INTRODUCTION: Dental caries is an undesirable side effect of orthodontic treatment with fixed appliances. Caries lesions can result in long-term esthetic disturbance, costly interventions, and even interrupted treatment. Therefore, it is crucial to assess accurately both a patient's caries risk before treatment and their suitability for orthodontic treatment. This study aimed to evaluate the validity of 5 caries risk assessment methods for predicting caries outcome during orthodontic treatment: Cariogram, Caries Management by Risk Assessment (CAMBRA), R2, decayed filled teeth (DFT), and decayed initial filled surfaces (DiFS). METHODS: A prospective longitudinal clinical study of 270 adolescents who were referred to the Specialist Clinic for Orthodontics, Molndal Hospital, Sweden for treatment with fixed orthodontic appliances. The following data were collected before treatment: plaque index, radiographs to determine caries prevalence (DFT, DiFS), photographs to determine white-spot lesions, saliva samples (Streptococcus mutans and Lactobacilli), and responses to a questionnaire (regarding diet and oral hygiene). The variables were compiled to assess caries risk according to Cariogram, CAMBRA, and R2. Radiographs were also taken posttreatment to assess caries incidence. The caries outcomes after treatment were analyzed and compared with the caries risk, assessed by the caries risk assessment methods at baseline. RESULTS: DiFS proved to be the most reliable method for predicting caries during orthodontic treatment, presenting the highest area under the receiver operating characteristic curve for both manifest caries (0.77) and initial caries (0.71). CONCLUSIONS: The DiFS prevalence index was demonstrated to be useful in identifying patients who are at risk for developing manifest and initial caries during orthodontic treatment.

INTRODUCTION: Root resorption is one of the leading problems in orthodontic treatment. Most earlier studies have assessed the incidence and severity of root resorption following orthodontic treatment using fixed appliances as well as associated factors. However, few studies have assessed these parameters in the context of orthodontic treatment using thermoplastic splints or aligners. The aim of this systematic review was to assess the incidence and severity of root resorption following orthodontic treatment using aligners and associated factors. A comparative analysis was also made with fixed multi-bracket treatments. MATERIALS AND METHODS: The data bases consulted were: Medline, Embase, EBSCO Host, Cochrane Library and Science Direct. Our search included meta-analyses, randomized and non-randomized controled trials, cohort studies and descriptive studies published before December 2015 and evidencing a connection with the incidence and severity of root resorption following orthodontic treatment using aligners alone or compared with fixed multi-bracket treatments. RESULTS: Among the 93 selected references, only 3 studies met our selection criteria. The incidence of root resorption ranged between 0 and 46%, of which 6% were severe cases. Relative to fixed multi-bracket non-extraction treatments to correct the same malocclusions, the incidence of resorption ranged between 2% and 50%, of which 22% were severe cases. In both techniques, the incidence of resorption was higher for the maxillary incisors and was not influenced by either age or sex. CONCLUSION: In malocclusion cases not requiring extractions, orthodontic aligner treatment is possibly associated with a lower incidence of resorption than fixed multi-bracket treatment. Further research encompassing extraction cases is needed to better assess the incidence and severity of root resorption following the use of these removable appliances.

The purpose of this study was to evaluate the distribution and incidence of two forms of alveolar bone resorption known as fenestration and dehiscence across time and space. To accomplish this a Medieval French population was studied and the results were compared with other studies to examine incidence and distribution of alveolar bone resorption. Thus, 1175 teeth were analysed for 81 individuals, from an agropastoral Medieval (12th-14th century) archaeological site of Vilarnau located in the South of France. Tooth presence and absence as well as dental alveolar resorption were recorded. A new standardised methodological approach to record alveolar resorption is presented and can be used for any skeletonised series. Measurements of dehiscence were made in the midline on each root in relation to the cemento-enamel junction and fenestration was considered as resorption restricted to alveolar bone. Through analyses of the distribution and incidence of alveolar bone resorption over-time in a Medieval French population, along with nine other studies, we present a list of predictive factors for alveolar bone resorption. Among these factors tooth position and function were the most important; anterior teeth were more commonly affected, bone resorption was more common on the labial/buccal versus palatal/lingual surfaces, fenestration was also more common on the maxilla and dehiscence on the mandible (p

