Assessment of relapse of skeletal open bite treatment in adult patients treated with molar intrusion using temporary anchorage devices and orthognathic surgery - a systematic review / Avaliação da recidiva do tratamento da mordida aberta esquelética em pacientes adultos tratados com intrusão molar utilizando dispositivos de ancoragem temporária e cirurgia ortognática - uma revisão sistemática

Objetivo: O objetivo deste estudo é avaliar sistematicamente as evidências disponíveis para recidiva do tratamento da mordida aberta esquelética usando dispositivos de ancoragem temporária e cirurgia ortognática. Material e Métodos: Cinco bases de dados eletrônicas como MEDLINE, COCHRANE, SCIELO, GOOGLE SCHOLAR, EMBASE foram pesquisadas sistematicamente até junho de 2020. Os estudos de qualidade metodológica foram classificados por meio da Ferramenta de Avaliação de Qualidade do Projeto de Práticas de Saúde Pública Eficazes (EPHPP). Resultados: No total, 1.005 estudos foram identificados para triagem e 6 estudos foram elegíveis. O instrumento de avaliação da qualidade apresentou qualidade moderada para todos os estudos. A correção imediata pós-tratamento da mordida aberta foi melhor nos estudos cirúrgicos do que nos estudos tratados com TADs. Conclusão: A estabilidade dos resultados do tratamento da mordida aberta anterior foi comparável nos casos tratados em ambas as modalidades de tratamento. A recidiva da mordida aberta anterior foi associada a casos em que a sobremordida pós-tratamento foi mínima. A sobremordida parece ser mais estável quando apenas a maxila foi operada do que com cirurgias bimaxilares. A rotação anti-horária da mandíbula com subsequente redução da altura facial anterior foi melhor na correção cirúrgica do que através de TADs (AU)

Objective: The purpose of this study is to systematically assess the available evidence for relapse of skeletal open bite treatment using temporary anchorage devices and orthognathic surgery. Materials and Methods: Five electronic databases such as MEDLINE, COCHRANE, SCIELO, GOOGLE SCHOLAR, EMBASE were systematically searched up to June 2020. Methodological quality studies were graded by means of the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool. Results: In total, 1005 studies were identified for screening, and 6 studies were eligible. The quality assessment tool showed moderate quality for all the studies. The immediate post treatment correction of open bite was better in the surgical studies than in the studies treated with TADs. Conclusion: Stability of treatment results of anterior openbite was comparable in cases treated in both the treatment modalities. Relapse of anterior open bite was associated with cases in which the posttreatment overbite was minimal. Overbite seems to be more stable when only the maxilla has been operated on than with bi-maxillary surgeries. Counterclockwise rotation of the mandible with subsequent reduction of anterior facial height was better in surgical correction than through TADs. (AU)

Use of orthodontic mini-screws among orthodontists in Saudi Arabia

Background: Orthodontic anchorage is a technique used to avoid undesired tooth movement. The miniature screw (mini-screw) implant is an orthodontic innovation that was introduced to circumvent the limitations of conventional anchorage systems. Mini-screws, known as temporary anchorage devices (TADs), give clinicians good control over tooth movement in 3 dimensions and can assist orthodontists in anchorage-demanding cases.Methods: A questionnaire was distributed by online survey using SurveyMonkey and on paper during orthodontic meetings in Saudi Arabia. Collected data were analyzed using SPSS statistical software (version 23, IBM). A 2-way cross-tabulation and Fisher’s exact or Pearson chi-square tests were used to evaluate statistically significant differences. A P-value < 0.05 was considered to be statistically significant.Results: Of 133 respondents, 72 (54.1%) of practitioners worked in the governmental sector and 61 (45.9%) worked in the private sector. A total of (87.3%) of practitioners in the governmental sector and (80%) of practitioners in the private sector reported using mini-screws in clinical practice. Practitioners who reported that they did not use mini-screws in clinical practice listed the following reasons: “I don’t have enough information” (33.3%), “It’s a surgeon’s job” (11.1%), “Not available in the hospital” (29.6%), and “Other” (25.9%). A total of 60.2% of practitioners loaded mini-screws immediately, 8.3% loaded them 1 week after implantation, 11.3% loaded them 2-3 weeks after implantation, and 3.8% loaded them >3 weeks after implantation. Regarding the method of placement, 63.2% of practitioners used radiography for placement guidance/confirmation, 9.8% used a self-made guide, and 8.3% did not use a guide.Conclusions: Lack of education and training are major reasons that practitioners do not use orthodontic mini-screws in Saudi Arabia. Increased efforts to organize seminars and workshops may motivate practitioners to incorporate mini-screw usage into routine practice.

