Comparación Morfológica de Zonas de Inserción de Miniplacas Ortodóncicas en la Región Mandibular entre Edad, Sexo, Biotipo y Clase Esqueletal

El manejo del anclaje en los tratamientos de ortodoncia ha sido un reto constante, por lo que la utilización de miniplacas aparece como un rescate a esta interrogante. Determinar las diferencias morfológicas en la zona de inserción de miniplacas ortodóncicas en las regiones anterior y posterior mandibular, comparandolas entre edad, sexo, biotipo y clase esqueletal. Se estudiaron 40 registros de cone-beam de pacientes y se realizaron mediciones de grosor del hueso, donde se identificaron los sitios que permitan posicionar una miniplaca y fueron comparados entre sexo, grupos etarios, biotipo y clase esqueletal. Se observó diferencias significativas entre hombres y mujeres a nivel anterior mandibular, en los hombres se observaron mayores grosores óseos y corticales. No se observaron diferencias significativas entre pacientes adultos y jóvenes a nivel anterior mandibular, pero sí hubo diferencias a nivel mandibular posterior. La zona 3 mm debajo del 2do molar no es una zona confiable para la inserción de mini placas, ya que muchos de los pacientes no presentaban hueso en esa zona. Las miniplacas son un recurso seguro de anclaje las cuales deben ser adaptadas a cada paciente.

The anchorage management in orthodontic treatments has been a constant challenge, the use of miniplates may be a viable solution to this query. The objective of this study was to determine the morphological differences in the area of insertion of orthodontic miniplates in the anterior and posterior mandibular regions, comparing them between age, sex, biotype and skeletal class. In this analysis 40 cone-beam records of patients were studied, bone thickness measurements were carried out, the sites that allowed the positioning of a miniplate were identified and compared between sex, age groups, biotype and skeletal class. Significant differences were observed between men and women at the anterior mandibular level, in men greater bone and cortical thicknesses were observed. No significant differences were observed between adult and young patients at the anterior mandibular level, but there were differences at the posterior mandibular level. The area 3 mm below the 2nd molar was not a reliable area for the insertion of mini plates, since many of the patients had no bone in that area. Miniplates are a safe anchoring resource which must be adapted to each patient.

Protocolo BAMP: Reporte de Caso Clínico

El presente reporte tiene como objetivo presentar de manera secuencial y visual la protracción maxilar de un paciente clase III esqueletal, utilizando el protocolo BAMP. Una vez realizado el análisis clínico del caso se decidió realiza un tratamiento ortopédico a través del uso de miniplacas de titanio con elásticos intermaxilares de clase III siguiendo el protocolo BAMP, junto a un tratamiento ortodóncico dento alveolar con aparatología fija bimaxilar prescripción Roth 0.22" Mini sprint forestadent. Se observa el éxito del enfoque interceptivo utilizando el protocolo BAMP. Este enfoque logró reducir tanto el tiempo como la complejidad del tratamiento ortodóncico, y también disminuyó la necesidad de someterse a una cirugía ortognática en la edad adulta. El tratamiento BAMP, diseñado para ciertas edades y crecimiento, se demostró exitoso en un paciente de 12 años sin potencial de crecimiento. Las miniplacas como anclaje son efectivas para protracción maxilar en varios casos, aunque se necesita seguimiento y educación postquirúrgica. Se recomienda retirar las miniplacas cuando no sean necesarias, adaptando el protocolo a cada paciente. En resumen, el tratamiento con miniplacas es eficaz para corregir anomalías Clase III esqueléticas.

The present report aims to sequentially and visually present the maxillary protraction of a Class III skeletal patient using the BAMP protocol. After conducting a clinical analysis of the case, it was decided to perform orthopedic treatment using titanium miniplates with Class III intermaxillary elastics following the BAMP protocol, in conjunction with dentoalveolar orthodontic treatment using fixed bimaxillary appliances with Roth prescription 0.022" Mini Sprint Forestadent. The success of the interceptive approach using the BAMP protocol is observed. This approach managed to reduce both the time and complexity of orthodontic treatment and also decreased the need for orthognathic surgery in adulthood. The BAMP treatment, designed for specific ages and growth stages, proved successful in a 12-year-old patient without growth potential. Miniplates as anchorage are effective for maxillary protraction in various cases, although post-surgical follow-up and education are required. It is recommended to remove the miniplates when they are no longer necessary, adapting the protocol to each patient. In summary, miniplate treatment is effective in correcting Class III skeletal anomalies.

