Clinical use of miniscrew implants as orthodontic anchorage: success rates and postoperative discomfort

Mini-implants in orthodontics: a systematic review of the literature

INTRODUCTION

In this article, we systematically reviewed the literature to quantify success and complications encountered with the use of mini-implants for orthodontic anchorage, and to analyze factors associated with success or failure.

METHODS

Computerized and manual searches were conducted up to March 31, 2008, for clinical studies that addressed these objectives. The selection criteria required that these studies (1) reported the success rates of mini-implants on samples sizes of 10 implants or more, (2) gave a definition of success, (3) used implants with a diameter smaller than 2.5 mm, and (4) applied forces for a minimum duration of 3 months. Factors associated with implant success were accepted only if potentially influencing variables were controlled. The Cochrane Handbook for Systematic Reviews of Interventions was used as the guideline for this article.

RESULTS

Nineteen reports met the inclusion criteria, but definitions of success, duration of force application, and quality of the methodology of these studies varied widely. Rates of primary outcomes ranged from 0% to 100%, but most articles reported success rates greater than 80% if mobile and displaced implants were included as successful. Adverse effects of miniscrews included biologic damage, inflammation, and pain and discomfort. Only a few articles reported negative outcomes. All proposed correlations between clinical success and specific variables such as implant, patient, location, surgery, orthodontic, and implant-maintenance factors were rejected because they did not meet the selection criteria for controlling those variables.

CONCLUSIONS

Mini-implants can be used as temporary anchorage devices, but research in this field is still in its infancy. Interpretation of findings was conditioned by lack of clarity and poor methodology of most studies. Questions concerning patient acceptability, rate and severity of adverse effects of miniscrews, and variables that influenced success remain unanswered. This article includes a guideline for future studies of these issues, based on specific definitions of primary and secondary outcomes correlated with specific operational variables.

Use of Palatal Miniscrew Anchorage and Lingual Multi-Bracket Appliances to Enhance Efficiency of Molar Scissors-Bite Correction

This article reports the successful treatment method of scissors-bite correction using miniscrew anchorage and a lingual multi-bracket appliance. A female patient, 17 years and 4 months old, had a chief complaint of crowding of anterior teeth. The patient was given the diagnosis of Angle Class I malocclusion with bimaxillary protrusion and incisor crowding. She also showed a scissors-bite of the second molar on the right side. Miniscrews were inserted into the palatal region of the upper second molar to reinforce the anchorage, and a lingual multi-bracket appliance was placed into the maxilla. Miniscrews inserted palatally were used to correct the scissors-bite in the first 3 months; afterward, they were used to retract the six anterior teeth. The total active treatment period was 26 months. Because of the bite-plane effect, the upper and lower molars were separated in occlusion, and the scissors-bite was corrected effectively within a short time. The combined use of palatal miniscrew anchorage and lingual multi-bracket appliances enhances efficiency of molar scissors-bite correction.

Bone density at interradicular sites: implications for orthodontic mini-implant placement

OBJECTIVES

Implant stability is primarily related to local bone density; Few studies have evaluated interradicular bone density related to mini-implant placement for orthodontic anchorage. Therefore, this study evaluated bone density differences between interradicular sites.

SETTING AND SAMPLE POPULATION

Computed tomographic (CT) images were obtained from 14 males and 14 females (mean age 27 years, range 23-35 years). Bone density in Hounsfield units (HU) was measured at 13 interradicular sites and four bone levels.

RESULTS

Bone densities in most areas were higher than 850 HU. Statistically significant differences in bone density were detected at different levels and sites. Bone densities in both maxilla and mandible significantly increased from the alveolar crest toward basal bone in posterior areas, while the opposite was observed in anterior areas. There were statistically significant differences in bone densities between the maxilla and mandible in posterior areas. Bone densities progressively increased from anterior to posterior areas in the mandible.

CONCLUSION

The results suggest that mini-implants for orthodontic anchorage may be effective when placed in most areas with equivalent bone density up to 6 mm apical to the alveolar crest. Site selection should be adjusted according to bone density assessment.

Distal movement of maxillary molars using miniscrew anchorage in the buccal interradicular region

OBJECTIVE

To quantify the treatment effects of interradicular miniscrew anchorage and to confirm the validity of the clinical usage of interradicular miniscrews in the distal movement of maxillary molars in nonextraction treatment.

