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Short-term skeletal and dental changes following bone-borne versus tooth-borne surgically assisted rapid maxillary expansion: a randomized clinical trial study. Zandi Mohammad,Miresmaeili Amirfarhang,Heidari Ali Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery AIM:To evaluate and compare the short-term (post-retention) skeletal and dental changes following bone-borne and tooth-borne surgically assisted rapid maxillary expansion (SARME) using cone beam computed tomography (CBCT). SUBJECTS AND METHODS:In this randomized clinical study, 30 patients with transverse maxillary deficiency underwent either tooth-borne (n = 15) or bone-borne (n = 15) SARME. Before treatment and immediately after the consolidation period, CBCT was obtained and the nasal floor width, interdental root distance, palatal bone width and interdental cusp distance were measured at first premolar and first molar regions of maxilla. RESULTS:Twenty eight patients completed the study protocol. In both tooth-borne (n = 13) and bone-borne (n = 15) groups the highest degree of expansion occurred in the dental arch, followed by palatal bone, and nasal floor (V-shaped widening in coronal dimension). The amount and pattern of expansion was comparable between anterior and posterior maxillary regions in each group (parallel posteroanterior expansion) and between the two groups. CONCLUSION:Dental and skeletal effects of tooth-borne and bone-borne devices were comparable. The overall complication rate was negligible. Selection of an expansion device should be based on each individual patient's requirements. Future long-term clinical trial studies to evaluate the stability and relapse of these two techniques are recommended. 10.1016/j.jcms.2014.02.007
The mouse palate and its cellular responses to midpalatal suture expansion forces. Katebi N,Kolpakova-Hart E,Lin C Y,Olsen B R Orthodontics & craniofacial research OBJECTIVES:To investigate the anatomy of the mouse palate, the midpalatal suture, and the cellular characteristics in the sutures before and immediately after midpalatal suture expansion. MATERIALS AND METHODS:Wild-type C57BL/6 male mice, aged between 6 weeks and 12 months, were chosen for all the experiments. The complete palate of the non-operated group and the midpalatal suture-expanded group at different ages was used for histological, micro-CT, immunohistochemistry, and sutural cell analyses. RESULTS:This study documents precise morphological and histological characteristics of the mouse palatal sutures. In addition to the opening of the midpalatal suture caused by expansion, both transverse and interpalatine sutures were also seen to be affected. Cellular density was decreased in different types of sutures following the application of mechanical force. CONCLUSIONS:The detailed morphology and histology of the mouse palate and the cellular changes that occur following midpalatal suture expansion, as described here, will be helpful as a basis for further investigations of palatal suture tissue responses to mechanical force. 10.1111/j.1601-6343.2012.01547.x
Effect of soft laser in bone repair after expansion of the midpalatal suture in dogs. Santiago Vânia Cristina Costa Evangelista,Piram Adriana,Fuziy Acácio American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics INTRODUCTION:The purpose of this research was to study the influence of soft laser treatment on the process of bone repair after expansion of the midpalatal suture. METHODS:The sample for this case-control experimental study was 11 dogs. They were randomly divided into 2 groups, both of which underwent rapid maxillary expansion with a hyrax appliance. The animals in group 1 were also treated with laser therapy. They were killed, and histologic specimens of the palatal suture were prepared. The Student t test was applied for independent data, and the Mann-Whitney test was used for nonparametric data. RESULTS:A significant difference was observed in the quality of the palatal sutures between the animals in groups 1 and 2. The connective tissues of the sutures in the group 1 animals were similar to the original configurations, with more advanced osteogenesis and fibrogenesis, compared with those of group 2. CONCLUSIONS:Soft laser appears to influence the behavior of the repair process, contributing to suture reorganization and palatal bone osteogenesis during and after expansion. 10.1016/j.ajodo.2012.05.015