Effect of miniscrew placement height on the distribution of biological forces produced by clear aligner for mandibular molar distalization / 口腔疾病防治

Objective@#To explore the effect of different miniscrew placement heights on the distribution of biological forces produced by clear aligner combined with intramaxillary traction for mandibular molar distalization, to identify the miniscrew location that is conducive to the protection of lower anterior tooth anchorage and to provide a reference that can be used when designing clinical treatments.@*Methods@#Mimics, GeomagicStudio 2017, SolidWorks 2016, and Ansys workbench were used to establish finite element analysis models and perform mechanical analysis under the following six working conditions: working condition 1 was the control group without miniscrews; working conditions 2 to 5 had miniscrew in the buccal bone cortex between the first and second molars of the lower jaw 10 mm, 7 mm, 4 mm, and 1 mm from the top of the alveolar crest, respectively; working condition 6 had the miniscrew in the center of the buccal tongue at the anterior edge of the ascending branch of the lower jaw 5 mm above the occlusal plane.@*Results@#On the sagittal axis, miniscrew anchorage caused distal displacement of all teeth. Compared to the control group, in the miniscrew group, the displacement of the anterior molars exceeded that of the second molars. On the vertical axis, the result in the control group was similar to backward bending; the results in the miniscrew groups resembled the effect of a lever, lowering the lateral incisors and canines and raising the central incisors and first premolars. On the coronal axis, the second premolars and the first molars showed lingual displacement in the control group, and only the premolars and first molars showed lingual displacementin the miniscrew groups. The canines were the teeth that were most strongly affected by the change in miniscrew placement height.@*Conclusion@#The higher the miniscrew position is, the stronger the protective effect on the anterior anchorage. According to the miniscrew placement height, the mandibular arch should be properly narrowed, the central incisors and first premolars should be lowered, and the lateral incisors and canines should be raised when designing clinical treatments.

Comparison of the effects of early Skeletal Class Ⅲ facemask therapy between dental and skeletal anchora-ges / 实用口腔医学杂志

Objective:To compare the effects of treatment with Hybrid-Hyrax-Facemask(FM)versus miniscrews in the anterior pal-ate combined with Hybrid-Hyrax-Facemask(MSI/FM)for patients with early Class Ⅲ malocclusion and maxillary deficiency.Methods:18 patients aged with early Class Ⅲ malocclusion and maxillary deficiency were randomly divided into 2 groups(n=9)and treated with FM and MSI/FM respectively.Alternating rapid maxillary expansion and constriction(Alt-RAMEC)protocol combined with a maxillary protraction force of 3.92 N was applied on each side of all patients from elastics connected to the facemask in a down-ward and forward direction of 30° to the occlusal plane.Iortho cephalometric software was used to analyze the data of lateral cephalo-grams of the patients before(T0)and after(T1)treatment.Results:Improvement was verified in the facial profile and occlusion of all patients.In MSI/FM group the average treatment time was shorter.There were significant differences(P＜0.05)between T0 and T1 in the following measurements in FM group:SNA,ANB,Co-A,Co-Gn,Wits,S-Go,Na-Me,MP,U1-SN,UADH,LADH,Overjet,UL-EP increased,U1-L1 decreased.There were significant differences(P＜0.05)between T0 and T1 in the following measurements in the MSI/FM group:SNA,ANB,Co-A,Wits,Na-Me,MP,Y-axis,U1-SN,Overjet,UL-EP increased,SNB,Co-Gn-Co-A,S-Go/N-Me,U1-L1,L1-MP decreased.Conclusion:Both FM and MSI/FM combined with Alt-RAMEC protocol and a maxillary protraction force are effective in the treatment for Class Ⅲ patients with maxillary deficiency.MSI/FM may produce more significant bone effect and re-duce dental compensation,promote more forward growth of midface and more improvement in the growth direction of mandible and re-duce compensatory lip inclination of anterior teeth in shorter treatment time.

CBCT study of the maturation of the midpalatal suture fusion ratio in different vertical skeletal patterns of class Ⅰ malocclusion adults / 实用口腔医学杂志

Objective:To compare the variability of midpalatal suture maturation ratio of skeletal class Ⅰ malocclusion adults between genders,among positions and vertical skeletal patterns.Methods:173 skeletal class Ⅰ malocclusion adult patients were included and divided into 6 groups according to GoGn-SN Angle and gender:dolichofacial group(male 22,female 24)with GoGn-SN＞37.7°,me-sofacial Group(male 30,female 33)with 27.2°≤GoGn-SN≤37.7° and brachyfacial group(male 33,female 31)with GoGn-SN＜27.2°.The midpalatal suture maturation ratio in the corresponding area of anterior,medial and posterior region were measured and calculated by Mimics 21.0 software,the overlap of the anterior nasopalatine canal with the measurement site was recorded.Results:In the comparison of different genders,there was a statistically significant difference between males and females in the brachyfacial an-terior region(P＜0.001).In the comparison of different positions,except the females among the anterior,middle and posterior regions in brachyfacial group(P＞0.05),there were statistical differences in the fusion degree of the other parts of the palate suture(P＜0.05),and it gradually decreased from the posterior region to the anterior region.In the comparison of different vertical skeletal pat-terns,there was no statistical difference except the difference between the mesofacial and brachyfacial and dolichofacial groups in the middle area of males(P＞0.05),and the difference was significant among brachyfacial,dolichofacial and mesofacia groups in the ante-rior area of females(P＜0.05).Rates of anterior nasopalatine duct influence measurements were statistically significant in the compari-son between dolichofacial and brachyfacial males,and between brachyfacial males and brachyfacial females(P＜0.05),the remainder was not statistically significant(P＞0.05).Conclusion:In adult patients,the palatal suture is not completely fused,and palatal mi-croimplant anchorage should be avoided in the midpalatal suture.

