Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ORTHODONTICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,333 records · Page 74Linked to original sources
PubMed2004

Hypersensitivity to metals in orthodontics.

To study the incidence of hypersensitivity to orthodontic metals, patch tests were carried out before and 2 months after the placement of orthodontic appliances in 38 patients (17 male, 21 female). The tested substances were cobalt chloride, copper sulfate, potassium dichromate, iron sulfate, manganese chloride, molybdenum salt, nickel sulfate, and titanium oxide. Eight strips containing the test substances were positioned on the patients' backs. They were removed after 48 hours and assessed by a dermatologist at 48 and 72 hours after antigen application. The obtained data were analyzed by the chi-square test and McNemar's chi-square test. Statistically significant positive reactions were observed for nickel sulfate (21.1%), potassium dichromate (21.1%), and manganese chloride (7.9%); reactions to nickel sulfate had the greatest intensity. No differences were observed between the reactions before and after placement of the orthodontic appliances; this indicates that they did not sensitize the patients or affect their tolerance to these metals during the study period. No statistical difference was observed regarding sex for any evaluated substance, although a greater tendency to positivity to nickel sulfate was observed among female patients and to potassium dichromate in male patients.

Adolescent↗
PubMed2004

Orthodontic therapy in a patient with white sponge nevus.

An undesirable effect of fixed orthodontic appliances is irritation of the oral mucosa. Lesions are common, but they usually heal quickly because of the fast metabolism of oral mucosa cells. Alterations accompanying some injuries are temporary, but some are irreversible because of attrition. White sponge nevus constitutes a special situation, and little information about it is available in the orthodontic literature. This report presents a patient with white sponge nevus who received orthodontic treatment over a 40-month period. The condition was also noted in a sibling. Because of the similarity between white sponge nevus and other diseases, including some that are malignant, a thorough clinical history and differential diagnosis are essential.

Adolescent↗
PubMed2004

In vitro neuronal cytotoxicity of latex and nonlatex orthodontic elastics.

Although the toxicity of many dental materials has been thoroughly investigated, the toxicity of orthodontic elastic materials has not been extensively tested. We evaluated the neurotoxicity of 3 latex and 3 nonlatex orthodontic elastics in murine cerebral cortical cell cultures. Standard-sized pieces of each material from 3 manufacturers (American, Masel, and GAC) were placed on culture well inserts, allowing the material to be exposed to the culture bathing media without causing physical disruption of the cells. Cell death was quantified by assaying the release of the cytosolic enzyme lactate dehydrogenase. Exposure of cortical cultures to the nonlatex elastics did not cause significant neuronal death, but exposure to each of the latex elastics resulted in significant neuronal death. The neuronal death induced by each of the latex elastics was blocked by adding the metal chelator, EDTA (calcium disodium ethylenediaminetetraacetate). Because many latexes use zinc-containing compounds in the prevulcanization process, and the death induced had characteristics similar to zinc-induced neuronal death, it seems likely that the toxicity of latex elastics was mediated by zinc release. Because ingestion of zinc is not a health risk, the results suggest that, in spite of the finding that latex elastics have higher in vitro cytotoxicity than nonlatex elastics, the use of latex elastics in orthodontics is acceptable.

Analysis of Variance↗
PubMed2005

Duration of orthodontic treatment and mandibular lengthening by means of distraction or bilateral sagittal split osteotomy in patients with Angle Class II malocclusions.

BACKGROUND: The purpose of this study was to investigate the duration of treatment of patients with skeletal Angle Class II malocclusions treated with orthodontic appliances and surgical lengthening of the mandible to close residual overjets. METHODS: In this retrospective study, the patients were divided into 3 groups. Group A consisted of 10 patients (5 boys, 5 girls; mean age, 10.11 years; range, 9.1-13.9 years at the beginning of treatment) who were treated with a headgear-activator, fixed appliances, and intraoral osteodistraction of the mandible. Group B consisted of 19 patients (10 boys, 9 girls; mean age, 12.3 years; range, 9.6-16.1 years) treated with fixed appliances and intraoral distraction. In group C, 13 patients (4 men, 9 women; mean age, 27.3 years; range, 12.11-40.7 years) were treated with fixed appliances and bilateral sagittal split osteotomy (BSSO). RESULTS: In patients treated with orthodontic appliances and surgical lengthening of the mandible, treatment time was influenced by the appliances and the surgical technique used. Patients treated with a headgear-activator, fixed appliances, and intraoral distraction osteogenesis (group A) needed significantly more treatment time than patients treated with fixed orthodontic appliances and intraoral distraction (group B) or fixed appliances and BSSO (group C). Duration of treatment with intraoral mandibular distraction (group B) was significantly (P < .05) shorter compared with mandibular lengthening with BSSO (group C). However, no definitive conclusions can be drawn, because of the retrospective study design. CONCLUSIONS: The best time and the best surgical procedure for correcting mandibular length have yet to be determined, and a prospective randomized trial is recommended.

