Factors that may increase the risk of external apical root resorption during orthodontic treatment : Retrospective clinical investigation.

PURPOSE: To determine the correlation between external apical root resorption and malocclusion-related variables in patients treated with fixed orthodontic appliances. METHODS: In all, 103 patients aged 12-15 years and treated with edge-wise appliances either without extractions or with four premolar extractions were included in this retrospective cohort study. External apical root resorption was assessed in the pre- and posttreatment panoramic radiographs of these patients for incisors, canines, premolars, and first molars. A total of 2332 teeth were evaluated in 206 panoramic radiographs obtained from 103 patients. The gender of the patients, duration of orthodontic treatments, presence of premolar extractions, Angle classification, overbite, overjet and amount of crowding were assessed. Wilcoxon signed-rank test, Mann-Whitney U test, and Kruskal-Wallis test were used for statistical analysis of the data. RESULTS: Statistically significant (p < 0.001) root resorption occurred in all examined teeth during orthodontic treatment. The degree of root resorption observed in the premolars was significantly greater in premolar extraction cases than in nonextraction cases. Statistically significant negative correlations were found between the degree of root resorption of the maxillary lateral teeth and between the maxillary first premolar teeth and the amount of maxillary crowding. CONCLUSIONS: The orthodontic treatment protocols and the amount of tooth movements achieved were shown to be dependent on the severity of dental malocclusions and they have an influence on the amount of external apical root resorption that occurs during the course of orthodontic treatment.

Pharyngeal airway and hyoid bone position changes of skeletal anchored Forsus Fatigue Resistant Device and activator appliances.

OBJECTIVES: To evaluate the effects of miniplate anchored Forsus Fatigue Resistant Device (MAF) and activator treatments in the pharyngeal airway dimensions and hyoid bone position. MATERIALS AND METHODS: Thirty-eight patients with mandibular retrusion who were treated with either MAF or activator were selected retrospectively and compared with an untreated control group. The data of 114 lateral cephalograms, comprising those taken before treatment (T1) and at the end of functional treatment (T2), were evaluated with regard to their linear, angular, and area measurements. RESULTS: The mandibular length increased and the hyoid bone moved forward with both treatments (P < 0.05). The horizontal change in the hyoid bone position with MAF treatment was correlated with changes in the point B and ANB angle. Increases of 1.8 mm, 1.4 mm, and 1.8 mm in the pharyngeal airway dimensions were obtained at the levels of the second, third, and fourth cervical vertebra, respectively, with the MAF treatment. On the other hand, an increase of 1.9 mm was found at the level of the fourth cervical vertebra with the activator treatment. The greatest vertical movement in the Menton and the highest increase in the oropharyngeal area were observed in the MAF group (P < 0.05). CONCLUSION: Both the MAF and activator treatments caused favorable maxillomandibular changes; however, the MAF treatment provided a greater increase in the oropharyngeal area according to both the increase in mandibular length and the change in the vertical position of the mandible. CLINICAL RELEVANCE: Functional appliances were found to be useful in increasing the pharyngeal airway dimensions in the short-term. The skeletal anchored fixed functional appliance caused a greater increase in the oropharyngeal airway area that may be beneficial for Class II patients who carry a risk of having respiratory problems.

Comparative evaluation of periodontal effects and survival rates of Memotain and five-stranded bonded retainers : A prospective short-term study.

PURPOSE: To prospectively compare the short-term periodontal effects and survival rates of mandibular lingual canine-to-canine Memotain (CA-Digital, Mettmann, Germany) and five-stranded bonded retainers. METHODS: In all, 52 patients requiring retention after orthodontic treatment were assigned to 2 study groups (n = 26 in each group). Retention was provided by Memotain retainers which were fabricated digitally using CAD-CAM (computer-aided design and computer-aided manufacturing) technology in the first group and by five-stranded retainers which were fabricated manually using a conventional bending method in the second group. The patients were examined at the following time points: 1 week, 1 month, 3 months and 6 months. Plaque index, gingival index, probing depth, marginal recession, bleeding on probing, failure rate per tooth, and survival rate of retainer wires were analyzed by Mann-Whitney U, Friedman, Wilcoxon signed-rank, and χ2 tests. RESULTS: The differences between the groups were nonsignificant for plaque index, gingival index, probing depth, marginal recession, bleeding on probing, failure rate per tooth and survival rate of retainer wires. Significant differences were observed within the groups throughout the follow-up period for plaque index and probing depth. The survival rates of retainer wires were 77% for the Memotain retainers and 73% for the five-stranded retainers for the 6­month follow-up period. CONCLUSIONS: Periodontal outcomes and survival rates of Memotain and five-stranded mandibular lingual bonded retainers were similar. Furthermore, periodontal health was maintained and considerably high survival rates were achieved with both retainer types.

Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances.

OBJECTIVES: The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance. MATERIALS AND METHODS: Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed. RESULTS: The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05). CONCLUSION: The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors. CLINICAL RELEVANCE: Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.

