Mini-implant Insertion Research Articles

Retracted:Selective use of hand and forearm muscles during mini-implant insertion: a natural torquimeter

To compare maximum torque produced by different muscular groups and its influence on mini-implant insertion torque and fracture prevention. A prospective study involving in vivo and in vitro laboratory experiments. Eighty-seven professionals were evaluated for maximum torque produced using a screwdriver with combined action between thumb and index fingers [maximum digital torque (MDT)] and by forearm supination movement [maximum brachial torque (MBT)]. Ninety mini-implants distributed over nine different diameters and twenty commercially available mini-implants of two different diameters and trademarks were fractured to determine the fracture torque (FT). The fracture resistance index (FRI) was obtained from: FRI_MDT = FT/MDT and FRI_MBT = FT/MBT. The analysis of variance (ANOVA) and t tests were used to compare the groups. MDT was smaller than MBT and both were smaller in females. FT increased for each 0·1 mm of diameter increment. FRI_MDT was greater than FRI_MBT for all diameters. FRI_MDT>1 was found when the diameter was greater than or equal to 1·5 mm. FRI_MBT>1 occurred with diameters equal or greater than 1·7 mm for females and 1·8 mm for males. The 1.5 mm and 1.6 mm diameter of commercially available and mini-implants presented FRI_MBT<1 and FRI_MDT>1. Digital torque was 42% smaller than brachial torque, and it was mechanically safer and biologically more compatible, allowing fracture prevention of 1·5 mm or thicker mini-implant diameter due to insertion torque limitation at 15 N/cm.

Orthodontic mini-implant diameter does not affect in-situ linear microcrack generation in the mandible or the maxilla

Microdamage reduces bone mechanical properties and thus could contribute to implant failure. The objective of this study was to investigate whether the diameter of mini-implants affects linear microcrack generation and whether this differs between the mandible and the maxilla because of their contrasting cortical thicknesses. Maxillary and mandibular quadrants of 5 dogs were randomly assigned to receive, in situ, no pilot drilling or mini-implant insertion (control), pilot drilling only without mini-implants, or pilot drilling plus a mini-implant of 1 of 3 diameters: 1.4 mm (n = 18), 1.6 mm (n = 18), and 2.0 mm (n = 18). Linear microcracks were assessed on basic fuchsin-stained sections by using epifluorescence microscopy. Pilot drilling without mini-implant insertion produced significantly higher linear microcrack burdens in the mandible compared with the maxilla. In the both the mandible and the maxilla, all implants produced higher linear microcrack burdens than did the controls, yet there were no differences between the 3 implant diameters. Neither the diameter of the mini-implant nor the site of insertion (mandible vs maxilla) had a significant effect on the amount of linear microdamage adjacent to the implant when the implants were inserted after pilot drilling in situ.

Insertion torque and success of orthodontic mini-implants: A systematic review

In this systematic review, we analyzed whether recommended maximum insertion torque values of 5 to 10 Ncm were associated with higher success rates of orthodontic mini-implants compared with mini-implants inserted with maximum insertion torque values beyond this range. Objective assessments of stability, variables that influence maximum insertion torque values, and adverse effect of interventions were also assessed in the studies selected for our PICO (patient problem or population, intervention, comparison, and outcomes) question. Computerized and manual searches of the literature were conducted up to February 24, 2012, for human studies that assessed these objectives. Our eligibility criteria selected studies that (1) used sample sizes of 10 or more, (2) recorded maximum insertion torque during the insertion of orthodontic mini-implants, (3) inserted implants with a diameter smaller than 2.5 mm, and (4) applied orthodontic forces for a minimum duration of 4 months. Confounding was assessed through the analysis of risk of bias, and the validity of outcomes was rated according to the GRADE approach. The Cochrane Handbook for Systematic Reviews of Interventions was our main guideline for the methodology. Seven nonrandomized studies met the eligibility criteria. All associations between specific maximum insertion torque values and success were based on literature rated as having low quality. The reasons for these judgments included subjective definitions of success, poor-quality torque sensors, and high risks for selection, performance, detection, and reporting biases. A risk of multiple publication bias was also suspected. All associations between maximum insertion torque and factors related to implant, patient, location, and surgery were rejected; few studies reported on adverse effects. Currently, no evidence indicates that specific maximum insertion torque levels are associated with higher success rates for orthodontic mini-implants. Additional research on this topic is therefore necessary. The following guidelines for future studies are suggested: (1) systematically review the animal and laboratory literature, (2) perform maximum insertion torque tests on artificial bone, (3) test associations in animal studies before conducting clinical trials, (4) test associations between maximum insertion torque and the stability of orthodontic mini-implants with objective quantitative recordings rather than subjective qualitative measures, (5) measure maximum insertion torque with digital sensors rather than with mechanical devices, (6) assess the stability of orthodontic mini-implants at preestablished times, (7) consult our risk-of-bias analysis, and (8) analyze the adverse effects of interventions.

