Clinical and microbiologic changes after removal of orthodontic appliances

The goal of this study was to evaluate the clinical and microbiological factors associated with orthodontic appliances during an episode of gingival inflammation and the impact of appliance removal on periodontal health. This prospective study included 10 patients, aged 12 to 20 years, with clinical signs of gingival inflammation at the final phase of orthodontic treatment (appliance removal). Plaque index, gingival index, and probing depth were evaluated, and microbiological samples were collected from teeth 16, 11, and 26 at 2 times: during the gingival inflammation (baseline) and 30 days after the removal of the appliance and professional prophylaxis. Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Prevotella nigrescens. A statistically significant improvement of the plaque and gingival indexes was seen, as well as a reduction in probing depth (P <.05). Periodontal pathogens were associated with gingival inflammation during orthodontic treatment. The improvement in periodontal health at 30 days was concomitant with a reduction of sites positive for A. actinomycetemcomitans and B. forsythus (P <.05). Periodontal pathogens associated with gingival inflammation during orthodontic treatment can be significantly reduced by orthodontic appliance removal and professional prophylaxis.

Nickel allergy and orthodontic treatment

OBJECTIVES

Tolerance induction to prevent development of nickel allergy has been suggested with permanent dental braces. We wanted to find out which effect orthodontic treatments had had on the development of nickel allergy in university students.

STUDY DESIGN

We examined and patch tested 153 students, of whom 113 had a history of pierced skin, and 70 a history of orthodontic treatment roughly 10 years earlier.

RESULTS

All except one student with pierced skin were females. Development of nickel allergy was significantly associated with skin piercing (54% compared with 12%). At the time of the study, there was a slight but non-significant difference in the prevalence of nickel allergy between students who had been subjects for orthodontic treatment (49%) compared with non-treated ones (58%) if they had pierced skin. There were no significant differences in the development of nickel allergy among students who had had permanent dental braces before (50%) or after skin piercing (48%). However, from 40 students without skin piercing four of 11 (three males) with a history of permanent braces had developed nickel allergy, as compared with none of 22 (P = 0.008) without orthodontic treatment suggesting possibility of sensitization through dental devices.

CONCLUSIONS

Orthodontic treatment may not lead to tolerance induction on all occasions, and sensitization through permanent devices seems to be possible.

Mucocele on the Lower Lip?a Case Report

A patient with a superficial oral mucocele on the lower lip is presented. The lesion developed in temporal relationship with the insertion of a functional appliance. The etiology and pathogenesis of this lesion are discussed.

Malocclusion and temporomandibular disorder: a comparison of adolescents with moderate to severe dysfunction with those without signs and symptoms of temporomandibular disorder and their further development to 30 years of age

A total of 1018 subjects were examined at the age of 11 years, 791 were reexamined at 15 years, 456 at 19 years, and 337 at 30 years. Anamnestic and clinical recordings of temporomandibular disorder (TMD) were made. Morphology, including calculation of peer assessment rating (PAR) scores, was recorded. Previous history of orthodontic treatment was assessed. Muscular endurance was recorded. The subjects completed four psychological measures. The malocclusion prevalence, occlusal contacts, psychological factors, and muscular endurance in subjects with no recorded signs and symptoms of TMD were compared with those with the most severe dysfunction at 19 years of age. The further development of TMD to 30 years of age was followed. PAR scores were significantly higher in the subjects with the most severe dysfunction. Apart from crowding of teeth, no other significant differences were found between the groups with regard to separate malocclusions, tooth contact pattern, orthodontic treatment, or extractions. A greater proportion of subjects with low endurance were found in those with TMD. Significant associations between TMD and general health and psychological well-being as well as the personality dimension of neuroticism and self-esteem were found. During the period from 19 to 30 years, the prevalence of muscular signs and symptoms showed considerable reduction, whereas clicking showed a slight increase. Locking of the joint showed a decrease from 19 to 30 years. One-quarter of the TMD subjects showed complete recovery. Thus, orthodontic treatment seems to be neither a major preventive nor a significant cause of TMD.

Hypersensitivity to metals in orthodontics

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

Combined bone grafting and orthodontic treatment of an iatrogenic periodontal defect: a case report with clinical reentry

BACKGROUND

This case report discusses the treatment of an iatrogenic periodontal defect caused by an inadequate orthodontic appliance in a 9-year-old girl.

METHODS

The multidisciplinary approach to this case consisted of periodontal treatment using a bone grafting technique to restore the 10 mm bone dehiscence. Three months later orthodontic treatment was initiated to straighten and level the central incisors. Six months later mucogingival surgery was performed to cover 2 to 3 mm gingival recession.

RESULTS

The bony defects were completely filled and the 10 mm dehiscence was reduced to 4 mm. The connective tissue graft resulted in a complete coverage of the recessions and a thickening of the keratinized gingiva. The patient is still undergoing orthodontic treatment. So far, straightening of the upper central incisors and closure of the diastema are satisfactory.

CONCLUSIONS

Inadequate orthodontic appliances can cause iatrogenic periodontal defects. A multidisciplinary approach in a well-defined sequence can restore lost periodontal tissue, thus achieving comfort, function, and esthetics.

