastomas, odontogenic keratocysts, and dentigerous cysts. They have specific features of well-demarcated, unilocular, and radiolucent lesions that are often associated with tooth impaction. Although it rarely occurs, these cysts can become extremely large. Furthermore, cyst enlargement causes additional symptoms that can challenge the success of tooth recovery through orthodontic treatment. This clinical report presents the successful eruption of 2 impacted molars in a large dentigerous cyst treated with marsupialization and orthodontic traction usingan orthodontic miniplate anchorage over a 4-year treatment period.

Surgically removal of maxillary impacted canine: labial and palatal approach

Background: The maxillary canines most frequently to be involved in eruption problem and become impacted following maxillary and mandibular thirdmolars. When impacted maxillary canines have unfavorable position or they are not susceptible to orthodontic traction or reimplantation, surgical extraction isthe most appropriate treatment. Objective: Report a surgical removal of impacted maxillary canine which accessed both labially and palatally. Case: A 19-years-old woman came to the oral and maxillofacial clinic complained her left upper anterior tooth missing and reported mild pain around the area since twoyears ago. There was a fluctuation on the labial mucosa. Panoramic radiograph confirmed the horizontal impaction of the maxillary left canine. Conclusion:The maxillary canine was removed by surgery under under local anesthesia.

Cone-beam computed tomography evaluation of impacted and transmigrated mandibular canines: a retrospective study.

The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental patients applied between December 2015 and December 2017 were evaluated retrospectively.2591 CBCT images, including mandible in their field of view, were determined and evaluated regarding the presence of mandibular canine impaction. 66 impacted mandibular canines of 58 patients were analyzed in detail regarding their location, morphology, associated pathologies, and their relationship with the neighboring anatomic structures, the role of these factors on transmigration, as well as treatments applied. The Pearson Chi square test was used between the groups. Transmigration was observed in 53% of impacted mandibular canines. Teeth with transmigration were localized horizontally, below the apex of adjacent teeth frequently, and had no contact with mandibular cortical bone mostly. 62% of mandibular canines were in contact/proximity with the incisive mandibular canal. The most applied treatment for transmigrated teeth was surgical removal, followed by radiographic monitoring, but orthodontic traction was not preferred in any case. For non-transmigrated teeth, the most applied treatment options were surgical removal, orthodontic traction, and radiographic monitoring, respectively. Autotransplantation was not preferred in any case of impacted teeth. Vertical position of the crown tip (p < 0.05) and the presence of deciduous mandibular canines and their resorption showed significant relation to transmigration (p < 0.05). Transmigration is common among impacted mandibular canines. Resorption of adjacent teeth roots was one of the possible complications of impaction and likely contact/proximity of incisive mandibular canal with impacted mandibular canines, which may pose difficulties in surgical treatment, can be better detected by CBCT.

Orthodontic management of impacted maxillary canines

The prevalence of impacted maxillary canines is 2–3%. In Caucasian populations, it is reported to be more palatally displaced than buccally, with the opposite trend seen in Asian populations. At the ages of 9–11 years, the position of the canine germ should be diagnosed, for most children through clinical supervision. In 7–10% of children, the clinical investigation must be supplemented with radiographic investigation, in most cases with intraoral radiographs. About 50% of impacted canines cause root resorption of the adjacent teeth. To detect the severity of resorption, cone-beam computed tomography is necessary. Root resorptions on incisor roots occur most often at 11–12 years of age. Early diagnosis of ectopically positioned maxillary canines is very important. In cases with palatally displaced canines and no root resorptions, extraction of the primary canines has been found in different studies to give good results. If the permanent canine has not started to normalize its position within 12 months, orthodontic treatment must be taken in consideration. Often, this is done by surgical exposure and orthodontic traction of the canine out into the dental arch.

Complete removal of dentigerous cysts with preservation of associated teeth as an alternative to marsupialization in children and preadolescents

The aim of this study is to evaluate the results of dentigerous cysts enucleation with preservation of cyst-associated teeth as a single procedure in a group of children and preadolescents. A retrospective case series of seven patients with 15 unerupted developing teeth associated with or adjacent to dentigerous cysts was conducted. Patients were treated using the uniform surgical protocol (cystectomy, preservation of cyst-associated teeth, without use of orthodontic traction, primary wound closure). The metric analysis of the cysts and unerupted teeth on CBCT and an evaluation of the state of involved teeth after the treatment was performed. The mean age of patients was 9.0 ± 2.1 years (range 5–12 years, median = 9 years). All teeth erupted spontaneously. No serious postoperative complications or recurrences of lesions were detected. The mean follow-up was 53.1 ± 15.7 months (range 25–71 months, median = 52 months). The cystectomy of dentigerous cysts with preservation of associated teeth may be considered an alternative to marsupialization in children and preadolescents.