Selective Use of Hand and Forearm Muscles During Bone Screw Insertion: A Natural Torque Meter

To compare the maximum torque produced by different muscle groups and its influence on mini-implant insertion torque and fracture prevention. Eighty-seven professionals were evaluated for the maximum torque produced on a screwdriver by a combined action between the thumb and index finger (maximum digital torque [MDT]) and by the forearm supination movement (maximum brachial torque [MBT]). Ninety mini-implants distributed among 9 different diameters were fractured to determine the fracture torque (FT). The fracture resistance index (FRI) was obtained from: FRI_MDT = FT/MDT and FRI_MBT = FT/MBT. Analysis of variance and t tests were used to compare the groups. The MDT was smaller than the MBT, and the 2 measurements were smaller in female subjects. The FT increased for each 0.1-mm increment in diameter. The FRI_MDT was greater than FRI_MBT for all diameters. An FRI_MDT greater than 1 was found when the diameter was greater than or equal to 1.5 mm. An FRI_MBT greater than 1 occurred with diameters equal to or greater than 1.7 mm for female subjects and 1.8 mm for male subjects. The digital torque was 42% smaller than the brachial torque, and it was mechanically safer and biologically more compatible, allowing the prevention of the fracture of mini-implants with a diameter 1.5 mm or thicker owing to an insertion torque limitation at 15 N-cm.

An evaluation of insertion sites for mini-implants

(1) To report the thickness of the cortical bone in insertion sites commonly used for orthodontic mini-implants, (2) to assess the impact of a change in insertion angle on primary cortical bone-to-implant contact, and (3) to evaluate the risk of maxillary sinus perforation. At autopsy, 27 human samples containing three to five adjacent teeth were excised and scanned using a table-top micro-computed tomography system. Bone thickness measurements were taken at 45° and 90° to the long the axis of the adjacent teeth, simulating a mini-implant insertion at the mid-root level. In the maxilla, the overall mean cortical thickness at 90° was 0.7 mm buccally in the lateral region, 1.0 mm buccally in the anterior region, and 1.3 mm palatally. In the mandible, the mean cortical thickness was 0.7 mm buccally and 1.8 mm lingually in the anterior region; 1.9 mm buccally and 2.6 mm lingually in the lateral region. Changing the insertion angle from 90° to 45° increased the cortical bone-to-implant contact by an average of 47%. Perpendicular insertion at the mid-root level only rarely interfered with the sinus, whereas apically inclined insertion increased the risk of sinus perforation. Buccally and palatally in the maxilla and buccally in the anterior mandible, the thickness of the alveolar cortical bone is often less than 1 mm. In contrast, the alveolar cortical bone is frequently thicker than 2 mm laterally in the mandible. Changing the insertion angle to 45° will generally enhance implant stability but increase the risk of perforation to the maxillary sinus.