Clinical response to allergies in patients

Allergenic reactions are becoming a more prevalent concern of practitioners in health-related fields. As patient susceptibility increases, the need for understanding and successfully treating such heterogeneous responses becomes paramount. This article presents a theoretical bioengineering model that considers the influences of specific concentrations on their chemical effects. This model then is applied to contemporary orthodontics in which nickel and, to a lesser extent, chromium are antagonists in as many as 1 in 500 patients-which, for North America, amounts to about 4000 patients per year. For the occasional patient who responds positively to a questionnaire, a skin patch test would be administered to establish whether alternative alloys could be used, whether they be gold, platinum, nickel-free stainless steel, or titatnium-molybdenum alloys.

Behavior of partially formed roots of teeth submitted to orthodontic movement

The occurrence of root resorption in orthodontically treated permanent incisors with partially formed roots was investigated using periapical radiographs taken before and after the orthodontic leveling in the mixed dentition. The mean age at the beginning of treatment was 9 years and the mean treatment time was 7.1 months. The findings showed that the orthodontic movement during root formation causes no root resorption. The longitudinal follow-up showed that incompletely formed roots developed normally.

Cutaneous and Oral Eruption from Oral Exposure to Nickel in Dental Braces

Oral eruptions due to nickel allergy are rare. A common presentation of intraoral contact dermatitis is the presence of lichenoid plaques on the buccal mucosa adjacent to the offending antigen. We report an unusual case of cutaneous and mucosal nickel allergy arising after placement of dental braces. An 11-year-old boy was referred by his orthodontist to the University of Minnesota Occupational and Contact Dermatitis Clinic to be evaluated for a possible metal allergy. The patient developed an itchy rash on his abdomen and under his wristwatch 1 week after dental braces were placed. He was diagnosed with allergic contact dermatitis from nickel. The patient avoided cutaneous nickel exposure and had a minimal resolution of his symptoms. One year later, the patient developed swelling and burning of the lips. Secondary to extreme discomfort, the braces, which contained nickel, titanium, and zinc, were removed. The patient underwent standard patch testing; the final reading at 96 hours showed a +++ reaction to nickel, palladium, cobalt chloride, and neomycin. The patient experienced relief of his oral symptoms after removal of the braces. No current relevance to palladium, cobalt, or neomycin has been found.

Allergies Induced by Orthodontic Alloys: Incidence and Impact on Treatment

BACKGROUND

The incidence of allergies in general is on the increase. An allergic reaction can also occur during any dental and orthodontic treatment. However, the allergic potential of orthodontic appliances is frequently overestimated.

MATERIAL AND METHOD

The incidence of suspected allergic reactions during fixed appliance therapy in 68 orthodontic offices in the German State of Hesse was determined by questionnaire at approximately 0.3% of the 60,000 patients covered.

RESULTS

More extraoral (45%) than intraoral (17%) skin changes were registered, with both intraoral and extraoral changes being observed in 38%. In 53% of the affected cases the therapy was adapted to nickel-free materials, whereas it was continued as planned after a brief recovery period in 33%. The treatment was discontinued in 14% of the affected patients, corresponding to one in every 3150. The individual tolerance can often be tested by inserting one bracket or one band. In addition, early orthodontic treatment seems to promote a certain immune tolerance, especially towards extraoral nickel contacts. However, if a patient is known to have a nickel allergy, materials containing nickel should be renounced on principle in the orthodontic appliances.

CONCLUSION

Skin changes occurring in the course of orthodontic treatment should be examined and verified if necessary by a dermatologist. Gold plating and other coatings (titanium nitride) of the metal elements even encourage corrosion after a brief protection period. Soldering should be avoided.

Effect of orthodontic forces on root resorption in molars submitted to experimental periodontitis

The present experimental study addresses the issue of the development and size of root resorption areas in molars of rats submitted to orthodontic forces of 51 or 75 g and the induction of periodontal disease by placing a cotton ligature around the cervix of the first upper molars for 48 hours. Immediately on removal of the ligature or 48 hs later we put an orthodontic device in place. The device comprised two steel bands. The arms of a helicoidal spring that exerted force towards palatine passed through the palatine tubes welded to the bands. The number of odontoclasts and the percentage of root resorption areas were determined histomorphometrically on bucco-palatine sections obtained at the level of the central roots. The data showed an increase in root resorption areas when the orthodontic forces were applied to molars of rats following the induction of periodontitis. The magnitude of the force was proportional to the size of the resorption areas and to the number of odontoclasts. Both these end-points exhibited smaller values when the forces were applied once the inflammatory reaction had subsided. The present study shows that the risk of development of root resorption areas in patients with periodontal disease submitted to orthodontic treatment would be lower if lighter forces were applied and treatment were delayed until the inflammatory signs have subsided.

Gingival necrosis in relation to palatal expansion appliance: an unwanted sequelae

A palatal expansion appliance is frequently used for the expansion of the palatal arch. The expansion can be rapid or slow. The degree of turn given to the screw of the appliance determines the rapidity and amount of expansion achieved. This report describes a case of necrosis of the palatal gingiva as a result of an attempt to expand the palatal arch rapidly and is of great importance to the pediatric dentist as palatal expansion is done more often in pediatric patients.

