Publications by authors named "Sarandeep S Huja"

30 Publications

  • Page 1 of 1

Inhibition of osteoclastogenesis by opsonized .

FASEB Bioadv 2019 Apr 29;1(4):213-226. Epub 2018 Nov 29.

Division of Orthodontics, College of Dentistry, University of Kentucky, Lexington, KY, USA.

A crucial step in the pathogenesis of periodontal disease (PD) is activation of osteoclasts (OC) by numerous virulence factors produced by (). To understand pathogenesis of periodontal disease and the role of specific adaptive immune responses, effects of antibodies on -induced OC differentiation and function were investigated. Human peripheral blood-derived monocytes were differentiated to osteoclasts in the presence or absence of: a) ; b) antibodies to ; and c) antibody-opsonized . Findings suggest significant induction of osteoclastogenesis by when compared to control cultures, whereas opsonization decreased osteoclastogenesis by 45%. Immune receptor gene expression profile in the presence of opsonized showed marked up-regulation of TLR1 (3-fold) and TLR2 (2-fold) along with FcγRIIB (2-fold) and FcγRIII receptors (5-fold), but not TLR4 and FcRγ receptors. Interestingly, blocking FcγRIIB, but not FcγRIII receptor, reversed the inhibitory effects of opsonized suggesting a critical role played by FcγRIIB in osteoclastogenesis. Furthermore, opsonized transformed OC precursors to a "macrophage phenotype" suggesting a bone protective role of the immune complexes in modulating osteoclastogenesis, probably by competing as an agonist for PRRs, and inducing selective activation of FcγRs with simultaneous suppression of FcRγ which regulates bone resorptive process. Further defining effective antibody isotypes, avidity, and antigenic specificity could improve targets for eliciting protective immunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1096/fba.2018-00018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660169PMC
April 2019

Influence of mini-screw diameter and loading conditions on static and dynamic assessments of bone-implant contact: An animal study.

Orthod Craniofac Res 2019 May;22 Suppl 1:96-100

Department of Orthodontics, James B. Edwards College of Dental Medicine, Medical University of South Carolina, Charleston, South Carolina.

Objectives: The goal was to compare static versus dynamic bone-implant interface histology of mini-screws and to evaluate its relation to diameter and load.

Setting And Sample Population: Canine animal model.

Material And Methods: Custom-machined, titanium alloy (Ti6AI4V) mini-screws (n = 70) of 1.60, 2.00, 3.00 and 3.75 mm diameter were placed into edentulous sites in five skeletally mature beagle dogs. Using a split-mouth design, no load (NL) was applied to one side while a 2N load (L) was applied by calibrated coil springs on the other side. Intravenous bone labels were administered 21 and 7 days prior to sacrifice. Dogs were euthanized 90 days after screw placement. Bone sections were analysed under bright-field and epifluorescent light. The region of interest was defined as the bone within the threads of the screws. The following parameters were quantified: (a) Static-bone volume/tissue volume (BV/TV %) and bone-implant contact (BIC, %); (b) Dynamic-labelled bone/bone volume (LB/BV, %), and dynamic BIC (DBIC, %).

Results: BV/TV ranged from 71.2% to 85.0% of the screw surface. BIC ranged from 45.7% to 55.4% of the screw surface and was not affected by diameter (P = 0.66). In contrast, the percentage of DBIC did not vary with the applied load (P = 0.41); however, it correlated significantly with the diameter of the screw (P = 0.001).

Conclusion: The percentage of DBIC that is actively remodelling increases with increasing diameter of the screw. Dynamic histomorphometry is more sensitive to detecting changes in bone-implant contact when compared to static measurements.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ocr.12293DOI Listing
May 2019

Novel application and validation of in vivo micro-CT to study bone modelling in 3D.

Orthod Craniofac Res 2019 May;22 Suppl 1:90-95

Department of Orthodontics, James B. Edwards College of Dental Medicine, Medical University of South Carolina, Charleston, South Carolina.

Objectives: The aim is to highlight a novel three-dimensional (3D) imaging methodology using micro-CT scans to visualize and measure bone modelling in an animal model. In order to validate the new methodology, we compared the 3D imaging method to traditional two-dimensional (2D) histomorphometry to assess growth changes in the jaws of a rodent.

Setting And Sample Population: Rodent animal models.

Material And Methods: Eleven rats were obtained from a larger previously published study. Sixty undecalcified histological sections from the maxilla and corresponding high-resolution in vivo micro-CT reconstructions were obtained. Bone modelling changes on specific alveolar surfaces were measured using traditional histomorphometry. Measurements of bone growth were also obtained via 3D Slicer software from 3D micro-CT generated models from the same plane containing the histological images. Both qualitative and quantitative 3D methods were compared to traditional histological measurements. Quantitative agreement between methods was categorized as follows: poor (>150 μm), good (150-100 μm) and excellent (<100 μm).

Results: Both qualitative (88.3%) and quantitative (86.7%) 3D measurements showed excellent agreement, when compared to histomorphometric measurements. Only 1.7% and 5% of the comparisons exhibited poor agreement (>150 μm) for qualitative and quantitative methods, respectively.

Discussion: The new 3D superimposition method compares very favourably with traditional histology. It is likely that in the future, such methods will be used in studies of bone adaptation.

Conclusion: The 3D micro-CT qualitative and quantitative methods are reliable for measuring bone modelling changes and compare favourably to histology for the specific application described.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ocr.12265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660907PMC
May 2019

Preface to COAST 2018 Innovators' Workshop: Bridging the biology and technology gap in orthodontics and craniofacial care.

Orthod Craniofac Res 2019 May;22 Suppl 1:5-7

Department of Orthodontics, School of Dentistry, Oregon Health and Science University, Portland, Oregon.

Objective: A third focused workshop explored how to transfer novel findings into clinical orthodontic practice.

Setting And Sample Population: Participants met at the Scottsdale Plaza Resort, 12-16 September 2018 for the Consortium for Orthodontic Advances in Science and Technology 2018 Innovators' Workshop. Thirty speakers and four lunch-hour focus group leaders shared and exchanged information with approximately 45 registered attendees.