OBJECTIVES: To examine the relationship between sagittal facial pattern and dehiscence/fenestration presence in conjunction with buccolingual tooth inclination by using cone beam computed tomography. MATERIALS AND METHODS: The study was carried out on the cone beam computed tomography scans of the following three groups of patients (n = 20 in each group): Class I, Class II, Class III. Buccolingual tooth inclination, buccal dehiscence/fenestration presence, and lingual dehiscence/fenestration presence were evaluated on each tooth. Analysis of variance, Kruskall-Wallis H, Scheffe, and chi-square tests were used for statistical comparisons. RESULTS: Differences (P < .05) were observed between the groups for inclination of upper incisors and all lower teeth except for second molars. Dehiscence prevalence in the upper buccal and posterior buccal regions was higher (P < .05) in the Class I group when compared with the other groups. Lower buccal and anterior buccal regions showed higher (P = .0001) dehiscence prevalence in all groups. No difference was observed in fenestration prevalence between the groups. The upper buccal and anterior buccal regions showed higher (P = .0001) fenestration prevalence in all groups. CONCLUSIONS: Orthodontists must consider concealed alveolar defects in treatment planning to avoid gingival recession or tooth mobility.

OBJECTIVE: To test the null hypothesis that the presence of alveolar defects (dehiscence and fenestration) was not different among patients with different vertical growth patterns. MATERIALS AND METHODS: A total of 1872 teeth in 26 hyper-divergent (mean age: 24.4 +/- 4.8 years), 27 hypo-divergent (mean age: 25.1 +/- 4.5 years), and 25 normo-divergent (mean age: 23.6 +/- 4.1 years) patients with no previous orthodontic treatment were evaluated using cone-beam computed tomography. Axial and cross-sectional views were evaluated with regard to whether dehiscence and/or fenestration on buccal and lingual surfaces existed or not. For statistical analysis, the Pearson chi-square test was used at a P < .05 significance level. RESULTS: According to the statistical analysis, the hypo-divergent group (6.56%) had lower dehiscence prevalence than the hyper-divergent (8.35%) and normo-divergent (8.18%) groups (P = .004). Higher prevalences of dehiscence and fenestration were found on buccal sides in all vertical growth patterns. While fenestration was a common finding for the maxillary alveolar region, dehiscence was a common finding in the mandible in all groups. CONCLUSION: The null hypothesis was rejected. Although the prevalence of fenestrations was not different, significant differences for dehiscences were found in patients with different vertical growth patterns.

BACKGROUND: Correcting posterior crossbite in adult patients using nonsurgical methods may involve buccolingual tooth movement. Knowing the extent of the pretreatment alveolar bony dehiscences and fenestrations in the posterior area will aid orthodontists in planning posterior crossbite patients accordingly to minimize posttreatment bony defects. Before the advent of cone beam computed tomography (CBCT), observing buccal and lingual bony defects was not possible unless other treatment needs allowed for an open-flap procedure. With CBCT technology, we can now detect posterior defects with some accuracy. The aim of the present study was to determine the prevalence of posterior alveolar bony dehiscence and fenestration in adults with posterior crossbite compared with noncrossbite adults. METHODS: The study group consisted of pretreatment CBCTs of 28 samples with at least one or more teeth in posterior crossbite or edgebite. The comparison group consisted of pretreatment CBCTs of 28 samples with no posterior crossbite or edgebite. All buccal and lingual sides of the upper and lower posterior segments were measured for the presence of dehiscence, fenestration, and combined total bony defects. RESULTS: The prevalence of total bony defects was higher in the study group (61.6%) than in the comparison group (52.1%) (p < 0.05). While there was no difference in prevalence between crossbite teeth in the study group and noncrossbite teeth in the comparison group, the noncrossbite teeth in the study group showed a higher prevalence of total bony defects, dehiscence, and fenestration than the noncrossbite teeth in the comparison group (p < 0.05). The prevalence of dehiscence was higher in the study group (41.2%) than in the comparison group (33.3%) (p < 0.05). Neither the prevalence of fenestration nor the mean bony defect size showed statistical significance between the two groups. First premolars showed a higher prevalence of dehiscence than other posterior teeth, and maxillary posterior teeth had a higher prevalence of fenestration than mandibular posterior teeth. Among the maxillary posterior teeth, second premolars had the least amount of fenestration. CONCLUSIONS: Adult subjects with posterior crossbite had a higher prevalence of total bony defects and dehiscence, especially buccal dehiscence, in the posterior region than subjects with no posterior crossbite. This was due to the high prevalence observed in the noncrossbite teeth in posterior crossbite subjects.