In vivo study on metal release from fixed orthodontic appliances and DNA damage in oral mucosa cells

Interest in the amount of metal ion intake from dental alloys has grown. Fixed orthodontic appliances usually include brackets, bands, and archwires made of stainless steel, nickel-titanium, or nickel-cobalt alloys, and these can release metal ions. The purpose of this study was to investigate the biocompatibility in vivo of fixed orthodontic appliances, evaluating the presence of metal ions in oral mucosa cells, their cytotoxicity, and their possible genotoxic effects. Mucosa samples were collected by gentle brushing of the internal part of the right and left cheeks of 55 orthodontic patients and 30 control subjects who were not receiving orthodontic treatment. The cells were immediately prepared for cell viability and the comet assay. Nickel and cobalt cellular content was quantified by inductively coupled plasma mass spectrometry (ICP-MS). The results indicate that nickel and cobalt concentrations were 3.4-fold and 2.8-fold higher, respectively, in the patients than in the controls; cellular viability was significantly lower in the patients than in the controls, and there was a significant negative correlation with metal levels. The biologic effects, evaluated by alkaline comet assay, indicated that both metals induced DNA damage (more cells with comets and apoptotic cells). There were significant positive correlations between (1) cobalt levels and the number of comets and apoptotic cells, (2) nickel levels and number of comet cells, and (3) cobalt levels and comet tails. This study corroborates that nickel and cobalt released from fixed orthodontic appliances can induce DNA damage in oral mucosa cells.

Changes in occupational health problems and adverse patient reactions in orthodontics from 1987 to 2000

The purpose of the present investigation was to assess the reasons for changes in occupational health problems and patient reactions to orthodontic treatment after a survey carried out in 1987. Questionnaire data on occupation-related health complaints and patient reactions over the preceding 2 years were obtained from 121 of 170 Norwegian orthodontists (71 per cent). Most health complaints were dermatoses of the hands and fingers related to the processing of acrylic removable appliances, to composite bonding materials, or gloves. A few reactions were of a respiratory or systemic nature. In total, occupation-related dermatoses were reported by 17.4 per cent (21/121) compared with 40 per cent previously. Non-dermal complaints comprised 9 per cent compared with 18.2 per cent in 1987. Patient reactions were distributed equally between intra-oral reactions affecting lips, gingiva, oral mucosa, and tongue, and dermal reactions affecting the corner of the mouth, the dorsal part of the neck, the peri-oral area, cheeks, chin or skin elsewhere. A few patients had systemic reactions. The assumed eliciting agents of intra-oral reactions were fixed metallic appliances, acrylic removable appliances, polymer brackets or composite bonding materials, or were related to elastics. Extra-oral (dermal) reactions were attributed to metallic, elastic or textile parts of the extra-oral appliances. Some reactions were verified as allergies. The percentage of patient reactions in total was estimated to be 0.3-0.4 per cent compared with 0.8-0.9 per cent in 1987. The reduction in occupation-related health complaints among orthodontists was explained by changes in previously important hygiene factors such as soaps, detergents, etc., whereas the biomaterials-related reactions persisted. The reduction in the 2 year incidence of patient reactions was associated with a marked reduction in extra-oral reactions following preventive measures such as coating metallic devices, whereas the intra-oral reactions persisted at the same level as previously.

Comparison of 3 bonded lingual appliances by auditive analysis and subjective assessment

The aim of this prospective study was to compare for the first time the influences of lingual appliances of different dimensions on sound performance and oral comfort. The study group comprised 12 subjects (10 women, 2 men; mean age, 33.96 years). Their sound production was recorded by means of a digital audio tape recorder before, 10 minutes after, and 24 hours after placement of the different appliances for semiobjective assessment by 3 blinded speech professionals. This was followed by supplementary subjective ratings of sound performance and oral comfort by the patients. All lingual appliances induced significant impairment in sound performance and oral comfort. However, they varied significantly with respect to the degree of impairment. The smaller the appliance, the less pronounced the impairments it induced. The smallest changes were induced by a bonded canine-to-canine retainer, followed by customized lingual brackets and prefabricated lingual brackets. By using lower-profile customized brackets, the orthodontist can significantly enhance patient comfort and significantly reduce impairments of sound performance in comparison with prefabricated brackets with larger dimensions. Before placing a lingual appliance, however, patients should be briefed on possible effects such as impaired sound production and decreased oral comfort.

[Allergies in orthodontics]

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

[Complex approach to the problem of individual intolerance of orthodontic constructions made of different materials]

The problem of intolerance of materials used in dentistry is reviewed in brief. Characteristic situations when this intolerance manifests are described. Approaches (practical and organizational) which can help reduce the incidence of individual intolerance of dentures and materials used in dentistry are outlined. Methods for individual selection of materials are analyzed. The possibility of using electropuncture methods for this purpose is demonstrated. Arguments in favor of creating a special laboratory for studies of specific problems of dentistry are presented and the list of problems to be solved by this laboratory is offered.

External apical root resorption in Class II malocclusion: a retrospective review of 1- versus 2-phase treatment

External apical root resorption (EARR) is an imperfectly understood problem of orthodontic treatment. The records of 138 children with Class II malocclusion (overjet > 7 mm) participating in a randomized clinical trial of early orthodontic treatment were reviewed. The patients were treated in either 1 phase with fixed appliances only (n = 49) or 2 phases with headgear (n = 49) or bionator (n = 40) followed by fixed appliances. The 3 groups were similar in age, sex, and malocclusion severity at enrollment. The records examined included anamnestic data, clinical examination records, panoramic radiographs before and after fixed appliance therapy, and posttreatment periapical radiographs. All radiographs were reviewed and scored independently by 2 examiners for maxillary incisor root development, morphology, and EARR. Of the 532 incisors scored, 11% of central and 14% of lateral incisors demonstrated moderate to severe (>2 mm) EARR. The proportion of incisors with moderate to severe EARR was slightly greater in the 1-phase treatment group. There was no difference in the incidence of EARR between teeth that had had trauma and those that had not, and there was only a slight increase in frequency of root resorption in teeth with unusual root morphology. Significant associations exist among EARR, the magnitude of overjet reduction, and the time spent wearing fixed appliances. However, not all incisors in a child respond in the same way, so other variables must play a role in determining the root response to orthodontic forces.

