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PubMed2004

Microcracks in the alveolar bone following orthodontic tooth movement: a morphological and morphometric study.

Microcracks and microdamage have been associated with bone remodelling. The aim of this study was to investigate the role of microcracks as a trigger for alveolar bone remodelling after the application of an orthodontic load. In 25 3-month-old male Danish land-race pigs, the lower right first molar was moved buccally with a force of 130 cN. The contralateral molar was not treated and was used as an internal control. After 1, 2, 4, 7 and 15 days of treatment, the regions containing the right and left molars were excised and en bloc stained in basic fuchsin. The presence of microcracks on the buccal and lingual sides of both treated and untreated teeth was detected and expressed as crack density (number/mm2). The buccal treated side showed significantly more cracks than the buccal untreated side at day 1. This difference was significantly larger than that observed at days 2, 7 and 15. The same side showed significantly more microcracks than the lingual treated side at day 1, and this difference was larger compared with that observed at days 4 and 15. The presence of more microcracks on the treated side than on the untreated side suggests a role for microcracks in the initiation of bone remodelling after orthodontic loading. The increased presence of microcracks on the side towards which the tooth was moved, and where bone resorption is usually observed, suggests that microcracks could represent the first damage induced by orthodontic force that has to be repaired by bone remodelling. Finally, the strain levels in the alveolar bone during the orthodontic load transfer in the experiment were examined by finite element (FE) analysis. Although this showed that the strains were very low (10-100 microstrain), it should be noted that occlusal loading was not taken into account. In addition, high-resolution microtomography of the alveolar bone/periodontal ligament (PDL) interface revealed that the actual surface of the alveolar bone was very rough, predisposing it to high local stress/strain peaks.

Alveolar Process↗
PubMed2000

The reliability of the Index of Orthodontic Treatment Need over time.

The aim of this investigation was to establish whether the Index of Orthodontic Treatment Need is reliable over time between the ages of 11 and 19 years. It consisted of a longitudinal sample of 314 11- and 15-year-old and 142 19-year-old subjects who had not received orthodontic treatment or extractions. The changes in the aesthetic component (AC) and the dental health component (DHC) of the Index of Orthodontic Treatment Need (IOTN) were measured between the ages of 11 and 19 years. The results suggested that the dental health component of IOTN was reliable over time between the ages of 11-19 years despite temporal changes in the separate occlusal traits that comprise the index. The aesthetic component of IOTN tended to show an improvement over time. The Index of Orthodontic Treatment Need is a reliable index over time when taking into account occlusal changes that are occurring during the 11-19-year age range. The study provides some reassurance to clinicians that an IOTN grading at age 11 years is unlikely to change by the time the patient is 19 years. Refereed Scientific Paper

Adolescent↗
PubMed2001

The use of the Index of Orthodontic Treatment need (IOTN) in a school population and referred population.

The aim of this study is to assess the need for orthodontic treatment in a Turkish school population and a group of population referred for orthodontic treatment. The study groups were 250 school children, 11-14 years of age, and 250 patients, 11-14 years of age, referred to the department of orthodontics. The Index of Orthodontic Treatment Need (IOTN) was used by two examiner in order to estimate the treatment need. The differences between the IOTN values for the boys and girls were also not statistically significant in both groups. When the dental health component of IOTN is considered, 38.8 per cent of Turkish school population showed great need treatment, 24.0 per cent moderate need treatment and slight or no need was 37.2 per cent. On the other hand, the referred population represented an 83.2 per cent great need treatment, 12.0 per cent moderate need treatment, 4.8 per cent no need treatment according to the DHC. The AC of IOTN in school population resulted in 4.8 per cent great need, 4.8 per cent moderate need, 90.4 per cent no need. These percentage were 36.8 per cent great need, 17.6 per cent moderate need, 45.2 per cent no need in referred population. Grade 8 was 28.8 per cent out of the 36.8 per cent great need percentage in referred population. Therefore, it can be concluded that the ectopic canines were the driving factor for the referred population.

Adolescent↗
PubMedDate not supplied

Physiological responses of preterm infants to breast-feeding and bottle-feeding with the orthodontic nipple.

