Dentoalveolar changes observed after the use of customized bonded Shark-Tooth-Like Spurs (JAWs) in adult patients with anterior open bite.

INTRODUCTION: Tongue spurs have been successfully used for the early treatment of anterior open bite (AOB). However, according to our knowledge, their effectiveness in the treatment of adults has not been evaluated. OBJECTIVES: The purpose of the study was to assess the dentoalveolar changes observed after the use of customized bonded shark-tooth-like spurs (JAWs) in adults with AOB. METHODS: Twenty-three adults (22.1±4.4 years) with AOB were selected for the treatment. JAWs made from compomer cement were bonded on the lingual surfaces of the maxillary and mandibular anterior teeth to correct tongue-thrusting. Lateral cephalograms and 3D digital models were obtained to evaluate dentoalveolar features observed before and at three time points after JAWs use. Paired t-test and repeated measure ANOVA tests were used to compare dentoalveolar changes, and Pearson's correlation was used to analyze the association of dentoalveolar changes and overbite changes. The significance level was set at p<0.05. RESULTS: Significant 3D dentoalveolar changes were observed after the three months of treatment with JAWs. Improvement of overbite (1.0±0.6 mm) and overjet (0.2±0.3 mm), combined with a retroclination of maxillary (3.0±3.0°) and mandibular (2.2±2.7°) incisors, were observed (p<0.05). Moreover, a significant decrease in anterior dental arch width in both maxillary and mandibular arches (0.4±0.4 mm; 0.3±0.3 mm, respectively), and an increase of posterior maxillary (0.1±0.2 mm) dental arch width were observed (p<0.05). These significant changes occurred in the first month after the JAWs use. A significant correlation was found between the initial arch length discrepancy and the amount of overbite correction (r=0.456, p<0.05). CONCLUSIONS: Dentoalveolar changes occurred after the first-month therapy with JAWs. The retroclination of the anterior teeth combined with the expansion of posterior teeth suggests a posterosuperior change in the tongue position. These changes were beneficial for the treatment of AOB in adult patients.

Dentoalveolar changes observed after the use of customized bonded Shark-Tooth-Like Spurs (JAWs) in adult patients with anterior open bite

ABSTRACT Introduction: Tongue spurs have been successfully used for the early treatment of anterior open bite (AOB). However, according to our knowledge, their effectiveness in the treatment of adults has not been evaluated. Objectives: The purpose of the study was to assess the dentoalveolar changes observed after the use of customized bonded shark-tooth-like spurs (JAWs) in adults with AOB. Methods: Twenty-three adults (22.1±4.4 years) with AOB were selected for the treatment. JAWs made from compomer cement were bonded on the lingual surfaces of the maxillary and mandibular anterior teeth to correct tongue-thrusting. Lateral cephalograms and 3D digital models were obtained to evaluate dentoalveolar features observed before and at three time points after JAWs use. Paired t-test and repeated measure ANOVA tests were used to compare dentoalveolar changes, and Pearson's correlation was used to analyze the association of dentoalveolar changes and overbite changes. The significance level was set at p<0.05. Results: Significant 3D dentoalveolar changes were observed after the three months of treatment with JAWs. Improvement of overbite (1.0±0.6 mm) and overjet (0.2±0.3 mm), combined with a retroclination of maxillary (3.0±3.0°) and mandibular (2.2±2.7°) incisors, were observed (p<0.05). Moreover, a significant decrease in anterior dental arch width in both maxillary and mandibular arches (0.4±0.4 mm; 0.3±0.3 mm, respectively), and an increase of posterior maxillary (0.1±0.2 mm) dental arch width were observed (p<0.05). These significant changes occurred in the first month after the JAWs use. A significant correlation was found between the initial arch length discrepancy and the amount of overbite correction (r=0.456, p<0.05). Conclusions: Dentoalveolar changes occurred after the first-month therapy with JAWs. The retroclination of the anterior teeth combined with the expansion of posterior teeth suggests a posterosuperior change in the tongue position. These changes were beneficial for the treatment of AOB in adult patients.