INTRODUCTION: We evaluated the dehiscence and fenestration presence in maxillary and mandibular anterior teeth of patients affected by bilateral cleft lip and palate (BCLP) and compared the findings with a well-matched control group of noncleft patients using cone-beam computed tomography. METHODS: Cone-beam computed tomography images of 51 patients were divided into 2 groups (group 1, 21 patients affected by BCLP; mean age; 14.62 +/- 2.89 years; and group 2, 30 patients as the noncleft control group; mean age, 14.22 +/- 1.05 years) and assessed them for dehiscence and fenestration in the anterior maxillary and mandibular teeth. Data were analyzed with the Student t test, Pearson chi-square test, and Fischer exact test. RESULTS: The prevalences of dehiscence in patients affected by BCLP were 61.11% in the maxillary and 48.41% in the mandibular anterior teeth, whereas the rates in the noncleft group were 7.78% and 16.67%, respectively (P < 0.001). The presence of fenestration was found to be statistically significantly higher in the maxillary central incisors of the BCLP group compared with the noncleft controls (P < 0.05), and almost similar rates were noted for the other teeth, with no statistically significant differences (P > 0.05). CONCLUSIONS: Our data suggest that patients affected by BCLP may have higher prevalences of dehiscence in the maxillary and mandibular anterior teeth and of fenestration in the maxillary central incisors.

INTRODUCTION: Rapid maxillary expansion (RME) might cause buccal displacement of anchor teeth. Dislocation of teeth outside their alveolar process can damage the periodontium; for this reason, maxillary expansion using deciduous teeth as anchorage in the mixed dentition might be suggested. The aim of this study was to compare changes of buccal bone plate thickness on the maxillary permanent first molars after RME in the mixed and permanent dentitions with different types of anchorage. METHODS: Two groups of patients were evaluated with cone-beam computed tomography before and after RME. Group E (21 patients) underwent RME using deciduous teeth as anchorage; group 6 (16 patients) underwent RME using permanent teeth as anchorage. The Wilcoxon test was used to compare changes between the time points in the same groups, and the Mann-Whitney U test was used to compare differences between the groups. RESULTS: In group E, generally, no statistically significant reduction was found in buccal bone plate thickness between the time points. In group 6, most measurements showed significant reductions in buccal bone plate thickness (P <0.05) between the time points, with a maximum decrease of 1.25 mm. CONCLUSIONS: RME in the mixed dentition with the appliance anchored to deciduous teeth did not reduce the buccal bone plate thickness of the maxillary permanent first molars, except for the mesial roots on both sides. RME in the permanent dentition caused a reduction of the buccal bone plate thickness of the maxillary permanent first molars when they were used as anchorage in the permanent dentition.

BACKGROUND: To evaluate the changes of alveolar dehiscence and fenestration after augmented corticotomy-assisted orthodontic treatment on cone-beam computed tomography (CBCT) compared with traditional pre-surgical orthodontics, both quantitatively and qualitatively. METHODS: Two hundred and four anterior teeth from 17 skeletal class III malocclusions were divided into four groups. Groups G1 (upper teeth) and G3 (lower teeth), comprising 120 teeth, accepted traditional pre-surgical orthodontics; groups G2 (upper teeth) and G4(lower teeth), comprising 84 teeth, accepted augmented corticotomy-assisted pre-surgical orthodontics. The changes of alveolar bone dehiscence and fenestration of each tooth in all groups were evaluated with the help of CBCT. RESULTS: Quantitative analysis for comparing both groups: For the upper teeth, d1 - d0 was different between both groups while f1 - f0 was not statistically different. For the lower teeth, d1 - d0 was statistically different between both groups while f1 - f0 was not statistically different. Qualitative analysis: For the teeth that had no dehiscence before treatment, G2 and G4 had a better transition than did G1 and G3. For those having dehiscence before treatment, G4 had a better transition than did G3. For teeth having no fenestration before treatment, there was no statistically significant difference in transition between the control and treatment groups. For those having fenestration before treatment, G4 had a better transition than did G3. CONCLUSIONS: For skeletal class III patients, augmented corticotomy-assisted orthodontic treatment is a promising method of improving alveolar bone dehiscence and fenestration for lower anterior teeth, and it also has the potential to protect both lower and upper anterior teeth against dehiscence.