Adolescent↗
PubMed2005

Apical root resorption 6 months after initiation of fixed orthodontic appliance therapy.

INTRODUCTION: Individual predisposition might be a major reason for the observed variation in apical orthodontic root resorption. If so, resorption might be expressed during the initial stages of orthodontic therapy in patients at risk. METHODS: To explore this hypothesis, we evaluated standardized, digitized periapical radiographs made before treatment (T1) and at a mean period of 6.4 months (SD 0.9) after placement of maxillary incisor brackets (T2) in 290 patients (age range, 10.1 to 57.1 years at T1). Anamnestic and treatment parameters were recorded according to a protocol, and maxillary incisor irregularity was measured on T1 study models. RESULTS: The mean average root resorption for 4 incisors was 0.53 mm (SD 0.47), whereas the sample mean of the most severely resorbed tooth per patient was 1.18 mm (SD 0.86). A total of 4.1% of the patients had an average resorption of 1.5 mm or more, and 15.5% had at least 1 tooth with 2.0 mm or more resorption. The maximum amount of resorption was 4.4 mm. Multivariate linear regression showed that deviated root form and increased T1-to-T2 time period were risk factors for apical root resorption of the central incisors; normal root form and wide roots were preventive factors, with an explained variance of 14%. Similarly, long roots, narrow roots, and increased T1-to-T2 time period were risk factors for resorption of the lateral incisors, whereas normal root form was a preventive factor, with an explained variance of 24%. Parameters associated with use of rectangular wire, presence of incisor irregularity, and history of trauma were not identified as risk factors. Use of elastics was not included in the regression analyses. CONCLUSIONS: Root resorption can begin in the early leveling stages of orthodontic treatment. About 4.1% of patients studied had an average resorption of 1.5 mm or more of the 4 maxillary incisors, and about 15.5% had 1 or more maxillary incisors with resorption of 2.0 mm or more from 3 to 9 months after initiation of fixed appliance therapy. Although teeth with long, narrow, and deviated roots are at increased risk of resorption during this early stage, the explained variance of these risk factors is less than 25%.

Adolescent↗
PubMed2005

Histomorphometric and mechanical analyses of the drill-free screw as orthodontic anchorage.

INTRODUCTION: Drill-free screws were developed to provide convenient orthodontic anchorage. The purpose of this study was to evaluate the effects of the drilling procedure on the stability of the screws under early orthodontic loading. METHODS: Thirty-two screws were inserted into the jaws of 2 beagles. The screws were divided into 2 groups of 16: the drilling group and the drill-free group. Screws in the drilling group were inserted into the site that had been drilled with a pilot drilling bur, and those in the drill-free group were inserted without drilling. A force of 200 to 300 g was applied using nickel-titanium coil springs 1 week after insertion. Twelve weeks after insertion, mobility was tested with Periotest (Siemens AG, Bensheim, Germany), and the screws with the surrounding bone were prepared for histomorphometric evaluation. RESULTS: Screws in the drill-free group showed less mobility and more bone-to-metal contact; they had more bone area compared with the drilling group, although bone osseointegration was generally found in both groups. CONCLUSIONS: With careful technique, drill-free screws can provide stable orthodontic anchorage.

Animals↗
PubMed2005

Long-term posttreatment changes measured by the American Board of Orthodontics objective grading system.

