Try a new search

Format these results:

Searched for:


Total Results:


MOPs and accelerated tooth movement: A biased conclusion? [Letter]

Nervina, Jeanne M; Khoo, Edmund; Alikhani, Mani; Teixeira, Cristina C
PMID: 32561350
ISSN: 1097-6752
CID: 4492522

Perinatal interference with the serotonergic system affects VTA function in the adult [Meeting Abstract]

Teixeira, C; Cunha, C; Smiley, J; Chuma, N; Shah, R; Rayport, S; Ansorge, M; Castellanos, F
Background: Serotonin and dopamine are neurotransmitters associated with multiple psychiatric disorders. How they interact during development to affect subsequent behavior remains unknown. Knockout of the serotonin transporter or administration of selective-serotonin-reuptake inhibitors (SSRIs) during early-life lead to novelty-induced exploration deficits in adulthood.
Method(s): Using a combination of optogenetics, behavioral testing and electrophysiology we tested the effects of perinatal exposure to fluoxetine (PN-FLX) on dopaminergic system's function in the adult. Between 10 to 15 mice per group, male and female, were administered with saline or fluoxetine (10 mg/kg IP) from P2 to P11. Mice were tested after 8 weeks of age.
Result(s): Here we show that Raphe nucleus serotonin neurons activate ventral tegmental area (VTA) dopamine neurons via glutamate cotransmission and that this cotransmission is impaired in postnatally SSRI treated animals. Moreover, we show that the SSRI-induced hypolocomotion is mimicked by blocking serotonin neuron glutamate cotransmission. Optogenetic activation of dopamine neurons rescued this hypolocomotor phenotype.
Conclusion(s): Our data demonstrate that serotonin neurons modulate dopaminergic activity via glutamate cotransmission and that this pathway is developmentally malleable, with high serotonin levels during early life blunting this capacity, resulting in reduced novelty-induced exploration in adulthood
ISSN: 1740-634x
CID: 4456532

Biphasic sutural response is key to palatal expansion

Alikhani, M; Alansari, S; Al, Jearah M M; Gadhavi, N; Hamidaddin, M A; Shembesh, F A; Sangsuwon, C; Nervina, J M; Teixeira, C C
Introduction: It is assumed that transverse force physically open maxillary sutures and induce tensile stress that directly stimulates bone formation. However, orthopedic tensile stress is static, which cannot directly stimulate bone formation. We hypothesize that the anabolic response to transverse forces is indirect, the result of inflammation-induced osteoclast activation followed by a transition into osteogenesis. To test our hypothesis, we evaluated tissue, cellular, and molecular responses in the sutures during maxillary expansion.
Material(s) and Method(s): Sprague-Dawley rats (n = 95) were divided into four groups (n = 5 rats/group/time point, except for the expansion group, which did not have a day 0 sample): untreated control (C), sham (S), expansion (Exp), and expansion with nonsteroidal anti-inflammatory medication (Exp + NSAID). Maxillae were collected 0, 1, 3, 7, 14, and 28 days postexpansion for micro-computed tomography, light microscopy, gene expression, protein, and immunohistochemistry analysis.
Result(s): Compared with the sham group, the Exp group showed early expression of cytokines in the mid-palatal suture, osteoclast activation, and bone resorption resulting in widening of the suture. Anabolic bone formation was delayed, occurring after this initial catabolic phase. NSAIDs significantly decreased sutural widening, bone formation, and skeletal and dental expansion. During the transition from catabolic to anabolic phase, expression of osteoclast-osteoblast communicator molecules increased significantly.
Conclusion(s): Transverse force stimulates two distinct phases in the mid-palatal suture. An early catabolic phase, characterized by inflammation, osteoclast recruitment, and activity, results in bone resorption and sutural widening. Then osteoclasts activate osteoblasts resulting in an anabolic phase, during which the integrity of the skeleton is reestablished.
ISSN: 2212-4438
CID: 4329742