Anatomical and mechanical properties of swine midpalatal suture in the premaxillary, maxillary, and palatine region. Scientific reports The mechanical properties of the midpalatal suture and their relationship with anatomical parameters are relevant for both tissue engineering and clinical treatments, such as in sutural distraction osteogenesis. Soft tissues were dissected from ten swine heads and the hard palate was sliced perpendicularly to the midpalatal suture. Thirteen specimens were collected from each animal and analysed with micro-computed tomography and 4-point-bending for sutural width (Sw), interdigitation (LII), obliteration (LOI), failure stress (σ ), elastic modulus (E), and bone mineral density (BMD). Values of the premaxillary, maxillary, and palatine region were compared with Kruskal-Wallis one-way ANOVA and Spearman's rank coefficient was used to analyse the correlation between parameters and their position along the suture (α = 0.05). LII had values of 1.0, 2.9, and 4.3, LOI had values of 0.0%, 2.5%, and 4.5%, and E had values of 12.5 MPa, 31.3 MPa, and 98.5 MPa, in the premaxillary, maxillary, and palatine region, respectively (p < 0.05). Failure stress and rigidity of the midpalatal suture increased from rostral to caudal, due to greater interdigitation and obliteration. These anatomical and mechanical findings contribute to characterise maxillary growth, and may help to understand its mechanical reaction during loading, and in virtual simulations. 10.1038/s41598-018-25402-y
Effects of different settings for 940 nm diode laser on expanded suture in rats. Tas Deynek Gul,Ramoglu Sabri Ilhan The Angle orthodontist OBJECTIVES:To evaluate the effects of the Indium Gallium Arsenide Phosphoride (InGaAsP) diode laser at different energy levels on orthopedically expanded midpalatal sutures of rats. MATERIALS AND METHODS:Eighty Wistar rats were randomly divided into four groups: a control group and low-, moderate-, and high-level laser groups with amounts of energy irradiated at 0 J, 18 J, 42 J, and 60 J, respectively. Each group was divided into two subgroups (n = 10) according to the schedule of sacrifice (7 and 21 days). Laser application (940 ± 10 nm, 0.1 W) was completed twice weekly until sacrifice. The number of osteoblasts (OB), osteocytes (OC), and vessels (V); area of connective tissue (CT); inflammation (IN); and newly formed bone (NB); as well as the ratio of newly formed bone to the total bone area (N/T) were evaluated statistically at a significance level of .05. RESULTS:For the low-level laser group, OB, NB, and N/T were significantly higher, and CT was lower, on both the 7th and 21st days. The amount of OC was significantly higher in the low-level laser group compared with the control group on the 7th day and the control and high-level laser groups on the 21st day. The IN was significantly higher for the high-level group on the 21st day compared with other groups. Both the moderate-level and high-level laser groups possessed fewer vessels than the low-level laser group on the 21st day. CONCLUSIONS:The InGaAsP laser at the low dosage induced a favorable effect on bone formation in the orthopedically expanded midpalatal suture of rats. 10.2319/052318-392.1
Buccal bone plate thickness after rapid maxillary expansion in mixed and permanent dentitions. Digregorio Michele Vito,Fastuca Rosamaria,Zecca Piero Antonio,Caprioglio Alberto,Lagravère Manuel O American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics INTRODUCTION:Rapid maxillary expansion (RME) might cause buccal displacement of anchor teeth. Dislocation of teeth outside their alveolar process can damage the periodontium; for this reason, maxillary expansion using deciduous teeth as anchorage in the mixed dentition might be suggested. The aim of this study was to compare changes of buccal bone plate thickness on the maxillary permanent first molars after RME in the mixed and permanent dentitions with different types of anchorage. METHODS:Two groups of patients were evaluated with cone-beam computed tomography before and after RME. Group E (21 patients) underwent RME using deciduous teeth as anchorage; group 6 (16 patients) underwent RME using permanent teeth as anchorage. The Wilcoxon test was used to compare changes between the time points in the same groups, and the Mann-Whitney U test was used to compare differences between the groups. RESULTS:In group E, generally, no statistically significant reduction was found in buccal bone plate thickness between the time points. In group 6, most measurements showed significant reductions in buccal bone plate thickness (P <0.05) between the time points, with a maximum decrease of 1.25 mm. CONCLUSIONS:RME in the mixed dentition with the appliance anchored to deciduous teeth did not reduce the buccal bone plate thickness of the maxillary permanent first molars, except for the mesial roots on both sides. RME in the permanent dentition caused a reduction of the buccal bone plate thickness of the maxillary permanent first molars when they were used as anchorage in the permanent dentition. 10.1016/j.ajodo.2018.03.020
