Miniscrews for orthodontic anchorage: analysis of risk factors correlated with the progressive susceptibility to failure.

INTRODUCTION: The phenomenon of orthodontic anchorage miniscrews loosening after being implanted several times happens in daily clinical practice, and the reasons need to be traced. This study aimed to investigate the underlying risk factors influencing the progressive susceptibility of orthodontic miniscrews to failure. METHODS: Overall, 889 miniscrews were successively inserted into 347 patients because some loosened or fell off once, twice, or more before achieving their purposes. The number of miniscrew failures (ie, once, twice, or more) was defined as progressive susceptibility to failure. The clinical indicators were assessed via univariate analysis, multicollinearity diagnosis, and Poisson log-linear regression model with stepwise calculation to screen out. RESULTS: The progressive susceptibility of miniscrews to failure was proved to be affected by the age of patients, the onset of force application, site of placement, and appliance type. Age and onset of force application presented a negative relationship with susceptibility. Miniscrews inserted in the palatal region appeared to be more stable than the forepart of the arch. In contrast, the retromaxillary and retromandibular areas obtained the lowest stability. The patients with fixed appliances were more unlikely to suffer progressive failure than removable appliances. In addition, the larger number of screws inserted in each patient, the greater probability of failure. CONCLUSIONS: Younger people with removable appliances that miniscrews inserted in the retromaxillary or retromandibular regions and earlier onsets of loading had a higher progressive susceptibility to loosening. Meanwhile, the failure rate was elevated with the increasing number of screws per patient received.

Novel digital technique to analyze the accuracy and intraoperative complications of orthodontic self-tapping and self-drilling microscrews placement techniques: An in vitro study.

INTRODUCTION: The objectives of this study were to analyze and compare the accuracy and intraoperative complications of orthodontic self-tapping and orthodontic self-drilling microscrew placement techniques. METHODS: A total of 60 orthodontic microscrews were randomly distributed into 2 study groups: (1) group A, orthodontic self-drilling microscrew placement technique (n = 30); and (2) group B, orthodontic self-tapping microscrew placement technique (n = 30). Cone-beam computed tomography and intraoral scans were performed before and after the orthodontic microscrew placement techniques and uploaded in 3-dimensional implant planning software to analyze the deviation angle and the horizontal deviation measured at the coronal entry point and apical endpoint between orthodontic microscrews planned and performed, using the Student t test. In addition, intraoperative complications, such as root perforations after the orthodontic microscrews placement and the fracture of the orthodontic self-tapping microscrews during their placement, were also analyzed. RESULTS: The paired t test revealed statistically significant differences at the apical endpoint (P <0.001) between planned and performed orthodontic self-tapping and self-drilling microscrew placement techniques. However, the paired t test revealed no statistically significant differences at the coronal entry point (P = 0.1047) and angular deviations (P = 0.3251) between planned and performed orthodontic self-tapping and self-drilling microscrews placement techniques. Furthermore, 4 root perforations were observed at the orthodontic self-tapping microscrews placement technique, and 1 orthodontic self-tapping microscrew was fractured during the placement procedure. CONCLUSIONS: The results show that the orthodontic self-drilling microscrew technique increases the accuracy of orthodontic microscrews placement, resulting in fewer intraoperative complications.

Influence of impacted maxillary canine orthodontic traction complexity on root resorption of incisors: A retrospective longitudinal study.