Optimization of orthodontic treatment using the Centrex System to retract anterior teeth

INTRODUCTION: In the end of 90's the adoption of mini-implants as Anchorage allowed a paradigm change influencing even the way of thinking orthodontic mechanics. The overlapping of the specialties of Orthodontics and Implantology started with orthodontic preparations for prosthetic implants insertion, aroused with the use of palatal implants and late with the introduction of mini-implants. The improvement of mini-implants insertion technique with the appearing of self-drilling screws has allowed orthodontists to plan and to place this precious Anchorage piece. Taking into account the versatility of positioning of these screws it was developed a concept that allows the construction of force action lines aiming at optimize the planning and predictability of orthodontic motion. OBJECTIVE: To present some clinical results treatments conduct using Centrex System of orthodontic treatment, approximating the force line action of resistance center of units to be moved. The traced way to its development, previously treated in this journal, will be detailed for better understanding of its functioning.

Assessment of potential orthodontic mini-implant insertion sites based on anatomical hard tissue parameters: a systematic review.

To estimate the applicability of potential sites for insertion of orthodontic mini-implants (OMIs) by a systematic review of studies that used computed tomography (CT) or cone beam CT to evaluate anatomical bone quality and quantity parameters, such as bone thickness, available space, and bone density. Medline and the Cochrane Database of Systematic Reviews were searched to identify all relevant papers. Several key words were used, such as computerized/computed tomography, mini-implants, and OMIs. The anatomical variables that were assigned in each article to a specific site suggesting it as the ideal or best alternative were assessed separately and evaluated with a scoring system. Twenty-two articles were included in the study. The most favorable areas for OMI insertion in the maxilla are proposed between the first and second molars buccally and palatally. The best area in the mandible is also between the first and second molars, both buccally and lingually. In the palate, the paramedian area 3 to 6 mm posterior to and 2 to 9 mm lateral to the incisive foramen was identified as the best site for OMI placement. Despite the heterogeneity of the studies, there was considerable agreement regarding the optimal site for OMI insertion among most studies that investigated anatomical hard tissue parameters based on CT or CBCT data. In this respect, the posterior area from the second premolar to the second molar is the best option for OMI placement in alveolar bone.

Microdamage of the cortical bone during mini-implant insertion with self-drilling and self-tapping techniques: A randomized controlled trial

The purpose of this research was to evaluate microdamage accumulation after mini-implant placement by self-drilling (without a pilot hole) and self-tapping (screwed into a pilot hole) insertion techniques. The null hypothesis was that the mini-implant insertion technique would have no influence on microcrack accumulation and propagation in the cortical bones of the maxillae and mandibles of adult hounds. Mini-implants (n = 162; diameter, 1.6 mm; length, 6 mm) were placed in the maxillae and mandibles of 9 hounds (12-14 months old) with self-drilling and self-tapping insertion techniques. The techniques were randomly assigned to the left or the right side of each jaw. Each hound received 18 mini-implants (10 in the mandible, 8 in the maxilla). Histomorphometric parameters including total crack length and crack surface density were measured. The null hypothesis was rejected in favor of an alternate hypothesis: that the self-drilling technique results in more microdamage (microcracks) accumulation in the adjacent cortical bone in both the maxilla and the mandible immediately after mini-implant placement. A cluster level analysis was used to analyze the data on the outcome measured. Since the measurements were clustered within dogs, a paired-samples t test was used to analyze the average differences between insertion methods at both jaw locations. A significance level of 0.05 was used for both analyses. The self-drilling technique resulted in greater total crack lengths in both the maxilla and the mandible (maxilla: mean difference, 18.70 ± 7.04 μm/mm(2); CI, 13.29-24.11; mandible: mean difference, 22.98 ± 6.43 μm/mm(2); CI, 18.04-27.93; P <0.05), higher crack surface density in both the maxilla and the mandible (maxilla: mean difference, 10.39 ± 9.16 μm/mm(2); CI, 3.34-17.43; mandible: mean difference, 11.28 ± 3.41 μm/mm(2); CI, 8.65-13.90; P <0.05). This study demonstrated greater microdamage in the cortical bones of adult hounds in both the maxilla and the mandible by the self-drilling insertion technique compared with the self-tapping technique.