RESUMO Introdução: Esporões linguais têm sido utilizados com sucesso para o tratamento precoce da mordida aberta anterior (MAA). No entanto, de acordo com nosso conhecimento, sua efetividade no tratamento em adultos ainda não foi avaliada. Objetivo: O objetivo do presente estudo foi avaliar as mudanças dentoalveolares observadas após o uso de esporões colados customizados JAWs (tipo dente de tubarão) em adultos com MAA. Métodos: Vinte e três adultos (idade média de 22,1±4,4 anos) com MAA foram selecionados para tratamento. Esporões confeccionados de compômero foram colados na superfície lingual dos dentes anteriores superiores e inferiores, para corrigir a interposição lingual. Radiografias laterais e modelos digitais 3D foram obtidos para avaliar as características dentoalveolares observadas antes do uso dos esporões e em três tempos distintos após seu uso. O testet pareado e testes ANOVA para medições repetidas foram utilizados para comparar as mudanças dentoalveolares, e a correlação de Pearson foi utilizada para analisar a associação entre as mudanças dentoalveolares e as mudanças na sobremordida. O nível de significância foi estabelecido em p<0,05. Resultados: Foram observadas mudanças dentoalveolares 3D significativas após três meses de tratamento com os esporões. Foram observadas melhorias na sobremordida (1,0±0,6 mm) e sobressaliência (0,2±0,3 mm), associadas à retroinclinação dos incisivos superiores (3,0±3,0°) e inferiores (2,2±2,7°) (p<0,05). Além disso, foi observada diminuição significativa na largura anterior das arcadas superior e inferior (0,4±0,4 mm; 0,3±0,3 mm, respectivamente) e um aumento na largura posterior da arcada dentária superior (0,1±0,2 mm) (p<0,05). Essas mudanças significativas ocorreram no primeiro mês após o uso dos esporões. Foi encontrada uma correlação significativa entre a discrepância inicial no comprimento da arcada e a quantidade de correção da sobremordida (r=0,456, p<0,05). Conclusões: Mudanças dentoalveolares ocorreram após o primeiro mês de tratamento com os esporões. A retroinclinação dos dentes anteriores combinada com a expansão dos dentes posteriores sugere uma mudança posterossuperior na posição da língua. Essas mudanças foram benéficas para o tratamento da MAA em pacientes adultos.

Comparison of one versus two maxillary molars distalization with iPanda: a finite element analysis.

BACKGROUND: The purpose of this study was to compare the stress distribution and displacement patterns of the one versus two maxillary molars distalization with iPanda and to evaluate the biomechanical effect of distalization on the iPanda using the finite element method. METHODS: The finite element models of a maxillary arch with complete dentition, periodontal ligament, palatal and alveolar bone, and an iPanda connected to a pair of midpalatal miniscrews were created. Two models were created to simulate maxillary molar distalization. In the first model, the iPanda was connected to the second molar to simulate a single molar distalization. In the second model, the iPanda was connected to the first molar to simulate "en-masse" first and second molar distalization. A varying force from 50 to 200 g was applied. The stress distribution and displacement patterns were analyzed. RESULTS: For one molar, the stress was concentrated at the furcation and along the distal surface in all roots with a large amount of distalization and distobuccal crown tipping. For two molars, the stress in the first molar was 10 times higher than in the second molar with a great tendency for buccal tipping and a minimal amount of distalization. Moreover, the stress concentration on the distal miniscrew was six times higher than in the mesial miniscrew with an extrusive and intrusive vector, respectively. CONCLUSIONS: Individual molar distalization provides the most effective stress distribution and displacement patterns with reduced force levels. In contrast, the en-masse distalization of two molars results in increased force levels with undesirable effects in the transverse and vertical direction.

Periodontal ligament enhancement in mesio-angulated impaction of third molars after orthodontic tooth movement: A prospective cohort study.