Material And Methods: This Innovators' Workshop was organized according to five themed sessions which covered: (a) The relevance of genetics, biology and environment to therapeutic outcomes; (b) Application of bioinformatics in craniofacial research; (c) Regeneration with and for orthodontic treatment; (d) Technology in precision orthodontics; and (e) Muscle, joint, and airway: Growth, function and pain.

Results: The papers that comprise this supplemental issue exemplify the important outcomes of the 2018 COAST Workshop. In addition, matters identified as important needs include improved understanding of neural, skeletal and muscle tissue crosstalk in early craniofacial growth; standardized methods for three-dimensional radiographic and surface landmark and reference plane identification, measurements and serial superimpositioning techniques for use in the clinic; sharing and making available existing data sets (eg, cone beam computed tomography images, genotype-phenotype data); evidence of the usefulness and effectiveness of new devices; guidelines of what to measure to characterize the airway; more information about the influences of the soft tissues on craniofacial morphology; and information about effective digital work flows applied to clinical and educational settings.

Conclusions: Progress in bridging the biology-technology gap has identified new needs for improvements in orthodontics and craniofacial care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ocr.12303DOI Listing
May 2019

A rodent model using skeletal anchorage and low forces for orthodontic tooth movement.

Am J Orthod Dentofacial Orthop 2019 Feb;155(2):254-263

Department of Orthodontics, Medical University of South Carolina, Charleston, SC. Electronic address:

Introduction: Nonhuman animal models have been used extensively to study orthodontic tooth movement (OTM). However, rodent models have disadvantages, including a reported reduction in bone volume during OTM. The purpose of this study was to determine the viability of a skeletal anchorage and the effect of low force (∼3 cN) on interradicular bone volume during OTM.

Methods: Ninety Sprague-Dawley rats were divided into 5 time points. A miniscrew and a nickel titanium coil spring placed a load of 3 cN (experimental) or 0 cN (sham) on the maxillary first molar in a split-mouth design. Displacement of the first molar and bone volume/total volume (BV/TV) in the interradicular region were quantified.

Results: The success rate of the miniscrew was 98.9% (89 out of 90). Linear and angular tooth movement increased steadily (mean 0.1 mm/wk, 0.48 mm at 40 days). BV/TV was significantly reduced between the tooth movement and non-tooth movement sides in the 3 cN group: by 13%, 23%, 15%, 23%, and 16% at 3, 7, 14, 28, and 40 days, respectively.

Conclusions: Our model resulted in efficient OTM without skeletal anchorage failure. BV/TV reduction was lower than in previous reports. This novel validated model is likely to be the basis for future studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajodo.2018.03.022DOI Listing
February 2019

Compensations in Bone Morphology and the Dentition in Patients With Untreated Unilateral Cleft Lip and Palate: A Cone-Beam Computed Tomographic Analysis.

Cleft Palate Craniofac J 2018 11 28;55(10):1358-1366. Epub 2018 Feb 28.

4 Department of Orthodontics, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA.

Objective: The purpose of this study was to quantitatively assess dentoalveolar and skeletal compensations in patients with untreated unilateral cleft lip and palate (UCLP). We hypothesized that there are significant skeletal and dental adaptations in UCLP cases compared to a comparison maxillary crossbite group.

Design: A convenience retrospective sample of 30 patients with UCLP and a comparison group of 30 patients with unilateral posterior crossbite without CLP. Cone-beam computed tomography scans (CBCTs) were used to evaluate dental and skeletal compensations. In addition, alveolar bone thickness was measured at 2-mm increments in mesiodistal and faciolingual cross-sectional views along the long axis of the central incisors. Alveolar bone height was measured, and the percentage of root length supported by bone was calculated.

Results: Compensations for unilateral cleft lip and palate were restricted to the cleft site and adjacent structures. Dental compensations include alteration in the position of cleft-adjacent maxillary incisors and maxillary canines. No gross skeletal compensations were found. Alveolar support of cleft adjacent incisors was similar to controls except for measurements in the most coronal and apical regions. The cleft group contralateral incisors exhibited buttressing effects and had significantly higher alveolar thickness in the coronal half of the tooth. There was less (5%) alveolar coverage of the cleft-facing aspect of the central incisor root than all other incisors.

Conclusion: The bone adaptation to the presence of a cleft was localized in the vicinity of the cleft, and adaptations in the mandible were not apparent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1055665618757635DOI Listing
November 2018

Testing of a bioactive, moldable bone graft substitute in an infected, critically sized segmental defect model.

J Biomed Mater Res B Appl Biomater 2018 07 19;106(5):1878-1886. Epub 2017 Sep 19.

F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky.

Large infected bone defects, often resulting from high energy traumas, are difficult to treat due to their variability in complexity and location. Standard treatment for infected bone defects begins with a protocol that includes a series of debridements in conjunction with an extended course of systemic antibiotics. Only after the infection has been eliminated will repair of the defect commence, typically with implantation of autologous bone. To address some of the shortcomings of the standard treatment methods, such as serial procedures, limited grafting material, and the need for a second surgical site for autologous bone, a sequential, dual drug-releasing, moldable, calcium sulfate-based bone graft substitute was developed previously. In the present studies, the effectiveness of the material for treating both the infection with vancomycin and bone defect with simvastatin was evaluated in vivo using a critically sized, infected segmental defect model in rat femurs. Although the infection was not fully eliminated, the local release of vancomycin increased survivorship of infected animals by 464% compared to nontreated controls. Infected animals receiving antimicrobial treatment showed comparable amounts of new bone formation within the defect site when compared to noninfected controls. Incorporating agents capable of disrupting established biofilms into bone graft substitutes may enhance effectiveness in treating a biofilm infection within a bone defect. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1878-1886, 2018.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbm.b.34001DOI Listing
July 2018

Soft Tissue Changes Measured With Three-Dimensional Software Provides New Insights for Surgical Predictions.