MATERIALS AND METHODS

Twenty-four maxillary molars were moved to the distal using miniscrews placed in the interradicular space between the second premolar and the first molar at an oblique angle of 20 to 30 degrees to the long axis of the proximal tooth. The teeth were evaluated as to how the molars were moved to the distal with the use of lateral cephalograms and dental casts.

RESULTS

Maxillary molars were moved to the distal by 2.8 mm with distal tipping of 4.8 degrees and intruded by 0.6 mm. Maxillary incisors were moved to the distal by 2.7 mm with palatal tipping of 4.3 degrees. Molar extrusion and/or consequent mandibular rotation was not observed in any patient.

CONCLUSION

Miniscrews placed in the maxillary interradicular space provide successful molar distal movement of 2.8 mm without patient compliance and with no undesirable side effects such as incisor proclination, clockwise mandibular rotation, or root resorption.

Critical factors for the success of orthodontic mini-implants: a systematic review

INTRODUCTION

This systematic review was undertaken to discuss factors that affect mini-implants as direct and indirect orthodontic anchorage.

METHODS

The data were collected from electronic databases (Medline [Entrez PubMed], Embase, Web of Science, Cochrane Library, and All Evidence Based Medicine Reviews). Randomized clinical trials, prospective and retrospective clinical studies, and clinical trials concerning the properties, affective factors, and requirements of mini-implants were considered. The titles and abstracts that appeared to fulfill the initial selection criteria were collected by consensus, and the original articles were retrieved and evaluated with a methodologic checklist. A hand search of key orthodontic journals was performed to identify recent unindexed literature.

RESULTS

The search strategy resulted in 596 articles. By screening titles and abstracts, 126 articles were identified. After the exclusion criteria were applied, 16 articles remained. The analyzed results of the literature were divided into 2 topics: placement-related and loading-related factors.

CONCLUSIONS

Mini-implants are effective as anchorage, and their success depends on proper initial mechanical stability and loading quality and quantity.

Stability of Mini-Screws Invading the Dental Roots and Their Impact on the Paradental Tissues in Beagles

Objective: To examine the stability of mini-screws that invade a dental root by measuring the retention period/failure rate, and to illustrate their effects on paradental tissues.

Materials and Methods: Three adult male beagle dogs received 48 orthodontic mini-screws. Half of the mini-screws were implanted to invade the roots, and the rest were placed in the middle of the alveolar bone. Half of the mini-screws were loaded immediately. The retention period of the mini-screws was documented. The dogs were euthanized after 8 weeks, and tissue samples were examined histologically.

Results: The failure rate of the mini-screws that invaded the roots was 79.2%, and that of the mini-screws in the middle of the alveolar bone was 8.3%. The application of force had little effect on the failed mini-screws. Moderately injured roots were repaired with osteoid and/or cementoid tissues with normal periodontal ligaments, followed by recovery of the original configuration.

Conclusion: Orthodontic mini-screws had a higher failure rate when placed to invade the dental roots. However, minimally damaged dental roots do not adversely affect the healing process. (Angle Orthod. 2009:79; )

Stability of miniplates and miniscrews used for orthodontic anchorage: experience with 492 temporary anchorage devices

OBJECTIVES

The aim of this retrospective study was to evaluate systematically the potential factors that influence failure rates of temporary anchorage devices (TADs) used for orthodontic anchorage.

MATERIALS AND METHODS

Data on 492 TADs (miniplates, pre-drilling miniscrews, and self-drilling miniscrews) in 194 patients were collected. The factors related to TAD failure were evaluated using univariate analysis and multivariate forward stepwise logistic regression analysis.

RESULTS

There were no significant differences in failure rates among the TADs for the following variables: gender, type of malocclusion, facial divergency, implantation site (buccal, lingual, or crestal/midpalatal), location (anterior or posterior), method of force application (power chain or Ni-Ti coil spring), arch (upper or lower), type of soft tissue (attached gingiva or removable mucosa), and most of the cephalometric measurements that reflect dento-cranio-facial characteristics. An increased failure rate was noted for the self-drilling miniscrew type of TAD, TADs used for tooth uprighting, those inserted on bone with lower density, those associated with local inflammation of the surrounding soft tissue, those loaded within 3 weeks after insertion, and those placed in patients with greater mandibular retrusion. Failure rates of the self-drilling miniscrews installed by an oral surgeon and by an orthodontist did not differ significantly.