Mini-Implants: When Orthodontists are Caught in their Own Web

Introduction: Mini-implants are being extensively used in orthodontics, providing a new field of possibilities for treatment of the cases when a maximum anchorage is required. The procedure is critical during the insertion of miniimplants in the alveolar process between the roots of the tooth, and major complications can include contact and damage to adjacent tooth roots. Objective: The following case report describes a failure because of unintentional root damage after orthodontic mini-implant placement, resulting in longitudinal root fracture followed by extraction of the damaged mandibular second molar. Discussion: Factors which might have contributed to the irreversible iatrogenic injury associated with the use of mini-implants in a diabetic patient submitted to orthodontic treatment are discussed and analyzed. Conclusion: Although mini-implant placement has become a routine procedure in the orthodontic practice, it still represents an intrinsic risk to the process of insertion, which is the damage to adjacent structures. The placement of mini-implants must be carefully monitored, even in those cases which present low risk for iatrogenic injury. However much confident the professional may be, self-confidence in excess often leads to failure, provoking irreversible damages.

Evaluation of the Palatal Bone for Placement of Orthodontic Mini-Implants in Japanese Adults

Mini-implants are increasingly being used for orthodontic anchorage in the palate. The anatomical structure of the jaw must be properly evaluated prior to use; however, there are a few research reports providing basic data regarding the palate. Bone thickness was measured and bone morphology evaluated in the palates of Japanese people. The palates of five Japanese adult cadavers and 15 skulls were examined. The samples were imaged and measured using the micro-CT system. In the mid-palatine suture region, the cortical bone had a complex mesh-like structure and was thicker than surrounding areas. Cortical bone thickness varied depending on the site. The mid-palatine suture region is an ideal site for mini-implant insertion; however, because bone and cortical bone thickness markedly decrease in the lateral region, careful attention should be paid when inserting mini-implants in the midpalatine suture.

Cortical bone thickness and bone depth of the posterior palatal alveolar process for mini-implant insertion in adults

Cortical bone thickness and bone depth are important factors when placing an orthodontic mini-implant. The objective of this study was to investigate both variables for the palatal alveolar process. Thirty dry human skulls were imaged by using cone-beam computed tomography technology. Two-dimensional slices bisecting the posterior interdental sites were generated, and cortical bone thickness and bone depth were measured at 4, 8, and 12 mm from the alveolar crest. Two-way repeated measures analysis of variance (ANOVA) was used to analyze the measurements. Interdental site and measurement level had a significant impact on both cortical bone thickness and bone depth. Cortical bone thickness was typically greatest at the 8-mm measurement level and more anterior interdental sites. Bone depth decreased with higher measurement levels and was smallest at the most posterior-superior measurement points. Cortical bone thickness and bone depth of the palatal alveolar process are, on average, favorable for the insertion of orthodontic mini-implants; however, some sites should routinely be avoided to prevent damage to the maxillary sinus unless 3-dimensional imaging is available.

Mini-implant insertion based on tooth crown references: a guide-free technique

Mini-implant insertion requires accurate surgical technique. This study shows an insertion technique using only tooth crown references; its scientific basis is evaluated radiographically. The sample consisted of 213 inter-radicular septa, evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width. The midpoint of the septum width was linked to the interdental contact point to determine septum midline. The distances from septum midline to mesial and distal teeth were measured to evaluate the septum midline centralization degree in two different septum heights. The difference between mesial and distal distances represented the septum midline deviation degree. The mesial and distal distances were compared by t-tests, and the septum midline deviation was correlated with septum height using Pearson's correlation test. The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height. There was a moderate correlation ( r = 0.45) between septum midline deviation and septum height. The tooth crown references evaluated on interproximal radiographs determine a high centralization degree of the septum midline on which the insertion site could be defined. The greater centralization degree was observed at the coronal septum area.