J Oral Maxillofac Surg 2017 Oct 24;75(10):2191-2201. Epub 2017 May 24.

Professor, Division of Orthodontics, University of Kentucky, Lexington, KY. Electronic address:

Purpose: Although computer-aided craniofacial reconstructions allow for simulation of hard tissue changes, the prediction of the final soft tissue facial changes remains a challenge. The purpose of the present study was to evaluate the 3-dimensional (3D) soft tissue changes in patients undergoing 2-jaw orthognathic surgery.

Patients And Methods: For the present retrospective cohort study, 40 consecutive patients (11 men and 29 women; mean age 23.5 ± 4.9 years) who had undergone 2-jaw orthognathic surgery were selected. We obtained the medical and dental records from 3 weeks before surgery and 6 months after surgery. We used image processing software to segment, superimpose, and quantify the hard and soft tissue displacements in 3 dimensions before and after surgery at 15 paired locations. The soft tissue and hard tissue changes were determined through quantification of homologous landmark displacements between the preoperative and postoperative computed tomography data. We measured the 3D soft and hard tissue changes and the anteroposterior, inferosuperior, and transverse components of the changes. We quantified the ratios between the soft and hard tissue changes, tested Pearson's correlation between these changes, and developed a predictive regression equation for the observations at each location.

Results: We found that soft tissue movement followed the hard tissue movement, with a correlation nearly equal to 0.9 (range 0.85 to 0.98), suggesting that in general the soft tissues of the maxillary and mandibular landmarks are affected similarly by the skeletal movements. The anteroposterior component of the soft tissue 3D displacements followed the hard tissue movement with a ratio greater than 0.9 and with high correlation (r > 0.9) in the mandible.

Conclusion: The results of the present study provide surgeons with a ratio of hard to soft tissue change and the strength of the correlations, which will allow for more accurate 3D predictions for both midline and lateral structures in bimaxillary orthognathic surgical cases. In addition, predictive equations for various landmarks were developed and can be used in computer-based prediction programs to aid in treatment planning of soft tissue changes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.joms.2017.05.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5698014PMC
October 2017

Screw-type device diameter and orthodontic loading influence adjacent bone remodeling.

Angle Orthod 2017 May 8;87(3):466-472. Epub 2016 Dec 8.

Objective: To evaluate the effect of diameter and orthodontic loading of a screw-type implantable device on bone remodeling.

Materials And Methods: Screw-shaped devices of four distinct diameters, 1.6, 2, 3, and 3.75 mm, were placed into edentulous sites in five skeletally mature beagle dogs (n = 14/dog) following premolar extraction. Using a split-mouth design, devices on one side were loaded using calibrated 2N coil springs. Epifluorescent bone labels were administered intravenous prior to sacrifice. Bone-implant sections (∼ 70 μm) were evaluated to quantify bone formation rate (BFR), and other histomorphometric variables were assessed in the implant supporting bone.

Results: The mean BFR ranged from 10.93 percent per year to 38.91 percent per year. BFR in the bone adjacent to the device was lower for the loaded 1.6-mm screws when compared with the nonloaded 1.6-mm screws (P < .01) and the loaded 2.0-, 3.0-, and 3.75-mm diameter screws (P < .01). No significant differences in BFR were noted, regardless of loading condition, between the 2.0-, 3.0-, and 3.75-mm diameter screws.

Conclusions: We detected a dramatic reduction in bone remodeling. Although orthodontic loading of 2N did not alter bone remodeling associated with screws with a 2.0-mm diameter or larger, it did decrease bone remodeling adjacent to a loaded 1.6-mm screw. The long-term effect of this diminished remodeling should be further investigated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2319/041316-302.1DOI Listing
May 2017

Aging, inflammation, immunity and periodontal disease.

Periodontol 2000 2016 10;72(1):54-75

The increased prevalence and severity of periodontal disease have long been associated with aging, such that this oral condition affects the majority of the adult population over 50 years of age. Although the immune system is a critical component for maintaining health, aging can be characterized by quantitative and qualitative modifications of the immune system. This process, termed 'immunosenescence', is a progressive modification of the immune system that leads to greater susceptibility to infections, neoplasia and autoimmunity, presumably reflecting the prolonged antigenic stimulation and/or stress responses that occur across the lifespan. Interestingly, the global reduction in the host capability to respond effectively to these challenges is coupled with a progressive increase in the general proinflammatory status, termed 'inflammaging'. Consistent with the definition of immunosenescence, it has been suggested that the cumulative effect of prolonged exposure of the periodontium to microbial challenge is, at least in part, a contributor to the effects of aging on these tissues. Thus, it has also been hypothesized that alterations in the function of resident immune and nonimmune cells of the periodontium contribute to the expression of inflammaging in periodontal disease. Although the majority of aging research has focused on the adaptive immune response, it is becoming increasingly clear that the innate immune compartment is also highly affected by aging. Thus, the phenomenon of immunosenescence and inflammaging, expressed as age-associated changes within the periodontium, needs to be more fully understood in this era of precision and personalized medicine and dentistry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/prd.12135DOI Listing
October 2016

PhyloToAST: Bioinformatics tools for species-level analysis and visualization of complex microbial datasets.

Sci Rep 2016 06 30;6:29123. Epub 2016 Jun 30.

Division of Periodontology, College of Dentistry, The Ohio State University, Columbus, Ohio, USA.

The 16S rRNA gene is widely used for taxonomic profiling of microbial ecosystems; and recent advances in sequencing chemistry have allowed extremely large numbers of sequences to be generated from minimal amounts of biological samples. Analysis speed and resolution of data to species-level taxa are two important factors in large-scale explorations of complex microbiomes using 16S sequencing. We present here new software, Phylogenetic Tools for Analysis of Species-level Taxa (PhyloToAST), that completely integrates with the QIIME pipeline to improve analysis speed, reduce primer bias (requiring two sequencing primers), enhance species-level analysis, and add new visualization tools. The code is free and open source, and can be accessed at http://phylotoast.org.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep29123DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4928119PMC
June 2016

Bone biology-related gingival transcriptome in ageing and periodontitis in non-human primates.