BACKGROUND: Although the orthodontic nipple has been recommended for many years to supplement breast-feeding infants, it is not known if this nipple is suitable for hospitalized preterm infants whose mothers wish to breast-feed. OBJECTIVES: To describe and compare short-term physiologic responses of preterm infants serving as their own controls for two feeding methods, breast-feeding and bottle-feeding with the orthodontic nipple. METHOD: The sample consisted of eight preterm infants, mean birth weight of 1,370 grams and mean gestational age at birth of 30.2 weeks' gestation, who served as their own controls for breast- and bottle-feeding sessions. The dependent variables, sucking, breathing, and oxygen saturation, were measured noninvasively throughout breast- and bottle-feeding sessions and recorded on a polygraph. Data were analyzed quantitatively and qualitatively for 14 breast-feeding sessions and 15 bottle-feeding sessions. RESULTS: Statistically significant differences were found in that infants breathed more during sucking bursts for breast-feeding sessions when compared to bottle-feeding sessions and had fewer episodes of oxygen desaturation during breast-feeding. A characteristic sucking waveform associated with organized breathing was observed for some infants during bottle-feeding with the orthodontic nipple. CONCLUSIONS: These data suggest that the orthodontic nipple is appropriate for supplementing breast-feeding for some preterm infants. Further research is needed to examine long-term outcomes.

Bottle Feeding↗
PubMed2005

Pulp-dentine complex changes and root resorption during intrusive orthodontic tooth movement in patients prescribed nabumetone.

Pulpitis, external root resorption, and pain may be experienced during orthodontic movement. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested to control these changes. The purpose of this study was to observe pulp-dentinal reactions, root resorption, tooth pain, and tooth movement after the application of a 4-ounce intrusive orthodontic force to human maxillary first premolars in patients given the NSAID nabumetone. Thirty-four maxillary first premolars were evaluated. A placebo was prescribed to 17 patients after an intrusive force was activated and reactivated for an 8-week period on the right side. The same procedure was repeated on the left side after patients were given nabumetone. Pulp-dentinal reactions and external root resorption were evaluated by histology. Pain and movement were also evaluated. Nabumetone was found to be useful in reducing pulpitis, external root resorption, and pain caused by intrusive orthodontic movement, without altering tooth movement in response to the application of orthodontic force.

Adolescent↗
PubMed1987

Some periodontal tissue reactions to orthodontic tooth movement in monkeys.

The purpose of the experiment reported was to study soft tissue changes at teeth which were orthodontically moved into areas with varying thickness and quality of periodontal tissues. The maxillary central incisors and first premolars in 5 adult monkeys were used as experimental teeth. 6 months prior to the start of the orthodontic treatment phase, the maxillary second premolars were extracted. By surgical means, areas with varying width of the keratinized gingiva were established in the incisor and premolar region. Following a clinical baseline examination which involved assessments of gingival width, location of the gingival margin in relation to cemento-enamel junction and probing attachment level, fixed orthodontic appliances were inserted in order to bodily move the two contral incisors in labial direction through the alveolar bone envelope and the first premolars in distal direction into contact with the first molars. Orthodontic forces were applied for a period of 3-4 months. The lateral incisors and first molars were selected as non-moved control teeth. After the experimental teeth had been retained in their new positions for 1 month, the clinical examination was repeated. Tissue blocks containing test and control specimens were subsequently dissected and prepared for microscopic analysis. The analysis included histometric assessments of loss of connective tissue attachment and height of alveolar bone. The results showed that at every second labially moved incisor, the gingival margin had become displaced in apical direction. The degree of displacement, however, was small and only at 2 teeth accompanied by loss of connective tissue attachment. Throughout the study, these particular teeth also showed obvious signs of gingival inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗
PubMed2006

Orthodontic movement after periodontal regeneration of class II furcation: a pilot study in dogs.

PURPOSE: The effect of orthodontic movement on the periodontal tissues of maxillary second pre-molars, after regenerative treatment for class II furcations, was evaluated in four mongrel dogs. MATERIAL AND METHODS: Class II furcation lesions were created. After 75 days they were treated with bovine bone mineral matrix and guided tissue regeneration with absorbable membrane. After 2 months of daily plaque control, each of the dog's furcation pre-molars was randomly assigned to a test or control group. Orthodontic appliances were placed on both sides of the maxilla using third pre-molars and canines as anchorages. In the test group, bodily orthodontic movement of the second pre-molars was performed in the mesial direction for 3 months while control pre-molars remained unmoved. The dogs were sacrificed for histometric and histologic analyses. RESULTS: There were no statistically significant differences between the two groups in total bone and biomaterial areas or linear extension of periodontal regeneration on the radicular surfaces. In the test group, however, there was a tendency to a greater quantity of bone and a lesser quantity of biomaterial. CONCLUSION: The orthodontic movement was not pre-judicial to the results obtained with the regenerative periodontal treatment.

Animals↗
PubMed2004

Correlation of stress and strain profiles and the distribution of osteoclastic cells induced by orthodontic loading in rat.