Patient Expectations, Acceptance and Preferences in Treatment with Orthodontic Mini-implants

The objective of this study was to compare two different insertion techniques as well as two different anesthesia injection methods carried out on patients undergoing orthodontic treatment with mini-implants to reinforce skeletal anchorage. A total of 30 patients were enrolled and randomly divided into two groups, A and B. For the patients in group A the mini-implants were inserted manually after pre-drilling with a dental handpiece. In group B self-drilling mini-implants were inserted without pre-drilling. Furthermore, all patients were given a local anesthetic injected into the root tip area in the second quadrant. In the first quadrant the anesthetic was injected directly next to the insertion region. The patients were questioned concerning pain perception prior to, immediately after, and 1 day after the treatment. There were no significant differences between the two groups in the degree of discomfort described by the patients. While patients in group A considered the noise from the dental handpiece as the main discomfort factor, patients in group B reported that the pressure applied when inserting the self-drilling mini-implants was the main source of discomfort. Overall discomfort from injections immediately next to the mini-implant insertion area was lower than that resulting from the standard injection methods, where the longer lasting anesthesia was considered unpleasant. Patients tolerated the various insertion procedures equally well. However, there were differences with regard to the injection technique: The patients favored an injection immediately next to the mini-implant insertion area.

Effect of zoledronic acid on bone healing subsequent to mini-implant insertion

To examine remodeling in bone supporting mini-implants by comparing a no drug (ND) group with a group that received a potent intravenous bisphosphonate in a canine model. Twelve skeletally mature (2- to 3-year-old) male dogs were divided into two groups. Seven dogs were administered 0.1 mg/kg/mo of zoledronic acid (ZA) for 16 weeks, while five age-matched dogs received no drug. Two mini-implants (Tomas, Dentaurum, Newton, Pa) were placed unilaterally in the maxilla and mandible (4 mini-implants per animal × 12 = 48). Serial fluorescent bone labels were administered in vivo. Postmortem, the bone blocks containing the mini-implants were harvested and used for histomorphometric analyses at two regions of interest (adjacent: within 1 mm of interface; distant: 1-4 mm from the interface) supporting the mini-implant. Data were analyzed using mixed models. In general, the ZA group had a significantly lower bone formation rate than the ND group (P < .05) for all jaws/regions except for the adjacent region in the maxilla, P = .12. Despite the reduction, mean intracortical remodeling in the ZA group ranged from 35%-42% per year in the implant adjacent bone. This rate is substantially higher than that reported for noninjured sites in the jaw. Bone remodeling is typically elevated in implant supporting bone. After ZA administration, the healing response represented by elevated turnover in implant supporting bone was diminished but was not abolished.

In vitro evaluation of insertion and removal torques of orthodontic mini-implants

This study evaluated the influence of bone cortical thickness on the maximum torque required for insertion and removal of orthodontic mini-implants of different shapes. Five different types of orthodontic mini-implants were examined Cylindrical 1 (CYM), Cylindrical 2 (CYI) and Cylindrical 3 (CYT) Conical 1 (CON), Conical 2 (COS). Insertion and removal torque tests were performed in mini-pig medullary bone (8mm thick) and cortical bone 1, 2, 3 and 6mm thick. A digital torque meter measured the torque forces; the maximum values of insertion and removal were obtained (N/cm). There were no statistically significant differences between the different implants in the torque forces required for insertion and removal from medullary bone (P>0.05). During insertion into 1-2mm cortical bone, COS, CON and CYT had torque values statistically higher, but CON had higher torque values compared with the others when 3-6mm cortical bone was used (P<0.05). The removal torque values were significantly lower for CYM and CYI. Conical type mini-implants require a greater torque force for insertion and removal compared with cylindrical types. Torque values were directly related to cortical thickness.

Two-dimensional radiographic and clinical references of the tooth crown for orthodontic mini-implant insertion: A guide-free technique

This study evaluated the reliability of tooth-crown radiographic references to aid in orthodontic mini-implant insertion and showed an insertion technique based on these references. The sample consisted of 213 interradicular septa evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width and its midpoint was linked to the interdental contact point to determine septum midline (SML). The distances from SML to mesial and distal teeth were measured and compared to evaluate SML centralization degree in 2 different septum heights. The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height. The tooth-crown radiographic references determine a high centralization degree of the SML on which an insertion site could be defined. The greater SML centralization degree was observed at the coronal septum area.