INTRODUCTION: The mesio-angulated impaction of mandibular third molars makes them unsuitable as donor teeth for tooth autotransplantation. However, uprighted molars may be applicable for autotransplantation. This study aimed to determine the amount of periodontal ligament (PDL) on the root surfaces of extracted third molars after an application of uprighting force and to examine the amount of PDL at the tension and compression sites. METHODS: In this prospective cohort study, 15 mesio-angulated mandibular third molars (iM8s) from 15 patients planned for orthodontic extraction, were uprighted using springs connected to miniscrews, whereas 15 nonopposing and fully erupted mandibular third molars from 15 other patients served as controls. The altered angulation was monitored and assessed from panoramic radiographs. All 30 molars, removed by simple extraction, were stained with 0.04% (w/v) toluidine blue to analyze the percentages of stained PDL on the root surfaces. RESULTS: An average period of 3.4 months was necessary to upright the iM8s at a mean rate of 8.3° per month. The mean percentage of stained PDL on the loaded iM8s was significantly greater than that on the unloaded molars (P <0.05). The mean percentages of stained PDL were significantly increased at the cervical and middle thirds and the buccal, mesial, and distal surfaces of the loaded iM8s compared with those of the unloaded molars (P <0.05), whereas the apical third and the lingual surface, corresponding to the compression sites, showed no significant increases. CONCLUSIONS: Orthodontic uprighting leads to significantly increased proliferative PDL on certain radicular portions and surfaces of iM8s, which might be useful for tooth autotransplantation.

Periodontal ligament proliferation and expressions of bone biomolecules upon orthodontic preloading: Clinical implications for tooth autotransplantation.

OBJECTIVE: Preservation of the periodontal ligament (PDL) is vital to the success of tooth autotransplantation (TAT). Increased PDL volumes and facilitated tooth extraction have been observed upon orthodontic preloading. However, it is unclear whether any changes occur in the expressions of bone biomolecules in the increased PDL volumes. This study aimed to determine the expressions of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in PDL upon preloading. METHODS: Seventy-two premolars from 18 patients were randomly assigned to experimental groups that received a leveling force for 1, 2, or 4 weeks or to a control unloaded group. Following extraction, PDL volumes from 32 premolars of eight patients (21.0 ± 3.8 years) were evaluated using toluidine blue staining. The expressions of the biomolecules in the PDL from 40 premolars of ten patients (21.4 ± 4.0 years) were analyzed via immunoblotting. RESULTS: The median percentage of stained PDL was significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05). The median RUNX2 and ALP expression levels were significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05), whereas the median RANKL/OPG ratios were significantly higher at 1 and 4 weeks after preloading (p < 0.05). CONCLUSIONS: Orthodontic preloading for 4 weeks enhances PDL volumes as well as the expressions of RUNX2, ALP and the RANKL/OPG ratio in the PDL, suggesting this loading period is suitable for successful TAT.

Enhancement of human periodontal ligament by preapplication of orthodontic loading.

INTRODUCTION: The quantity of remaining periodontal ligament (PDL) on the root surface of donor teeth is essential for the success of tooth autotransplantation. Preapplication of orthodontic loading increases this quantity on rat tooth root surfaces. However, little is known about the effects of preloading on human PDL or the ease of tooth extraction. This study aimed to determine the optimal duration of preloading for enhanced PDL on the root surface of extracted human premolars and for facilitating extraction. METHODS: Sixty patients received orthodontic preloading with a bracket connected to an archwire on one of their maxillary first premolars for 2, 4, 6, or 8 weeks, whereas the contralateral premolar was not loaded as a control. Premolar extractions were performed with a record of the duration and difficulty of extraction. The extracted premolars were fixed and stained with toluidine blue. Digitized images were recorded under a stereomicroscope, and the percentage of stained PDL was analyzed. RESULTS: Orthodontic preloading for 4, 6, and 8 weeks significantly increased the percentage of stained PDL on the root surface compared with the control (P <0.05). The duration and difficulty of extraction were significantly less in preloaded than that of unloaded teeth after 4, 6, and 8 weeks (P <0.05). CONCLUSIONS: A 4-week duration of orthodontic preloading is suggested as the shortest duration to adequately enhance PDL and ease tooth extraction; both outcomes may be beneficial for tooth autotransplantation.

Biomechanical comparison of two intraoperative mobilization techniques for maxillary distraction osteogenesis: Down-fracture versus non-down-fracture.