Comparative radiographic evaluation of the alveolar bone crest after orthodontic treatment

This study evaluated and compared the heights of the alveolar bone crests (AC) among orthodontic patients treated with either the simplified standard edgewise technique (group 1, n = 30), the edgewise straight-wire system (group 2, n = 30), or bioefficient therapy (group 3, n = 26). These 3 groups were compared with an untreated control group (group 4, n = 30). A comparison by sex of AC height was also conducted. The first premolars were extracted in every treated patient, and measurements were performed on bitewing radiographs taken after a mean posttreatment period of 2.17 years. The distances from the AC to the cementoenamel junction (CEJ) on the mesial and distal surfaces of the first molars and second premolars and on the distal surface of the canines were measured; the larger the distance, the greater the alveolar bone loss. The data were analyzed by 1-way analysis of variance and the Newman-Keuls test (P <.05) for comparison among the groups. Sex differences of the AC height were evaluated with the t test. All treated groups had larger, statistically significant CEJ-AC distances than the untreated group, primarily at the extraction areas. There were no consistent statistically significant differences in the areas among the treated groups. Mean distances of the CEJ-AC in boys were larger than or similar to those in girls. The patients in the treated groups showed a greater number of proximal surfaces with statistically significant differences between sexes, compared with the control subjects.

Results of double-blind placebo-controlled challenge with nickel salts in patients affected by recurrent aphthous stomatitis

BACKGROUND

The aetiology of recurrent aphthous stomatitis (RAS) has so far not been completely clarified. Recently, several studies reported that patients affected by cutaneous diseases (i.e. dermatitis, eczema and urticaria) with positive patch test to nickel have a positive oral nickel challenge.

OBJECTIVE

A retrospective data analysis of patch test and oral nickel challenge in 380 patients (204 women and 176 men) affected by RAS was performed.

PATIENTS AND METHODS

We examined 380 consecutive patients affected by RAS during the period 1990-1999. In 28/380 patients the appearance of their oral symptoms coincided with the fitting of orthodontic appliance, while 352/380 reported that their oral symptoms worsened after the fitting of orthodontic appliance. All patients were studied with the series (European standard series and series for dental materials) for patch tests.

RESULTS

Seventy out of 380 patients (18.4%) presented a contact sensitization to nickel sulphate (positive patch test). In all of these, the orthodontic appliance was replaced with one made of nickel-free materials. All patients were re-examined by the dentist 6 months after the removal of the orthodontic appliance. The symptoms had completely remitted in 28/70 patients, partially had improved in 31/70 patients and had remained unchanged in 11/70 patients. In all patients (n = 70) with a positive patch test to nickel we performed an oral double-blind placebo-controlled challenge (DBPC) test with nickel sulphate. The DBPC was positive in 32/70 patients, 21 of whom had partially improved and 11 had not, even after the replacement of the orthodontic appliance with material not containing nickel. None of the 28 patients in complete remission showed an adverse reaction to oral nickel challenge.

CONCLUSION

The results of this study demonstrate that, in some patients with a positive patch test to nickel sulphate, the perpetuation of RAS can be related to a hypersensitivity to ingested nickel salts, independently of local contact to nickel.

Peripheral ossifying fibroma in a child: report of case

A typical peripheral ossifying fibroma in the anterior maxilla of an 11-year-old boy is presented. The importance of differential diagnosis and proper treatment for prevention of recurrence is discussed.

Evaluation of immunologic profile in patients with nickel sensitivity due to use of fixed orthodontic appliances

The aim of this study was to develop a new approach to testing the impact of nickel antigen on in vitro cell-proliferation assay, to identify adverse reactions to casting alloys among orthodontic patients. Cell-proliferation assay in vitro was used as the basic methodology to assess the influence of such variables as source of nickel antigen, type of serum used to supplement the culture medium, and number of cells in the culture. We selected 35 orthodontic patients who were classified as nickel sensitive and non-nickel sensitive, based on their clinical records. Our results showed that hexahydrated nickel sulfate at 10 microg/mL, 10% of autologous sera, and 2 x 10(5) cells was the best condition for inducing the most marked nickel proliferation response in vitro. This optimized method was able to distinguish nickel-sensitive from non-nickel-sensitive dental patients and also to discriminate those with positive skin tests. Our data suggest that continuous exposure to nickel casting alloys might lead to oral tolerance mechanisms that modulate nickel sensitivity, as evidenced by the lower cell proliferation index in patients undergoing orthodontic treatment over 24 months. Finally, our findings demonstrated a known nickel-induced type 2 immune response and a marked lack of type 1 immunity (interferon gamma) as the hallmarks of nickel-sensitive patients. Further studies are needed to clarify the major cell phenotype associated with this type 2 immune response and the lack of type 1 immunity observed in nickel-sensitive people.

Dental abnormalities, bone graft quality, and periodontal conditions in patients with unilateral cleft lip and palate at different phases of orthodontic treatment

OBJECTIVES

To evaluate the dental and periodontal condition of patients with unilateral cleft lip and palate (UCLP) before orthodontic treatment and evaluate whether the dental and periodontal condition of these patients during and after orthodontic treatment was jeopardized by the duration of the orthodontic and surgical treatment.