The aim of this study was to investigate whether stress or strain within the periodontal ligament (PDL), or rather in the bone, plays a role in initiating biological responses in orthodontic tooth movement. The upper first molars of 11 Wistar rats were moved mesially with a closed nickel titanium alloy coil spring for 3-12 d and three rats served as controls. After preparation of the maxillae for paraffin histology, tartrate-resistant acid phosphatase (TRAP) activity was evaluated to detect osteoclasts and their mononuclear precursors in four regions around the mesial root. Based on histological sections, finite element models were developed. The stress/strain distributions associated with the orthodontic loading were determined in the alveolar bone and in the PDL and compared with the osteoclast distributions. In the PDL, the normal stresses and strains were compressive (negative) in regions where the number of osteoclasts was highest, whereas the positive normal tensile stresses and strains were coincident with regions with small numbers of osteoclasts. The results indicate a direct correlation of the calculated stress/strain values in the PDL with the distributions of osteoclasts in the alveolar bone and PDL. Thus, these seem to be the dominant mechanical factor of tissue reaction to orthodontic force application, whereas the mechanical loading of the bone does not seem to play a role in orthodontic bone remodeling.

Acid Phosphatase↗
PubMed2006

Composition changes in gingival crevicular fluid during orthodontic tooth movement: comparisons between tension and compression sides.

The aim of this study was to evaluate whether the application of tension or compression forces exerted on the periodontium during the early phase of orthodontic tooth movement is reflected by differences in the composition of the gingival crevicular fluid (GCF), at the level of interleukin-1beta (IL-1beta), substance P (SP), and prostaglandin E(2) (PGE(2)). Eighteen children (mean age 10.8 yr) starting orthodontic treatment were included in the study. Molar elastic separators were inserted mesially to two first upper or lower molars. One of the antagonist molars served as the control. GCF was collected from the mesial and distal sites of each molar, before (-7 d, 0 d) and immediately after (1 min, 1 h, 1 d, and 7 d) the placement of separators. The levels of IL-1beta, SP, and PGE(2) were determined by enzme-linked immunosorbent assay. At the orthodontically moved teeth, the GCF levels of IL-1beta, SP, and PGE(2) were significantly higher than at the control teeth in both tension and compression sides, and at almost all occasions after insertion of separators. The increase, relative to baseline values, was generally higher in tension sides. For the control teeth, the three mediators remained at baseline levels throughout the experiment. The results suggest that IL-1beta, SP, and PGE(2) levels in the GCF reflect the biologic activity in the periodontium during orthodontic tooth movement.

Adolescent↗
PubMed2006

Interleukin-1alpha and tumor necrosis factor-alpha expression during the early phases of orthodontic tooth movement in rats.

Remodelling of the periodontium after application of mechanical forces constitutes the basis of clinical orthodontics and various immunoregulatory molecules are involved in this process. The aim of this study was to investigate the expression of the cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) in dental tissues during the early phases of orthodontic tooth movement. Eightteen male Wistar rats were used. All maxillary right first molars were moved orthodontically, with a force of 0.5 N, for 3 h, 1 d, and 3 d. The contralateral sides served as untreated controls. Parasagittal sections of the maxillary molars and the surrounding tissues were subjected to immunohistochemical staining for IL-1alpha or TNF-alpha, and were evaluated with light microscopy. IL-1alpha and TNF-alpha were expressed in the bone and periodontal ligament (PDL) along the roots of the orthodontically moved molars and in the gingiva. Increased expression of both cytokines was observed in the aforementioned areas after 1 and 3 d of tooth movement. The pulp tissue exhibited only minor changes in cytokine expression during tooth movement. The results suggest that mechanical stress results in almost immediate inflammatory reactions in various dental tissues.

Analysis of Variance↗
PubMed2006

The effect of drugs on orthodontic tooth movement.

OBJECTIVE: Molecules produced in various diseased tissues, or drugs and nutrients consumed regularly by patients, can reach the mechanically stressed paradental tissues through the circulation, and interact with local target cells. The combined effect of mechanical forces and one or more of these agents may be inhibitory, additive or synergistic. The objective of this review is to outline the mechanisms of action and effects of some commonly used drugs on tissue remodeling and orthodontic tooth movement. DESIGN: All the existing published literature on the effects of various drugs that are prescribed by orthodontists, which are consumed by patients for systemic diseases and those that are known to promote and retard the tooth movement process was obtained and subjected to thorough review process. RESULTS: All the drugs reviewed have therapeutic effects, as well as side effects, that may influence the cells targeted by orthodontic forces. Therefore, it is imperative that the orthodontist pays close attention to the drug consumption history of each and every patient, before and during the course of orthodontic treatment. When the use of drugs is revealed, their effects and side effects on tissue systems should be explored, to determine their potential influence on the outcome of mechanotherapy. CONCLUSION: Drug-consumption history must be an integral part of every orthodontic diagnosis and treatment plan.