PURPOSES: The purpose of this study was to compare the distraction forces and the biomechanical effects between two different intraoperative surgical procedures (down-fracture [DF] and non-DF [NDF]) for maxillary distraction osteogenesis. MATERIALS AND METHODS: Eight patients were assigned into two groups according to the surgical procedure: DF, n = 6 versus NDF, n = 2. Lateral cephalograms taken preoperatively (T1), immediately after removal of the distraction device (T2), and after at least a 6 months follow-up period (T3) were analyzed. Assessment of distraction forces was performed during the distraction period. The Mann-Whitney U-test was used to compare the difference in the amount of advancement, the maximum distraction force and the amount of relapse. RESULTS: Although a significantly greater amount of maxillary movement was observed in the DF group (median 9.5 mm; minimum-maximum 7.9-14.1 mm) than in the NDF group (median 5.9 mm; minimum-maximum 4.4-7.6 mm), significantly lower maximum distraction forces were observed in the DF (median 16.4 N; minimum-maximum 15.1-24.6 N) than in the NDF (median 32.9 N; minimum-maximum 27.6-38.2 N) group. A significantly greater amount of dental anchorage loss was observed in the NDF group. Moreover, the amount of relapse observed in the NDF group was approximately 3.5 times greater than in the DF group. CONCLUSIONS: In this study, it seemed that, the use of the NDF procedure resulted in lower levels of maxillary mobility at the time of the maxillary distraction, consequently requiring greater amounts of force to advance the maxillary bone. Moreover, it also resulted in a reduced amount of maxillary movement, a greater amount of dental anchorage loss and poor treatment stability.

Maxillary molar distalization with the indirect Palatal miniscrew for Anchorage and Distalization Appliance (iPANDA).

AIM: Distalization of the maxillary molars is an important treatment option for the correction of Class II malocclusions. The purposes of this study were to introduce the clinical application of the indirect Palatal miniscrew Anchorage and Distalization Appliance (iPanda) and to describe the dental and skeletal effects obtained with this innovative appliance. METHODS: Pretreatment (TO), post-distalization (T1), and posttreatment (T2) lateral cephalometric radiographs and dental casts of 20 consecutively treated adult patients (mean age 23.2 ± 4.7 years) with Class II molar relationship were analyzed. All patients were treated with the iPanda for maxillary molar distalization. The iPanda was anchored on a pair of midpalatal miniscrew implants to deliver the distalizing force to the maxillary first molars. The iPanda was the only appliance used during the distalization phase of treatment. A paired t test analysis was used to statistically assess the effects of treatment. RESULTS: A Class I molar relationship was obtained in a mean period of 3.2 ± 0.6 months. Cephalometric analysis demonstrated that the maxillary first molars were significantly distalized by an average 4.5 ± 1.5 mm (P < .001) and were intruded by a mean of 1.0 mm ± 0.8 mm (P < .05). No significant change in the inclination of the first molars was observed. No significant change in the mandibular plane was observed. Dental model analysis demonstrated an asymmetric pattern of distalization between right (4.5 ± 2.2 mm) and left (3.1 ± 2.1 mm) first molars. The transverse width of the dental arch was maintained. No significant rotation of the first molars was observed. CONCLUSIONS: This study demonstrated that the innovative iPanda is effective to bodily distalize the maxillary molars into a Class I molar relationship and to provide maximum anchorage.

Placement and removal torque values of orthodontic miniscrew implants.

INTRODUCTION: The purpose of this study was to analyze the maximum insertion torque (MIT) and maximum removal torque (MRT) values of orthodontic miniscrews. METHODS: Two hundred eighty titanium miniscrews were placed in several sites in the maxillae and mandibles of orthodontic patients to provide skeletal anchorage. Two types of miniscrews were used: predrilling, cylindrical miniscrews, and self-drilling, conical miniscrews. A force of 50 g was applied with nickel-titanium coil springs 2 weeks after placement. MIT and MRT values were assessed with a digital torque gauge. Torque values were subjected to the paired t test, Student t test, chi-square test, and 1-way analysis of variance (ANOVA) (P <0.05). RESULTS: MIT values were significantly higher for the self-drilling miniscrews (mean, 14.5 Ncm; 95% CI, 13.6-15.3) than for the predrilling miniscrews (mean, 9.2 Ncm; 95% CI, 8.6-9.9) in all implant sites. For both predrilling and self-drilling miniscrews, the highest MIT values were observed at the midpalatal suture site followed by the dentoalveolar bones of the mandible and maxilla, respectively. In contrast, MRT values were significantly higher for the predrilling miniscrews (mean, 22.6 Ncm; 95% CI, 22.0-23.3) than for the self-drilling miniscrews (mean, 17.6 Ncm; 95% CI, 16.8-18.4). Accordingly, the mean torque ratio of predrilling miniscrews was twice that of the self-drilling miniscrews. CONCLUSIONS: An inverse relationship between MIT and MRT values was observed. The results suggest that relatively lower MIT values were more favorable to osseointegration than higher values.