BACKGROUND: The American Board of Orthodontics (ABO) developed the objective grading system (OGS) to evaluate cases submitted as part of the phase III examination for board certification. This study examines the long-term changes in 6 of the 8 criteria measured by the board, with an emphasis on the relationship between posttreatment results and subsequent improvement or worsening. MATERIAL: One hundred subjects were randomly chosen from the postretention archives of the Department of Orthodontics at the University of Washington. Pretreatment peer assessment rating (PAR) scores and posttreatment and postretention OGS scores were measured on study casts. The ABO criteria studied were alignment, marginal ridges, buccolingual inclinations, occlusal contacts, occlusal relationships, and overjet. Interproximal contacts and root angulations were not scored. RESULTS: The mean overall OGS score at posttreatment was 21.5 points. At postretention, this score had improved significantly, by approximately 4 points. When comparing posttreatment scores and long-term changes, similar patterns were seen for all criteria, except alignment; increased posttreatment scores were associated with increased long-term improvement. Well-treated cases tended to deteriorate, and poorly finished cases tended to improve, illustrating a regression to the mean. Alignment was the only criterion associated with a mean long-term worsening, as well as a less predictable pattern of change. CONCLUSIONS: The results of this study indicate that settling occurs after orthodontic treatment, and that the attainment of perfect occlusal results does not ensure stability.

Adolescent↗
PubMed2005

The influence of a structured telephone call on orthodontic pain and anxiety.

INTRODUCTION: This purpose of this study was to examine the effects of a structured telephone call after orthodontic appliance placement on self-reported pain and anxiety. METHODS: One hundred-fifty orthodontic patients were randomly assigned to 1 of 3 groups and matched for age, sex, and ethnicity. The subjects completed baseline questionnaires to assess their levels of pain (on a 100-mm visual analog scale) and anxiety (Spielberger's State-Trait Anxiety Inventory) before orthodontic treatment. After the initial archwires were placed, all subjects completed the pain questionnaire and state-anxiety inventory at the same time daily for 1 week. One group also received a structured telephone call demonstrating care and reassurance; the second group received an attention-only telephone call, thanking them for participating in the study; the third group served as a control. RESULTS: Although both telephone groups reported significantly less pain (P = .005) and state-anxiety (P = .033) than the control group, there was no difference between the 2 telephone groups (P > .12 for pain; P > .81 for state-anxiety). CONCLUSIONS: A telephone call from a health-care provider reduced patients' self-reported pain and anxiety; the content of the telephone call was not important.

Adaptation, Psychological↗
PubMed2006

Effect of debonding force direction on orthodontic shear bond strength.

INTRODUCTION: The aim of this study was to determine the influence of debonding force direction in shear bond strength testing of orthodontic brackets in vitro. METHODS: One hundred fifty extracted bovine permanent mandibular incisors were randomly divided into 5 groups of 30 specimens each. Before bonding with a composite adhesive, enamel surfaces were etched with 37% phosphoric acid for 30 seconds. Teeth were bonded with mesh-based stainless steel orthodontic brackets. Shear bond strength was measured with a universal testing machine. Debonding forces were directed either parallel to the bracket base (group B), toward the enamel surface (group A: 15 degrees), or away from the enamel surface (group C: 15 degrees; group D: 30 degrees; group E: 45 degrees). RESULTS: Shear bond strength measurements were as follows: 22.90 (SD, 1.72) MPa (group A), 17.90 (SD, 2.63) MPa (group B), 12.99 (SD, 1.71) MPa (group C), 7.93 (SD, 1.14) MPa (group D), and 6.65 (SD, 1.14) MPa (group E). Analysis of variance indicated that shear bond strengths were significantly different between the groups investigated. Mean adhesive remnant index scores ranged between 1.60 in group B and 2.13 in group D. CONCLUSIONS: Shear bond strength measurements were significantly influenced by the direction of the debonding force, indicating the need for control and standardization of this testing parameter in orthodontic shear bond strength testing.

Adhesives↗
PubMed2005

Evaluation of the accuracy of digital model analysis for the American Board of Orthodontics objective grading system for dental casts.