Effect of arch shapes and missing second premolars on anchorage during maxillary molar distalization with clear aligners / 中国组织工程研究

BACKGROUND:The reciprocal force generated by the molar distalization with clear aligners can lead to anchorage loss.The effect of arch shapes and missing second premolars on anchorage has not been reported. OBJECTIVE:To analyze the effect of arch shapes and missing second premolars on anchorage during molar distalization with clear aligners using the finite element method. METHODS:Cone-beam CT data from an adult male were acquired from the database to establish the maxilla-upper dentition-periodontium-rectangular attachment-clear aligner model.The distal movement amount designed on the bilateral second molars was set to 0.25 mm.First,there were two groups in the study:second premolar bilateral presence and absence groups.Then,four subgroups in each group were created:tapered arch,ovoid arch,square Class Ⅱ Division 1 arch,and Class Ⅱ Division 2 arch groups.The Ansys software was used to calculate the displacement of the anchorage tooth and the stress of the periodontal ligament. RESULTS AND CONCLUSION:Mesial tipping and extrusion of first molars and premolars,labial inclination and intrusion of anterior teeth occurred during the upper second molar distalization with clear aligners.When the bilateral second premolars were missing,the mesial displacement of first molars increased significantly while that of first premolars and anterior teeth decreased in all groups.The square Class Ⅱ Division 1 arch group showed the least anterior labial inclination,while the tapered arch group showed the most.There was no significant difference between the ovoid arch group and the tapered arch group.Moreover,the magnitude of tipping in the square Class Ⅱ Division 2 arch group was slightly higher than that in the Class Ⅱ Division 1 arch group.The stress of the periodontal ligament of the anchorage teeth was concentrated on the cervical and apical regions of the teeth.And the lowest stress level was detected in the square arch group.Compared with the other groups,the stress on the labial cervical area of the periodontal ligaments was also significantly relieved in the square arch group.To conclude,the square arch is more favorable in terms of anterior anchorage control and periodontal ligament stress distribution.Anterior labial inclination efficiency can be increased in cases of Class Ⅱ Division 2 by designing the anterior labial inclination in conjunction with molar distalization.If the second premolar is missing during molar distalization,it is not conducive to opening up the space in the area of the missing tooth.

Contribution of Digital Technology to the Surgical Technique of Miniscrew Insertion: a Literature Review

Orthodontic miniscrews are used to achieve absolute anchorage. Their insertion technique is simple but must be precise to avoid intra- and postoperative complications. This study aimed to review the literature on the role of digital technology in the precise placement of miniscrews and to describe the different stages of the insertion guide manufacturing chain. The databases used were PubMed, Science Direct, and Google Scholar, including the following English descriptors: "Orthodontic Anchorage Procedures," "Cone Beam Computed Tomography." Digital technology improves the accuracy of miniscrew placement by using 3D imaging to assess the quantity and quality of bone and the proximity of anatomical structures in the area to be implanted. By combining 3D imaging with the new techniques of 3D printing and virtual planning, the orthodontist can obtain a personalized placement guide for the patient using computer-aided design and manufacturing techniques. A digitally-assisted miniscrew insertion system is a promising technique for precise and safe miniscrew insertion but cannot be used routinely. Therefore, large-scale studies are needed to map miniscrew insertion in different areas, considering ethnicity, gender, and different anatomical characteristics.

Harmonização do sorriso: aliando ortodontia e estética / Smile harmonization: combining orthodontics and aesthetics

Atualmente é evidente a demanda contínua por padrões de beleza, cada vez mais impecáveis, um sorriso alinhado e harmônico com dentes brancos para se sorrir com confiança. O tratamento odontológico interdisciplinar tem como intuito proporcionar uma boa saúde periodontal, restabelecer a estética e a função do sistema estomatognático. Objetivo: apresentar um relato de caso clínico envolvendo harmonização do sorriso como cirurgia plástica periodontal para alinhamento da margem gengival na região anterior e restaurações diretas em resina composta após a finalização do tratamento ortodôntico, evidenciando a importância da abordagem conservadora e multidisciplinar no âmbito do tratamento estético. Relato de caso: Realizamos o tratamento ortodôntico com aparelho autoligado cerâmico para alinhamento do arco dental e intrusão do elemento 13, em sequência executamos um recorte gengival nos elementos 12 e 22, clareamento dental associado após 15 dias, subsequentemente, reanatomização dentária no elemento 44 para que o elemento 13 não voltasse a extruir pela falta de contato oclusal, e por fim, remodelação dental fazendo uso de resina composta nos elementos 12, 21 e 22 devido a manchas de hipocalcificação dental. Conclusão: Contudo, a estética bucal tem a capacidade de possibilitar a melhoria na autoestima, devolvendo à função, proporcionando satisfação e bem-estar ao indivíduo, enaltecendo o sorriso.