PURPOSE: To investigate cone beam computed tomography (CBCT) accuracy in measuring facial bone height and detecting dehiscence and fenestration defects around teeth. MATERIALS AND METHODS: Patients who were treatment planned for periodontal flap or dental implant surgeries were enrolled (n = 25). CBCT imaging (Carestream CS 9300) was obtained at 0.09-mm voxels (n = 10 patients, 23 teeth) and at 0.18-mm voxels (n = 15 patients, 33 teeth). Facial bone height measurements, from cusp tip to crest of bone height along the long axis of the tooth, and presence or absence of dehiscence or fenestration defects were recorded from CBCT images in triplicates independently by two examiners. The corresponding clinical measurements were made at the time of surgery. Comparisons of CBCT and clinical measurements were made using paired t tests for teeth: anterior and posterior, maxillary and mandibular, with or without restorations, or root canal therapy. Level of agreement between investigators was assessed by concordance correlation coefficients (CCC), Pearson's correlation coefficient (PCC), and Cohen's Kappa. RESULTS: Comparing mean CBCT and clinical measurements, statistically significant differences were noted for 0.09-mm and 0.18-mm voxel sizes, for anterior and posterior teeth, for maxillary and mandibular teeth, for teeth with or without restorations, and for teeth without root canal therapy (P < .05). Clinical and CBCT measurements were similar for teeth with crowns and with root canal therapy (P > .05). CBCT measurements underestimated mean facial bone height from 0.33 +/- 0.78 to 0.88 +/- 1.14 mm (mean +/- SD) and absolute facial bone height values from 0.56 +/- 0.35 to 1.08 +/- 0.92 mm. Intraexaminer and interexaminer reliability for measuring facial bone height ranged from poor to substantial (PCC = 0.78 to 0.97 and CCC = 0.63 to 0.96, respectively). Interexaminer reliability for detection of dehiscence and fenestration defects ranged from poor to moderate (Cohen's Kappa = -0.09 to 0.66). CONCLUSION: CBCT imaging underestimated facial bone height and overestimated the presence of dehiscence and fenestration defects.

INTRODUCTION: Our aim in this study was to evaluate the effect of augmented corticotomy on the decompensation pattern of mandibular anterior teeth, alveolar bone, and surrounding periodontal tissues during presurgical orthodontic treatment. METHODS: Thirty skeletal Class III adult patients were divided into 2 groups according to the application of augmented corticotomy labial to the anterior mandibular roots: experimental group (with augmented corticotomy, n = 15) and control group (without augmented corticotomy, n = 15). Lateral cephalograms and cone-beam computed tomography images were taken before orthodontic treatment and before surgery. The measurements included the inclination and position of the mandibular incisors, labial alveolar bone area, vertical alveolar bone height, root length, and alveolar bone thickness at 3 levels surrounding the mandibular central incisors, lateral incisors, and canines. RESULTS: The mandibular incisors were significantly proclined in both groups (P <0.001); however, the labial movement of the incisor tip was greater in the experimental group (P <0.05). Significant vertical alveolar bone loss was observed only in the control group (P <0.001). The middle and lower alveolar thicknesses and labial alveolar bone area increased in the experimental group. In the control group, the upper and middle alveolar thicknesses and labial alveolar bone area decreased significantly. There were no significant differences in dentoalveolar changes between the 3 kinds of anterior teeth in each group, except for root length in the experimental group (P <0.05). CONCLUSIONS: Augmented corticotomy provided a favorable decompensation pattern of the mandibular incisors, preserving the periodontal structures surrounding the mandibular anterior teeth for skeletal Class III patients.