CONCLUSIONS

Inflammation of soft tissue surrounding a TAD and early loading within 3 weeks after insertion were the most significant factors predicting TAD failure. Both orthodontists and oral surgeons who install orthodontic TADs must undergo sufficient training to achieve clinical excellence.

Success rate and risk factors associated with mini-implants reinstalled in the maxilla

OBJECTIVE

To determine the difference in the success rate for two types of oral installed mini-implants (OMIs): one type of initially installed OMI and a new implant of the same type that is reinstalled.

MATERIALS AND METHODS

The subjects consisted of 58 patients (19 male, 39 female; mean age = 21.78 +/- 5.85 years) who had received at least one OMI (self-drilling type, conical shape with 2.0-mm upper diameter and 5-mm length) in the attached gingiva of the upper buccal posterior regions for maximum anchorage during en masse retraction. If an OMI failed, a new one was immediately installed in the same area after 4 to 6 weeks or in an adjacent area immediately. The total number of initially installed OMIs (II-OMI) was 109 and the total number of reinstalled OMIs (RI-OMI) was 34. Statistical analysis was performed using chi2 test, Kaplan-Meier method, log-rank test, and Cox proportional hazards regression model.

RESULTS

The success rate and mean duration were 75.2% and 10.0 months, respectively, for II-OMI and 66.7% and 6.4 months, respectively, for RI-OMI. Age, vertical skeletal pattern, and site and side of implantation were not related to the success rates of II-OMI and RI-OMI. Log-rank test showed that II-OMI in males and Class III malocclusions were more prone to failure. The relative risk of II-OMI failure in Class III malocclusions as opposed to Class I malocclusions was 5.36 (95% confidence interval, 2.008 to 14.31, P = .001).

CONCLUSION

The success rate of the II-OMI was not statistically different from that of the RI-OMI. Sex and ANB angle might be more important factors for better II-OMI results.

Quantitative evaluation of cortical bone thickness and root proximity at maxillary interradicular sites for orthodontic mini-implant placement

Few studies have evaluated interradicular anatomy for cortical bone thickness and root proximity when placing a mini-implant for orthodontic anchorage. The purpose of this study was to provide a clinical guideline to indicate the best location, according to different insertion angles, for placement of a mini-implant with respect to the thickness of cortical bone and root proximity. CT images from 14 men and 14 women (mean age, 27 years; range, 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness and root proximity from and mesial to the central incisor to the second molar. A measure of cortical bone thickness was performed at four different angles. Generally, thin cortical bone thickness was found in the central/central incisors and central/lateral incisors interradicular sites. Cortical bone thickness increased significantly as the insertion angle increased except for interradicular sites at the 2 mm level from the alveolar crest. The volume of cortical bone engagement increased significantly at the 4 and 6 mm levels from the alveolar crest with an insertion angle of 30 degrees and 45 degrees in most interradicular sites. The lateral incisor/canine and second premolar/first molar interradicular sites showed greater space between roots compared with other sites, although this was not statistically significant. Based on the findings of this study, we recommend that mini-implants be placed at the 4 and 6 mm levels from the alveolar crest with 30 degrees and 45 degrees angles for the majority of interradicular sites to ensure better cortical bone to mini-implant contact without root damage.

Grau de aceitação de mini-implantes por pacientes em tratamento ortodôntico: estudo preliminar

OBJETIVOS: os mini-implantes atualmente representam um grande avanço na Ortodontia, por proporcionarem máxima ancoragem com o mínimo de cooperação dos pacientes. No entanto, ainda existem algumas dúvidas quanto ao uso destes dispositivos temporários de ancoragem no que se refere, principalmente, aos aspectos psicológicos de aceitação pelos pacientes durante o tratamento ortodôntico. METODOLOGIA: dez pacientes adultos, portadores de má oclusão de Classe I, com biprotrusão, que foram submetidos a tratamento ortodôntico com a colocação de quatro mini-implantes nos arcos dentários, entre os primeiros molares e segundos pré-molares superiores e inferiores, responderam a um questionário, com o objetivo de avaliar as condições de aceitação dos mini-implantes. RESULTADOS: as respostas indicaram que a maioria dos pacientes aceitou prontamente o procedimento, estavam satisfeitos e recomendariam para outros pacientes (90%), enquanto 50% tiveram alguma preocupação com os procedimentos cirúrgicos e os outros 50% não relataram nenhum desconforto. O tempo médio de tolerância a partir da colocação foi de 3 dias e a maioria tolerou os implantes durante todo o tratamento ortodôntico. CONCLUSÕES: pôde-se concluir que os mini-implantes foram aceitos de forma positiva pela maioria dos pacientes submetidos ao tratamento ortodôntico.