Currently, the continuous demand for increasingly impeccable beauty standards is evident, an aligned and harmonic smile with white teeth to smile with confidence. Interdisciplinary dental treatment aims to provide good periodontal health, restore the aesthetics and function of the stomatognathic system. Objective: to present a clinical case report involving smile harmonization as periodontal plastic surgery for aligning the gingival margin in the anterior region and direct composite resin restorations after completion of orthodontic treatment, highlighting the importance of a conservative and multidisciplinary approach in the field of aesthetic treatment . Case report: We performed orthodontic treatment with a self-ligating ceramic appliance for aligning the dental arch and intruding element 13, then performed a gingival cutout on elements 12 and 22, associated tooth whitening after 15 days, subsequently, dental reanatomization on element 44 to that element 13 would not extrude again due to the lack of occlusal contact, and finally, dental remodeling using composite resin in elements 12, 21 and 22 due to dental hypocalcification stains. Conclusion: However, oral aesthetics has the ability to improve self-esteem, returning to function, providing satisfaction and well-being to the individual, enhancing the smile.

Resolución de maloclusión con severo escalón anterior empleando fuerzas diferenciales / Resolution of a malocclusion with a severe anterior step employing differential forces

Paciente de 21 años de sexo masculino con una distoclusión esqueletal y alveolo dentaria severa, hábito de succión del dedo que contribuye a agravar el escalón de 15 mm. Demanda tratamiento para mejorar su oclusión y estética. Si bien lo indicado es un tratamiento ortodóncico con cirugía ortogná- tica para modificar su perfil muy convexo con una distancia mentocervical acortada, no es aceptado por el paciente, planificándose entonces camuflaje ortodóncico con exodoncias de PD 14 y 24 y reduc- ción del escalón mediante anclaje diferencial que emplea fuerzas de volcamiento para no perderlo dado el gran overjet a reducir. Habiendo varias piezas dentarias con anomalías de color, defectos en el esmalte, una corona metálica en PD 36 y limitacio- nes presupuestarias se realizó la estética final con reconstrucciones de resina (AU)

A 21-year-old male patient with a severe skeletal and alveolar distoclusion, finger sucking habit that contributes to aggravate the 15 mm step. He demands treatment to improve its occlusion and aesthetics. Although orthodontic treatment with orthognathic surgery is indicated to modify its highly convex profile with a shortened mentocervical distance, it is not accepted by the patient, so orthodontic camouflage is planned with extractions of 14 and 24 and reduction of the step by means of differential anchorage that uses overturning forces so as not to lose anchorage due to the great overjet. Having several dental pieces with color anomalies, enamel defects, a metallic crown in 36 and budgetary limitations, the final aesthetics was performed with resin reconstructions (AU)

Histological Evaluation of the Effect of Alendronate on the Maxillary Bone of Wistar Rats Combined with Orthodontic Movement of Intense Force / Evaluación Histológica del Efecto del Alendronate en el Hueso Maxilar de Ratas Wistar Combinado con Movimiento de Ortodoncia de Fuerzas Intensas

SUMMARY: To evaluate the histological adverse effects of alendronate administered systemically and topically in combination with orthodontic movement by intense force. Thirty-six 24-week-old female Wistar rats, ovariectomized, were used and divided into three groups (n = 12/group): control, locally treated with saline (0.07 ml/kg/week) (group 1) and experimental, treated with alendronic acid systemically (0.07 mg/kg/week) (group 2) and locally (7 mg/kg/week) (group 3). At 14 days, an orthodontic anchor was installed in the right first molar, and a force of 144 cN was applied for 28 days. The samples were processed for histological evaluation. Descriptive statistics, Shapiro-Wilk tests, one-way ANOVA with Bonferroni correction, one-way repeated measures ANOVA and chi-square tests were performed. All tests were statistically significant at p <0.05. The adverse events found in all groups were inflammation and osteoclastic activity. In the bisphosphonate-treated groups, there were statistically significant differences (p = 0.005) in the osteoclastic activity between the two hemiarcates. All rats in group 2 presented paralytic ileus. Compared to local administration, systemic treatment with alendronic acid produces more adverse effects, such as inflammation, fibrinoid necrosis, and osteoclastic activity. During the application of intense forces, it was not possible to show that there is necrosis associated with bisphosphonates.

Evaluar los efectos adversos histológicos del alendronato administrado sistémica y tópicamente en combinación con movimientos ortodóncicos de fuerza intensa. Treinta y seis ratas Wistar hembras de 24 semanas de edad, ovariectomizadas, fueron utilizadas y divididas en tres grupos (n = 12/grupo): control, tratado localmente con solución salina (0,07 ml/kg/semana) (grupo 1) y experimental, tratados con ácido alendrónico por vía sistémica (0,07 mg/kg/semana) (grupo 2) y local (7 mg/kg/semana) (grupo 3). A los 14 días se instaló un anclaje de ortodoncia en el primer molar derecho y se aplicó una fuerza de 144 cN durante 28 días. Las muestras fueron procesadas para evaluación histológica. Se realizó estadística descriptiva, pruebas de Shapiro-Wilk, ANOVA de una vía con corrección de Bonferroni, ANOVA de medidas repetidas de una vía y pruebas de chi-cuadrado. Todas las pruebas fueron estadísticamente significativas con un p <0,05. Los eventos adversos encontrados en todos los grupos fueron inflamación y actividad osteoclástica. En los grupos tratados con bisfosfonatos hubo diferencias estadísticamente significativas (p = 0,005) en la actividad osteoclástica entre los dos hemiarcados. Todas las ratas del grupo 2 presentaron íleo paralítico. En comparación con la administración local, el tratamiento sistémico con ácido alendrónico produce más efectos adversos, como inflamación, necrosis fibrinoide y actividad osteoclástica. Durante la aplicación de fuerzas intensas, no fue posible demostrar que existe necrosis asociada con los bisfosfonatos.