PURPOSE: The aim of this meta-analysis was to evaluate different methods for guided bone regeneration using collagen membranes and particulate grafting materials in implant dentistry. MATERIALS AND METHODS: An electronic database search and hand search were performed for all relevant articles dealing with guided bone regeneration in implant dentistry published between 1980 and 2014. Only randomized clinical trials and prospective controlled studies were included. The primary outcomes of interest were survival rates, membrane exposure rates, bone gain/defect reduction, and vertical bone loss at follow-up. A meta-analysis was performed to determine the effects of presence of membrane cross-linking, timing of implant placement, membrane fixation, and decortication. RESULTS: Twenty studies met the inclusion criteria. Implant survival rates were similar between simultaneous and subsequent implant placement. The membrane exposure rate of cross-linked membranes was approximately 30% higher than that of non-cross-linked membranes. The use of anorganic bovine bone mineral led to sufficient newly regenerated bone and high implant survival rates. Membrane fixation was weakly associated with increased vertical bone gain, and decortication led to higher horizontal bone gain (defect depth). CONCLUSION: Guided bone regeneration with particulate graft materials and resorbable collagen membranes is an effective technique for lateral alveolar ridge augmentation. Because implant survival rates for simultaneous and subsequent implant placement were similar, simultaneous implant placement is recommended when possible. Additional techniques like membrane fixation and decortication may represent beneficial implications for the practice.

This case report describes the successful extraction treatment of a Class II malocclusion with excessive maxillary sinus pneumatization. A 20-year-old man sought treatment with the major complaint of protrusive mouth and anterior teeth. He was diagnosed with a skeletal Class II relationship and protrusion of the maxilla. The clinical examination showed a severe Class II molar relationship with excessive overjet and deep overbite. Panoramic radiograph showed obvious maxillary sinus pneumatization bilaterally. Three premolars and one deciduous molar were extracted, and spaces were used to correct molar relationship and retract maxillary incisors. Light forces and low speed movement were applied to overcome the challenge of moving teeth through the maxillary sinus wall. Balanced facial esthetic and stable occlusion were obtained posttreatment with a notable bone formation of the maxillary sinus wall. This result highlights the possibility of tooth movement through cortical floor with bone remodeling and no obvious complications.

Replantation of avulsed incisors in young children is a successful treatment modality. Almost all replanted teeth exhibit ankylosis followed by inflammatory or replacement resorption, as immediate replantation is practically rare. The purpose of the review is to report a series of cases of prolonged delay in replantation of avulsed incisors and discuss its sequelae, leading to different patterns of root resorption after a minimum follow-up period of 24 months. The present case series is a follow-up of five cases of delayed replantation (more than 24 h delay) without any root surface treatment. Extraoral endodontic therapy was performed before replantation. The avulsed teeth were stabilized using an acid-etch composite resin splint for 4 weeks. The patients were followed up at 3, 6, and 12 months interval and half-yearly thereafter, for examination of the replanted teeth clinically and radiographically. After 24-month follow-up, the replanted teeth were evaluated for gingival changes and clinical mobility. The radiographs were evaluated for external root resorption or inflammatory resorption, osseous root replacement, or replacement resorption. The case series concludes that avulsed teeth transported in dry as well as dessicated conditions and replanted after a delay of 24 h have a survival rate of more than 24 months, though there is no promising long-term prognosis. The sequelae in most of the cases are surface resorption followed by inflammatory resorption or resorption due to pulpal infection or replacement resorption.

BACKGROUND: Dentoalveolar ankylosis in growing patients is complex leading to continuing root replacement resorption, tooth infra-position, or may even affect the development of alveolar ridge and adjacent teeth. While extraction of ankylosed teeth might be associated with bone loss, decoronation of the offending tooth (removal of crown portion and instrumentation of pulp canal to stimulate bleeding) has been suggested as a more conservative approach of bone preservation until definitive implant placement is planned. OBJECTIVE: To primarily assess the efficacy of bone width and height preservation around ankylosed permanent teeth following decoronation. METHODS: Pubmed, Embase, Ovid Medline, Thomson's ISI Web of Science and Cochrane library were searched from the year 1984 up to May 2015. Two authors conducted the data extraction. To eliminate publication bias, Open Grey literature and Pro-quest Dissertation Abstracts and Thesis database was also consulted. RESULTS: Through our strict selection criteria, only 12 articles were considered for eligibility. No randomized controlled trials were identified. Only one retrospective cohort study, four case series and seven case reports, were analyzed. CONCLUSIONS: Following decoronation, preservation of ridge height and ridge width were both noted. To maximize the benefits of decoronation, a timely and wellmonitored intervention is required. Treatment in patients, who have surpassed pubertal growth peaks, may not yield maximum effective treatment outcomes.