Miniplacas permitem tratamento eficiente e eficaz da mordida aberta anterior

INTRODUÇÃO: o tratamento das deformidades e más oclusões que incluem mordidas abertas anteriores foi uma das primeiras aplicações de miniplacas como forma de ancoragem ortodôntica. A implementação desse sistema de tratamento reduz o número de pacientes indicados para a cirurgia ortognática e simplifica muitos problemas. Nessa abordagem, os dentes posteriores são intruídos e a mandíbula sofre um giro no sentido anti-horário, diminuindo a altura facial inferior e projetando os pogônios de tecidos duro e mole. OBJETIVO: o presente artigo apresenta os fundamentos da mecânica ortodôntica para correção da mordida aberta anterior e os ilustra com uma série de casos clínicos.

Success rate of miniscrews relative to their position to adjacent roots

The purpose of this study was to evaluate, histologically, root contact, proximity to a root, and proximity to marginal bone level as possible risk factors for the failure of mini-screws when inserted between neighbouring teeth. Twenty mini-screws were inserted into the mandible of five beagle dogs. Each dog received two bracket screw bone anchors in each lower quadrant, between the roots of the second and third, and third and fourth premolars. Every six weeks, apical radiographs were taken and vital stains were administered. Twenty-five weeks after insertion of the screws, the dogs were sacrificed and specimens prepared for histological evaluation. The distance between the screw and the roots and between the screw and the marginal ridge level (MRL) were measured on the histological slides. The presence or absence of root contact was evaluated histologically on serial sections. The number of screws was too small to allow for sound statistical analysis of the factors under investigation. During the evaluation period, 11 screws were lost. Six screws were in contact with a tooth root and five of these were lost. In five sites, the distance between the screw and the tooth was less than 1.0 mm, but only one of these screws was lost. The distance between the screw and the marginal bone level was less than 1.0 mm for nine screws and seven of these were lost. The results of this limited study suggest that root contact and marginal position might be major risk factors for screw failure.

Soft tissue thickness for placement of an orthodontic miniscrew using an ultrasonic device

OBJECTIVES

To evaluate area- and gender-related differences in the soft tissue thickness of potential areas for installing miniscrews in the buccal-attached gingiva and the palatal masticatory mucosa.

MATERIALS AND METHODS

The sample consisted of 61 Korean young adults. An ultrasonic gingival-thickness meter was used to measure the soft-tissue thickness in the buccal-attached gingiva just adjacent to the mucogingival junction of the upper and lower arches and 4 mm and 8 mm below the gingival crest in the palatal masticatory mucosa. Independent t-test, paired t-test, and one-way analysis of variance were used for statistical analysis.

RESULTS

Buccal-attached gingiva thickness in the upper arch was significantly greater in men than in women, but buccal-attached gingiva thickness in the lower arch and palatal masticatory mucosa thickness 4 and 8 mm below the gingival crest did not show gender differences. Significantly thicker soft tissue occurred in the anterior areas in the upper arch and in the posterior areas in the lower arch. In the palatal masticatory mucosa, significantly thicker soft tissue was found 4 mm below the gingival crest in the anterior areas and 8 mm below the gingival crest in the posterior areas. The areas between the canines and the premolars showed higher values than other areas 4 mm below the gingival crest. However, the soft-tissue thickness 8 mm below the gingival crest showed a progressive increase from the anterior to the posterior areas.

CONCLUSION

Measurements of the soft-tissue thickness using an ultrasonic device could help practitioners select the proper orthodontic miniscrew in daily clinical practice.

Patients' perceptions regarding microimplant as anchorage in orthodontics

OBJECTIVE

To determine patients' expectations, acceptance, and experience of pain with microimplant surgery compared to other orthodontic procedures.