J Clin Periodontol 2016 05 6;43(5):408-17. Epub 2016 Apr 6.

Division of Orthodontics, College of Dentistry, University of Kentucky, Lexington, KY, USA.

Aim: Cellular and molecular immunoinflammatory changes in gingival tissues drive alveolar bone loss in periodontitis. Since ageing is a risk factor for periodontitis, we sought to identify age-related gingival transcriptome changes associated with bone metabolism in both healthy and in naturally occurring periodontitis.

Materials And Methods: Adult (12-16 years) and aged (18-23 years) non-human primates (M. mulatta) (n = 24) were grouped into healthy and periodontitis. Gingival tissue samples were obtained and subjected to microarray analysis using the Gene Chip Macaque Genome Array. Gene expression profiles involved in osteoclast/osteoblast proliferation, adhesion and function were evaluated and compared across and between the age groups. QPCR was also performed on selected genes to validate microarray data.

Results: Healthy aged tissues showed a gene profile expression that suggest enhancement of osteoclastic adhesion, proliferation/survival and function (SPP1, TLR4, MMP8 and TFEC) and impaired osteoblastic activity (SMEK3P and SMAD5). The gingival transcriptome in both adult and aged animals with naturally occurring periodontitis (FOS, IL6, TLR4, MMP9, MMP10 and SPP1 genes) was consistent with a local inflammatory response driving towards bone/connective tissue destruction.

Conclusion: A pro-osteoclastogenic gingival transcriptome is associated with periodontitis irrespective of age; however; a greater bone-destructive molecular environment is associated with ageing in healthy tissues.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcpe.12528DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4844783PMC
May 2016

Bone ingrowth and initial stability of titanium and porous tantalum dental implants: a pilot canine study.

Implant Dent 2013 Aug;22(4):399-405

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA.

Purpose: To investigate if a dental implant system with a midsection covered by 3-dimensionally porous tantalum material would exhibit stability comparable with a traditional threaded titanium alloy implant system and whether bone would grow into the porous section.

Methods: Three experimental and 3 control implants were placed in the individual mandibles of 8 dogs. Resonance frequency analysis assessed implant stability at 0, 2, 4, 8, and 12 weeks of healing. Histomorphometric and backscattered scanning electron microscopic analyses examined the presence of bone ingrowth into the experimental implant's porous section and bone-to-implant contact along the titanium surfaces of both implants.

Results: Implant stability did not significantly differ during 0 to 12 weeks of healing. Progressive tissue mineralization developed inside porous sections from weeks 2 to 12. Porous implants exhibited a combination of progressive osseointegration along their titanium surfaces and bone ingrowth inside their porous tantalum sections.

Conclusions: Cortical and apical implant threads, combined with the porous section, were able to stabilize the experimental implant to the same degree as the fully threaded control implant.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/ID.0b013e31829b17b5DOI Listing
August 2013

Effect of estrogen deficiency on regional variation of a viscoelastic tissue property of bone.

J Biomech 2013 Jan 8;46(1):110-5. Epub 2012 Nov 8.

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH 43210-1267, USA.

Estrogen deficiency changes the regional distribution of tissue mineral density leading to alteration of the mechanical properties of bone at the tissue level. Direct measurement of the regional variation of elastic modulus and viscosity, which is the capacity to resist time-dependent viscoelastic deformation, will aid in our understanding of how estrogen deficiency alters bone quality. It was observed that, compared to bone from other anatomical sites, the jaw bone is less sensitive to estrogen deficiency. Thus, the objective of this study was to examine the effect of estrogen deficiency on (1) the regional variations of tissue modulus and viscosity of bone using nanoindentation, and (2) the modulus-viscosity relationships in jaw and vertebral bones for comparison between different anatomical sites. Mandibular and vertebral bone specimens of sham surgery and ovariectomized (OVX) rat groups were subject to nanoindentation in hydration. Indentation modulus and viscosity were measured at relatively new (less mineralized) tissue regions and at the corresponding pre-existing old (more mineralized) tissue regions of mandibular and vertebral bones. In the mandibular bones, significant regional variations of indentation modulus and viscosity were observed (p<0.039) and OVX increased the indentation viscosity. While significant positive correlations were found between indentation modulus and viscosity (p<0.001), the correlation slopes for the mandibular and vertebral bones were significant different (p<0.001). The current results indicated that changes in viscoelastic property and its regional variation should be examined to obtain a better understanding of estrogen deficiency-dependent alteration of bone quality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jbiomech.2012.10.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529751PMC
January 2013

Bone damage associated with orthodontic placement of miniscrew implants in an animal model.

Am J Orthod Dentofacial Orthop 2012 Apr;141(4):412-8

Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio, USA.

Introduction: The purposes of this study were to quantify bone damage associated with insertion of 2 types of miniscrew implants and to relate the amount of bone damage to monocortical plate thickness.

Methods: Nondrilling (n = 28) and self-drilling (n = 28) miniscrew implants (6 × 1.6 mm, Dentaurum, Newtown, Pa), and pilot holes (n = 26) were placed bilaterally in the maxillae and the mandibles of 5 adult dogs immediately after death. Bone blocks were cut, bulk stained with 1% basic fuchsin, embedded in methyl methacrylate, sectioned, and mounted. Monocortical plate thickness was measured adjacent to the miniscrew implant insertion site. Damage amounts were quantified at distances of 0 to 0.5 mm (adjacent region) and 0.5 to 1 mm (distant region) from the bone-implant interface. Total fractional damaged area (%), fractional microcracked area (%), and fractional diffuse damaged area (%) were quantified by using standard histomorphometric methods.

Results: The mean monocortical plate thickness of the specimens from the mandible (2.2 mm) was significantly (P <0.001) greater than that of the maxillary specimens (0.9 mm). In the mandible, the 3 damage parameters were greater with self-drilling miniscrew implants than with nondrilling miniscrew implants; however, there were no differences in the damage parameters in the maxilla.