Animals↗
PubMed1999

Condylar bony change and craniofacial morphology in orthodontic patients with temporomandibular disorders (TMD) symptoms: a pilot study using helical computed tomography and magnetic resonance imaging.

OBJECTIVE: To investigate how condylar bony changes relate to craniofacial morphology using helical CT and MRI. DESIGN: Craniofacial morphology of orthodontic patients with condylar bony changes was compared with Japanese standard. SETTING AND SAMPLE POPULATION: The Department of Orthodontics, Niigata University School of Dentistry, Twenty-nine subjects were selected from orthodontic patients (six males and 23 females, a mean age of 18.8 +/- 6.3 years) who were diagnosed by helical CT as having condylar bony changes. EXPERIMENTAL VARIABLE: Subjects were divided into two groups: a unilateral condylar bony change group (unilateral group) (four males and nine females) and a bilateral condylar bony change group (bilateral group) (two males and 14 females). OUTCOME MEASURE: Condylar bony changes were evaluated on reconstructed coronal and sagittal CT scans. Disk positions were evaluated by MRI scans. Five linear and four angular measurements in lateral and posteroanterior cephalograms were compared with those of an age- and sex-matched 'standard population' from the Japanese standard. RESULTS: In the bilateral group, osteophyte formation and erosion were the common bony changes and were present in adult as well as juvenile subjects. In the unilateral group, flattening was the most common features and erosion was only present in subjects below 19 years. Disk displacement without reduction was seen in 90.6% of the bilateral group, and in 76.9% of the unilateral group. Retrognathic mandibles were shown in the bilateral group. All subjects exhibited a lateral shift of the menton toward the condylar bony changed side in the unilateral group. CONCLUSION: Condylar bony changes might be progressive and unstable in adults of the bilateral group as well as in juveniles of the both groups. It appears that condylar bony changes may be related to a lateral shift of the mandible and a retrognathic mandible in orthodontic patients with TMD symptoms.

Adolescent↗
PubMed1996

Inhibitory effect of the topical administration of a bisphosphonate (risedronate) on root resorption incident to orthodontic tooth movement in rats.

Root resorption associated with tooth movement is an unsolved problem in orthodontics. If such root resorption could be prevented, it would be an important contribution toward reducing risk factors in orthodontic treatment. The purpose of this study was to examine the effects of the topical administration of a bisphosphonate, risedronate, which is known to be a potent blocker of bone resorption, on root resorption during tooth movement and on the repair of the resorbed root surface after tooth movement in rats. In the first experiment, both the right and left upper first molars were moved buccally with a standardized expansion spring under administration of risedronate. After day 7, extensive root resorption had occurred on the control side, and the area of root resorption reached a maximum on day 14. The topical administration of risedronate caused a significant and dose-dependent inhibition of root resorption after the orthodontic force was applied. In the second experiment, the right and left upper molars were first moved buccally for 3 weeks. Risedronate treatment began on the day the spring was removed. After the force was withdrawn, the resorbed root surfaces on both the control and risedronate-treated sides were gradually restored by apposition of repair cementum (cementoid). The topical administration of risedronate did not appear to inhibit the repair process of root resorption. These results suggest that the topical administration of risedronate may be useful in preventing root resorption of teeth during orthodontic treatment.

Administration, Topical↗
PubMed1983

The feasibility and validity of orthodontic screening of children in their tenth year.

The study set out to investigate the problems of the implementation of the Court Report's suggestion that every child in its tenth year be screened for orthodontic treatment by "a dentist with special training in orthodontics' using Grainger's Treatment Priority Index (TPI). The study was divided into two parts. The standardization exercises used 31 orthodontic models of children in their tenth year. The problem of examiner variability, using a Community Dental Officer instead of an orthodontist and of bias that the TPI might have were examined. The main study involved the examination of 362 children in ten separate schools in Oxfordshire and investigated the problem of orthodontic screening at annual school inspections. The findings showed that the TPI may be able to provide a method for screening children in their tenth year if the weights of the clinical entities which are reducing the level of validity of the TPI are identified. The problem of scoring tooth displacements consistently would have to be taken into consideration when training personnel to use the TPI.

Child↗
PubMed2000

Mucogingival interceptive surgery of buccally-erupted premolars in patients scheduled for orthodontic treatment. II. Surgically treated versus nonsurgically treated cases.