Therapeutic effect of localized vibration on alveolar bone of osteoporotic rats

Alikhani, Mani; Alikhani, Mona; Alansari, Sarah; Almansour, Abdullah; Hamidaddin, Mohammad A; Khoo, Edmund; Lopez, Jose A; Nervina, Jeanne M; Nho, Joo Y; Oliveira, Serafim M; Sangsuwon, Chinapa; Teixeira, Cristina C
OBJECTIVES/OBJECTIVE:Vibration, in the form of high frequency acceleration (HFA), stimulates alveolar bone formation under physiologic conditions and during healing after dental extractions. It is not known if HFA has an anabolic effect on osteoporotic alveolar bone. Our objective is to determine if HFA has a regenerative effect on osteoporotic alveolar bone. METHODS AND MATERIALS/METHODS:Adult female Sprague-Dawley rats were divided into five groups: 1) Ovariectomized Group (OVX), 2) Sham-OVX Group that received surgery without ovariectomy, 3) OVX-HFA Group that was ovariectomized and treated daily with HFA, 4) OVX+Static Force Group that was ovariectomized and received the same force as HFA, but without vibration, and 5) Control Group that did not receive any treatment. All animals were fed a low mineral diet for 3 months. Osteoporosis was confirmed by micro-CT of the fifth lumbar vertebra and femoral head. HFA was applied to the maxillary first molar for 5 minutes/day for 28 and 56 days. Maxillae were collected for micro-CT, histology, fluorescent microscopy, protein and RNA analysis, and three-point bending mechanical testing. RESULTS:Micro-CT analysis revealed significant alveolar bone osteoporosis in the OVX group. Vibration restored the quality and quantity of alveolar bone to levels similar to the Sham-OVX group. Animals exposed to HFA demonstrated higher osteoblast activity and lower osteoclast activity. Osteogenic transcription factors (RUNX2, Foxo1, Osterix and Wnt signaling factors) were upregulated following vibration, while RANKL/RANK and Sclerostin were downregulated. HFA did not affect serum TRAcP-5b or CTx-1 levels. The osteogenic effect was highest at the point of HFA application and extended along the hemimaxillae this effect did not cross to the contra-lateral side. CONCLUSIONS:Local application of vibration generated gradients of increased anabolic metabolism and decreased catabolic metabolism in alveolar bone of osteoporotic rats. Our findings suggest that HFA could be a predictable treatment for diminished alveolar bone levels in osteoporosis patients.
PMID: 30695073
ISSN: 1932-6203
CID: 3627252

Age-dependent biologic response to orthodontic forces

Alikhani, Mani; Chou, Michelle Y; Khoo, Edmund; Alansari, Sarah; Kwal, Rachel; Elfersi, Tali; Almansour, Abdullah; Sangsuwon, Chinapa; Al Jearah, Mohammed; Nervina, Jeanne M; Teixeira, Cristina C
INTRODUCTION/BACKGROUND:Orthodontic tooth movement results from increased inflammation and osteoclast activation. Since patients of all ages now routinely seek orthodontics treatment, we investigated whether age-dependent biologic responses to orthodontic force correlate with the rate of tooth movement. METHODS:We studied 18 healthy subjects, adolescents (11-14 years) and adults (21-45 years), with Class II Division 1 malocclusion requiring 4 first premolar extractions. Canines were retracted with a constant force of 50 cN. Gingival crevicular fluid was collected before orthodontic treatment and at days 1, 7, 14, and 28 after the canine retraction. Cytokine (IL-1β, CCL2, TNF-α) and osteoclast markers (RANKL and MMP-9) were measured using antibody-based protein assays. Pain and discomfort were monitored with a numeric rating scale. The canine retraction rate was measured from study models taken at days 28 and 56. RESULTS:Although the cytokine and osteoclast markers increased significantly in both age groups at days 1, 7, and 14, the increases were greater in adults than in adolescents. Interestingly, the rate of tooth movement in adults was significantly slower than in adolescents over the 56-day study period. Adults also reported significantly more discomfort and pain. CONCLUSIONS:Age is a significant variable contributing to the biologic response to orthodontic tooth movement. Adults exhibited a significantly higher level of cytokine and osteoclasts activity but, counterintuitively, had a significantly slower rate of tooth movement.
PMID: 29706211
ISSN: 1097-6752
CID: 3056742

Vibration paradox in orthodontics: Anabolic and catabolic effects

Alikhani, Mani; Alansari, Sarah; Hamidaddin, Mohammad A; Sangsuwon, Chinapa; Alyami, Bandar; Thirumoorthy, Soumya N; Oliveira, Serafim M; Nervina, Jeanne M; Teixeira, Cristina C
Vibration in the form of High Frequency Acceleration (HFA) is anabolic on the craniofacial skeleton in the absence of inflammation. Orthodontic forces trigger an inflammation-dependent catabolic cascade that is crucial for tooth movement. It is unknown what effect HFA has on alveolar bone if applied during orthodontic treatment. The objectives of this study are to examine the effect of HFA on the rate of tooth movement and alveolar bone, and determine the mechanism by which HFA affects tooth movement. Adult Sprague Dawley rats were divided to control, orthodontic force alone (OTM), and different experimental groups that received the same orthodontic forces and different HFA regimens. Orthodontic tooth movement was assessed when HFA parameters, frequency, acceleration, duration of exposure, and direct or indirect application were varied. We found that HFA treatment significantly enhanced the inflammation-dependent catabolic cascade during orthodontic tooth movement. HFA treatment increased inflammatory mediators and osteoclastogenesis, and decreased alveolar bone density during orthodontic tooth movement. Each of the HFA variables produced significant changes in the rate of tooth movement and the effect was PDL-dependent. This is the first report that HFA enhances inflammation-dependent catabolic cascades in bone. The clinical implications of our study are highly significant, as HFA can be utilized to enhance the rate of orthodontic tooth movement during the catabolic phase of treatment and subsequently be utilized to enhance retention during the anabolic remodeling phase after orthodontic forces are removed.
PMID: 29734391
ISSN: 1932-6203
CID: 3100832