Conclusions: Bone damage accumulation is related to the type of miniscrew implant and the thickness of the bone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajodo.2011.10.021DOI Listing
April 2012

Temporary anchorage device utilization: comparison of usage in orthodontic programs and private practice.

Orthodontics (Chic.) 2011 ;12(3):222-31

Division of Orthodontics, Ohio State University College of Dentistry, Columbus, OH, USA.

Aim: There is limited data on how temporary anchorage devices (TADs) are currently used in orthodontics. The aim of this study was to survey two groups of orthodontic providers-graduate orthodontic residencies and private practitioners-about their use.

Methods: A 15-question survey was prepared and administered to all 61 accredited orthodontic residencies and an equal number of private orthodontic practitioners (all in the United States). A second survey was also included and provided to the residency programs.

Results: The response rate was 63.9% for private practitioners and 70.4% for orthodontic residency programs. The majority of the residency programs (82.9%) and practitioners (69.2%) reported placing TADs in their practices. TADs were placed in 6.0% of the patients treated by private practitioner and in 5.3% of patients treated in residency programs. A combination of topical and local anesthesia was the anesthetic of choice for 59.0% of private practitioners and 65.0% of orthodontic residency programs. A large majority of the private practitioners (79.0%) and orthodontic residency programs (61.9%) reported that the TADs were loaded immediately. The most frequently cited use for TADs was anterior en masse retraction. In total, 27.9% of the residency programs used miniplates, compared to 17.9% of the practitioners.

Conclusion: Since 2005, a large number of US programs have incorporated TADs into their didactic/research curriculum and residency programs. Both mini-implants and miniplates may have a far-reaching impact on the clinical practice of orthodontics for decades to come. This survey detailed the trends and differences between practitioners and residencies in the TAD utilization experience and provided important information that is otherwise not available in the literature.
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2012

Bone remodeling surrounding primary teeth in skeletally immature dogs.

Angle Orthod 2011 Nov 1;81(6):931-7. Epub 2011 Jun 1.

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, USA.

Objective: To quantify remodeling in the bone surrounding fully erupted primary teeth and to compare bone remodeling in the primary and permanent dentitions.

Materials And Methods: Two bone sections were obtained bilaterally from the maxilla and mandible of the primary molar region of approximately 5-month-old male beagle dogs. Histomorphometric methods were used to estimate the osteonal remodeling in the alveolar and basal regions of the tooth supporting bone. The following variables were calculated: mineral apposition rate (MAR, µm/d), mineralizing surface/bone surface (MS/BS, %), bone formation rate (BFR, %/y), and erosion surface/bone surface (ES/BS, %). Comparisons were made between jaws (maxilla vs mandible) and bone types (alveolar vs basal), and data analyzed by analysis of variance (ANOVA) and Tukey-Kramer tests. Remodeling (BFR) surrounding primary teeth was compared to existing data from bone surrounding permanent teeth.

Results: The mean and standard deviation BFR values (%/y) were as follows: mandibular alveolar, 44.10 (±26.89); maxillary alveolar, 3.54 (±3.57); mandibular basal, 22.65 (±14.65); and maxillary basal, 12.33 (±7.11). The mandibular BFR was significantly (P < .05) higher than the maxillary bone. The BFR of the alveolar bone of primary teeth was not significantly (P = .48) different from the alveolar bone supporting permanent teeth.

Conclusions: The remodeling rate of alveolar bone in skeletally immature dogs was greater in the mandible than in the maxilla and remained unaltered between primary and permanent dentitions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2319/021611-114.1DOI Listing
November 2011

Effect of zoledronic acid on bone healing subsequent to mini-implant insertion.

Angle Orthod 2011 May 24;81(3):363-9. Epub 2011 Jan 24.

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio 43210, USA.

Objective: To examine remodeling in bone supporting mini-implants by comparing a no drug (ND) group with a group that received a potent intravenous bisphosphonate in a canine model.

Materials And Methods: Twelve skeletally mature (2- to 3-year-old) male dogs were divided into two groups. Seven dogs were administered 0.1 mg/kg/mo of zoledronic acid (ZA) for 16 weeks, while five age-matched dogs received no drug. Two mini-implants (Tomas, Dentaurum, Newton, Pa) were placed unilaterally in the maxilla and mandible (4 mini-implants per animal × 12  =  48). Serial fluorescent bone labels were administered in vivo. Postmortem, the bone blocks containing the mini-implants were harvested and used for histomorphometric analyses at two regions of interest (adjacent: within 1 mm of interface; distant: 1-4 mm from the interface) supporting the mini-implant. Data were analyzed using mixed models.

Results: In general, the ZA group had a significantly lower bone formation rate than the ND group (P < .05) for all jaws/regions except for the adjacent region in the maxilla, P  =  .12. Despite the reduction, mean intracortical remodeling in the ZA group ranged from 35%-42% per year in the implant adjacent bone. This rate is substantially higher than that reported for noninjured sites in the jaw.

Conclusions: Bone remodeling is typically elevated in implant supporting bone. After ZA administration, the healing response represented by elevated turnover in implant supporting bone was diminished but was not abolished.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2319/070710-384.1DOI Listing
May 2011

Effects of short-term zoledronic acid treatment on bone remodeling and healing at surgical sites in the maxilla and mandible of aged dogs.

J Oral Maxillofac Surg 2011 Feb 3;69(2):418-27. Epub 2010 Dec 3.

Division of Orthodontics, The Ohio State University, Columbus, OH, USA.

Purpose: It is unknown whether zoledronic acid (ZA) interferes with initial bone healing at extraction and implant sites. The goal of this study was to examine the effect of short-duration ZA on bone remodeling and healing after surgical insult in an aged dog model.