MATERIALS AND METHODS

Seventy-eight microimplants were placed in 37 patients as an anchorage unit for orthodontic treatment. Patients were asked to rate anticipated pain and pain experienced with various orthodontic procedures (tooth extraction, insertion of separators, initial tooth alignment, and microimplant surgery) on a visual analog scale (VAS) over a 7-day period. One month after insertion of microimplants, patients were asked to rate their acceptance of the procedure using a structured questionnaire.

RESULTS

Unlike other orthodontic procedures, patients expected to experience a significantly higher level of pain with microimplant surgery than they experienced (P < .001). The postoperative pain experienced decreased continuously from day 1 to day 7 for all orthodontic procedures (P < .05). The total area under the curve (AUC) of pain experienced over the 7-day period was significantly larger for initial tooth alignment than for microimplant surgery (P < .05). Most patients were satisfied with the microimplant surgery (76%) and would recommend it to a friend or family member (78%).

CONCLUSIONS

Patients tended to overestimate the pain anticipated with microimplant surgery. Patients were accepting of the surgery and would recommend it to others.

Factors associated with the success rate of orthodontic miniscrews placed in the upper and lower posterior buccal region

OBJECTIVE

To determine the success rate and the factors related to the success rate of orthodontic miniscrew implants (OMI) placed at the attached gingiva of the posterior buccal region.

MATERIALS AND METHODS

Four hundred eighty OMI placed in 209 orthodontic patients were examined retroactively. The sample was divided into young patients (range 10-18 years, N = 108) and adult patients (range 19-64 years, N = 109). The placement site was divided into three interdental areas from the first premolar to the second molar in the maxilla and mandible. According to soft tissue management, the samples were divided into incision and nonincision groups. Chi-square tests and multiple logistic regression analyses were used.

RESULTS

The overall success rate was 83.8%. Dislodgement of the OMI occurred most frequently in the first 1-2 months, and more than 90% of the failures occurred within the first 4 months. Sex, age, jaw, soft tissue management, and placement side did not show any difference in the success rate. Placement site, however, showed a significant difference in the mandible of adult patients. There was no difference in the success rate in the maxilla.

CONCLUSIONS

Placement site is one of the important factors for success rate of OMI.

Skeletal Class lll Severe Openbite Treatment Using Implant Anchorage

A female patient with a skeletal Class III severe anterior openbite was treated using miniplates as the anchorage. The patient was 15 years and 10 months of age when she reported to our university hospital with a chief complaint of anterior openbite and reversed occlusion. The patient had an anterior openbite with an overjet of −3.0 mm and overbite of −5.0 mm and a Class III molar relationship. The cephalometric analysis showed a skeletal Class III relationship (ANB 0°). After the extraction of the bilateral mandibular third molars, miniplates were placed in the mandibular external oblique line. The mandibular dentition was retracted using elastic chain and miniplates. After treatment, an Angle Class I molar relationship was achieved and overjet and overbite had become 2.0 mm and 1.5 mm. A good facial appearance and occlusal relationship were obtained. The total active orthodontic treatment period was 23 months. Wrap-around type retainers were placed on both jaws and a lingual bonded retainer was also attached in the mandibular incisors. After 1 year of retention, the occlusion was stable, and a good facial profile was also retained. The mandibular deviation to the left was improved and the strain in the circumoral musculature during lip closure disappeared. An appropriate interincisal relationship was achieved by the uprighting of mandibular dentition without changing the vertical intermaxillary relationship. A panoramic radiograph showed no marked root resorption. Our results suggest that implant anchorage is useful for correction of skeletal Class III severe anterior openbite cases.

A descriptive tissue evaluation at maxillary interradicular sites: Implications for orthodontic mini-implant placement

Few studies have evaluated interradicular anatomy for hard and soft tissue thickness. Because interradicular sites are common regions for mini-implant placement for orthodontic anchorage, the purpose of this study was to provide a guideline to indicate the best location for mini-implants as it relates to the thickness of cortical bone and soft tissue, and to the height of the attached gingival field. CT images from 15 men and 15 women (mean age 27 years, range 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness from and mesial to the central incisor to the 1st molar. To record soft tissue depth at the site of assessment for cortical bone thickness, the mucosa was pierced with a #15 endodontic K-file until the attached rubber stop rested on the mucosa. The height of attached gingiva was measured at the mid-aspect of each tooth using a caliper. There were no significant differences in cortical bone thickness within interradicular sites except for the 2nd premolar/1st molar site. There were also no significant differences in soft tissue thickness within interradicular sites except for the lateral incisor/canine and 2nd premolar/1st molar sites. The height of attached gingiva was greater in the anterior compared to the posterior region and was shortest in the premolar region. Given the limits of this study, mini-implants for orthodontic anchorage may be well placed with equivalent bone-implant contact anywhere within the zone of attached gingiva up to 6 mm apical to the alveolar crest with adequate interradicular space.