INTRODUCTION: In 1999, after 3 years of field testing, the American Board of Orthodontics (ABO) implemented a grading system for posttreatment orthodontic models and panoramic radiographs, to make the phase III examination both fair and objective. In the ABO's objective grading system, 7 occlusal criteria (tooth alignment, vertical positioning of marginal ridges, buccolingual inclination of posterior teeth, occlusal relationship, occlusal contacts, overjet, and interproximal contacts) are measured on plaster models to assess a patient's final occlusion. To date, no study has evaluated the ABO grading system for use on digital models. The purpose of this study was to determine whether digital models can be used with reasonable accuracy and reliability for assessing patients' final occlusions. METHODS: Plaster and digital (OrthoCAD, Cadent Inc, Carlstadt, NJ) posttreatment models of 24 patients were gathered from the postgraduate orthodontic clinic at Columbia University School of Dental and Oral Surgery. The plaster models were scored by using the ABO measuring gauge and the 7 criteria of the ABO grading system. A second analysis was done on the digital models. To determine interexaminer error, a fourth-year dental student at Columbia University served as a second examiner and repeated all the analyses. RESULTS: The means of the total score and those for marginal ridges, occlusal contacts, occlusal relationships, overjet, and interproximal contacts were not significantly different between plaster and digital models. However, the means for alignment and buccolingual inclination were significantly different. In addition, the scorings of 2 examiners differed for the 2 methods. CONCLUSIONS: This finding suggests that alignment and buccolingual inclination should be reevaluated with both methods, and adequate calibration of the examiners is essential to achieve repeatability in both methods. Digital models might be acceptable for use in the ABO model examination.

Analysis of Variance↗
PubMed2006

Shear/peel bond strength of orthodontic attachments to moist and dry enamel.

INTRODUCTION: The purpose of this study was to evaluate the in-vitro shear-peel bond strength of orthodontic attachments bonded to moist and dry enamel surfaces with orthodontic resin. METHODS: Two stainless-steel mesh-based buttons were bonded to pumiced and etched enamel of each of 60 human molars mounted in cylindrical molds with Transbond XT (3M/Unitek, St Paul, Minn) (control), Smartbond (Gestenco International, Goteborg, Sweden), or Assure (Reliance Orthodontic Products, Itasca, Ill) according to each manufacturer's instructions. Half of the teeth were bonded under dry conditions, and half were given a thick layer of whole, unstimulated, fresh human saliva just before bonding. The teeth were stored in distilled deionized water at 37 degrees C. The shear-peel bond strength of 1 button on each tooth was evaluated in a testing device (Zwick, Ulm, Germany) at 24 hours; the remaining button on each tooth was evaluated at 6 months. RESULTS: Statistically significant differences (P < .05) were evident in button adhesion to the tooth surface between moisture variations for Transbond XT, but not for Assure and Smartbond. Superior bond strengths were obtained for Transbond XT on dry enamel; the bond strength of Assure to saliva-contaminated enamel was better than that of the other materials. CONCLUSIONS: Bonding to moist and dry enamel appears to be material-specific. Adequate in-vitro bonding to moist, saliva-contaminated enamel is possible with certain bonding materials.

Compomers↗
PubMed2006

Orthodontic journals with impact factors in perspective: trends in the types of articles and authorship characteristics.

INTRODUCTION: The purposes of this study were to analyze the types of articles and their authorship characteristics in the 3 orthodontic journals with impact factors--American Journal of Orthodontics and Dentofacial Orthopedics (AJODO), Angle Orthodontist (AO), and European Journal of Orthodontics (EJO)--during 2 intervals of 5 years each (1993-1997 and 1998-2002) and to assess the changes in their contents during these periods. METHODS: The results of 3004 article entries were analyzed with the Pearson chi-square test, and the examination of the variability of the parameters studied among journals and across the 2 time intervals was performed at the 0.05 level of significance. RESULTS AND CONCLUSIONS: Significant differences were found between the journals with respect to the research component of articles (higher in the EJO) and case reports (higher in the AJODO and the AO). For each journal, differences were also identified between the 2 time intervals, with multi-authored papers and multiple affiliations appearing more frequently in the second interval. The contributions of articles from the United States and Canada to the AJODO and the AO were statistically higher than to the EJO. A similar trend was found for articles from Europe, which comprise more than 70% of the content of the EJO. An increased contribution of articles from East Asia and Oceania was noted in the second time interval, which reached almost 100% of the previous time frame. The potential sources of variation in the studied parameters are discussed.

Authorship↗
PubMed2006

Factors influencing treatment time in orthodontic patients.