BACKGROUND: The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography. MATERIAL AND METHODS: 120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements. RESULTS: Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If beta angle <18 degrees and Lindauer = I, the probability of resorption is 0.06. CONCLUSIONS: Evaluation of b angle and superimposition lateral incisor/impacted canine analysed on orthopantomographs could be one of the evaluation criteria for prescribing second level examination (CT and CTCB) and for detecting root resorption of impacted maxillary canine adjacent teeth.

Gingival invagination is an alteration of the ginviva often observed during orthodontic space closure. This finding appears as a

OBJECTIVE: To evaluate the relationship between facial growth pattern and electromyography (EMG) of facial muscles: anterior temporalis, masseter, buccinators, orbicularis oris, mentalis and anterior digastric. PATIENTS AND METHODS: The sample consisted of 77 subjects aged between 18-28 years (mean age 21.10+/-2.03), with dental Class I relationship, normal overjet and overbite, balanced facial profile, no signs of temporomandibular disorders, and no previous orthodontic treatment. Facial growth pattern was determined on the lateral cephalograms according to the Bjork sum (sum of the N-S-Ar, S-Ar-Go, and Ar-Go-Me angles) dividing the sample into three groups: horizontal facial pattern group (24 subjects), normal facial pattern group (41 subjects), and vertical facial pattern group (12 subjects). The EMG of anterior temporalis, masseter, buccinator, orbicularis oris, mentalis and anterior digastric muscles were examined for each patient in the rest position and in functional positions (central maximum intercuspation, chewing on right side, chewing on left side and swallowing). Mean values and standard deviation of EMG were obtained and compared between the three groups. RESULTS: At rest, the EMG of the masseter, orbicularis oris and anterior digastric were higher in the vertical facial pattern group compared with the other two groups, with a moderate positive correlation between the EMG of these muscles and the Bjork sum (P<.01). In contrast, during central maximum intercuspation, the activity of the anterior temporalis, masseter and buccinator was significantly lower in the vertical facial pattern group compared with the two other groups, with a moderate negative correlation between the Bjork sum and EMG in the maximum central intercuspation position of these muscles (P<.01). CONCLUSIONS: A significant relationship was found between facial muscle activity and facial growth pattern. The findings suggest that the activity of masticatory and perioral muscles could play a role in the direction of the facial growth.

OBJECTIVE: Alveolar bone surrounding mandibular incisors dictates the range of buccolingual inclination that can be achieved with treatment. The objective of this study was to evaluate the mandibular anterior alveolar thickness and height in individuals with different sagittal and vertical skeletal relationships. MATERIALS AND METHODS: Cone beam computed tomography scans of 53 individuals (22 males and 31 females; mean age 21.19+/-3.7 years) were classified into 3 groups according to the sagittal skeletal relationship (class I, class II, and class III) and the vertical growth pattern (hyperdivergent, normodivergent, and hypodivergent). The alveolar thickness and height of both mandibular central incisors were measured. Group comparisons were performed with analysis of variance and post hoc Scheffe tests. Multiple linear regression was applied to evaluate the influence of all variables on the alveolar conditions. RESULTS: Alveolar thickness and height showed no significant differences among the class I, II and III groups (6 and 7mm regardless of the sagittal group, P>0.05). The middle and lower alveolar thicknesses were significantly smaller in hyperdivergent (5.76mm and 6.34mm) and normodivergent (6.29mm and 7.40mm) than hypodivergent individuals (6.63mm and 8.27mm respectively). The lingual alveolar height was smaller in hyperdivergent (6.04mm) than hypodivergent individuals (7.93mm) (P=0.029, 95%CI: 0.15-3.63) and the lingual bone height was smaller in hypodivergent (3.24mm) than hyperdivergent individuals (5.06mm) (P=0.029, 95%CI: 0.15-3.48). Multiple linear regression indicated a significant influence of the root length on the alveolar thickness and height. CONCLUSIONS: The sagittal skeletal relationship showed no influence on the alveolar thickness or height, even if dental compensation was present. Hyperdivergent individuals showed smaller alveolar thicknesses and heights than hypodivergent individuals.