High Frequency Acceleration: A New Tool for Alveolar Bone Regeneration

Alikhani, M; Sangsuwon, C; Alansari, S; Nervina, J M; Teixeira, C C
Introduction/UNASSIGNED:A common problem in clinical dentistry is the significant and rapid bone loss that occurs after periodontitis, osteoporosis, tooth extractions, lack of function, or any other pathologic condition that target the alveolar bone. Currently there is no stable solution for the long-term preservation or rehabilitation of alveolar bone. In this article, we review the latest concepts on bone response to mechanical stimulation, and summarize the results of our studies on the effect of high frequency acceleration (HFA) on healthy alveolar bone and on healing alveolar bone after extractions. Methods/UNASSIGNED:In both studies, we used adult Sprague Dawley rats to test the response of alveolar bone to different frequencies and accelerations applied to the maxillary molars. Results/UNASSIGNED:Once we determined which parameters of HFA induced a higher osteogenic response, we tested the effect of this mechanical stimulation during bone healing after molar extraction. Our studies strongly show that HFA can stimulate bone formation in the healthy alveolar bone surrounding the tooth/point of application as well as the distant bone surrounding the neighboring teeth. When HFA was applied to the second molar, after extraction of the third molar, it accelerated bone healing and prevented alveolar bone resorption in and around the extraction socket. Conclusion/UNASSIGNED:HFA is a noninvasive safe treatment that can be used to prevent alveolar bone loss, accelerate bone healing and to improve the quality and quantity of alveolar bone under both physiological and pathological conditions.
PMID: 30215055
ISSN: 2573-1548
CID: 3277982

High-Frequency Acceleration: Therapeutic Tool to Preserve Bone following Tooth Extractions

Alikhani, M; Lopez, J A; Alabdullah, H; Vongthongleur, T; Sangsuwon, C; Alikhani, M; Alansari, S; Oliveira, S M; Nervina, J M; Teixeira, C C
A common problem in clinical dentistry is the significant and rapid bone loss that occurs after tooth extraction. Currently there is no solution for the long-term preservation of alveolar bone. Previously, we showed that high-frequency acceleration (HFA) has an osteogenic effect on healthy alveolar bone. However, it is not known if HFA can preserve alveolar bone after extraction without negatively affecting wound healing. The purpose of this study was to evaluate the effect of HFA on alveolar bone loss and the rate of bone formation after tooth extraction. Eighty-five adult Sprague-Dawley rats were divided into 3 groups: control, static (static load), and HFA. In all groups, the maxillary right third molar was extracted. The HFA group received HFA for 5 min/d, applied through the second molar. The static group received the same magnitude of static load. The control group did not receive any stimulation. Some animals received fluorescent dyes at 26 and 54 d. Samples were collected on days 0, 7, 14, 28, and 56 for fluorescence microscopy, micro-computed tomography, histology, RNA, and protein analyses. We found that HFA increased bone volume in the extraction site and surrounding alveolar bone by 44% when compared with static, while fully preserving alveolar bone height and width long-term. These effects were accompanied by increased expression of osteogenic markers and intramembranous bone formation and by decreased expression of osteoclastic markers and bone resorption activity, as well as decreased expression of many inflammatory markers. HFA is a noninvasive safe treatment that can be used to prevent alveolar bone loss and/or accelerate bone healing after tooth extraction.
PMID: 26672126
ISSN: 1544-0591
CID: 1878322

Biphasic theory of tooth movement: Cytokine expression and rate of tooth movement: Cytokines and rate of tooth movement

Chapter by: Alikhani, M; Alansari, S; Sangsuwon, C; Nervina, J; Teixeira, C
in: Biology of Orthodontic Tooth Movement: Current Concepts and Applications in Orthodontic Practice by
pp. 45-65
ISBN: 9783319266091
CID: 2483262

Biological principles behind accelerated tooth movement

Alansari, Sarah; Sangsuwon, Chinapa; Vongthongleur, Thapanee; Kwal, Rachel; Teo, Miang Chneh; Lee, Yoo B; Nervina, Jeanne; Teixeira, Cristina; Alikhani, Mani
Understanding the biology of tooth movement has great importance for developing techniques that increase the rate of tooth movement. Based on interpretations of data on the biology of tooth movement, the resulting accelerating techniques can be divided into two main groups: one group stimulates upstream events to indirectly activate downstream target cells, while the other group bypasses the upstream events and directly stimulates downstream target cells. In both approaches, there is a general consensus that the rate of tooth movement is controlled by the rate of bone resorption, which in turn is controlled by osteoclast activity. Therefore, to increase the rate of tooth movement, osteoclasts should be the target of treatment. In this article, both approaches will be reviewed and the biological limitations of each group will be discussed. (C) 2015 Elsevier Inc. All rights reserved.
ISSN: 1558-4631
CID: 1775562