INTRODUCTION: The purpose of this retrospective study was to identify (and quantify the effect of) factors that influence orthodontic treatment time. METHOD: The sample consisted of 366 consecutive orthodontic patients (220 female, 146 male, aged 10-20 years, treated by 1 orthodontist) who completed treatment in a single stage with fixed appliances. Four categories of data (sociodemographic characteristics, malocclusion characteristics, treatment methods, and patient cooperation) were collected from treatment records and analyzed. RESULTS: Average treatment time was 23.5 months (range, 12-37; SD, 4.7). A multiple regression model explained 38% of the variance and identified 9 significant variables. Five were pretreatment characteristics: male sex, maxillary crowding of 3 mm or more, Class II molar relationships, proposed treatment plan involving extractions, and delayed extractions. The remaining variables (3 of which were associated with patient cooperation) were poor oral hygiene, poor elastic wear, bracket breakages, and brackets rebonded for repositioning. CONCLUSIONS: Orthodontic treatment time is influenced by a number of patient characteristics and clinical decisions. It is possible to predict estimated treatment time for a patient by using a small number of personal characteristics and treatment decisions.

Adolescent↗
PubMed2006

Comparison of extraction versus nonextraction orthodontic treatment outcomes for borderline Chinese patients.

INTRODUCTION: The purpose of this study was to compare orthodontic treatment outcomes in Chinese patients with borderline problems treated with and without extractions. METHODS: Records of 39 borderline patients treated at the Faculty Clinic of the Peking University Orthodontic Department were evaluated retrospectively by 5 associate professors. Sixteen patients had been treated without extractions, and 23 had 4 first or second premolars extracted. Each judge evaluated the posttreatment records independently for tooth alignment, overbite, overjet, midline symmetry, lateral occlusion, and facial profile, and rated them on a scale from 1 to 5. RESULTS: The only statistically significant difference between the extraction and nonextraction groups was for facial profile, with the judges preferring the extraction profiles. Fifteen soft-tissue cephalometric variables were measured to determine the source of the difference, and 6 showed statistically significant differences. When profile changes from pretreatment to posttreatment were examined, significant differences in treatment-associated changes between extraction and nonextraction groups were all related to the lower lip and chin. CONCLUSIONS: In this sample of Chinese borderline orthodontic patients, Chinese clinicians had a statistically significant preference for the facial profiles of the extraction patients, but no statistically significant preferences for tooth alignment, overbite, overjet, midline symmetry, or posterior occlusion. Extraction treatment increases the inclination of the chin and reduces protrusion of the lower lip compared with nonextraction treatment, and this might explain the difference.

Asian People↗
PubMed2007

Orthodontic treatment experience and prevalence of malocclusion traits in an Icelandic adult population.

INTRODUCTION: The objectives of this study were to record the extent of orthodontic treatment and the prevalence of occlusal anomalies in an adult sample in Iceland. METHODS: The study was based on a random sample of 829 subjects, 342 men and 487 women, aged 31 to 44 years, who completed questionnaires about their orthodontic treatment experiences and were available for clinical examination. RESULTS: Complete dentitions in both jaws were present in 52.8% of the women and 45.3% of the men at the examinations. Significantly higher percentages of the women had received orthodontic treatment of some kind (24.3% compared with 16.9% for the men) and treatment with fixed appliances (16.0% compared with 9.5% for the men). Malocclusion traits were recorded with a standardized method, describing sagittal and vertical incisor relationships, sagittal and transverse molar relationships, and mandibular and maxillary space conditions. The results showed that 45.5% of the subjects had no malocclusions, 33.9% had 1 malocclusion trait, and 20.5% had 2 to 4 traits. The most frequent malocclusion traits were distal molar occlusion (27.7%), mandibular anterior crowding (13.4%), molar crossbite (11.9%), excessive overbite (11.8%), maxillary anterior crowding (7.1%), mesial molar occlusion (6.9%), and excessive overjet (5.3%). The prevalences of mandibular overjet, mesial occlusion, and scissors-bite were significantly higher in the men than in the women. CONCLUSIONS: The prevalences of malocclusion traits were similar in treated and untreated subjects, except for a significantly lower prevalence of overjet and a higher prevalence of molar crossbite in the treated group. Comparison with other studies showed low prevalences of overjet, overbite, open bite, and maxillary and mandibular spacing and crowding; other variables fell within the ranges of prevalence in previous surveys.

Adult↗
PubMed2004

Expression of tropoelastin in human periodontal ligament fibroblasts after simulation of orthodontic force.