DESIGN

Seventy-five individuals with UCLP (52 males, 23 females), between ages 8 and 20 years, participated in a retrospective study during their final follow-up visit with regard to dental abnormalities, such as hypodontia, external root resorption, crown and root malformation, and supernumerary teeth. Alveolar bone height and periodontal attachment loss on the cleft side were also screened before or after bone grafting and at different stages of orthodontic treatment.

RESULTS

Hypodontia of the lateral incisor was found in more than 50% of the patients on the cleft side. Second premolars and/or lateral incisors outside the cleft area were missing in 27.2% of the patients. In 32%, malformations of the teeth near the cleft were noticed. In general, the teeth around and in the cleft of the patients showed normal septal bone heights and a healthy periodontium. Sixty of the 75 patients received a bone graft to restore the interrupted alveolar process. In 93.3% of these patients, the cleft was grafted before the eruption of the canine.

CONCLUSION

The periodontium of the teeth in and around the cleft in patients with UCLP observed during and after orthodontic treatment can cope relatively well with the long orthodontic treatment and combined surgical interventions. The children, who had not yet started treatment, also showed enough bone support and no periodontal problems of the teeth besides the cleft. Early secondary bone grafting seems to give optimal periodontal results.

Distribution of the cement film beneath the orthodontic band: a morphometric in vitro study

BACKGROUND

During orthodontic treatment with a multiband appliance, enamel decalcifications and periodontal irritation may occur due to inevitable plaque retention. Besides the band itself, non-cemented gaps between tooth and band constitute a problem that has not yet been investigated from quantitative aspects.

MATERIALS AND METHODS

In this in vitro study, the cement distribution beneath the orthodontic band was investigated on 48 identical transparent resin replicas of upper molars and lower molars, respectively. The replicas with the cemented orthodontic bands were divided into buccal, distal, oral, and mesial segments so that the inner surfaces of the bands could undergo morphometric analysis for areas not covered with cement. Two different molar bands (Dentaform Snap by Dentaurum, Ispringen, Germany, and "Washbon" by Ormco, Orange, CA, USA), and two glass-ionomer cements (OptiBand by Ormco and Ultra Band-Lok Blue by GAC, Gräfelfing, Germany) were used. In this way, 8 test series with twelve specimens each were performed.

RESULTS

Not one cement-band combination was without defects in the cement film, with poorer cement flow properties being observed at the upper than at the lower molars. In general, fewer defects were recorded in the occlusal than in the cervical areas. Overall, the buccal surfaces yielded the best results, and the mesial surfaces the poorest.

CONCLUSIONS

Since defects in the cement film have so far been unavoidable, the indication for orthodontic treatment with a multiband appliance must continue to be strict. Unless accompanying professional prophylactic care coupled with optimal oral hygiene is ensured, multiband appliances should be used with great caution.

Nickel allergy and orthodontics

Nickel is the most common metal to cause contact dermatitis in orthodontics. Nickel-containing metal alloys, such as nickel-titanium and stainless steel, are widely used in orthodontic appliances. Nickel-titanium alloys may have nickel content in excess of 50 per cent and can thus potentially release enough nickel in the oral environment to elicit manifestations of an allergic reaction. Stainless steel has a lower nickel content (8 per cent). However, because the nickel is bound in a crystal lattice it is not available to react. Stainless steel orthodontic components are therefore very unlikely to cause nickel hypersensitivity. This article discusses the diagnosis of nickel allergy in orthodontics and describes alternative products that are nickel free or have a very low nickel content, which would be appropriate to use in patients diagnosed with a nickel allergy.

The in vitro detection of early enamel de- and re-mineralization adjacent to bonded orthodontic cleats using quantitative light-induced fluorescence

The purpose of this study was to determine whether quantitative light-induced fluorescence (QLF) could detect very early demineralization and remineralization longitudinally adjacent to orthodontic components in an in vitro model. Extracted human premolars (n = 13) were sectioned sagittally to produce two equal halves and an orthodontic cleat was bonded to the buccal surface of each tooth. Transparent nail varnish was placed over the remaining surface, leaving exposed enamel windows adjacent to the cleat on the coronal and gingival aspects. Each half-tooth was placed into the lid of an Eppendorf tube and randomly assigned to either control (distilled water) or experimental (lactic acid demineralizing buffer, pH 4.5) regimes. Digital photographs and QLF baseline images were taken. The tubes were mounted into a rotating holder and left for 24 hours. QLF and digital photographs were taken, the solutions refreshed and the teeth returned. This was continued every 48 hours for 288 hours. At this time the lactic acid buffer was replaced with a remineralizing solution (artificial saliva, fluoride, calcium) and the experiment continued with weekly examinations. QLF images were analysed and deltaQ at the 5 per cent threshold recorded. Analysis of the QLF images showed that both demineralization and remineralization were identified and monitored. Statistical differences between each of the timed examinations were found (P < 0.05). Analysis of the photographs demonstrated that QLF detected subclinical lesions. This initial pilot study has demonstrated the potential for QLF to longitudinally monitor de- and re-mineralization of enamel adjacent to orthodontic cleats in vitro.

Apical Root Resorption after Lingual Orthodontic Therapy

PURPOSE

Apical root resorptions are among the undesirable side effects of orthodontic therapy. The aim of the present study was to investigate radiologically whether and to what extent resorptions occur in patients treated solely with a fixed lingual appliance, as well as the pathogenetic relevance of the extent and direction of the therapeutically induced apical movement.