INTRODUCTION: The orthodontic traction of impacted canines is a procedure of variable complexity. The objective of this study was to determine the influence of this complexity on the root resorption (RR) of adjacent incisors, using cone-beam computed tomography. METHODS: This longitudinal retrospective study included 45 patients (19 female, 11 male; ages, 18.16 ± 7.3 years) with maxillary impacted canines, classified into 2 groups according to the level of orthodontic traction complexity: low complexity group (n = 20) and high complexity group (n = 25). The amounts of RR of 45 maxillary central and 45 lateral incisors were evaluated before and after treatment. Complexity was defined considering impaction sector, eruption inclination angle, and canine position (palatal, buccal, or bicortical). Three orthodontists measured RR in each maxillary incisor. Independent t tests or Mann-Whitney U tests were used to compare resorption between groups depending on the normality of the data. A multiple linear regression was calculated to evaluate the influence of all variables on RR (α = 0.05). RESULTS: RR of maxillary incisors in the sagittal, coronal, and axial sections showed no significant differences between groups (P > 0.05). Independently of the groups, RR ranged approximately from 1 to 1.5 mm and from 3 to 4 mm2. RR was less than 2 mm2 in the axial sections. Multiple linear regression indicated no significant influence of orthodontic treatment complexity on RR. Male patients had more RR, specifically in the maxillary central incisors than female patients (P < 0.05). CONCLUSIONS: The complexity of orthodontic traction of impacted maxillary canines is not a risk factor for greater RR of maxillary incisors close to the impaction area.

Finite Element Analysis of Stress in Maxillary Dentition during En-masse Retraction with Implant Anchorage.

The goal of this study was to investigate how the height of the archwire hook and implant anchor affect tooth movement, stress in the teeth and alveolar bone, and the center of resistance during retraction of the entire maxillary dentition using a multibracket system. Computed tomography was used to scan a dried adult human skull with normal occlusion. Three-dimensional models of the maxillary bone, teeth, brackets, archwire, hook, and implant anchor were created and used for finite element analysis. The heights of the hook and the implant anchor were set at 0, 5, or 10 mm from the archwire. Orthodontic force of 4.9 N was systematically applied between the hook and the implant anchor and differential stress distributions and tooth movements observed for each traction condition. With horizontal traction, the archwire showed deformation in the superior direction anterior to the hook and in the inferior direction posterior to the hook. Differences in traction height and direction resulted in different degrees of deformation, with biphasic movement clearly evident both in front of and behind the hook. With horizontal traction of the hook at a height of 0 mm, all the teeth moved distally, but not with any other type of traction. At a height of 5 mm or 10 mm, deformation showed an increase. The central incisor showed extrusion under all traction conditions, with the amount showing a reduction as the height of horizontal or posterosuperior traction increased. The center of resistance was located at the root of the 6 anterior teeth and entire maxillary dentition. The present results suggest that it is necessary to consider deformation of the wire and the center of resistance during en-masse retraction with implant anchorage.

Influence of orthodontic mini-implant penetration of the maxillary sinus in the infrazygomatic crest region.

INTRODUCTION: Mini-implants are widely used for predictable tooth movements, but insertion is often restricted by anatomic structures. The aims of this study were to investigate the incidence of penetration of mini-implants into the sinus and the relationship between penetration depth and sinus tissue. METHODS: Data from 32 patients who received mini-implants in the infrazygomatic crest were collected from a data base. The success rate of mini-implants was determined by clinical retrospective analysis. The incidence of penetration, penetration depth, and sinus configuration were investigated and compared between cone-beam computed tomography scans obtained immediately after insertion and before mini-implant removal. RESULTS: The overall success rate of mini-implants in the infrazygomatic crest was 96.7%, and 78.3% penetrated into the sinus. In the group in which penetration exceeded 1 mm, the incidence of membrane thickening was 88.2%, and the mean value of thickening was 1.0 mm; however, the variable values of penetration in the 1-mm group were only 37.5% and 0.2 mm, respectively (P <0.05). CONCLUSIONS: The incidence of penetration of infrazygomatic crest mini-implants into the sinus may be high. Penetration through double cortical bone plates with limitation of the penetration depth within 1 mm is recommended for infrazygomatic crest mini-implant anchorage.

Cone-beam computed tomography evaluation of bone plate and root length after maxillary expansion using tooth-borne and tooth-tissue-borne banded expanders.