Levels of Cytokines in Gingival Crevicular Fluid during Rapid Maxillary Expansion and the Subsequent Retention Period. Topal Sıla Çağlayan,Tuncer Burcu Balos,Elgun Serenay,Erguder Imge,Ozmeric Nurdan The Journal of clinical pediatric dentistry OBJECTIVE:To monitor the effects of rapid maxillary expansion (RME) on bone metabolic activities during and after 3 months of retention. STUDY DESIGN:Fifteen patients with a mean age of 12.9 ± 0.6 years were treated with a bonded expansion device, activated 2 turns per day. The retention period was 3 months. Clinical periodontal parameters were recorded at baseline and after retention. Gingival crevicular fluid (GCF) samples were collected from maxillary first molars from the compression sides at baseline, then at 1 and 10 days and after retention. Tension side samples were obtained at baseline and after retention. Interleukin-1beta (IL-1β), transforming growth factor beta1 (TGF-β1), prostaglandin E (PGE) and nitric oxide (NO) levels were specifically measured. RESULTS:Periodontal parameters increased significantly after retention relative to baseline values. Levels of IL-1β, TGF-β1 and PGE increased on day 10, and decreased after retention on the compression side. NO levels were elevated on day 10, and remained higher after retention on the compression side. Tension side cytokine levels remained higher relative to baseline values after retention. CONCLUSIONS:The results of this study indicate the importance of ongoing adaptive bone activities after 3 months of retention with RME, which should be considered questionable as an effective retention period. 10.17796/1053-4625-43.2.12
Factors affecting buccal bone changes of maxillary posterior teeth after rapid maxillary expansion. Rungcharassaeng Kitichai,Caruso Joseph M,Kan Joseph Y K,Kim Jay,Taylor Guy American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics INTRODUCTION:The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the factors that might affect buccal bone changes of maxillary posterior teeth after rapid maxillary expansion (RME). METHODS:Thirty consecutive patients (17 boys, 13 girls; mean age, 13.8 +/- 1.7 years) who required RME as part of their orthodontic treatment and had the pre-RME (T1) and post-RME (T2) CBCT images available were included in the study. The T1 and T2 measurements of interdental distance, interdental angle (IA), buccal bone thickness (BBT), and buccal marginal bone levels (BMBL) of the first premolar (P1), the second premolar (P2), and the first molar (M1) were compared with the Friedman and the Wilcoxon signed rank tests. To determine which variables were associated with the changes in IA, BBT, and BMBL, the Spearman rank correlation analysis was performed (alpha = .05). RESULTS AND CONCLUSIONS:The results suggest that buccal crown tipping, and reduction of BBT and BMBL of the maxillary posterior teeth are the expected immediate effects of RME. There were no significant differences in dental expansion among P1, P2, and M1 (P >.05). P2 had clinically more buccal crown tipping (P = .116) but statistically less reduction in BBT and BMBL (P <.0001 and P = .001) than P1 and M1. Buccal bone changes and dental tipping on P2 were not affected by any other variables. Factors that showed significant correlation to buccal bone changes and dental tipping on P1 and M1 were age, appliance expansion, initial buccal bone thickness, and differential expansion (P <.05), but rate of expansion and retention time had no significant association (P >.05). 10.1016/j.ajodo.2007.02.052
Evaluation of alveolar bone loss following rapid maxillary expansion using cone-beam computed tomography. Baysal Asli,Uysal Tancan,Veli Ilknur,Ozer Torun,Karadede Irfan,Hekimoglu Seyit Korean journal of orthodontics OBJECTIVE:To evaluate the changes in cortical bone thickness, alveolar bone height, and the incidence of dehiscence and fenestration in the surrounding alveolar bone of posterior teeth after rapid maxillary expansion (RME) treatment using cone-beam computed tomography (CBCT). METHODS:The CBCT records of 20 subjects (9 boys, mean age: 13.97 ± 1.17 years; 11 girls, mean age: 13.53 ± 2.12 year) that underwent RME were selected from the archives. CBCT scans had been taken before (T1) and after (T2) the RME. Moreover, 10 of the subjects had 6-month retention (T3) records. We used the CBCT data to evaluate the buccal and palatal aspects of the canines, first and second premolars, and the first molars at 3 vertical levels. The cortical bone thickness and alveolar bone height at T1 and T2 were evaluated with the paired-samples t-test or the Wilcoxon signed-rank