PATIENTS AND METHODS

The collective comprised 33 female and seven male patients with a mean age of 24.2 +/- 8.4 years. Permanent lower premolars were extracted in five, and permanent upper premolars in 22 patients. In total, 456 upper and lower incisors and canines were assessed. In order to evaluate the relative change in root length and the sagittal and vertical apical movements, pre- and posttherapeutic panoramic radiographs and/or lateral cephalograms were analyzed.

RESULTS

After completion of orthodontic treatment the mean root length was 96.3%, corresponding to a resorption rate of 3.7%. The resorption rates of teeth 11, 12 and 21 differed significantly from those of teeth 31, 32 and 43. Upper incisors presented increased mean resorption rates < or = 10%. Only 18% of the 456 teeth analyzed were affected by pronounced resorptions > 10%. 82% of the teeth were resorption-free. A patient-related evaluation revealed that 26 of the 40 patients had no resorptions > 20%, while 14 had between one and four affected teeth. No significant relationship between extent of resorption and parameters such as age, gender, active treatment time, Angle class, or extent and direction of apical movement was recorded.

CONCLUSIONS

The results suggest that lingual orthodontic therapy resulted in only slight root resorptions. Pronounced root shortenings were observed in some patients whose individual predisposition may constitute the main risk factor for the occurrence of root resorptions.

The adolescent patient: special whitening challenges

Vital tooth bleaching has become increasingly popular, even with the adolescent patient. Tooth whitening may be performed in adolescent patients with typical bleaching agents; with severe discolorations, it may be more appropriate to use the microabrasion technique with subsequent bleaching to achieve desirable esthetics.

Angiogenic growth factors released in human dental pulp following orthodontic force

OBJECTIVE

The aim of this study was to investigate if a combination of five diffusible angiogenic growth factors were released in human dental pulp during orthodontic force application, by using growth factor neutralising antibodies (NAs) to block their effects.

MATERIALS AND METHODS

Dental pulps from 18 premolar teeth treated with orthodontic fixed appliances for 2 weeks were divided vertically, and each half pulp further sectioned and co-cultured with a section of rat aorta in collagen surrounded by growth media. NAs (anti-h VEGF, anti-h FGF2, anti-h PDGF, anti-TGFbeta and anti-h EGF) were added to the media of the co-cultures from one half of each pulp from 10 teeth. The co-cultures from the remaining eight teeth acted as controls. Sections of rat aorta alone were also cultured with and without NAs. Cultures were examined daily by light microscopy for growth and number of microvessels.

RESULTS

NAs significantly reduced microvessel numbers in the co-cultures, but not in the rat aorta alone cultures.

CONCLUSIONS

The results show that a combination of these angiogenic growth factors are released in the pulp following orthodontic force.

The role of oral appliances in treating obstructive sleep apnea

BACKGROUND

Sleep-related breathing disorders are common and often are associated with vascular complications such as arterial hypertension, coronary heart disease and stroke. The most widely studied form of these disorders is obstructive sleep apnea. Patients usually are diagnosed with obstructive sleep apnea years after the onset of symptoms, which generally are nonspecific and include excessive daytime sleepiness, chronic fatigue and habitual snoring. The risk factors for sleep apnea are obesity, advancing age, male sex and maxillofacial abnormalities. This review focuses on the diagnosis and treatment of obstructive sleep apnea and, specifically, on the utility of oral appliances in the management of this disorder.

METHODS

The review is based on a MEDLINE search for articles in English on this topic. The article discusses results of randomized studies and prospective case series.

CLINICAL IMPLICATIONS

Several treatment options are quite effective. Nasal continuous positive airway pressure, with an overall acceptance rate of 70 percent, is the most widely used treatment modality. Maxillofacial surgery, although effective, is reserved for patients who have not responded to the more conventional therapies. Newer methods include application of oral appliances. Oral appliances have been shown to alleviate the severity of respiratory disturbances during sleep by about 60 percent, with an overall acceptance rate of 75 percent. The long-term complications generally are minor and are related to occlusal changes and temporomandibular joint discomfort.

CONCLUSIONS

With the advent of oral appliances, dentists are increasingly involved in managing the care of patients with sleep-related breathing disorders. Further studies are needed to determine the long-term complications of this type of intervention for the treatment of sleep-related breathing disorders.

Stress distribution produced by the correction of the mandibular second molar in lingual crossbite

The purpose of this study was to evaluate the stress distribution produced in the dentoalveolar system by a mandibular posterior crossbite appliance used for the correction of mandibular second molars in lingual version. A photoelastic model was fabricated using a photoelastic material (PL-3) to simulate alvelolar bone and ivory-colored resin teeth. The model was observed anteriorly and posteriorly with a circular polariscope and photographically recorded before and after activation of mandibular posterior crossbite appliances. An uncontrolled tipping and an extrusive force were generated when the traction force was applied on the buccal surface of the mandibular second molar. A controlled tipping and an intrusive force were generated when the traction force was applied on the lingual surface of the mandibular second molar. We concluded that to escape the extrusion and uncontrolled tipping that creates occlusal interferences associated with the correction of mandibular second molars in lingual version, the lingual traction force is more useful than the buccal traction force.

Potential hazards of orthodontic treatment--what your patient should know

Orthodontic treatment carries with it the risks of tissue damage, treatment failure and an increased predisposition to dental disorders. The dentist must be aware of these risks in order to help the patient make a fully informed choice whether to proceed with orthodontic treatment. This paper outlines the potential hazards and suggests how they may be avoided or minimized.