Titanium screw anchorage for correction of canted occlusal plane in patients with facial asymmetry

INTRODUCTION

Facial asymmetry is a major complaint of orthodontic patients. In those with severe facial asymmetry, combination treatment of LeFort I osteotomy and mandibular surgery was commonly used. This article demonstrates the usefulness of titanium screws for orthodontic anchorage to intrude the molars in 2 patients with facial asymmetry and canted occlusal plane.

METHODS AND RESULTS

The first patient was a woman, aged 29 years 6 months, with mandibular protrusion and canted occlusal plane; she was treated with molar intrusion and intraoral vertical ramus osteotomy. During presurgical orthodontic treatment, a titanium screw was implanted in the zygomatic process, and the molars were intruded for 6 months by using an elastic chain of 200 g. After intrusion, the molars were intruded 3.0 mm, and the canted maxillary occlusal plane was improved. The second patient was a young man, aged 16 years 5 months, with mandibular deviation and canted occlusal plane; he was treated with a combination of titanium screw anchorage and intraoral vertical ramus osteotomy. A miniscrew was implanted in the alveolar bone, and the orthodontic load began immediately after placement surgery by using an elastic chain. After 5 months of intrusion, the molars had been intruded by 3.0 mm.

CONCLUSIONS

Compared with 2-jaw surgery, this method of molar intrusion is less invasive, involves less psychological stress, is less expensive, and results in less postoperative discomfort. Therefore, treatment with titanium screws for molar intrusion to correct a canted occlusal plane could become a new treatment strategy for patients with facial asymmetry.

Root proximity is a major factor for screw failure in orthodontic anchorage

INTRODUCTION

The purpose of this study was to evaluate root proximity as a risk factor for the failure of miniscrews used as orthodontic anchorage.

METHODS

We used dental radiographs and 3-dimensional computed tomography images to examine 216 titanium screws in 110 patients. Each screw was classified according to its proximity to the adjacent root. Category I, the screw was absolutely separate from the root; category II, the apex of the screw appeared to touch the lamina dura; and category III, the body of the screw was overlaid on the lamina dura. If the orthodontic force could be applied to the screw for 1 year (or until completion of orthodontic treatment), we recorded the screw anchorage as a success.

RESULTS

The screws had a high success rate--above 80%. Screws placed in the maxilla had a significantly higher success rate than those in the mandible. There was a significant correlation between success rate and root proximity. There were significant differences in the success rates between categories I and II, I and III, and II and III. Although screws in all 3 categories in the maxilla and categories I and II in the mandible showed high success rates above 75%, screws in category III in the mandible had a low success rate of 35%.

CONCLUSIONS

The proximity of a miniscrew to the root is a major risk factor for the failure of screw anchorage. This tendency is more obvious in the mandible.

Titanium screw anchorage for traction of many impacted teeth in a patient with cleidocranial dysplasia

INTRODUCTION

Cleidocranial dysplasia (CCD) is a rare inherited skeletal dysplasia, often with prolonged retention of deciduous teeth and several impacted permanent successors and supernumerary elements.

METHODS

This article demonstrates the usefulness of titanium screws for orthodontic anchorage to induce eruption of the impacted teeth in a patient with CCD. A boy, aged 10 years 11 months, had a number of impacted permanent teeth. After the supernumerary teeth were extracted and the incisors were surgically exposed, 2 titanium screws were placed in the palate without incisions or flap surgery. After implantation, a lingual arch appliance was placed, and orthodontic load began 4 weeks after surgery with an elastic chain.

RESULTS

After 4 months of traction, 3 impacted incisors had erupted into the mouth.

CONCLUSIONS

This new method for retraction of impacted teeth can reduce the patient's treatment time and psychological stress. Treatment with titanium screws for traction of impacted teeth might be a new treatment strategy for managing CCD patients.