The ability of elastic fibers to respond to mechanical stimuli suggests that they play a central role in physiological adaptation to external stimuli including application of orthodontic force. The purpose of this study was to examine the effect of external pressure simulating orthodontic force on tropoelastin gene expression in cultured human periodontal ligament fibroblasts (hPDLF). External pressure simulation was achieved by centrifugation for 10, 30, 60, 90 and 120 min of hPDLF in a horizontal microplate rotor. Semi-quantitative RT-PCR analysis of tropoelastin mRNA was performed and beta-actin was used as an internal invariant control. While centrifugal force on mRNA levels of beta-actin showed almost no change, the mRNA levels of tropoelastin increased significantly to a peak level of more than four-fold after 30 min. Thereafter, at 60 min, the mRNA levels remained at more than three-fold. After 90 min, mRNA levels decreased to control levels. The finding that no changes in mRNA levels of beta-actin occurred during the first 90 min of centrifugation validates its use as an invariant control gene in such an experimental model. This study demonstrated that tropoelastin is expressed in hPDLF and that the pressure caused significant time-dependent upregulation of the tropoelastin gene. The responsiveness of the tropoelastin gene to force shows its possible clinical importance in orthodontic tooth movement. Further studies, however, are essential in order to learn whether the high expression of the gene in vitro will also be followed by corresponding protein synthesis and deposition in vivo in the extracellular matrix (ECM) of the periodontal ligament (PDL).

Actins↗
PubMed2006

RANKL expression in rat periodontal ligament subjected to a continuous orthodontic force.

OBJECTIVES: This study investigated longitudinal changes in receptor activator NF kappa B ligand (RANKL) expression in periodontal ligament (PDL) cells subjected to a continuous orthodontic force. DESIGN: Fifty-five-day-old male Wistar rats were divided into experimental and control groups. The experimental group had the first molars laterally expanded by a continuous orthodontic force. In each group, the horizontal section specimens were embedded in OTC compound and frozen at 0, 1, 3 and 7 days after the expansion. Sections were observed by immunostaining with anti-RANKL and the tartrate-resistant acid phosphatase (TRAP) staining. RESULT: Immunoreaction of RANKL and TRAP-positive cells were observed in the distal region of the controls and on the compressed side of the expansion group in the 3 and 7 days. Immunoreaction of RANKL was also observed after 1 day on the compression side of the expansion group, but here TRAP-positive cells were few. CONCLUSIONS: The experiments have showed that PDL cells are continuously producing RANKL on the PDL pressure side of rats subjected to mechanical stress with a continuous orthodontic force, there was no noticeable the excessive appearance of osteoclasts however. Considering this, it is expected that not only RANKL production but also other cytokines play an important role in the balancing adjustment in the alveolar bone remodeling.

Acid Phosphatase↗
PubMed2006

CMT-3 inhibits orthodontic tooth displacement in the rat.

OBJECTIVE: Orthodontic tooth movement requires extensive remodeling of the periodontal ligament (PDL) and the alveolar bone. Osteoclasts resorb bone, allowing teeth to migrate in the direction of the force. Matrix metalloproteinases (MMPs) are able to degrade the extracellular matrix of the periodontal tissues. Chemically modified tetracyclines (CMTs) can inhibit MMPs, but lack antimicrobial activity. We hypothesize that CMT-3 will decrease the rate of orthodontic tooth movement in the rat. DESIGN: Eighteen Wistar rats received a standardized orthodontic appliance at one side of the maxilla. During 14 days, three groups of six rats received a daily dose of 0, 6 or 30mg/kg CMT-3, and tooth displacement was measured. Thereafter, osteoclasts were counted on histological sections using an ED-1 staining. Multi- and mononuclear ED-1-positive cells in the PDL were also counted. In addition, sections were stained for MMP-9. RESULTS: CMT-3 significantly inhibited tooth movement (p=0.03) and also decreased the number of osteoclasts at the compression sides in the 30mg/kg group (p<0.05). Significantly more mono- than multinuclear ED-1-positive cells were present in the PDL, but no significant differences were found between the dosage groups. Osteoclasts in the 30mg/kg group seemed to contain less MMP-9 than in the control. CONCLUSIONS: CMT-3 inhibits tooth movement in the rat, probably by reducing the number of osteoclasts at the compression side. This might be due to induction of apoptosis in activated osteoclasts or reduced osteoclast migration. Reduced MMP activity by CMT-3 might also directly inhibit degradation of the organic bone matrix.

Alveolar Process↗