Comparison of mechanical and biological properties of zirconia and titanium alloy orthodontic micro-implants / 대한치과교정학회지

OBJECTIVE: The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. METHODS: Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of 0°, 10°, 20°, 30°, and 40°. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. RESULTS: There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was 56.88 ± 6.72%. CONCLUSIONS: Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.

Microimplantes, una nueva opción en el tratamiento de Ortodoncia

Los microimplantes son pequeños pines de titanio o de aleación de titanio de 1,2 mm de diámetro y 6 mm de longitud. Están diseñados con una superficie suave para que no se oseointegren. Son utilizados en Ortodoncia como anclaje temporal. Han sido usados como anclaje esqueletal, también para distalizar y protraer molares, intruir molares e incisivos, para el cierre de espacios edéntulos extensos que con los métodos convencionales en ortodoncia habría sido imposible. Los microimplantes son removidos con relativa facilidad una vez efectuado el procedimiento. Como toda técnica nueva, es importante que los clínicos sepan elegir bien en qué casos van a utilizar los micro implantes y los sitios de su colocación.

The miniimplants are small devices of 1,2 mm of wide and 6 mm of length. Manufactured with a smooth machined surface that is not designed to osseointegrate. In orthodontics they are used as temporary anchorage for molar distalization, protraction and intrusion of molars and incisors. Also for closing wide edentulous spaces once considered impossible with conventional orthodontics.. The miniimplants are easily removed. As with any new technique clinicians should be aware in which cases use this devices and the sites of placing them.

Reasons for mini-implants failure: choosing installation site should be valued!

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that: a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants. Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows: 1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant.

As perdas de mini-implantes estão quase sempre relacionadas aos aspectos físicos e mecânicos decorrentes de uma escolha inadequada do local de inserção. Deve se destacar que: a) As cristas ósseas alveolares interdentárias têm flexão e se deformam, e podem não oferecer ancoragem tão absoluta. Quanto mais cervicais, as estruturas são mais delicadas e oferecem menos suporte físico para os mini-implantes; b) as cristas ósseas alveolares triangulares se deformam mais, e as retangulares são menos flexíveis; c) as bases do processo alveolar nos corpos da maxila e mandíbula não têm capacidade flexiva, e seu volume e estruturas são maiores, logo, são mais receptivas para mini-implantes; d) quanto mais próximo da cervical se coloca um mini-implante, maior é o risco de se perdê-lo; quanto mais apical se coloca o mini-implante, melhor é o seu prognóstico; e) avaliar a região tridimensionalmente representa um passo fundamental no planejamento do uso de mini-implantes. Com base nessas considerações, as hipóteses para a perda de mini-implantes são: 1) Deflexão do processo alveolar da maxila e mandíbula, quando fixados em posições mais cervicais; 2) proximidade com o ligamento periodontal e o movimento dentário intra-alveolar normal; 3) densidade óssea menor, pouca espessura e menor volume ósseo alveolar; 4) espessura menor da cortical óssea alveolar; 5) pressão excessiva, induzindo microfraturas ósseas trabeculares; 6) locais de maior fragilidade anatômica mandibular e maxilar; 7) espessura maior do tecido gengival não considerada na escolha do mini-implante.

Temporary anchorage devices in orthodontics.

Anchorage control is one of the main aspects of orthodontic treatment plan. A good appliance system should put minimum taxation of anchorage on the anchor units. The structures present with in the confinement of oral cavity are very less in number. In such cases the anchor unit gets its reinforcement from extraoral structures or intraoral appliances. Extraoral anchorages have their inherent drawbacks and most of them rely on patient cooperation. The use of implants in orthodontics to reinforce the anchorage is a recent concept. The purpose of this article is to review the implants in the context of orthodontics which are called as TAD- temporary anchorage devices.