2019, Number 4
Orthodontic correction of maxillary cantationing through a single temporary anchoring device with micro-oseoperforations
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Language: English/Spanish [Versión en español]
References: 12
Page: 258-266
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ABSTRACT
Introduction: Temporary anchorage devices (TADs), offer stability in orthodontic treatments to achieve various objectives like distalization, mesialization, and intrusion. Providing the advantage of managing biomechanics in a stable way. To accomplish the treatment in less time, a method that produce a RAP (regional acceleratory phenomenon) can be applied, such as micro-perforations to obtain the desired results. 24-year-old female patient attends the Orthodontic Clinic at the National School of Higher Studies León Unit, to correct an evident maxilla asymmetry that she presents. Biprotrusive skeletal class I, neutral growth. Brachifacial, retrochelia, straight profile. Vertical asymmetry of the upper occlusal plane, proclined upper and lower incisors, gyroversions of teeth 32, 31, 41. Bilateral molar class III, bilateral cuspid class I. Low torque Damon appliance placement. After leveling, in 0.01810.025 NiTi arches, micro-osseoperforations are performed in the maxilla with a microimplant. Subsequently, it was left as a temporary anchor in the interradicular of teeth 23 and 24 for quadrant intrusion. Activation with elastic chain for three months. The edging correction is achieved with the application of a temporary skeletal anchored device for a period of three months. Conclusion: The intrusion with a single microimplant was successful, handling the adequate forces with relevant biomechanics. The short time and good results are also the product of the RAP procedure applied in the case. In three months we improved the smile curve and corrected the maxilla asymmetry.INTRODUCTION
Aesthetics plays an important role for society and for the individual. One of the many advantages of orthodontics is that it offers solutions to aesthetic problems of the facial complex. Patients should be provided with aesthetics accompanied by stable biological functions.
Posnick JC mentions in Herrera that the term "dentofacial deformity" is defined as a significant deviation from the normal proportions of the maxillomandibular complex that adversely affects the relationship of the teeth to their arch and the relationship of each arch to its antagonist.1 These discrepancies in size, shape, or position will be treated according to their severity, the age of the patient, and the general condition of the patient. When they are major discrepancies, in adult patients, where their growth spurt has stopped and ended, surgical orthodontic treatment is determined. When the discrepancies are minor or at ages where the patient is still growing, treatments that prevent an irreversible evolution of the condition can be chosen, and some patients even opt for compensations. All these decisions are always taken together with routine studies or even tomographies. In the case of compensations, we now have methods that help us to maintain stability during treatment.
Temporary anchorage devices (TADs) provide multiple biomechanical management options. In treatments related to vertical management of the maxilla, it is important to determine the diagnosis in order to choose the right location for successful biomechanics at the time of intrusion. Clinical photography is an important adjunct to help us make decisions that favor the patient's aesthetics and show the patient his or her options. TADs offer stability in treatment to achieve various goals. Such as distalisation, mesialisation, and intrusion. Providing the advantage of managing biomechanics in a stable manner.
To perform the treatment in less time, a method that produces a regional acceleratory phenomenon (RAP), such as micro-drilling, can be applied to obtain the desired results in less time. Yina Li mentions that, under normal/healthy conditions, such movement is carried out by highly coordinated and efficient bone remodeling, which requires the coupling of bone formation after bone resorption.2 To achieve a shorter treatment time with stable results, the RAP procedure can be performed. The aim here is to injure the bone and soft tissue so that the cells involved in bone remodeling are present and movements can be performed with less force and more quickly. There are invasive methods like surgical interventions of any kind and non-invasive methods as physical methods such as direct electrical currents, pulsed electromagnetic fields, resonance vibration, and low power laser. Other non-invasive methods include drugs as inflammatory mediators, for example prostaglandin injection, which is still under study.3
J. Cano in Yani Li's paper says that surgical techniques to accelerate orthodontic treatment have been tried and tested for over 100 years in clinical practice. Initial approaches involve alveolar osteotomy alone (defined as a surgical cut through the cortical and trabecular bones) or combined with corticotomy (defined as a surgical cut where only the cortical bone is involved).2 There are now more refined techniques with minimal tissue invasion, where no flaps or piezoelectrics are required.2
CASE REPORT
24-year-old female patient attended the Orthodontic Clinic at the National School of Higher Studies León Unit to correct an evident edging. She had no chronic diseases or pathological data that would interfere with the treatment. Diagnosis: biprotrusive skeletal class I with neutral growth, facially she is a brachyfacial patient with a straight profile and retro-chelation, facial asymmetry was observed in the comparison of the left and right sides. Proinclined upper incisors, gyroversions, class III molar right and left, bilateral class I canine, deviated midline, and the canted maxillary plane where it is observed that a 5 mm intrusion is needed to correct it (Figures 1, 2 and 3).
Treatment objective: correct maxillary canthus and asymmetry of the lower third.