Technological progress and the introduction of modern therapeutic methods are constantly changing contemporary orthodontics. More and more orthodontic patients are working adults, who expect satisfactory therapeutic effects as soon as possible, increasing the importance of methods accelerating tooth movement. The aim of this study was to review the current literature regarding methods of accelerating tooth movement and reducing the duration of the active phase of therapy. The literature was collected from the PubMed and EBSCO databases using

INTRODUCTION: The purpose of this study was to investigate the variations of orthodontically induced tooth movement in the maxillary and mandibular arches between patients and the factors such as age, sex, and presence of an interference that might influence the amount of tooth displacement. METHODS: By using a standardized experimental orthodontic tooth movement in 30 subjects, 57 premolars were moved buccally during 8 weeks with the application of a 1-N force. Forty-four contralateral premolars not subjected to orthodontic tooth movement served as the controls. Plaster models from before and after the experimental tooth movement were digitized and superimposed to evaluate the amounts of tooth movement. Differences in tooth movement between the experimental and control groups were tested by an unpaired t test. For the experimental teeth, subject-related factors (age and sex) and tooth-related factors (location in the maxillary or mandibular dental arch, and the presence or absence of an intra-arch or interarch obstacle such as neighboring touching teeth or teeth interfering with the occlusion) were examined with analysis of variance. Multiple linear regression analysis was performed to determine correlations between tooth displacement, age, sex, tooth location, and presence of an interference. RESULTS: Each subject contributed at least 2 experimental premolars and 1 control premolar. The displacement of the orthodontically moved teeth was 2.42 mm (range, 0.3-5.8 mm). Younger subjects (<16 years; n = 19; number of teeth, 36) had significantly greater amounts of tooth displacement compared with older subjects (>/=16 years; n = 11; number of teeth, 21): 2.6 +/- 1.3 mm vs 1.8 +/- 0.8 mm; P <0.01. When an interarch or intra-arch obstacle was present, the amount of tooth movement was significantly less (2.6 +/- 1.3 mm vs 1.8 +/- 0.8 mm) (P <0.05). Neither sex nor the location of the experimental teeth in the mandible or the maxilla had any effect. CONCLUSIONS: Younger patients showed greater tooth movement velocity than did older ones. An interarch or intra-arch obstacle decreased the amount of tooth displacement.

Dense bone islands (DBIs) are usually asymptomatic and do not require any treatment. This case report presents a DBI of an unusual presentation, which was an incidental finding on a radiograph of a 15-year-old orthodontic patient. The DBI lesion was 24 mm in size, occupying at least 50% of the alveolar process between the upper right canine and lateral incisor, extending up the lateral aspect of the anterior margin of the right nasal fossa. Generally, DBIs are 2-3 mm in size and more commonly found in the mandible in the molar and premolar region. This article further discusses the impact of DBIs on orthodontic treatment such as difficulty with achieving space closure and adequate root tip or torque. We also examine the potential medical implications of DBIs. This is clinically important, especially if multiple DBIs, or osteomas which have a similar radiographic appearance to DBIs, are found in a patient as they may be associated with adenomatous intestinal polyps, which, if not treated, have a 100% chance of becoming malignant transformation.

The level of kinetic frictional forces generated during in vitro translation at the bracket-wire interface were measured for two sintered stainless steel brackets as a function of two slot sizes, four wire alloys, and five to eight wire sizes. The two types of sintered stainless steel brackets were tested in both 0.018-inch and 0.022-inch slots. Wires of four different alloy types, stainless steel (SS), cobalt chromium (Co-Cr), nickel-titanium (Ni-Ti), and beta-titanium (beta-Ti), were tested. There were five wire sizes for the 0.018-inch slot and eight wire sizes for the 0.022-inch slot. The wires were ligated into the brackets with elastomeric ligatures. Bracket movement along the wire was implemented by means of a mechanical testing instrument, and time dependent frictional forces were measured by a load cell and plotted on an X-Y recorder. For most wire sizes, lower frictional forces were generated with the SS of Co-Cr wires than with the beta-Ti or Ni-Ti wires. Increase in wire size generally resulted in increased bracket-wire friction. There were no significant differences between manufacturer for the sintered stainless steel brackets. The levels of frictional force in 0.018-inch brackets ranged from a low of 46 gm with 0.016-inch Co-Cr wire to a high of 157 gm with 0.016 x 0.025-inch beta-Ti wire. In comparing the data from a previous study by Kapila et al. 1990 performed at OUHSC with the same apparatus, the friction of sintered stainless steel brackets was approximately 40% to 45% less than the friction of the conventional stainless steel brackets.