Root changes in buccal versus palatal maxillary impacted canines of adults: A longitudinal and retrospective 3-dimensional study before and after orthodontic traction

Maxillary impacted canines (MIC) could suffer root changes after canine traction. The aim of this study was to evaluate the 3-dimensional root changes in buccal versus palatal MIC after orthodontic traction. This longitudinal and retrospective study included pre-treatment and after traction cone beam computed tomography scans (CBCTs) of 30 subjects with unilateral/bilateral MIC. A total of 43 MIC were divided into 2 groups: buccal (n=17) or palatal (n=26). Root changes in length and area after orthodontic traction were measured at sagittal, coronal and axial sections. Intergroup comparison was carried out by t or U Mann-Whitney tests, depending on normality. Multiple linear regression analysis was used to evaluate the influence of all predictor variables on root changes (P<0.05). Significant difference between groups was found for root area changes in the upper limit of the cervical third at axial section that showed greater appositional values for the palatal impacted canine group (-1.18mm2) and resorptive values for the buccal impacted canine group (0.62mm2) (P=0.024). Position of impaction palatal influenced the increase of root area in the coronal section and in the upper limit of the cervical third at axial section. Age directly influenced the decrease of total length and root area in sagittal and coronal sections, respectively. Orthodontic traction of MIC produced an important appositional root change in the palatal impaction group in the axial root area of the upper limit of the cervical third. Impaction position and age influenced the increase and decrease of root area and length of some specific radicular regions.

Eruption Guidance of Horizontally Impacted Permanent First Molar with Primary Retention of Primary Second Molars: Case Reports

Tooth eruption involves a complex developmental process of tooth migration from the dental follicular origin to the final occlusion position in the oral cavity via the alveolar process. Disturbance of tooth eruption can occur at any point in a series of eruption stages; however, horizontal impaction of the mandibular first molar and primary retention of the primary mandibular second molar are rarely observed simultaneously. This study describes the treatment for two cases of horizontally impacted first molar with primary retention of primary molar. The primary retention of the primary mandibular second molar was extracted, and orthodontic traction was applied to the horizontally impacted primary mandibular first molar. Subsequently, displacement of the premolar tooth bud was improved and space regaining for eruption was achieved, guiding to normal eruption of the first molar.

Comparative analysis of panoramic radiography and cone-beam computed tomography in treatment planning of palatally displaced canines

The objective of this research was to compare the predictive value of panoramicradiographs (PRs) and cone-beam computed tomography (CBCT) scans for the estimation of root resorption, spontaneous eruption of a canine, and time for orthodontic traction. CBCT scans and PR images of 88 patients (27 male and 61 female; aged between 11 and 44years) with 106 palatally displaced maxillary canines were retrieved from a database. Predictive values of several radiographic parameters, including the 3-dimensional angle of the canine, were analyzed using the area under the curve and multiple regression analysis. The angle to the midline and canine position category had a discriminative ability for root resorption of the central incisors with area under the curve values of 0.63 (95% confidence interval, 0.56-0.79) and 0.83 (95% confidence interval, 0.75-0.91), respectively. PR measurements were not reliable predictors of resorptions, except severe resorptions, of the lateral incisors and the premolars. The measurements describing the position of the canine in relation to the midline could predict spontaneous eruption of the canine, regardless of the imaging method. The canine angle to the midline assessed on CBCT was significantly associated with traction time of the canine, producing the following equation: canine traction time=49.6 - 0.24×canine angle to the midline (r2=0.360). Only severe resorptions of roots can be predicted with PRs. The use of CBCT is indicated in cases of impacted canines.

Inter-premolar width changes related to the orthodontic traction of maxillary impacted canines in adolescents and young adults: A retrospective CBCT study