INTRODUCTION: The objective of this research was to evaluate the buccal bone plate and root length of maxillary permanent first molars using cone-beam computed tomography after maxillary expansion with different activation protocols. METHODS: Cone-beam computed tomography images of growing patients were obtained from the orthodontic department of Pontifical Catholic University of Rio Grande do Sul in Brazil. The groups were Haas-type 2/4 turns, Haas-type 4/4 turns, hyrax-type 2/4 turns, and hyrax-type with alternate rapid maxillary expansions and constrictions (alt-RAMEC) 4/4 turns a day. Tooth length, periodontal insertion, alveolar bone thickness, and intermolar distances were evaluated. The data at the start of treatment and 6 months later were compared using generalized linear models. The intergroup differences were determined by univariate analysis of variance with the Bonferroni adjustment. RESULTS: Tooth length was significantly shortened after expansion in all groups (-0.28 to -0.51 mm), except for the alt-RAMEC group. Bone level variables (bone level and bone level at the tooth tip) changed statistically in all groups, except for the Haas 4/4 turns group. There was significant periodontal attachment loss after rapid maxillary expansion with the hyrax/alt-RAMEC (5.09 mm). The hyrax/alt-RAMEC and hyrax groups had more dehiscences, fenestrations, and exposures of the root. CONCLUSIONS: The consequence of rapid maxillary expansion using the hyrax was alveolar bone resorption, especially in the hyrax/alt-RAMEC group, whereas the Haas expander caused mild root resorption.

The influence of miniscrew insertion torque.

Objective: The aim of this in vitro study was to evaluate the progressive development of surface microdamage produced following the insertion of orthodontic miniscrews (OMs) into 1.5 mm thick porcine tibia bone using maximum insertion torque values of 12 Ncm, 18 Ncm, and 24 Ncm. Methods: Aarhus OMs (diameter 1.5 mm; length 6 mm) were inserted into 1.5 mm porcine bone using a torque limiting hand screwdriver set at 12 Ncm, 18 Ncm, and 24 Ncm. A custom rig equipped with a compression load cell was used to record the compression force exerted during manual insertion. A sequential staining technique was used to identify microdamage viewed under laser confocal microscopy. Virtual slices were created and stitched together to form a compressed two-dimensional composition of the microdamage. Histomorphometric parameters, including total damage area, diffuse damage area, maximum crack length, maximum damage radius, and maximum diffuse damage radius, were measured. Kruskal-Wallis Tests and Wilcoxon Rank-Sum Tests were used to analyse the generated data. Results: All OMs inserted using 12 Ncm failed to insert completely, while partial insertion was observed for two OMs inserted at 18 Ncm. Complete insertion was achieved for all OMs inserted at 24 Ncm. Histomorphometrically, OMs inserted using 24 Ncm produced a significantly larger diffuse damage area (P < 0.05; P < 0.05) and maximum diffuse damage radius (P < 0.05; P < 0.05), for both the entry and exit surfaces, respectively, compared with the 12 Ncm and 18 Ncm groups. Conclusions: Insertion torque can influence the degree of OM insertion and, subsequently, the amount of microdamage formed following insertion into 1.5 mm thick porcine tibia bone. An increase in insertion torque corresponds with greater insertion depth and larger amounts of microdamage.

Alveolar bone changes after rapid maxillary expansion with tooth-born appliances: a systematic review.