"Safe zones" for miniscrew implant placement in different dentoskeletal patterns.

OBJECTIVE: To assess the influence of different dentoskeletal patterns on the availability of interradicular spaces and to determine the safe zones for miniscrew implant placement. MATERIALS AND METHODS: Periapical radiographs of 60 subjects with skeletal Class I, II, or III patterns were examined. For each interradicular site, the areas and distances at 3, 5, 7, 9, and 11 mm from the alveolar crest were measured. RESULTS: In the maxilla, the greatest interradicular space was between the second premolar and the first molar. In the mandible, the greatest interradicular space was between the first and second molars, followed by the first and second premolars. Significant differences in interradicular spaces among the skeletal patterns were observed. Maxillary interradicular spaces, particularly between the first and second molars, in the subjects with skeletal Class II patterns, were greater than those in the subjects with skeletal Class III patterns. In contrast, in the mandible, interradicular spaces in the subjects with skeletal Class III patterns were greater than those in the subjects with skeletal Class II patterns. CONCLUSIONS: For all skeletal patterns, the safest zones were the spaces between the second premolar and the first molar in the maxilla, and between the first and second premolars and between the first and second molars in the mandible.

Assessment of miniscrew implant stability by resonance frequency analysis: a study in human cadavers.

PURPOSE: Resonance frequency analysis (RFA) is a reliable, noninvasive method of measuring dental implant stability in vivo. However, the possibility of using this method to assess the stability of miniscrew implant has not been investigated. The purpose of this study was to evaluate the possibility of using RFA to assess the stability of miniscrew implants placed in different sites in the maxillae and mandibles of cadavers. MATERIALS AND METHODS: Ten pairs of dentate maxillas and mandibles were retrieved from human cadavers. Two hundred self-drilling miniscrew implants of 1.5-mm diameter and 8-mm length were systematically inserted into the dentoalveolar bones aided by a 3-dimensional surgical guide. Maximum insertion torque value was recorded during implantation procedures. Assessment of primary stability was carried out immediately after implantation using the RFA method, and implant stability quotient (ISQ) values were recorded. Analysis of variance, the Student t test, and generalized estimating equation regression analyses were used to analyze the data. RESULTS: A strong correlation was found between maximum insertion torque and ISQ values (r = 0.873). Maximum insertion torque and ISQ values were significantly higher in the mandible (15.8 ± 3.3 N-cm and 71.7 ± 12.1) than in the maxilla (11.8 ± 3.8 N-cm and 56.0 ± 15.8). Miniscrews inserted in the posterior region of the maxilla exhibited the lowest ISQ values. No significant difference among ISQ values of miniscrews inserted in the anterior, middle, or posterior regions of the mandible was observed. CONCLUSIONS: Estimates of implant stability using resonance frequency analysis are highly correlated with maximum insertion torque. Further studies to assess the primary stability of miniscrew implants in the clinical situation are necessary.

A simple mechanism for measuring and adjusting distraction forces during maxillary advancement.