Materials And Methods: Four 2- to 3-year-old male dogs were administered ZA (0.1 mg/kg per month for 4 months), and 3 age-matched untreated dogs received no drug. In both groups, after the ZA-treated group had completed receiving the drug, the third premolar was extracted unilaterally and 2 orthodontic mini-implants per jaw per dog were placed on the ipsilateral side. After a 6-week healing period, a pair of calcein bone labels were administered. Bone sections from the mandible, maxilla, rib, and femur were obtained. The percent necrosis in the alveolar and basal regions of tooth-supporting bone was assayed by lactate dehydrogenase, and dynamic histomorphometric parameters were quantified and analyzed by use of mixed models.

Results: All extraction sites healed uneventfully, and no lesions resembling osteonecrosis were detected. The total percent necrosis was limited to less than 1% for all the bone sites examined. The ZA reduced bone remodeling at both surgical sites (extraction sites and mini-implant site) and nonsurgical sites. Although there was a significant (P < .05) increase in bone formation rate at the surgical sites in the untreated group, this increase was not significant (P = .3) in the ZA-treated group.

Conclusions: Bone remodeling occurs in ZA-treated animals at surgical sites. ZA dramatically reduced bone turnover, but no exposed lesions resembling osteonecrosis developed at extraction and mini-implant sites after the 4-month drug duration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.joms.2010.05.062DOI Listing
February 2011

Short-term zoledronic acid reduces trabecular bone remodeling in dogs.

Eur J Oral Sci 2010 Oct 16;118(5):460-5. Epub 2010 Aug 16.

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA.

The effects of zoledronic acid, a bisphosphonate, on the trabecular bone remodeling (TBR) of the mandibular condyle are unknown. The objectives of this study were to quantify and compare TBR in the mandibular condyle and vertebrae of 2- to 3-yr-old dogs and to evaluate the effects of short-term zoledronic acid on TBR. Bone samples from two, age-matched groups of dogs [seven dogs were given no treatment (NT group) and seven dogs were treated with four total infusions of zoledronic acid administered monthly (ZOL group)] were analyzed using histomorphometry. Trabecular bone remodeling and microarchitecture were quantified and analyzed statistically. Physiologic TBR, quantified in the NT group, was significantly higher (more than sixfold) in the vertebrae than in the mandibular condyle. Trabecular bone remodeling in the vertebrae of dogs of the ZOL group was 96% lower than in dogs of the NT group. By contrast, TBR in the mandibular condyle of dogs in the ZOL group was statistically equivalent to that of dogs in the NT group. Our results demonstrate that the physiological TBR in aged dogs is vastly different in the mandibular condyle compared to that in the vertebra. A higher level of physiologic TBR in the vertebra than in the mandibular condyle results in greater reduction of TBR in response to short-term treatment with zoledronic acid.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1600-0722.2010.00762.xDOI Listing
October 2010

Relationships of viscosity with contact hardness and modulus of bone matrix measured by nanoindentation.

J Biomech Eng 2010 Feb;132(2):024502

Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA.

Creep is an active form of time-dependent viscoelastic deformation that occurs in bone tissue during daily life. Recent findings indicate bone mineralization, which is involved in determining the elastic and plastic properties of bone matrix, can also contribute in controlling its viscoelastic property. Nanoindentation viscosity was used as a direct measure for the capacity of a material to resist viscous-like flow under loading. The objectives of this study were to examine (1) whether the nanoindentation viscosity obtained using the traditional viscoelastic Voigt model can describe creep response of bone matrix and (2) how the nanoindentation viscosity is related to contact hardness and elastic modulus. The Voigt model accurately described the creep behavior of bone matrix (r(2)>0.96, p<0.001). The nanoindentation viscosity had strong relationships with nanoindentation contact hardness (r(2)=0.94, p<0.001) and modulus (r(2)=0.83, p<0.001) independent of tissue ages of osteonal bone matrix. The strong positive relationships of nanoindentation viscosity with contact hardness and modulus can be interpreted as increases in the mineral portion of bone matrix may limit the interfibril motion of collagen while enhancing the mechanical stability of bone. We suggest that previous nanoindentation results can be reanalyzed to characterize the viscoelastic creep using the Voigt model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1115/1.4000936DOI Listing
February 2010

Alveolar process anabolic activity in C3H/HeJ and C57BL/6J inbred mice.

J Periodontol 2008 Jul;79(7):1255-62

Section of Oral Biology, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA.

Background: The purpose of this study was to characterize bone activity of the alveolar process in C3H/HeJ (C3H) and C57BL/6J (B6) inbred mice. Based on observations in other animal species, we hypothesized that the bone-formation rate/bone surface (BFR/BS) is greater in the alveolar process compared to the body of the mandible and that the bone anabolic activity is greater in the alveolar process of the mandible than in the maxilla. We also examined the alveolar process of C3H and B6 mice for the presence of secondary osteons.

Methods: Jaws from 17-week-old C3H and B6 female mice (N = 15/group) were harvested. Histomorphometric parameters were evaluated in sections from the alveolar process, each of which included at least one molar root.

Results: In C3H and B6 mice, BFR/BS was not significantly different (P >0.05) between the alveolar process and the body of the mandible. In C3H mice, BFR/BS was significantly greater (P = 0.05) in the mandible compared to the maxilla. BFR/bone volume (BV) was not significantly different (P >0.05) between C3H mandible and maxilla. In the B6 inbred mouse, BFR/BS and BFR/bone volume (BV) were not significantly different (P >0.05) between jaws. After analyzing 165 bone sections, we identified 25 secondary osteons.

Conclusions: The surface anabolic activity was not different between the body and the alveolar process of the mandible. The surface activity was greater in the C3H mandible than in the maxilla. Although secondary osteonal bone remodeling existed in the C3H and B6 alveolar bone, this process was not a consistent finding.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1902/jop.2008.070610DOI Listing
July 2008

Modifications of the lactate dehydrogenase assay, a histochemical determinant of osteocyte viability--a qualitative study.

Acta Histochem 2009 13;111(2):166-71. Epub 2008 Jun 13.

Division of Orthodontics, College of Dentistry, The Ohio State University, 305 W. 12th Avenue, Columbus, OH 43210, USA.