Background: During rapid maxillary expansion (RME), heavy forces are transmitted to the maxilla by the anchored teeth causing buccal inclination and buccal bone loss of posterior teeth. Objective: To systematically review the literature in order to investigate whether RME causes periodontal sequelae, assessed by cone-beam computed tomography (CBCT). Search methods: Fifteen electronic databases and reference lists of studies were searched up to March 2017. Selection criteria: To be included in the systematic review, articles must be human studies on growing subjects, with transversal maxillary deficiency treated with RME and with assessment of buccal bone loss by CBCT images. Only randomized and non-randomized trials were included. Data collection and analysis: Two authors independently performed study selection, data extraction, and risk of bias assessment. Study characteristics (study design, sample size, age, sex, skeletal maturity, type of appliance, daily activation, evaluated linear measurements, observation period, CBCT settings), and study outcomes (loss of buccal bone thickness and marginal bone) were reported according to the PRISMA statement. Results: On the basis of the applied inclusion criteria, only six articles, three randomized clinical trials and three controlled clinical trials were included. An individual analysis of the selected articles was undertaken. The risks of bias of the six trials were scored as medium to low. Limitations: The results of the present systematic review are based on a limited number of studies and only one study included a control group. Conclusions and implications: In all considered studies, significant loss of buccal bone thickness and marginal bone level were observed in anchored teeth, following RME. Further prospective studies correlating the radiological data of bone loss to the periodontal soft tissues reaction after RME are required. A preliminary evaluation of the patient-related risk factors for RR may be advisable when considering to administering RME. Registration: This systematic review was registered in the National Institute of Health Research database with an appropriate protocol number (http://www.crd.york.ac.uk/PROSPERO Protocol: CRD42017062645). Funding: The present study has not received any contributions from private or public funding agencies.

Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

The impairment of orofacial motor function during orthodontic treatment needs to be addressed, because most orthodontic patients experience pain and motor excitability would be affected by pain. In the present study, the temporal alteration of the jaw-opening reflex excitability was investigated to determine if orthodontic treatment affects orofacial motor function. The excitability of jaw-opening reflex evoked by electrical stimulation on the gingiva and recorded bilaterally in the anterior digastric muscles was evaluated at 1 (D1), 3 (D3), and 7 days (D7) after orthodontic force application to the teeth of right side; morphological features (e.g., osteoclast genesis and tooth movement) were also evaluated. To clarify the underlying mechanism of orthodontic treatment-induced alteration of orofacial motor excitability, analgesics were administrated for 1 day. At D1 and D3, orthodontic treatment significantly decreased the threshold for inducing the jaw-opening reflex but significantly increased the threshold at D7. Other parameters of the jaw-opening reflex were also evaluated (e.g., latency, duration and area under the curve of anterior digastric muscles activity), and only the latency of the D1 group was significantly different from that of the other groups. Temporal alteration of the jaw-opening reflex excitability was significantly correlated with changes in morphological features. Aspirin (300 mg·kg-1·day-1) significantly increased the threshold for inducing the jaw-opening reflex, whereas a lower dose (75-150 mg·kg-1·day-1) of aspirin or acetaminophen (300 mg·kg-1·day-1) failed to alter the jaw-opening reflex excitability. These results suggest that an increase of the jaw-opening reflex excitability can be induced acutely by orthodontic treatment, possibly through the cyclooxygenase activation.NEW & NOTEWORTHY It is well known that motor function is affected by pain, but the effect of orthodontic treatment-related pain on the trigeminal motor excitability has not been fully understood. We found that, during orthodontic treatment, trigeminal motor excitability is acutely increased and then decreased in a week. Because alteration of trigeminal motor function can be evaluated quantitatively by jaw-opening reflex excitability, the present animal model may be useful to search for alternative approaches to attenuate orthodontic pain.

Effects of casein phosphopeptide-amorphous calcium phosphate application after interproximal stripping on enamel surface: An in-vivo study.

INTRODUCTION: The aim of this study was to investigate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application after interproximal stripping on enamel surface structures in vivo. METHODS: Fifteen patients with a mean age of 15.8 years participated in this study. For each patient, the extraction of 4 first premolars was part of the orthodontic treatment plan. The patients were randomly divided into 5 groups of 3 patients. With the exception of group 1, the mesial and distal surfaces of all first premolars were stripped with a stripping disc (Komet; Gebr Brasseler, Lemgo, Germany) under air cooling and then polished with Sof-Lex polishing discs (3M Dental Products, St Paul, Minn). In group 1, no stripping was performed, and the teeth were removed immediately. In group 2, the teeth were removed immediately after the stripping. In group 3, the stripped teeth were extracted after exposure to oral conditions for 3 months. In groups 4 and 5, CPP-ACP (Recaldent Tooth Mousse; GC Europe, Leuven, Belgium) or fluoride varnish (Bifluoride 12; Voco, Cuxhaven, Germany) was applied to the stripped surfaces for 3 months, respectively, before the teeth were extracted. Surface roughness and microhardness values were evaluated with 1-way analysis of variance and Tukey HSD tests. RESULTS: The CPP-ACP and the fluoride varnish applications increased the surface roughness and microhardness values that had been decreased by stripping. No statistically significant differences were found between groups 3, 4, and 5 for microhardness or between groups 4 and 5 for surface roughness (P > 0.5). CONCLUSIONS: The saliva and saliva plus remineralizing agents (fluoride varnish and CPP-ACP) increased the microhardness and surface roughness values of stripped enamel surfaces that had been decreased by stripping.