OBJECTIVE: Self-ligating brackets (SLBs) were compared to conventional brackets (CBs) regarding their effectiveness on transversal changes and space closure, as well as the efficiency of alignment and treatment time. METHODS: All previously published randomized controlled clinical trials (RCTs) dealing with SLBs and CBs were searched via electronic databases, e.g., MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, World Health Organization International Clinical Trials Registry Platform, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. In addition, relevant journals were searched manually. Data extraction was performed independently by two reviewers and assessment of the risk of bias was executed using Cochrane Collaboration's tool. Discrepancies were resolved by discussion with a third reviewer. Meta-analyses were conducted using Review Manager (version 5.3). RESULTS: A total of 976 patients in 17 RCTs were included in the study, of which 11 could be produced quantitatively and 2 showed a low risk of bias. Meta-analyses were found to favor CB for mandibular intercanine width expansion, while passive SLBs were more effective in posterior expansion. Moreover, CBs had an apparent advantage during short treatment periods. However, SLBs and CBs did not differ in closing spaces. CONCLUSIONS: Based on current clinical evidence obtained from RCTs, SLBs do not show clinical superiority compared to CBs in expanding transversal dimensions, space closure, or orthodontic efficiency. Further high-level studies involving randomized, controlled, clinical trials are warranted to confirm these results.

OBJECTIVES:: To compare the extent of root resorption and the amount of tooth movement between continuous orthodontic force and intermittent orthodontic force that was activated in a similar way to a 4-week orthodontic adjustment period. MATERIALS AND METHODS:: Twenty-five patients who required the extraction of upper first premolars were recruited in this study. A buccally directed continuous force of 150 g was applied to the upper first premolar on one side for 15 weeks. A buccally directed intermittent force (28 days on, 7 days off) of the same magnitude was applied to the contralateral first premolar. The teeth were extracted at the end of the experimental period and processed for volumetric evaluations of resorption craters. The degree of tooth movement and rotation were measured on the study models. RESULTS:: Continuous force application displayed significantly higher root resorption volume than the intermittent force application ( P < .05), particularly on the buccal and lingual surfaces (P < .05) and the middle third of the root ( P < .01). There was more tipping and rotational movement in the continuous force group. CONCLUSIONS:: In a 4-week orthodontic adjustment period, intermittent force significantly reduced the amount of root resorption compared with continuous force. Although there was less degree of tooth movement with intermittent force, unwanted rotational movement was avoided. This is crucial in patients who are predisposed to orthodontically induced inflammatory root resorption, and the use of this intermittent regimen should be considered.

OBJECTIVES: Collagen remodeling of the periodontal tissue is an important mechanism that involves several biologically active substances to accelerate orthodontic tooth movement. It is known that Vitamin C (VC) enhances collagen production and induces tooth movement. Moreover, the eggshell membrane (ESM) is an integral component of various formulations used to promote wound healing. The purpose of our study was to determine the effects of combined treatment with VC and ESM on periodontal tissues during tooth movement. METHODS: Nine-week-old male osteogenic disorder Shionogi rats were randomized into four groups: control, VC, ESM, and VC + ESM. The control group was given tap water, and the VC, ESM, and VC + ESM groups were orally administered 0.1% VC solution, 1 wt% ESM solution, and a combination of 0.1 wt% VC and 1 wt% ESM solutions, respectively. A force of 25 or 75 g was applied for 10 days to produce orthodontic tooth movement. Distances of tooth movement were measured on days 3, 7, and 10 of treatment. Histological examination of the periodontal ligament was performed to determine the increase in type I and III collagen levels in response to treatment. RESULTS: Distances of tooth movement were significantly greater in the VC + ESM group than in the control group. The compression area of the alveolar bone showed increased osteoclastic activity and higher levels of bone resorption in the VC + ESM group. Expression levels of type I and III collagen in the tension area of the alveolar bone were higher in the VC + ESM group than in the control group. CONCLUSIONS: This study revealed that the combined administration of VC and ESM accelerated tooth movement by protecting the periodontal tissue during orthodontic treatment. The combined clinical application of VC and ESM could potentially shorten orthodontic treatment time.

OBJECTIVE: The objective was to systematically-review the effect of statin drugs on orthodontic-tooth-movement (OTM). DESIGN: The focused-question was