Tomographic evaluation of mandibular buccal shelf in patients with different vertical growth pattern / Evaluación de la placa ósea mandibular en pacientes con diferente patrón de crecimiento vertical

The purpose of this research was the tomographic evaluation of the Mandibular Buccal Shelf (MBS) in orthodontic patients with different vertical growth pattern. An observational, descriptive, cross-sectional and retrospective study was conducted. Tomographic images of patients aged 14 to 40 years were observed and a database was formed with those that met the inclusion criteria. The sample size was 10 for each group according to vertical growth pattern (hypodivergent, normodivergent and hyperdivergent). Then four zones of frequent insertion of extralveolar mini-screws were selected in the MBS, taking as a reference the mesial and distal roots of the first and second mandibular molar. When comparing the characteristics of MBS between vertical growth patterns, between sexes and hemiarchs, no statistically significant differences were found. However, when the characteristics of MBS were compared according to the reference root, it was found that there were statistically significant differences. The vestibular area to the distal root of the second mandibular molar presented the highest values in terms of angulation, height and thickness. There are no significant differences in the bone characteristics of MBS according to vertical growth patterns, sexes or hemiarchs. Angulation, height and thickness progressively increase from the vestibular bone of the mesial root of the first mandibular molar to the distal root of the second molar.

El propósito de esta investigación fue la evaluación tomográfica de la placa ósea mandibular (POM) en pacientes de ortodoncia con diferente patrón de crecimiento vertical. Se realizó un estudio de tipo observacional, descriptivo, transversal y retrospectivo. Se observó imágenes tomográficas de pacientes de 14 a 40 años de edad y se formó una base de datos con las que cumplían los criterios de selección. El tamaño de muestra fue de 10 para cada grupo según patrón de crecimiento vertical (hipodivergentes, normodivergentes e hiperdivergentes). Luego se seleccionaron cuatro zonas de inserción frecuente de minitornillos extralveolares en la POM, tomando como referencia las raíces mesial y distal del primer y segundo molar mandibular. Al realizar la comparación de las características de la POM entre patrones de crecimiento vertical, entre sexos y hemiarcadas no se encontraron diferencias estadísticamente significativas. Sin embargo, cuando se comparó las características de la POM según la raíz de referencia se encontró que había diferencias estadísticamente significativas. La zona vestibular a la raíz distal de la segunda molar mandibular presento los mayores valores en cuanto angulación, altura y grosor. No existen diferencias significativas en las características óseas de la POM según patrones de crecimiento vertical, sexos o hemiarcadas. La angulación, la altura y el grosor aumenta progresivamente desde el hueso vestibular de la raíz mesial del primer molar mandibular hacia la raíz distal del segundo molar.

Calcitonin as a Pharmacological Anchorage in Orthodontics

Objective: This study aimed to evaluate the effects of salmon calcitonin administration as a pharmacological anchoring agent in orthodontics and to determine the influence of locally applied calcitonin on serum calcium levels. The secondary aim was to observe the response of dental and periodontal tissues using light microscopy. Methods: Fourteen healthy male adult Wistar rats with an average weight of 250 g had their teeth moved, seven of which received a local injection of salmon calcitonin in the furcation region of the left upper first molar. Concurrently, the remaining seven were used as controls. In the control group, saline solution was injected in the bifurcation region of tooth 26 to subject these animals to the same stress level as those of the experimental group. After 14 days, a 6 mm diameter orthodontic elastic band was inserted between teeth 26 and 27 in all animals to induce the movement of these teeth. The rats were anaesthetised and exsanguinated on day 21. In both groups, tooth movement and serum calcium levels were measured. The jaws were dissected with straight scissors, and tissue blocks containing gingiva, bone and teeth were identified, fixed and demineralised. Then, the pieces were cut into semi?serial slices, stained with hematoxylin, eosin, and Mallory’s trichrome, and analysed under an Axiophot light microscope. Results: There was significantly less tooth movement in the experimental group ( ±X DP ; 0,150 mm ± 0,037) than in the control group (0,236 mm ± 0,044; P = 0,003), while there was no significant difference in serum calcium levels between the two groups (control ±X DP ; 9,53 mg/dl ± 1,53; experimental 10,81 mg/dl ± 1,47; P = 0,15). Conclusion: While calcitonin did not completely inhibit osteoclast activity, it promoted orthodontic anchorage, apparently, by local action.