test. Repeated measure ANOVA or the Friedman test was used to evaluate the statistical significance at T1, T2, and T3. Statistical significance was set at p < 0.05. RESULTS:The buccal cortical bone thickness decreased gradually from baseline to the end of the retention period. After expansion, the buccal alveolar bone height was reduced significantly; however, this change was not statistically significant after the 6-month retention period. During the course of the treatment, the incidence of dehiscence and fenestration increased and decreased, respectively. CONCLUSIONS:RME may have detrimental effects on the supporting alveolar bone, since the thickness and height of the buccal alveolar bone decreased during the retention period. 10.4041/kjod.2013.43.2.83
Evaluation of interleukin-1β level and oxidative status in gingival crevicular fluid during rapid maxillary expansion. Ozel Nur,Aksoy Alev,Kırzıoglu Fatma Yesim,Doguc Duygu Kumbul,Aksoy Tutku Atış Archives of oral biology OBJECTIVES:The levels of interleukin-1β (IL-1β), nitric oxide (NO), total antioxidant capacity (TAC), and total oxidant status (TOS) in gingival crevicular fluid (GCF) were determined during rapid maxillary expansion (RME) treatment. MATERIALS AND METHODS:Fourteen patients (10-13 years old) were included. A modified hyrax appliance was used for the treatment. After periodontal parameters were recorded, GCF was collected from the first molars at each observation [T1:baseline:14 days after periodontal prophylaxis and instructions; T2:1 day later hyrax inserted, at passive position; T3:1 week later; after the first activation; T4:after 2 × 1/4 activation; T5:after 7 × 1/4 activation; T6:after 14 × 1/4 activation; T7:retention period on the 1 st month; and T8:retention period on the 3rd month]. RESULTS:Although the levels of IL1-β, NO, and PD increased significantly from T1 to T2, the GI, BOP%, and PI remained unchanged throughout treatment. GCF volume at buccal and palatal surfaces increased significantly from T1 to T4, T6, T7, and T8. The parameters in GCF and TAC levels were not only higher at palatal side in comparison with buccal, but also TOS levels increased at both buccal and palatal sides. CONCLUSIONS:In this study, the differences of oxidative status and IL-1β levels during RME treatment could be attributable to orthopedic effect of the heavy forces on maxilla and minimal orthodontic forces on teeth applied by the RME apparatus. 10.1016/j.archoralbio.2018.02.020
Maxillary suture expansion: A mouse model to explore the molecular effects of mechanically-induced bone remodeling. Guerrero Jose Alejandro,Silva Raquel Souto,de Abreu Lima Izabella Lucas,Rodrigues Bianca Cristina Duffles,Barrioni Breno Rocha,Amaral Flávio Almeida,Tabanez André Petenuci,Garlet Gustavo Pompermaier,Alvarado Diego Alexander Garzon,Silva Tarcília Aparecida,de Las Casas Estevam Barbosa,Macari Soraia Journal of biomechanics The aim of this study was to analyze the effect of rapid maxillary expansion (RME) on hard tissues. Opening loops bonded to the first and second maxillary molars on both sides were used to apply distracting forces of 0.28 N, 0.42 N and 0.56 N at the midpalatal suture for 7 and 14 days. Microcomputed tomography (MicroCT), histomorphometry and quantitative polymerase chain reaction (qPCR) analysis were performed to evaluate RME effectiveness, midpalatal suture remodeling, cell counting of osteoblasts, osteoclasts and chondrocytes and the expression of bone remodeling markers, respectively. All forces at the two different time points resulted in similar RME and enhanced of bone remodeling. Accordingly, increased number of osteoblasts and reduced chondrocytes counting and no difference in osteoclasts were seen after all RME protocols. RME yielded increased expression of bone remodeling markers as osteocalcin (Ocn), dentin matrix acidic phosphoprotein-1 (Dmp1), runt-related transcription factor 2 (Runx2), collagen type I Alpha 1 (Col1a1), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (Rankl), osteoprotegerin (Opg), cathepsin K (Ctsk), matrix metalloproteinases 9 and 13 (Mmp9 and 13), transforming growth fator beta 1, 2 and 3 (Tgfb 1, Tgfb 2 and Tgfb3), bone morphogenetic protein 2 (Bmp-2), sclerostin (Sost), beta-catenin-like protein 1 (Ctnnbl) and Wnt signaling pathways 3, 3a and 5a (Wnt 3, Wnt 3a and Wnt 5a). These findings characterize the cellular changes and potential molecular pathways involved in RME, proving the reliability of this protocol as a model for mechanical-induced bone remodeling. 10.1016/j.jbiomech.2020.109880