BACKGROUND: The aim of this 2-year longitudinal study was to compare the width of keratinized gingiva after orthodontic therapy for buccally erupting premolars that had been pretreated by extraction of deciduous teeth alone versus interceptive mucogingival surgery. METHODS: In 8 patients (aged 9 to 12 years) who presented with bilateral buccal eruption of homologous teeth (premolars), one side was randomly treated with extraction of the deciduous molar and mucogingival surgery (test site), while the other side was treated only by extraction of the deciduous molar (control site). All of the subjects underwent orthodontic treatment with fixed appliances. RESULTS: At the baseline visit prior to any treatment, there was no significant difference between the mean amount of keratinized gingiva at test sites (3.06 mm) and control sites (2.93 mm). Two years later, upon completion of orthodontic treatment, there was a significant difference between test (2.93 mm) and control (1.37 mm) sites in the mean width of keratinized tissue. In the control (untreated) group, 2 sites exhibited 1 mm of gingival recession after orthodontic treatment. CONCLUSIONS: Mucogingival interceptive surgery is an effective technique to maintain keratinized tissue in correspondence with buccally-erupted teeth.

Bicuspid↗
PubMed2002

Alveolar bone upper growth in furcation area using a combined orthodontic-regenerative therapy: a case report.

BACKGROUND: This case report demonstrates orthodontic and regenerative combined therapy in a 49-year-old male whose right maxillary premolar furcation had a bony defect with poor biologic width resulting from extensive subgingival caries. In these advanced interdisciplinary cases, crown lengthening with periodontal surgery alone does not solve the complex clinical problems. We believe that a combined orthodontic and periodontal regenerative combination therapy offers the best option for achieving a predictable outcome. METHODS: First, regenerative therapy by open debridement with a bioabsorbable synthetic bone graft, bioabsorbable membrane, and minocycline root conditioning was carried out. Eight weeks after initial surgery, orthodontic extrusion was initiated. RESULTS: Radiographs and reentry documentation suggest that the furcation defect associated with poor biologic width was successfully treated. CONCLUSION: This case report demonstrates that orthodontic-regenerative combined therapy can resolve complex clinical problems and enhance predictability.

Absorbable Implants↗
PubMed2004

Bone apposition in surgical bony defects following orthodontic movement: a comparative histomorphometric study between root- and periodontal ligament-damaged and periodontally intact rat molars.

BACKGROUND: The influence of orthodontic tooth movement with diminished periodontal support is unclear. The aim of the present study was to evaluate bone healing in surgical defects following orthodontic tooth movement with and without periodontal ligament (PDL) and root surface damage. METHODS: The study comprised 33 adult male Wistar rats, divided into two groups: group 1 (n = 14) with bony defect and no root damage and group 2 (n = 19) with periodontal bony defect including root/PDL damage on the mesial root of the maxillary first molar. One week after a surgical defect was created, orthodontic protraction of the right maxillary first molar was initiated in both groups. After 2 weeks of protraction, retention of 1 week was established; at the end of this period block sections were made. Histomorphometric analysis through light microscopy of decalcified tissue was performed. Results were statistically analyzed using independent samples t test and analysis of variance (ANOVA) with repeated measures. RESULTS: Differences between groups in total area of bone defect and bone apposition were not statistically significant. Bone apposition calculated as percentage of the bone defect was significantly (t-test) greater (P = 0.002) in group 2 (46.21%) than in group 1 (24.95%). Within each group, area of bone apposition was significantly (ANOVA) greater in the distal than in the mesial quadrants of the bony defect (P = 0.006) and in the apical than the occlusal ones (P = 0.021). CONCLUSION: Following orthodontic tooth movement, periodontal bony defects showed enhanced bony healing compared with alveolar bone defects with no direct association with the periodontal attachment apparatus.

Alveolar Bone Loss↗
PubMed1998

[HA-coated titanium implants used as orthodontic anchorage. An experimental investigation of implant stability and peri-implant neck tissue in dogs].

This study was aimed at the feasibility of using HA-coated titanium endosseous implants as orthodontic anchorage. These implants installed in dog's mandibles were loaded with the orthodontic force of 150 g for 3 months. The stability of the implant and the peri-implant neck tissue were investigated with radiograph and index evaluation. The findings demonstrated that no implant was mobile or loose or dislocated. The soft tissue around the cervical part of the implants had a slight inflammation because of bad oral hygiene and the stimulation of residual food attached to the stainless string. However, no resorption of marginal alveolor bone was found under sustained orthodontic force. The above results suggest that the HA-coated titianium implant can be used as anchorage for short-term orthodontic treatment.

Animals↗