Quadhelix appliance therapy resulting in pyogenic granuloma of the tongue

This paper describes the examination, diagnosis and treatment of a rapidly enlarging tongue mass presenting in a healthy 12-year-old girl. This mass caused distress to both the patient and her parents and diagnostic uncertainty for her general medical and dental practitioners. The lesion was in fact caused by an orthodontic quadhelix appliance and responded to simple treatment.

Periodontic and orthodontic treatment in adults

The purpose of this article is to provide an update of the interrelationship between periodontics and orthodontics in adults. Specific areas reviewed are the reaction of periodontal tissue to orthodontic forces, the influence of tooth movement on the periodontium, the effect of circumferential supracrestal fiberotomy in preventing orthodontic relapse, the effect of orthodontic treatment on the periodontium, microbiology associated with orthodontic bands, and mucogingival and esthetic considerations. In addition, the relationship between orthodontics and implants (eg, using dental implants for orthodontic anchorage) is discussed.

Evaluation of the relationship between the anterior component of occlusal force and postretention crowding

The aim of this study was to investigate whether a relationship exists between the anterior component of occlusal force (ACF) and postretention crowding in the mandibular incisor area. The study group comprised 32 adults who had undergone fixed orthodontic treatment in the department clinic at Marmara University in Istanbul, Turkey. In 13 subjects, the mandibular arch was treated without extractions; in 19, it was treated with bilateral first premolar extractions. The average postretention period was 3.5 years. The ACF created in the left side of the mandibular dentition was determined by measuring interdental frictional forces at each contact point mesial to the first molar and distal to the canine. Anatomic contact point displacements between the left mandibular anterior teeth (lateral incisor-canine, central incisor-lateral incisor, and central incisor-central incisor) were measured on plaster casts and summed to provide the irregularity index for these teeth. Correlation analysis was used to assess the relationship between the ACF values at each contact and the irregularity index. In the nonextraction group, statistically significant positive correlations were observed between the ACF and the irregularity index at the 3 contact points that were measured. The strongest correlation was found at the canine-first premolar contact (r = 0.65). In the extraction group, a positive correlation was found between the ACF and the irregularity index (r = 0.49, P <.05) at the second premolar-first molar contact, but no correlation was found at the canine-second premolar contact.

Effectiveness of a powered toothbrush compared with a manual toothbrush for orthodontic patients with fixed appliances

Orthodontic patients with fixed appliances have an increased risk for caries and gingivitis. Therefore, the use of special toothbrushes and additional cleaning tools is recommended. The aim of this longitudinal study was to compare the plaque removal efficacy and reduction of gingivitis from using a powered toothbrush compared to a manual toothbrush in patients with fixed orthodontic appliances. Eighty subjects were included in the study with a mean age of 13.53 years. After a baseline examination, patients were randomly assigned to two groups and their teeth were professionally cleaned. The patients were assessed at baseline, two and four weeks using the QHI and SBI. The results showed a significantly superior plaque removal effect (p = 0.0001) and reduction of gingival inflammation (p < 0.05) in those patients using the powered versus the manual toothbrush. The findings were for both whole mouth and partial mouth assessments. In accordance with previous studies, it was demonstrated that the use of a powered toothbrush can be recommended for orthodontic patients with fixed appliances.

Case report: orthodontic separators as periodontal ligatures in periodontal bone loss

Periodontal destruction due to subgingival elastic bands was first reported in the dental literature nearly 130 years ago, and has involved over 20 cases. Destruction due to orthodontic separators used during fixed appliance therapy is a less common occurrence. A case report is presented which illustrates the severe periodontal destruction, which can occur when separators are misused. The subsequent treatment of this problem is also described. Emphasis is placed on the correct use of these orthodontic adjuncts and, appropriate monitoring of the gingival health of orthodontic patients.

Correlation between mandibular central incisor proclination and gingival recession during fixed appliance therapy

The purpose of this study was to determine whether proclination of mandibular central incisors during fixed appliance therapy results in gingival recession. Complete records of 67 patients (39 female and 28 male patients; mean age, 16.4 years; age range, 10-45 years) were used in this retrospective case-control study. Using pretreatment and posttreatment lateral cephalograms, the change in mandibular central incisor inclination was measured to divide the patients into an experimental group (proclination) and a control group (no proclination). Changes in clinical crown length were determined from pretreatment and posttreatment study models, and changes in gingival recession were determined from intraoral slides. Eight of the 67 patients exhibited a measurable increase in gingival recession of at least 0.5 mm, and 27 patients had an increase in clinical crown length of at least 0.5 mm. Statistical analyses showed no correlation between mandibular central incisor proclination and gingival recession or clinical crown length. A t-test analysis showed no statistically significant difference in gingival recession or change in clinical crown length between patients whose mandibular central incisors were proclined and those whose incisors were not proclined. Multiple regression analysis demonstrated that age, sex, race, treatment duration, extraction, treatment type, Angle classification, and proclination were not related to gingival recession or change in clinical crown length of mandibular central incisors. We conclude that the degree of proclination of mandibular central incisors during fixed appliance therapy was not correlated to gingival recession in this sample.