Effects of class Ⅲ traction assisted by implant anchorage on unilateral cleft and palate patients in treatment of skeletal class Ⅲ malocclusion / 中华医学美学美容杂志

Objective:To evaluate and compare the outcomes of maxillary protraction treatment assisted by temporary anchorage devices (TADs) and removable biteplate in cleft lip and palate patients using cephalometric analysis.Methods:Fifty-four cleft lip and palate patients were divided into 3 groups based on different maxillary protraction treatments: bitepalate removable appliance group (group A), maxillary protraction treatment assisted by TADs group (group B) and control group (group C). Lateral cephalograms were taken at the start and the end of maxillary protraction. Skeletal, dental and soft tissue changes were measured using Dolphin software and compared between groups.Results:The average protraction time of groups A and B were (8.51±1.33) and (9.20±1.45) months ( P=0.146), respectively. A point moved forward by 4.08 mm in group A and 4.83 mm in group B were noted, without significant differences between the two groups. Compared to group C, ANB and wits was highly improved after protraction in groups A and B. U6-VRmx increased by 0.46 mm and U1-pp increased by 0.63 mm in group B, both of which were significantly smaller than those of group A (both P<0.05), suggesting that maxillary protraction treatment assisted by TADs could reduce molar advancement and upper incisor protrusion. Conclusions:Both maxillary protraction treatment assisted by TADs and removable biteplate could significantly improve skeletal class Ⅲ malocclusion in unilateral cleft and palate patients. Maxillary protraction treatment assisted by TADs could reduce molar advancement and upper incisor protrusion.

Three-dimensional finite element study of mandibular first molar distalization with clear aligner / 华西口腔医学杂志

OBJECTIVES@#This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar.@*METHODS@#Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed.@*RESULTS@#In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased.@*CONCLUSIONS@#The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.

Application of modified articular disc anchorage in treating the perforation and rupture of temporomandibular joint disc / 华西口腔医学杂志

OBJECTIVES@#This study aimed to use modified articular disc anchorage in treating old irreducible temporomandibular joint (TMJ) disc displacement with perforation and rupture, as well as to explore its efficacy.@*METHODS@#A total of 31 patients (34 sides) with 47 TMJ disc perforations who underwent surgical treatment in the Affiliated Stomatolo-gical Hospital of Nanchang University from January 2018 to December 2021 were selected. According to the location of disc perforation, it has five types: posterior disc perforation (typeⅠ), anterior disc perforation (typeⅡ), lateral disc perforation (type Ⅲ), composite disc perforation, and destruction disc perforation. The modified methods of disc anchoring were divided into two types according to the location of the perforation. TypesⅠandⅢ disc perforation were trea-ted by posterior anchoring method. For posterior ancho-ring, a screw was implanted into the posterolateral side of the condylar neck, and the disc was fixed on the screw by horizontal mattress suture. TypeⅡdisc perforation and compo-site disc perforation combined typeⅡperforation were treated by anterior and posterior double-anchoring method. For anterior anchoring, anchor screws or holes were placed at the anterior edge of the condylar neck, and horizontal mattress suture was performed at the posterior edge of the anterior perforation with an anchor wire. The articular disc was then fixed on the anchor screws or holes. For the posterior anchoring method, it was the same as the previous one. Paired t test was used to analyze the visual analog scale (VAS), maximum interincisal opening (MIO), and TMJ disorder index (CMI) of the patient before surgery and 1, 3, and 6 months after surgery. Disk-condyle position relationship by magnetic resonance imaging and postoperative quality of life in postoperative were analyzed.@*RESULTS@#The incidence of perforation was 41.2% (14/34) in typeⅠ, 11.8% (4/34) in typeⅡ, 8.8% (3/34) in typeⅢ, 29.4% (10/34) in composite type, and 8.8% (3/34) in destruction type. The VAS, MIO, and CMI at 3, 6 months after operation significantly improved compared with those before operation (P<0.05). The effective reduction rate of disc was 96.77% (30/31). The quality of life at 6 months after surgery was 47.22±2.13, and the rate of excellent evaluation was 96.4% (27/28).@*CONCLUSIONS@#Modified articular disc anchorage achieves a good curative effect for treating temporomandibular joint disc perforation and rupture. Nevertheless, its long-term effect requires further observation.

Development and application of a new type of assisted micro implant anchorage 3D guide plate / 中国医师杂志

Objective:To establish a computer-aided design and 3D printing system for precise implantation of micro implant anchorage, and accurately calibrate the position and direction of micro implant implantation.Methods:A retrospective selection was conducted on 15 patients (30 in total) who underwent micro implant implantation surgery from the Department of Stomatology, the Affiliated Hospital of Jiangnan University from November 2019 to November 2021, including 6 males and 9 females, aged (17.1±6.3)years old. The preoperative patient was photographed with cone beam computed tomography (CBCT) and the collected DICOM data format was output. A 3D scan was performed on the patient′s preoperative analysis model to obtain the STL file of the model scan. The CBCT data and model data were fitted and matched using 3Shape Implant Studio software, and the thickness of the guide plate, the amount of undercut compensation, and the size of the key component collar were designed. The 3D printer was used for printing after resizing. Using the assist method to implant micro implants, CBCT was taken postoperatively to compare the preoperative design with the postoperative results.Results:After fitting the postoperative CBCT with the designed CBCT of the micro implant, it was found that the micro implant was consistent with the preoperative design, maintained a safe distance and parallel to the adjacent tooth root, and did not damage the maxillary sinus and other areas. No detachment of the micro implant anchorage was observed 1 or 3 months after surgery. The application of assisted micro implant anchorage 3D guide plate was reliable, with accurate implantation position and direction, and can be implanted in most parts of the oral cavity.Conclusions:The use of computer-aided design and 3D printing system to create an assistive micro implant anchorage 3D guide plate can accurately locate the position and direction of the micro implant, which is worthy of clinical promotion and application.