Laser photonics application in prosthetic dentistry for denture design optimization

The aim of this work is to demonstrate that holographic and speckle interferometry—laser photonics methods are compatible and useful for prosthetic stomatology. These methods allow to study the deformation of the mandible after insertion of mini-implants of various forms, and to give the practical medical recommendations.

Análisis del Uso de un Protocolo de Inserción de Microimplantes Ortodóncicos Basado en una Guía Radiográfico-Quirúrgica Estampada

PurposeTo analyze the security of a orthodontic mini-implants insertion protocol, using a printed x-ray-surgical guide and periapical x-ray for the surgical study pre. Methodselected themselves for this study 10 patients in treatment in the Program of post degree of Ortodoncia and Ortopedia Dento-maxilar of the University of Chile, that required the use of you microimplant due to the complexity to obtain the wished movements. I make for each case a printed guide and he came himself to the taking of periapicales x-rays. I adapt the guide for the insertion you microimplant of them and once inserted one came to control by means of x-rays and tomography. ResultsOf a total of 35 you implant, 4 invaded the maxilary sinus and one of them I injure a dental root. The amount of you microimplant lost, that displayed an increased mobility or that had to be removed to injure some neighboring structure, during the first week of load was of 3 microimplant, which it indicates a 91% of insertion success. ConclusionAlthough the surgical x-ray guide is means of important aid, it is seen with limitations due to the bidimensional vision that gives the x-ray and to be a strict guide of direction for the insertion of does not to microimplant, leaving many dependent actions of the experience of the operator.

Effects of the Taper Shape, Dual-Thread, and Length on the Mechanical Properties of Mini-Implants

To analyze the mechanical effects of the length and the various shapes such as cylindrical shape, taper shape, and dual-thread shape on the insertion and removal torque of mini-implants. Mini-implants (diameter 1.6 mm and length 6 mm and 8 mm) consisting of cylindrical, taper, and dual-thread groups were inserted and removed in Sawbones while measuring the torque and time. Mechanical analysis was done of maximum insertion torque (MIT), maximum removal torque (MRT), torque ratio (TR; MRT/MIT), insertion angular momentum (IAM), removal angular momentum (RAM), and time of MIT. Measurements were statistically evaluated to analyze any differences of shapes and lengths. The cylindrical shape had the lowest MIT and MRT in each length. Although taper shape showed the highest MIT in each length, dual-thread shape showed significantly higher MRT, TR, and RAM in each length (P < .05). Dual-thread groups showed a gentle increase of insertion torque and a gentle decrease of removal torque in contrast to the other shape groups. However, it had higher IAM and time of MIT. The long length group showed significantly higher measurements except for TR. Dual-thread shape provided better mechanical stability with high removal torque on the broad range than other shapes. However, dual-thread shape may need improvement for reducing the long insertion time to decrease the stress to the surrounding tissue.

Densidade mineral óssea de sítios específicos da maxila para a inserção de mini-implantes

OBJETIVOS: avaliar a Densidade Mineral Óssea (DMO) de sítios específicos na maxila, por meio da Tomografia Computadorizada (TC) Multi-Slice. METODOLOGIA: foram realizadas 15 TC Multi-Slice da maxila para a avaliação da densidade mineral óssea de 30 regiões de interesse entre os segundos pré-molares e primeiros molares - 15 do lado direito e 15 do lado esquerdo - de 15 indivíduos (7 homens e 8 mulheres, com idade média de 21 anos) a serem submetidos ao tratamento ortodôntico, com mini-implantes como unidades de ancoragem. RESULTADOS: o resultado do teste t para observações pareadas revelou uma diferença estatisticamente significativa, quando os lados direito e esquerdo foram comparados (p &lt; 0,05). CONCLUSÃO: a média dos valores obtidos para a DMO encontrou-se próxima ao valor máximo de uma escala considerada normal para a região posterior da maxila, podendo, assim, ser considerada essa uma área segura em termos de qualidade óssea para a inserção de mini-implantes.