PURPOSE: Direct measurement of distraction forces on the craniofacial skeleton has never been reported. The present report describes the development of a method of assessing and adjusting traction forces applied through maxillary distraction osteogenesis. MATERIALS AND METHODS: A simple mechanism to measure and adjust tension force during maxillary distraction osteogenesis was developed and connected bilaterally to the traction screws of a rigid external distraction device. Measurements were carried out before and after activation using a Shimpo (Nidec-Shimpo America Corporation, Itasca, IL) force gauge in 4 patients (2 with unilateral cleft lip and/or palate, 1 with bilateral cleft lip and palate, and 1 with noncleft) during the distraction process. Activation was performed twice a day at a rate of 1 mm/day. RESULTS: The average maximum force applied throughout the distraction period was 42.5 N (range 16.4 to 65.3 N), with increments, after activation, averaging 10.5 N (range 7.9 to 15.7 N). In patients with unilateral cleft lip and/or palate, distraction forces on the larger segment were 65.1% higher than on the lesser segment. A differential pattern of forces was also observed in the patients with asymmetric noncleft. However, the differential forces between lateral segments were not observed in the patient with bilateral cleft lip and palate. During the activation period, distraction forces progressively increased, whereas the amount of maxillary movement decreased. Pain and discomfort were reported with high forces. CONCLUSIONS: Through this mechanism, direct measurement and adjustment of distraction forces during maxillary advancement was possible. The unbalanced pattern of forces observed in patients with cleft suggests the necessity of individual adjustments for controlling pain and clinical symptoms. Accordingly, assessment of distraction forces during maxillary distraction osteogenesis is extremely helpful in understanding the biomechanics of the distraction process.

Treatment of a periodontally compromised patient with mini-implant anchorage.

BACKGROUND: Advanced periodontal disease and its sequelae are characterized by severe attachment loss, tooth mobility, and migration. This pathology often leads to compromised function and esthetics. A multidisciplinary approach combining orthodontic, periodontic, and restorative treatment is necessary to provide complete rehabilitation both in terms of function and esthetics with a satisfactory long-term prognosis. METHODS: A simple and effective treatment of an adult patient with periodontally migrated teeth using mini-implants in the maxilla and mandible is described. Mini-implant placement was aided by a 3D surgical guide, which made the procedure exceedingly safe. RESULTS: Gradual intrusion of the maxillary and mandibular anterior teeth was achieved with a relatively simple orthodontic force system. A significant profile improvement was observed during the 18 months of treatment due to the retraction and intrusion of the incisors in both arches. This intrusion was accomplished without any sign of apical root resorption. The mandibular incisors were uprighted 6.5 degrees, and their maxillary counterparts were uprighted 13.4 degrees. The 2-year follow-up examination revealed a stable result with an increase in periodontal attachment as well as esthetics and function. CONCLUSION: A combined orthodontic, periodontic, and restorative treatment approach with adequate patient motivation can lead to improved masticatory function, esthetics, and periodontal conditions.

Accuracy of miniscrew implant placement with a 3-dimensional surgical guide.

PURPOSE: Deviation in the trajectory during drilling or tapping of miniscrew implants increases the risks of root injury. The purposes of this study were to assess the accuracy of miniscrew placement into the dentoalveolar bone, aided by a 3-dimensional (3D) surgical guide, and to compare the results with those from conventional procedures. MATERIALS AND METHODS: A total of 220 miniscrews implanted, aided by a 3D surgical guide (n = 180), a conventional wire guide (n = 20), or no surgical guide (n = 20), were retrospectively examined in relation to the accuracy of placement. Coordinates, distances, and angles of the superimposed images of the planned and the correspondent implants were assessed and analyzed by 1-way analysis of variance. RESULTS: The results demonstrate that using the 3D surgical guide produced a significantly smaller variation between the planned and actual implant positions at the miniscrew head and tail (0.6 +/- 0.5 mm [mean +/- standard deviation] and 2.0 +/- 0.4 mm) compared with the wire guide (1.0 +/- 0.4 mm and 5.3 +/- 1.1 mm) and no guide (3.6 +/- 1.7 mm and 10.5 +/- 3.5 mm). The accuracy of placement was significantly improved with the 3D surgical guide (1.8 +/- 0.9 degrees) compared with the wire guide (16.9 +/- 2.6 degrees) and no guide (21.2 +/- 2.9 degrees). CONCLUSIONS: The 3D surgical guide provides a precise method for miniscrew placement into the dentoalveolar bone. The accurate insertion of miniscrews using the 3D surgical guide allows orthodontists to precisely transfer the radiographic information from preoperative planning to the surgical site, thus minimizing the risks of root injury.