Stress distribution in lower second molar mesialization using mini-implants: a pilot study using 3D finite element analysis / Distribuição de tensões na mesialização do segundo molar inferior usando mini-implantes: um estudo piloto usando análise de elementos finitos 3D

Objective: to analyze the stress distribution in a 3D model that simulates second molar mesialization using two different types of mini-implants. Material and Methods: a mandible bone model was obtained by recomposing a computed tomography performed by a software program. The cortical and trabecular bone, a lower second molar, periodontal ligament, orthodontic tube, resin cement and the mini-implants were designed and modeled using the Rhinoceros 4.0 software program. The characteristics of self-drilling orthodontic mini-implants were: one with 7 mm length, 1 mm transmucosal neck section and 1.6 mm diameter and another with 5 mm length and 1.5 mm diameter. A total of 235.161 and 224.505 elements were used for the mesh. These models were inserted into the bone block and then subjected to loads of 200 cN (centinewton). The results were calculated and analyzed by the Ansys 17.0 software program for qualitative verification through displacement and maximum principal stress maps. Results: it was possible to observe that the periodontal ligament presented low displacement and stress values. However, the physiological values presented are among those capable to provide orthodontic movement, with compression and tensile area visualization staggered between 0.1 and -0.1 MPa (megapascal). Conclusion: within the limitations of the study, the mini-implants tested showed similar results where the load on the tooth allowed dental displacement (molar mesialization), with a tendency to rotate it, theoretically allowing the second molar to take the location of the first molar. (AU)

Objetivo: analisar a distribuição de tensões em um modelo 3D que simula a mesialização do segundo molar usando dois tipos diferentes de mini-implantes. Material e Métodos: um modelo de osso mandibular foi obtido por recomposição de uma tomografia computadorizada realizada por um software. O osso cortical e trabecular, um segundo molar inferior, ligamento periodontal, tubo ortodôntico, cimento resinoso e os mini-implantes foram projetados e modelados no software Rhinoceros 4.0. As características dos mini-implantes ortodônticos auto perfurantes foram: um com 7 mm de comprimento, 1 mm de secção transmucosa e 1,6 mm de diâmetro e outro com 5 mm de comprimento e 1,5 mm de diâmetro. Para a malha, foram utilizados 235.161 e 224.505 elementos. Esses modelos foram inseridos no bloco ósseo e então submetidos a cargas de 200 cN (centinewton). Os resultados foram calculados e analisados pelo software Ansys 17.0 para verificação qualitativa por meio de mapas de deslocamento e tensões máximas principais. Resultados: foi possível observar que o ligamento periodontal apresentou baixos valores de deslocamento e tensões. Porém, os valores fisiológicos apresentados são capazes de proporcionar movimentação ortodôntica, com visualização da área de compressão e tração escalonada entre 0,1 e -0,1 MPa (megapascal). Conclusão: dentro das limitações do estudo, os mini-implantes testados apresentaram resultados semelhantes onde a carga sobre o dente permitiu o deslocamento dentário (mesialização do molar), com tendência a girá-lo, permitindo teoricamente que o segundo molar ocupe do lugar do primeiro molar (AU)

Mechanical Properties of Mini-Implants Used in Extra-Radicular Anchorage

ABSTRACT Objective: To evaluate the mechanical properties of mini-implants (MIs) manufactured from stainless steel and compare them with conventional titanium-aluminum-vanadium alloy MIs. Material and Methods: The following groups were formed: G1 (n=24), 8×1.5 mm steel MIs; G2 (n=24), 12×2.0 mm steel MIs; and G3 (n=24), 10×1.5 mm titanium MIs. The 72 MIs were inserted in the infra zygomatic crest region of the maxilla and retromolar trigone in the jaw of 10 pigs. Pull-out, insertion torque, fracture and percussion tests were performed in order to measure the tensile strength, primary stability and fracture strength of MIs. A digital torque gauge was used to measure insertion and fracture torque, a universal mechanical testing machine was used for pull-out testing and a periotest device was used to measure the micromovement of MIs. For morphological and MI component evaluation, scanning electron microscopy (SEM) was performed. D'Agostino & Pearson, Kruskal-Wallis, and Dunn post-hoc and normality tests were used. Results: G2 insertion and fracture torques were significantly higher than G1 and G3 insertion and fracture torques (p<0.05). The pull-out and percussion tests presented similar values among the groups. SEM revealed that the fracture point was predominantly on the fourth thread for steel MIs (G1 and G2) and on the seventh thread for titanium-aluminum-vanadium MIs (G3). Conclusion: The mechanical properties of stainless steel MIs are superior to those of titanium-aluminum-vanadium alloy MIs.