RANK/RANKL/OPG Expression in Rapid Maxillary Expansion. Arnez Maya Fernanda Manfrin,Ribeiro Larissa Soares Nogueira,Barretto Gabriel Dessotti,Monteiro Patrícia Maria,Ervolino Edilson,Stuani Maria Bernadete Sasso Brazilian dental journal The aim of this study was to evaluate osteoclastogenesis signaling in midpalatal suture after rapid maxillary expansion (RME) in rats. Thirty male Wistar rats were randomly assigned to two groups with 15 animals each: control (C) and RME group. RME was performed by inserting a 1.5-mm-thick circular metal ring between the maxillary incisors. The animals were euthanized at 3, 7 and 10 days after RME. qRT-PCR was used to evaluate expression of Tnfsf11 (RANKL), Tnfrsf11a (RANK) and Tnfrsf11b (OPG). Data were submitted to statistical analysis using two-way ANOVA followed by Tukey test (a=0.05). There was an upregulation of RANK and RANKL genes at 7 and 10 days and an upregulation of the OPG gene at 3 and 7 days of healing. Interestingly, an increased in expression of all genes was observed over time in both RME and C groups. The RANKL/OPG ratio showed an increased signaling favoring bone resorption on RME compared to C at 3 and 7 days. Signaling against bone resorption was observed, as well as an upregulation of OPG gene expression in RME group, compared to C group at 10 days. The results of this study concluded that the RANK, RANK-L and OPG system participates in bone remodeling after RME. 10.1590/0103-6440201601116
Peroxisome proliferator-activated receptor gamma regulates bone remodeling after midpalatal suture expansion in mice. Wu Jing,Ru Nan,Li Song The International journal of oral & maxillofacial implants PURPOSE:The effectiveness of rapid maxillary expansion is adversely affected by failure and relapse. It is important to identify key factors that increase new bone formation and improve bone remodeling of midpalatal sutures to improve the stability and effectiveness of this commonly used orthodontic procedure. Peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in modulating osteogenesis and bone resorption in long bones. This study was designed to explore the function of PPARγ in bone remodeling and tissue engineering of midpalatal sutures. MATERIALS AND METHODS:Pioglitazone, a PPARγ agonist, and osteoclast PPARγ knockout mice were used to explore the impact of PPARγ activation and inactivation, respectively, on bone remodeling in a mouse model of midpalatal suture expansion (MSE). Histologic analysis including staining with hematoxylin-eosin, tartrate-resistant acid phosphatase, and alkaline phosphatase was used to evaluate tissue remodeling. Reverse-transcriptase quantitative polymerase chain reaction was used to measure gene expression. RESULTS:Pioglitazone decreased new bone formation after MSE. This was accompanied by an increased amount of osteoclasts and expression of genes promoting osteoclastogenesis, as well as a decreased amount of osteoblasts and expression of genes promoting osteoblastogenesis in midpalatal sutures. Conversely, osteoclast PPARγ knockout mice increased new bone formation and decreased the amount of osteoclasts and expression of genes promoting osteoclastogenesis. CONCLUSION:In the process of bone remodeling after MSE, PPARγ, particularly in osteoclasts, is an important regulator of osteoblast and osteoclast homeostasis and bone remodeling in midpalatal sutures. Blockade of PPARγ might be an effective strategy to improve stability and decrease relapse in the practice of rapid maxillary expansion. 10.11607/jomi.3916
Cytokine expression pattern in compression and tension sides of the periodontal ligament during orthodontic tooth movement in humans. Garlet Thiago P,Coelho Ulisses,Silva João S,Garlet Gustavo P European journal of oral sciences Orthodontic tooth movement is achieved by the remodeling of periodontal ligament (PDL) and alveolar bone in response to mechanical loading and is believed to be mediated by several host mediators, such as cytokines. By means of real-time polymerase chain reaction (PCR), we studied the pattern of expression of mRNA encoding several pro- and anti-inflammatory cytokines in relation to several extracellular matrix and bone remodeling markers, in tension (T) and compression (C) sides of the PDL of human teeth subjected to rapid maxillary expansion. The PDL of normal teeth was used as a control. The results showed that both T and C sides exhibited significantly higher expression of all targets when compared with controls, except for type I collagen (COL-I) and tissue inhibitor of metalloproteinase-1 (TIMP-1) on the C side. Comparing C and T sides, the C side exhibited higher expression of tumor necrosis factor-alpha (TNF-alpha), receptor activator of nuclear factor-kappaB ligand (RANKL), and matrix metalloproteinase-1 (MMP-1), whereas the T side presented higher expression of interleukin-10 (IL-10), TIMP-1, COL-I, osteoprotegerin (OPG), and osteocalcin (OCN). The expression of transforming growth factor-beta (TGF-beta) was similar in both C and T sides. Our data demonstrate a differential expression of pro- and anti-inflammatory cytokines in compressed and stretched PDL during orthodontic tooth movement. 10.1111/j.1600-0722.2007.00469.x