Digital evaluation of nasal changes induced by rapid maxillary expansion with different anchorage and appliance design.

BACKGROUND: Scientific evidence showed that rapid maxillary expansion (RME) affects naso-maxillary complex, increasing nasal width and volume. This study aimed to evaluate nasal changes induced by rapid maxillary expansion with different anchorage and appliance design by using low dose and cone beam computed tomography. METHODS: A total of 44 patients (20 males, mean age 8y 8 m ± 1y 2 m; 24 females mean age 8y 2 m ± 1y 4 m) were included in the investigation and divided into three groups according to the appliance: Hyrax-type expander anchored to permanent teeth, modified Hyrax-type expander anchored to deciduous teeth, modified Haas-type expander anchored to deciduous teeth. Maxillary expansion was performed until overcorrection and the expander was passively kept in situ for 7 months at least. All patients had three-dimensional imaging before expansion (T0) and after the retention period (T1). Nasal floor width, nasal wall width, maxillary inter-molar width were measured by means of Mimics software. The paired sample t-test was employed to assess the significance of the differences between the time points; the analysis of variance test (ANOVA) was used to compare differences between groups. RESULTS: The statistical analysis revealed significant differences between T0 and T1 for each recorded measurement in each group; no significant differences were found by comparing groups. CONCLUSIONS: Rapid maxillary expansion produces a significant skeletal transverse expansion of nasal region in growing patients. No significant differences in nasal effects are expected when the appliance is anchored onto deciduous teeth, with or without the palatal acrylic coverage.

Surgical difficulties, success, and complication rates of orthodontic miniplate anchorage systems: Experience with 382 miniplates.

PURPOSE: The aim of this study was to evaluate the complications and success rates of the miniplates using both maxilla and mandible for orthodontic anchorage in growing patients. MATERIALS AND METHODS: One hundred and fifty-five consecutive patients (range 8.7-13.8 years) with Class II and III malocclusion without congenital or acquired deformities were included in this study. A total of 382 titanium miniplates were placed by the same surgeon. All miniplates were inserted under local anesthesia. Loading of the miniplates with a force of 200 g with the help of elastics or functional devices were initiated 3 weeks after surgery. RESULTS: The overall success rate of miniplate anchorage in terms of stability was 96.8%. Twenty-one patients reported irritation of the mucosa of the cheeks or lower lip after the surgery in the mandible group. Twelve miniplates needed to be removed and were successfully replaced. CONCLUSION: Skeletal anchorage miniplates is effective for correcting malocclusions. Success depends on proper presurgical patient counseling, minimally invasive surgery, good postsurgical instructions, and orthodontic follow-up.

Natural reversal of tooth discoloration and pulpal response to testing following removal of a miniscrew implant for orthodontic anchorage: a case report.