Assessment of influence of facemask treatment with skeletal anchorage on the temporomandibular joint using magnetic resonance imaging: a preliminary study

ABSTRACT Objective: The aim of the study was to investigate the influence of facemask treatment with skeletal anchorage on the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI), in patients with Class III malocclusion, accompanied by maxillary retrusion. Methods: Fifteen patients with a mean age of 12.1±1.43 years were included in the study. All patients were treated using facemask with skeletal anchorage after eight weeks of Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol. Magnetic resonance imaging was performed before and immediately after facemask treatment for TMJ evaluation. Disc position, condylar translation, degenerative changes of the condyles, and joint effusion were evaluated. To assess whether the alterations associated with the treatment were statistically significant, McNemar and marginal homogeneity tests were used. Results: After facemask treatment, a statistically significant change was observed in the disc position (an anterior disc displacement with/without reduction in five TMJs) (p<0.05). The alteration in the condylar translation was not statistically significant (p>0.05). This treatment did not cause degenerative changes of the condyles or effusion in any of the TMJs. Conclusion: Facemask treatment with skeletal anchorage following the Alt-RAMEC protocol had a minimal influence on the TMJ, only by means of disc position, which was not negligible. Long-term results of such treatment are required for following up the changes observed in the TMJs.

RESUMO Objetivo: O objetivo desse estudo foi investigar a influência do tratamento com máscara facial com ancoragem esquelética na articulação temporomandibular (ATM), por meio de ressonância magnética (RM), em pacientes com má oclusão de Classe III acompanhada de retrusão maxilar. Métodos: Quinze pacientes com idade média de 12,1±1,43 anos foram incluídos no estudo. Todos os pacientes foram tratados com máscara facial com ancoragem esquelética após oito semanas de protocolo de Expansão Rápida da Maxila e Constrição Alternadas (Alt-RAMEC). Os exames de ressonância magnética foram realizados antes e imediatamente após o tratamento com máscara facial, para avaliação da ATM. Foram avaliados posição do disco, translação condilar, alterações degenerativas dos côndilos e derrame articular. Os testes de McNemar e de homogeneidade marginal foram utilizados para avaliar se as alterações associadas ao tratamento foram estatisticamente significativas. Resultados: Após o tratamento com máscara facial, uma mudança estatisticamente significativa foi observada na posição do disco (deslocamento anterior do disco com/sem redução em cinco ATMs) (p<0,05). A alteração na translação condilar não foi estatisticamente significativa (p>0,05). Esse tratamento não causou alterações degenerativas dos côndilos ou derrame em qualquer das ATMs. Conclusão: O tratamento com máscara facial com ancoragem esquelética ápós o protocolo Alt-RAMEC teve uma influência mínima na ATM, apenas quanto à posição do disco, que não foi desprezível. Resultados em longo prazo desse tratamento são necessários para acompanhar as mudanças observadas nas ATMs.

Class III treatment with mini-implants anchorage in young adult patients: short and long-term results

ABSTRACT Introduction: Class III malocclusion should be intercepted and treated at early age, to prevent the necessity of future complex and expensive procedures. The orthopedic facemask therapy has the goal to achieve skeletal changes, minimizing side effects on dentition. The use of skeletal anchorage, combined with Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol, may be effective in treating a greater number of growing Class III patients. Objective: To summarize the existing evidence-based literature on Class III malocclusion treatment in young adult patients, and to illustrate its application and effectiveness, by presenting an emblematic case report. Conclusion: The resolution of the present case, its long-term follow up, along with the studies conducted on a larger sample, demonstrate the effectiveness of the strategic combination of orthopedic and orthodontic treatments by using an hybrid rapid palatal expander and Alt-RAMEC protocol for treating Class III malocclusions in adult patients.

RESUMO Introdução: A má oclusão de Classe III deve ser interceptada e tratada em idade precoce, a fim de evitar uma futura necessidade de procedimentos complexos e invasivos. O tratamento com máscara facial ortopédica tem o objetivo de obter alterações esqueléticas, minimizando os efeitos colaterais na dentição. O uso de ancoragem óssea em mini-implantes, associada ao protocolo Alt-RAMEC (Alternate Rapid Maxillary Expansion and Constriction) pode ser eficaz no tratamento de um grande número de pacientes Classe III em crescimento. Objetivo: Realizar uma síntese da literatura baseada em evidência sobre o tratamento da má oclusão de Classe III em pacientes adultos jovens, e ilustrar sua aplicação e eficácia por meio do relato de um caso emblemático. Conclusão: A resolução e o acompanhamento em longo prazo do caso apresentado, juntamente com estudos conduzidos em uma amostra maior, demonstram a eficácia da combinação estratégica dos tratamentos ortopédico e ortodôntico usando um expansor palatal híbrido e o protocolo Alt-RAMEC para corrigir a má oclusão de Classe III em pacientes adultos.