Interleukin-1beta and beta-glucuronidase in gingival crevicular fluid from molars during rapid palatal expansion. Tzannetou S,Efstratiadis S,Nicolay O,Grbic J,Lamster I American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics This study examined whether the inflammatory mediators interleukin (IL-1beta) and beta-glucuronidase (betaG) are present in the gingival crevicular fluid (GCF) of children undergoing rapid palatal expansion and whether their levels vary upon activation of the appliance and movement of the maxillary first molars. Nine adolescent patients who needed palatal expansion were studied. Each patient received a periodontal prophylaxis and instruction in proper home care, including rinsing with chlorhexidine. Four weeks later, a modified Hyrax appliance was inserted. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected at 2 pretreatment observation periods and 9 observation periods after placement of the appliance. Samples were collected with filter paper strips and analyzed by means of ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded at the observation period 2 weeks after the periodontal prophylaxis were used as baseline. Paired t tests were used to compare mediator levels at this baseline to the levels obtained at each of the subsequent observations. The results indicate that (1) betaG and IL-1beta are present in GCF of young, healthy individuals, (2) their levels decrease following a strict regimen of plaque control, (3) orthodontic/orthopedic forces evoke changes in the levels of the inflammatory mediators IL-1beta and betaG in the periodontal tissues that can be detected in GCF. The results of this study support the hypothesis that mechanical stimulus causes an inflammatory reaction within the periodontal tissues, which in turn may trigger the biological processes associated with bone remodeling.
Comparison of levels of inflammatory mediators IL-1beta and betaG in gingival crevicular fluid from molars, premolars, and incisors during rapid palatal expansion. Tzannetou Sappho,Efstratiadis Stella,Nicolay Olivier,Grbic John,Lamster Ira American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics INTRODUCTION:Previously, we reported fluctuation of the levels of the inflammatory mediators interleukin-1beta (IotaL-1beta) and beta-glucuronidase (betaG) in gingival crevicular fluid (GCF) from the maxillary first molars in adolescents undergoing rapid palatal expansion. In this study, we compared the responses of IL-1beta and betaG in the GCF of the maxillary first molars, first premolars, and central incisors during palatal expansion at the same patients. METHODS:Nine patients requiring palatal expansion were selected at the postdoctoral orthodontic clinic at Columbia University College of Dental Medicine. Each patient received periodontal prophylaxis and instructions in proper home care including rinsing with chlorhexidine. Four weeks after periodontal prophylaxis, a modified hyrax appliance was placed. The jackscrew was activated twice daily until the appropriate expansion was achieved. GCF samples were collected before and after periodontal prophylaxis and during passive wearing of the appliance, active orthodontic treatment, and retention. Fluid samples were collected with filter paper strips and analyzed by ELISA and time-dependent fluorometry for IL-1beta and betaG, respectively. The values recorded after periodontal prophylaxis were used as the baseline. Paired t tests were used to compare mediator levels at baseline with the levels obtained at each subsequent observation. RESULTS:The results validate that IL-1beta and betaG are present in the GCF of adolescents, and, although their level decreases after a strict regimen of plaque control, it increases during orthodontic or orthopedic movement. Moreover, this study demonstrates that both heavy and light forces evoke increased levels of IL-1beta and betaG, stronger forces cause higher levels of inflammatory mediators, and both IL-1beta and betaG respond to direct and indirect application of mechanical force to teeth. CONCLUSIONS:This investigation corroborates previous findings that an inflammatory process occurs during application of mechanical force to teeth. Although this inflammation is considered relatively aseptic, additional inflammation, such as that induced by plaque accumulation, must be avoided during orthodontic or orthopedic treatment. 10.1016/j.ajodo.2006.03.044