We have refined a technique for assessment of osteocyte viability in a canine and murine model using a modification of the lactate dehydrogenase assay (LDH). With this method, viable osteocytes react to form non-reversible tetrazolium-formazan granules, while non-viable osteocytes are distinguished by a methyl green stain. LDH assay in canine and murine models have not been reported and our initial efforts were not successful. We examined the effect of (a) concentration of coenzyme and tetrazole (b) bone specimen thickness (c) ability to use frozen sections and (d) incubation time/dilution. We concluded that a 1000-fold increase in the concentration of coenzyme and tetrazole were required. Fresh bone produced optimal results and near-complete viability. Special considerations must be taken with smaller, more fragile specimens (e.g., mouse bone), such as increasing specimen thickness, dilution of incubation medium and/or the reduction of incubation time. Sections from thawed frozen bone resulted in a diffuse reaction. Osteocyte viability can be assessed via LDH assay in both dog and mouse bones; however, this approach requires modifications from the previous published method.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acthis.2008.03.003DOI Listing
May 2009

Bone remodeling in maxilla, mandible, and femur of young dogs.

Anat Rec (Hoboken) 2008 Jan;291(1):1-5

Section of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio, USA.

Bone remodeling in the jaw is essential for metabolic needs, mechanical demands and for growth of the skeleton. Currently, there is no information on remodeling in the jaw of young dogs. Four approximately 5-month-old male dogs were given a pair of calcein bone labels. After killing, bone sections were obtained from the maxilla, mandible, and femur. The jaw specimens were obtained from regions associated with erupting permanent teeth. Undecalcified specimens were prepared for examination by histomorphometric methods to evaluate mineral apposition rate (microm/d), mineralizing surface/bone surface (%), and bone formation rate (BFR, %/yr) in the bone supporting erupting teeth and in the femurs. Only intracortical secondary osteonal remodeling units were measured. There were significant (P < 0.05) differences in the BFR for the three sites examined, with the highest BFR (72%/yr) being in the femur. The mandible had a BFR twofold greater than the maxilla (51%/yr vs. 25.5%/yr). The rate of turnover in the jaw and femur of young dogs is distinct from a similar comparison between the jaw and appendicular skeleton of adult ( approximately 1 yr old) dogs. Although BFR decreases with age in the femur, it remains elevated in the jaws.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ar.20619DOI Listing
January 2008

Changes in mechanical properties of bone within the mandibular condyle with age.

J Morphol 2008 Feb;269(2):138-43

Section of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio 43210, USA.

The purpose of the study was to compare indentation modulus (IM) and hardness of condylar bone in young and adult dogs. In addition we desired to examine histologic sections for bone formation activity in the two groups. Mandibular condyles were obtained from adult (1- to 2-year-old) and young (approximately 5-m old) dogs. Two sections/condyle were obtained and one was processed for histomorphometry and the other for mechanical analyses. Indents were made on moist condylar trabecular bone to a depth of 500 nm at a loading rate of 10 nm/s using a custom-made hydration system to obtain IM and hardness. Histomorphometric analyses measured the bone volume/total volume (BV/TV%) and ratio of labeled to unlabeled bone within the condyle. Data were analyzed using a repeated-measures factorial analysis of variance and Tukey-Kramer method. Overall, the IM of the adult condyles (10.0+/-3.4 GPa, Mean+/-SD) were significantly (P<0.0001) higher than in young dogs (5.6+/-2.6 GPa). There was a greater bone mass in the young (60.2%) versus the adult condyles (42%). Also, significantly more labeled bone in the young (66.1%) condylar bone suggested higher bone forming activity than in adult condyles (27.5%). With age there is a change in mass and material properties in the trabecular bone of the mandibular condyle in dogs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmor.10582DOI Listing
February 2008

Adaptations in the mandible and appendicular skeleton of high and low bone density inbred mice.

Calcif Tissue Int 2007 Aug 8;81(2):107-13. Epub 2007 Jun 8.

Section of Oral Biology, College of Dentistry, The Ohio State University, 3188 Postel Hall, 305 W. 12th Avenue, Columbus, OH, 43210, USA.

The appendicular skeletons of high [C3H/HeJ (C3H)] and low [C57BL/6J (B6)] density inbred mice have been shown to differ in morphology, mechanical properties, and cellular activity. The focus of the current study was to (1) characterize the mandibular bone formation rate (BFR/BS), bone mass, indentation modulus (IM), and hardness of C3H and B6 mice and (2) investigate the relationship of the mechanical properties in three skeletal sites: mandible, femur, and tibia. Specimens from 17-week-old female C3H and B6 (n = 15/group) mice were obtained. Mandibular bone mass was estimated from the lateral-view area (LVA) and transverse cross sections. BFR/BS was measured in the mandibular section distal to the third molar. In addition, bone blocks from the distal surface of the third molar and the femoral and tibial midshaft were obtained for mechanical testing. BFR/BS, cortical area, and LVA were greater (P < 0.001) in C3H mandibles. IM was approximately 2 GPa higher in the C3H mandible (P > 0.05), femur (P < 0.001), and tibia (P < 0.01). Mandibular IM was lower (P < 0.05) than the femoral and tibial IM within each inbred mouse. IM was not significant between C3H and B6 mandibles. However, the magnitude of the difference ( approximately 12%) in the mandible was similar to the difference in the appendicular skeleton. This mandibular bone phenotype is similar to that observed in the appendicular skeleton of these distinct inbred mice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00223-007-9029-xDOI Listing
August 2007

Objective structured clinical examination use in advanced orthodontic dental education.

Am J Orthod Dentofacial Orthop 2007 May;131(5):656-63

Section of Orthodontics, Ohio State University College of Dentistry, Columbus, Ohio 43218-2357, USA.

Introduction: Continuous evaluation of residents and the advanced education curriculum is required to maintain the quality of a program and ensure appropriate accreditation status. The purpose of this project was to describe the process of introducing the objective structured clinical examination (OSCE) into an advanced orthodontic education program and to evaluate its impact on the curriculum.