Maxillary canine impaction is directly associated with a narrow maxillary arch, mainly in the inter-premolar widths. This study compared the transverse changes at the level of maxillary premolars after traction of maxillary impacted canines (MICs) in adolescents and young adults through three main goals: to compare unilateral versus bilateral cases, to compare buccally versus palatally MIC cases, and to compare the affected versus non-affected side exclusively in the unilateral group. This before and after CBCT study involved 45 MIC orthodontically tractioned until the occlusal plane with a standardized protocol. The sample was classified regarding the impaction type (unilateral versus bilateral), impaction location (palatal versus buccal) and the affected versus unaffected sides in the unilateral cases. MIC characteristics as impaction sector, height, and complexity of the traction, as well as α and β angles, canine root length and area were measured. Moreover, cephalometric characteristics were also evaluated. Mann-Whitney U or Wilcoxon signed-rank tests and multiple regressions were applied (α=0.05). Maxillary inter-premolar widths (first or second) expanded approximately 3mm after traction of unilateral or bilateral MIC (P>0.05). Changes in hemi-arch widths between palatal (1.67mm) versus buccal (1.90mm) MIC were similar (P>0.05). In unilateral impaction, the transversal changes on the affected side were 2mm versus almost 1mm observed in the unaffected side (P<0.05). Finally, the multiple linear regressions were identified to the ANB angle, the impaction sectors and the distance from middle raphe to the cusp tip of MIC as influential variables. The maxillary inter-premolar widths increase after traction of MIC without differences between type or location of impaction. In addition, the transverse change in the affected side in unilateral MIC is greater than the unaffected side resolving the earlier transverse asymmetry.

Interarch traction for impacted canines

The impaction of the maxillary canines leads to many esthetic and functional problems. Calculated approach to the proper planning and execution of orthodontic traction of the canines is essential. A good biomechanical control to avoid possible side effects is often considered one of the most important strategies in traction of impacted canines. The aim of this paper is to present a technique in which a superior canine impacted labially was pulled into the arch with the aid of a modified power arm on the exposed canine and a miniscrew on the lower arch.

SUPERNUMERARIES: NO MORE AN ADDED NUMBER, BUT AN ADDED ADVANTAGE

In today’s world, extraction of an extra tooth is the rule of thumb and retention is never thought of. Here, we present a case series of two cases in which supernumeraries in the anterior region were retained to the advantage of the patient, for preventing malocclusion, retaining space, and enhancing esthetics of the individual. Supernumerary tooth refers to any tooth in excess of the usual configuration of the normal number of primary or permanent teeth. Its prevalence in permanent dentition is between 0.5% and 5.3% and between 0.2 and 0.8% in the primary. Treatment options involve surgical or conventional extraction. Complications associated with supernumeraries make it important to recognize and manage them early so as to prevent malocclusions and malalignments in permanent dentition. In the first case, supernumeraries were maintained until the eruption of permanent central to preserve space. In the second case, the supernumerary tooth was brought down with orthodontic traction and reshaped to simulate the contralateral tooth.

Tracionamento ortodôntico de canino permanente superior: relato de caso clínico

Objetivo: Descrever uma abordagem conservadora para tratamento de canino permanente superior impactado, através de tracionamento ortodôntico. Detalhamento do caso: Paciente BJFA, 16 anos, sexo feminino, acompanhada na clínica de Ortodontia da ABO em Montes Claros-MG, queixou-se de dentes tortos. Ao exame clínico intrabucal verificou-se atresia maxilar, desvio de linha média dentária superior, apinhamento dentário anteroinferior, incisivo lateral superior direito conóide, retenção prolongada de canino decíduo superior direito, cujo sucessor permanente não se apresentava palpável. Os exames de imagem, sobretudo a tomografia computadorizada, confirmaram a presença de canino permanente superior direito impactado, localizado em região palatina. O tratamento foi realizado através de aparelho ortodôntico fixo, aplicando a terapêutica de expansão transversal da arcada superior com quadrihélice de Ricketts e tracionamento ortodôntico pela técnica de colagem de acessório associada a cantilever. Considerações finais: As técnicas utilizadas permitiram uma abordagem conservadora e menos dispendiosa, mostrando resultados funcionais e estéticos positivos.

Orthognathic Surgery and Orthodontics: Inadequate Planning Leading to Complications or Unfavorable Results.

Complications in orthognathic surgery are commonly a result of inadequate preoperative planning and communication between the surgeon and orthodontist. Unfavorable outcomes can often be avoided when overall treatment goals along with a surgical and orthodontic plan are developed and agreed upon by the orthodontist, surgeon, and patient before the start of active tooth movement or any surgical procedures. Continuous evaluation of the patient's progress throughout treatment and subsequent communication between the surgeon and orthodontist are recommended to prevent frequent errors, such as inadequate dental decompensation, poor appliance selection or management, and occasional contraindicated orthodontic elastic traction or tooth movements.

First premolar ankylosis

A case is described of a 13-year-old boy who presented with infra-occluded primary molars in three quadrants. Creation of space allowed the second premolars in two quadrants to erupt spontaneously. The first premolar in the remaining quadrant did not erupt spontaneously, failing to reach occlusal contact despite orthodontic traction. CPD/Clinical Relevance: This case demonstrates apparent intermittent ankylosis of a maxillary first premolar.