Treatment planFull bonding, Damon low torque brackets on teeth 13, 12, 11, 21, 22 with standard torque on all other teeth.
Phase 1: CuNiTi round archwires placement, upper and lower 0.013" CuNiTi, followed by 0.018" CuNiTi, elastic class III left side from teeth 25 to 34, 3/16 light.
Phase 2: CuNiTi edgewise archsetting, 0.014" × 0.025" CuNiTi upper and lower, followed by 0.018" × 0.025" CuNiTi upper and lower arch and placement of temporary anchorage device in quadrant three for segment intrusion, with prior inter-radicular micro-osseous drilling.
Phase 3: main mechanicals, arch 0.019" × 0.025" SS upper and 0.016" × 0.025" SS lower.
Phase 4: final, TMA arches 0.019" × 0.025" upper and 0.016" CuNiTi lower and upper and lower seating elastics. Retention: fixed upper and lower (Figure 4).
The results after three months of revision were satisfactory, observing an evident intrusion, as well as biomechanical results such as posterior open bite which was solved with different methods and always having torque control (Figures 5, 6, 7 and 8).
DISCUSSION
Benavides et al mentions that Dr. Robert Moyers stated that one of the drawbacks in the success of orthodontic treatment was the limited collaboration of the patient in the use of attachments to achieve anchorage.4 For biomechanical stability, the anchorage is crucial to achieving the treatment goal. Once you have control with anchorage to perform the movements, you set the appropriate forces for intrusion.
The amount of force must be adequate for the movement to be performed and for the stability of the TADs. Tortolini says that the force should not exceed 26 g per cm2. Curiel Meza says that the optimum intrusion force is between 15 g and 25 g.5,6 Tortolini talks in his work that when chewing soft foods, forces of 1 to 2 kg are applied, and with more resistant foods up to 50 kg. When a tooth is subjected to such an overload the pressure is transmitted through the periodontal ligament and the incompressible hystic fluid prevents rapid displacement of the tooth in the periodontal ligament space, and the force is transmitted to the alveolar bone, which deforms in response to the force, and each tooth is slightly displaced.5
Hyo-Sang Park performed intrusion of the posterior sector using one micro implant per side, placing them in the palatal area between the first and second molar, with a palatal bar to control the inclination that may occur at the time of intrusion, performing the intrusion with 100 g of force. He concluded that intrusion with micro-implants is stable and effective.7 Xun, Zen, and Wang performed intrusion with 150 g of force and a single micro-implant with titanium springs attached to the arms of a transpalatal archwire.8 Roseberg mentions that Sugawara and Umemori placed mini-plates for molar intrusion where intrusion lasted six months.9 Kuroda, in Roseberg, reports that treatments with micro-implants for molar intrusion were 27.6 months and treatments with surgery lasted 33.5 months. This suggests that microimplant treatments contribute to making complicated treatments shorter.9
At the time of force application, performing the RAP improves the biological behavior.10 Mani Alikhani et al, measured the level of IL-1 in the gingival crevicular fluid before and after micro-osseoperforations, and found a more than 2-fold increase in tooth movement, along with increased IL1-? activity. Mani Alikhani also says that with what he discovered from his study in terms of magnitude and speed of movement, the drills do not need to be very close to the tooth to move and to accelerate the speed of tooth movement.11 Kuroda et al performed a study comparing the results of treatment for molar intrusion with TADs and orthognathic surgery, for patients with severe anterior open bite. Founding that the treatment with TADs could not only be effective for morphological improvements, but also for functional ones. Treated patients had good retention and stability after two years of treatment.12
CONCLUSION
The intrusion with a single TAD was satisfactory, managing adequate forces with relevant biomechanics. The short time and good results are also the product RAP procedure applied in the case, in which at three months we improved the smile curve, correcting the maxillary canthus.
Biological acceleration of the response to teeth movement is a good option for adult patients, for teeth movements that are usually complicated and to make treatments shorter in time.
Patients are looking for good results in less time, being able to apply all the tools at our disposal to reduce the time and make the treatment with biological and stable guidelines is our duty as orthodontists, the results of this clinical case prove that the tools and procedures at our disposal offer us stable treatment options with good results. By using passive self-ligating fixed appliances, producing a regional acceleration phenomenon that is minimally invasive and with a temporary bone anchorage, we obtained what we were looking for, a short and stable treatment, controlling the torque with attachments, with biomechanics and biological response, finding aesthetics and function.
REFERENCES
AFFILIATIONS
1 Alumna. Posgrado de Ortodoncia, Escuela Nacional de Estudios Superiores, Unidad León.
2 Profesor. Posgrado de Ortodoncia, Escuela Nacional de Estudios Superiores, Unidad León.
CORRESPONDENCE
Mitzy Avelina Vázquez Valle. E-mail: mitzyvazquezvalle@gmail.comReceived: Abril 2021. Accepted: Mayo 2021.