AIM: To highlight the reversal of signs suggesting pulpal necrosis following removal of a mini-implant without endodontic intervention. SUMMARY: A 23-year-old woman presented with a class III malocclusion, with crowded and malformed teeth and excessive gingival display. During orthodontic treatment, a Tomas orthodontic miniscrew was placed between the root apices of the maxillary central incisors. This was carried out by an orthodontic specialist who had treated more than 700 patients (with more than 2000 mini-implants) over the past 9 years. After 2 weeks of treatment, the right maxillary central incisor discoloured and did not respond to electrical pulp tests (EPT) but was sensitive to endo-ice. The miniscrew was removed under local anaesthesia. Teeth 11 and 21 were fixed with ligation wire, and glass-ionomer cement (GIC) was added to the occlusal surfaces of the first and second maxillary molars to heighten the occlusion and disclude the maxillary anterior teeth. After 4 months, the colour and pulp reactions to EPT and endo-ice of tooth 11 returned to normal. Because the use of a miniscrew had appeared to damage the pulp, subsequent a conservative orthodontic treatment using, traditional 'J' hooks was used and achieved satisfactory results. After 23 months of orthodontic treatment, the treatment was complete and a 15-month follow-up showed a successful outcome.

Preliminary study of genotoxicity evaluation of orthodontic miniscrews on mucosa oral cells by the alkaline comet assay.

Miniscrew implants are widely used nowadays in orthodontic treatments due to their good results in clinical practice. However, data regarding the biocompatibility of commercially available orthodontic miniscrews and temporary devices are very scarce, and their role as genotoxicity inducers has been not previously evaluated with the alkaline comet assay. The aim of this study was to investigate the DNA damage in buccal cells of patients subjected to orthodontic treatments. The alkaline comet assay has been applied in oral mucosa cells from patients treated with conventional orthodontic treatment in comparison to patients treated additionally with miniscrews, non-treated volunteers (control) and smoking volunteers (positive control). The application of orthodontic appliances and miniscrews induced significant and similar (2-fold) increases of %DNA in tail in comparison to control group. Females experienced a significant increase in %DNA in all the treatments in comparison to the control group, whereas males showed significant damage only with the combined orthodontic and miniscrew treatment. In conclusion, conventional orthodontic appliances induced genotoxicity, and the incorporation of miniscrews assayed did not imply any additional increase of DNA damage.

Case report: transpalatal arch resulting in soft tissue damage of the tongue 3 years post-orthodontic treatment.

Whilst transient effects of orthodontic appliances on the oral mucosa are well recognized, chronic lesions, persisting post therapy are unusual. We describe a persistent lingual mucosal defect related to a transpalatal arch (TPA) in a healthy 19-year-old female. The asymptomatic lesion is presently being monitored, however, surgical revision in the future may be requested by the patient if the area fails to remodel. Clinical Relevance: Soft tissue trauma to the tongue by anchorage reinforcing appliances may result in long-term effects that could require surgical management.

Complications and adverse patient reactions associated with the surgical insertion and removal of palatal implants: a retrospective study.

OBJECTIVES: The purpose of this study was to assess the frequency and variety of surgical complications and adverse patient reactions associated with the implantation and explantation of palatal implants. MATERIALS AND METHODS: The implantations and explantations of palatal implants in 146 patients who had undergone orthodontic treatment using a palatal implant for anchorage in the time period 1999-2010 were evaluated retrospectively. All complications and adverse patient reactions associated with the surgical intervention of implantation and explantation of the implant were assessed. RESULTS: Of the 146 palatal implants reviewed, 104 implantations and 44 explantations met the inclusion criteria and their data could be extracted. Of the 104 implantations, 25 (24.0%) surgical complications and adverse patient reactions could be documented. They consisted of lack of primary stability: 7 (6.7%), prolonged pain: 7 (6.7%), secondary bleeding: 6 (5.8%), perforation of nasal floor: 2 (1.9%), necrotic mucosa anterior of the implant: 2 (1.9%) and sensory impairment of the anterior palate: 1 (1%). The respective incidents for the 44 explantations were: disturbed wound healing: 3 (6.8%), perforation of nasal floor: 1 (2.3%), secondary bleeding: 1 (2.3%) and fracture of the implant: 1 (2.3%). CONCLUSIONS: A wide spectrum of surgical complications and adverse patient reactions after palatal implant insertion and removal was found. All complications were of minor severity and duration except after one implantation, where a prolonged hypoesthesia of the anterior palate was found. Although only a small risk of a permanent sensory impairment of the anterior palatal region remains, patients must be well informed accordingly.