Methods: To determine the content of the examination, 60 orthodontic practitioners were consulted to identify the most important clinical skills that an entry-level practitioner must be able to perform proficiently. From 18 critical clinical skills, 13 were evaluated by the OSCE in the areas of diagnosis, clinical evaluation and synthesis, and orthodontic technique. The OSCE was given to 3 classes of residents each year for 3 years (n = 46).

Results: The classes were tracked longitudinally, and the students' levels were evaluated cross-sectionally. Curriculum changes were evaluated for impact in areas of deficiency. There were no significant correlations between student confidence and performance or faculty prediction of proficiency and performance beyond the first year. Great gains in performance were observed between the first and second years of the 3-year program. All skills did not reach proficiency levels, and peak performance did not always occur during the third year. Some curriculum changes were fruitful, and others were not sustained by improved performance.

Conclusions: An OSCE can provide important information regarding students and the curriculum in a clinically meaningful way that might be otherwise unattainable.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajodo.2007.01.013DOI Listing
May 2007

Remodeling dynamics in the alveolar process in skeletally mature dogs.

Anat Rec A Discov Mol Cell Evol Biol 2006 Dec;288(12):1243-9

Section of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio 43210, USA.

Bone turnover rates can be altered by metabolic and mechanical demands. Due to the difference in the pattern of loading, we hypothesized that there are differences in bone remodeling rates between the maxillary and mandibular alveolar processes. Furthermore, in a canine model, the alveolar process of teeth that lack contact (e.g., second premolars) would have a different turnover rate than bone supporting teeth with functional contact (e.g., first molars). Six skeletally mature male dogs were given a pair of calcein labels. After sacrifice, specimens representing the anterior and posterior locations of both jaws were prepared for examination by histomorphometric methods to evaluate the bone volume/total volume (BV/TV; %), bone volume (mm2), mineral apposition rate (MAR; microm/day), and bone formation rate (BFR; %/year) in the alveolar process. There were no significant differences (P>0.05) in the BV/TV within the jaws. The bone volume within the alveolar process of the mandible was 2.8-fold greater than in the maxilla. The MAR was not significantly different between the jaws and anteroposterior locations. However, the BFR was significantly (P<0.0001) greater in the mandible than in the maxilla. The anterior location had higher (P=0.002) remodeling than the posterior location in the maxilla but not in the mandible. While there was a greater bone mass and increased remodeling in the mandible, no remodeling gradient in the coronal-apical direction was apparent in the alveolar process. Bone adaptation probably involves a complex interplay of bone turnover, mass, and architecture.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ar.a.20396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2612758PMC
December 2006

Pull-out strength of monocortical screws placed in the maxillae and mandibles of dogs.

Am J Orthod Dentofacial Orthop 2005 Mar;127(3):307-13

Section of Orthodontics, College of Dentistry, The Ohio State University, 4088 E. Postle Hall, 305 W. 12th Avenue, Columbus, OH 43210, USA.

Background: Mini-implants can facilitate orthodontic tooth movement by serving as anchors. The purpose of this investigation was to determine whether the pull-out strength of screws in bone varies depending on the site of insertion in the maxilla or the mandible.

Materials: Fifty-six titanium screws (2 mm diameter, 6 mm length, Synthes USA, Monument, Colo) were placed in 4 beagle dogs (14 screws per dog) within 30 minutes after they were killed. The screws were inserted to obtain monocortical anchorage, at predetermined sites in the anterior, middle, and posterior regions of the jaws bilaterally. Two screws were placed in the posterior palate in each dog. The jaws were harvested, and bone blocks, each containing a screw, were prepared for mechanical testing. The bone/screw block was aligned on a custom-made fixture, and the maximum force (F max ) at pullout was recorded. Cortical bone thickness was measured after extraction of the screw. Statistical analyses to test for differences were conducted with ANOVA and Tukey-Kramer tests.

Results: Screws placed in the anterior mandibular region had significantly ( P < .05) lower F max (134.5 +/- 24N, mean +/- SE) than those placed in the posterior mandibular region (388.3 +/- 23.1N). Regression analyses suggested a weak (r = 0.39, P = .02) but significant correlation between F max and cortical bone thickness.

Conclusions: The bone supporting monocortical screws would most likely withstand immediate loading and support tooth-moving forces.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajodo.2003.12.023DOI Listing
March 2005

A radiographic evaluation of the availability of bone for placement of miniscrews.

Angle Orthod 2004 Dec;74(6):832-7

The Ohio State University, Columbus, Ohio, USA.

Monocortical screws are increasingly being used to enhance orthodontic anchorage. The most frequently cited clinical complication is soft tissue irritation. It is thus clinically advantageous for these miniscrews to be placed in attached mucosa. The purpose of this study was to (1) determine radiographically the most coronal interradicular sites for placement of miniscrews in orthodontic patients and (2) determine if orthodontic alignment increases the number of sites with adequate interradicular bone for placement of these screws. Sixty panoramic radiographs (n = 30 pretreatment, n = 30 posttreatment) of orthodontic patients were obtained from an archival database after Institutional Review Board approval. Selection criteria included minimal radiographic distortion and complete eruption of permanent second molars. Interradicular sites were examined with a digital caliper for presence of three and four mm of bone. If three or four mm of bone existed, then a vertical measurement from the cementoenamel junction (CEJ) to first measurement was made. In addition, the magnification error inherent in panoramic radiographs was estimated. Ninety-five percent confidence intervals were calculated for the vertical distances from the CEJ to the horizontal bone location. Bone stock for placement of screws was found to exist primarily in the maxillary (mesial to first molars) and mandibular (mesial and distal to first molars) posterior regions. Typically, adequate bone was located more than halfway down the root length, which is likely to be covered by movable mucosa. Inability to place miniscrews in attached gingiva may necessitate design modifications to decrease soft tissue irritation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1043/0003-3219(2004)074<0832:AREOTA>2.0.CO;2DOI Listing
December 2004