Mandibular advancement appliances and obstructive sleep apnoea: a randomized clinical trial

This randomized placebo-controlled cross-over trial assessed the effectiveness of a mandibular advancement appliance (MAA) in managing obstructive sleep apnoea (OSA). Twenty-one adults, with confirmed OSA, were provided with a maxillary placebo appliance and a MAA for 4-6 weeks each, in a randomized order. Questionnaires at baseline and after each appliance assessed bed-partners' reports of snoring severity (loudness and number of nights per week), and patients' daytime sleepiness (Epworth Sleepiness Score, ESS). The Apnoea Hypopnoea Index (AHI) and Oxygen Desaturation Index (ODI) were measured at baseline and with each appliance during single night sleep studies. Seventy-nine per cent of subjects wore their MAA for at least 4 hours at night. Sixty-eight per cent of subjects wore their MAA for 6-7 nights per week. Excessive salivation was the most commonly reported complication. One subject was unable to tolerate the MAA and withdrew from the study. Among the remaining 20 subjects, the MAA produced significantly lower AHI and ODI values than the placebo. However, although the reported frequency and loudness of snoring and the ESS values were lower with the MAA than the placebo, these differences were not statistically significant. When wearing the MAA, 35 per cent of the OSA subjects had a reduction in the pre-treatment ODI to 10 or less, while 33 per cent had an AHI of 10 or less. The MAA was less effective in the subjects with the most severe OSA (pre-treatment ODI > 50 and/or pre-treatment AHI > 50).

Cytotoxicity of orthodontic bands, brackets and archwires in vitro

OBJECTIVES

In orthodontic therapy, different materials are used and subjected to a damp oral environment, which can modify their properties. In order to evaluate the biocompatibility of metallic and non-metallic orthodontic appliances their in vitro cytotoxicity has been measured.

METHODS

Twenty-eight new and nine clinically used materials, including brackets, molar bands and archwires were used. The metallic materials were made of stainless steel, gold-plated steel, pure titanium, nickel-titanium, titanium-molybdenum and silver-based soldering alloy. The non-metallic materials were in polycarbonates and ceramics. After a release period of the material in the culture medium (0.1 mg/ml) for 3 and 14 days, the viability of fibroblasts L929 cultivated with this medium was compared to negative control with MTT assay.

RESULTS

The results showed the non-cytotoxicity of the materials. The metallic and non-metallic materials were similar in terms of cytotoxicity. The cytotoxicity of clinically used samples was equivalent to that of the same non-used samples, except a cytotoxic sample, at 14 days, corresponding to a soldered and clinically used molar band. The 3 day results were different from the 14 day results in six cases out of 37.

SIGNIFICANCE

In spite of the presence of one cytotoxic sample, the orthodontic materials can be considered as non cytotoxic. However, the practitioner should pay attention to the composition and the polish of soldering silver-based alloys containing copper and zinc in order to limit cytotoxic ion release. The cytotoxicity of the used sample related to ion release might be related to some clinical sub-acute effects related with orthodontic materials, thus a long term release period may be suitable to evaluate in vitro the sub-acute clinical effects of alloys.

Orthodontics and temporomandibular disorder: a meta-analysis

As the importance of evidence-based health care has grown, meta-analysis has become more widely used in the medical and dental fields. In this meta-analysis, the relationship between traditional orthodontic treatment, including the specific type of appliance used and whether extractions were performed, and the prevalence of temporomandibular disorders (TMD) was investigated. After an exhaustive literature search of 960 articles, we found 31 that met the inclusion criteria (18 cross-sectional studies or surveys and 13 longitudinal studies). We divided and extracted data from the 31 articles according to study designs, symptoms, signs, or indexes. Due to severe heterogeneity, the results were summarized without further statistical analysis. The heterogeneous result might originate from lack of a universal diagnostic system and the variability of TMD. Because of heterogeneity, a definitive conclusion cannot be drawn. The data included in this comprehensive meta-analysis do not indicate that traditional orthodontic treatment increased the prevalence of TMD. It is apparent that a reliable and valid diagnostic classification system for TMD is needed for future research.

Orthodontically induced inflammatory root resorption. Part I: The basic science aspects

Orthodontically induced inflammatory root resorption (OIIRR) or, as it is better known, root resorption, is an unavoidable pathologic consequence of orthodontic tooth movement. It is a certain adverse effect of an otherwise predictable force application. Although it is rarely serious, it is a devastating event when it is radiographically recognized. Orthodontics is probably the only dental specialty that actually uses the inflammatory process as a means of solving functional and esthetic problems. Force application initiates a sequential cellular process. We know exactly how and when it is evoked, but we are unable to predict its actual overall outcome. The extent of this inflammatory process depends on many factors such as the virulence or aggressiveness of the different resorbing cells, as well as the vulnerability and sensitivity of the tissues involved. Individual variation and susceptibility, which are related to this process, remain beyond our understanding. We are therefore unable to predict the incidence and extent of OIIRR after force application. This contemporary review is divided into two parts. In Part I, we discuss the basic sciences aspects of OIIRR as a continuation of our previously published work. In Part II, we present the clinical aspects of this subject.

Orthodontically induced inflammatory root resorption. Part II: The clinical aspects

Over the past 10 years, orthodontically induced inflammatory root resorption (OIIRR) has been increasingly recognized as an iatrogenic consequence of orthodontic treatment. With this in mind, orthodontists should take all known measures to reduce the occurrence of OIIRR. The evidence that we present in this review suggests several procedures known today that can avert this phenomenon; however, none of them can be relied on to completely prevent OIIRR. We believe that future studies might clarify the exact cause and course of OIIRR and, hopefully, help eliminate it. In Part I, we discussed the basic sciences aspects of OIIRR; in Part II, we present the clinical aspects of this phenomenon.