Implants for orthodontic anchorage: success rates and reasons of failures.

INTRODUCTION: The aims of this study were to analyze the success rate of mini-implants and miniscrews and to report the reasons behind them. MATERIALS AND METHODS: An electronic literature search from PubMed databases and a hand search in implant- and orthodontic-related journals were performed until December 31, 2011. Human clinical studies in English that reported temporary anchorage devices used for orthodontic purpose with at least 6 months follow-up were included. In addition, the minimal number of implants had to be at least 10. Implants placed in maxilla, mandible, and hard palate were included. RESULTS: The initial search resulted in 847 articles, of which 46 were further evaluated. Finally, 29 studies were qualified and classified into 2 groups: implants placed in maxilla and mandible (group 1) and implants placed in hard palate (group 2). A meta-analysis performed for groups 1 and 2 showed 87.8% and 93.8% survival rate, respectively. In addition, the most common cause for implants failure was surgery-related factors. CONCLUSION: Mini-implant survival rate is location dependent, with those placed in the palate showing higher success rates. In addition, failures most commonly occur because of surgery-related factors.

Anterior open bite correction via molar intrusion: Diagnosis, advantages, and complications.

Anterior open bite can be effectively treated nonsurgically via molar intrusion. This technique, involving the intrusion of posterior teeth using temporary skeletal anchorage devices, prompts counterclockwise rotation of the mandible. This rotation not only corrects anterior open bite but also contributes to a decrease in anterior facial height, improvements in lip incompetency, and forward movement of the chin. For successful outcomes, temporary skeletal anchorage devices, installed on both the buccal and palatal sides, must deliver equivalent intrusion force to the maxillary teeth. Treatment planning should consider factors such as skeletal discrepancies, vertical excess, incisor exposure, and configuration of the occlusal plane. Clinicians are advised to closely monitor periodontal changes and consider overcorrection to ensure lasting stability and maintenance of incisal overlap post-treatment.

Clinical information in using mini-screws in orthodontics.

Mini-screws in orthodontics has become the most commonly used skeletal temporary anchorage device. The basic clinical information regarding its indications, contra-indications, implant sites, angulations, placement, maintenance and complications is presented to enlighten orthodontic practitioners planning to start using them.

Periodontal status following orthodontic mini-screw insertion: A prospective clinical split-mouth study.

BACKGROUND: Anchorage control is one of the most important determinants of orthodontic treatments. Mini-screws are used to achieve the desired anchorage. Despite all their advantages, there is a possibility that treatment will not be successful due to conditions related to their interaction with the periodontal tissue. OBJECTIVE: To evaluate the status of the periodontal tissue at the sites adjacent to the orthodontic mini-implants. METHODS: A total of 34 teeth (17 case and 17 control) in 17 orthodontic patients requiring a mini-screw in the buccal area to proceed with their treatment were included in the study. Oral health instruction was provided to the patients prior to the intervention. In addition, scaling and root planing of the root surface were done using manual instruments and ultrasonic instruments if needed. For tooth anchorage, a mini-screw with Elastic Chain or Coil Spring was used. The following periodontal indices were examined in the mini-screw receiving tooth and the contralateral tooth: plaque index, pocket probing depth, attached gingiva level (AG), and gingival index. Measurements were made before the placement of the mini-screws and 1, 2, and 3 months following that. RESULTS: The results revealed a significant difference only in the amount of AG between the tooth with mini-screw and the control tooth (p = 0.028); for other periodontal indices, there were no significant differences between the two groups. CONCLUSION: This study showed that periodontal indices in adjacent teeth of the mini-screws do not change significantly compared to other teeth and mini-screws can be used as a suitable anchorage without posing a threat to the periodontal health. Using mini-screws is a safe intervention for orthodontic treatments.