Effect of maxillary incisors, lower lip, and gingival display relationship on smile attractiveness.

INTRODUCTION: This study aimed to evaluate the effect of the relationship between maxillary incisors and lower lip in conjunction with the maxillary gingival display on perception of smile attractiveness. METHODS: The frontal intraoral photograph of ideally aligned teeth was modified using image processing software. Twenty different smiles were obtained with a combination of 10 different maxillary incisor edge-lower lip distances and 10 different maxillary gingival display amounts. Attractiveness of these 20 smiles was evaluated by orthodontists (n = 101), dentists (n = 107), and laypersons (n = 105). Two-way ANOVA was used to compare alterations on smile esthetics, and repeated measures ANOVA was used to evaluate the interaction between the variables. Bonferroni-adjusted pairwise comparisons were applied for determining the differences between the rater groups. RESULTS: Maxillary incisor edge-lower lip distance (P < 0.01), maxillary gingival display amount (P < 0.001), and rater group (P < 0.01) had statistically significant influences on perception of smile attractiveness. Orthodontists prefer to see a minimal amount of mandibular incisor exposure and almost full crowns of maxillary central incisors. Dentists and laypersons are more tolerant of mandibular incisor exposure and maxillary central incisor coverage by the upper lip. None of the rater groups preferred the coverage of maxillary incisor edges or maxillary gingival display. CONCLUSIONS: Elimination of maxillary gingival display helps to improve smile attractiveness, whereas the coverage of maxillary incisor edges has a negative influence.

Periodontal effects and survival rates of different mandibular retainers: comparison of bonding technique and wire thickness.

OBJECTIVES: This non-randomized prospective cohort study aimed to compare the periodontal effects and success rates of mandibular canine-to-canine fixed retainers having different bonding techniques and wire thicknesses. MATERIALS AND METHODS: Hundred patients requiring retention after orthodontic treatment were assigned to five study groups (n = 20 in each group, 61 females/39 males, median age range 16.5-18.0 years). Retention was provided by 0.0215"/direct, 0.0215"/indirect, 0.0175"/direct, 0.0175"/indirect bonded multistranded wires and removable Essix appliances. The primary and secondary outcomes were periodontal effects and success rates. The patients were examined in 1 week, 1 month, 3 months and 6 months follow-up appointments. Plaque index, gingival index, probing depth, marginal recession, bleeding on probing, failure rate per retainer wire and survival of retainer wires were analysed by Kruskal-Wallis H, Mann-Whitney U and chi-square tests. RESULTS: Significant differences were observed between the fixed retainer (FR) and Essix (E) groups in gingival index scores at 1 month [mean FR: 1.13 (95% confidence interval (CI): 0.81-1.44), mean E: 0.40 (95% CI: 0.14-0.69), mean difference: 0.73, P < 0.01], 3 months [mean FR: 0.97/1.01 (95% CI: 0.65-1.30/0.72-1.30), mean E: 0.52 (95% CI: 0.25-0.82), mean differences: 0.45/0.49, P < 0.05], 6 months [mean FR: 0.94 (95% CI: 0.62-1.27), mean E: 0.35 (95% CI: 0.15-0.58), mean difference: 0.59, P < 0.05] and in bleeding on probing scores at 1 month [mean FR: 3.05 (95% CI: 2.12-3.98), mean E: 1.15 (95% CI: 0.42-1.88), mean difference: 1.90, P < 0.01]. The survival rates of retainer wires were 85 per cent for the 0.0215" direct/indirect and 90 per cent for the 0.0175" direct/indirect groups for the 6 months follow-up. LIMITATIONS: Six months follow-up period, which demonstrates only short-term outcomes. CONCLUSIONS: The periodontal outcomes or survival rates of mandibular fixed retainers were not affected by bonding technique or wire thickness, whereas gingival health improved with Essix retainers but not with fixed retainers.

Fixed Orthodontic Retainers: A Review.

Orthodontic retention is defined as maintaining teeth in optimal aesthetic and functional position after treatment. Despite the necessity of retention phase and the factors influencing the stability of the teeth after orthodontic treatment was discussed by the orthodontist for a long time, it is accepted that a retention phase is essential for stability of orthodontic treatment results nowadays. Therefore, the application of a suitable retention method is important both for prevention of relapse after orthodontic treatment and for increasing patient satisfaction. Removable appliances had been used for many years for retention purposes. Later, fixed retainers were introduced to prevent relapse as having a number of advantages, such as better aesthetics, no need for patient cooperation, effectiveness, and suitability for lifelong retention. However, their need for precise bonding technique, fragility, and tendency to cause periodontal problems by weakening oral hygiene are some of their disadvantages.

Relationship between alveolar bone thickness, tooth root morphology, and sagittal skeletal pattern : A cone beam computed tomography study.

PURPOSE: The goal of this work was to examine the relationship between sagittal facial pattern and thickness of alveolar bone in conjunction with root morphology of teeth by using cone beam computed tomography (CBCT). METHODS: The study was carried out on the CBCT scans from 3 group of patients (n = 20 in each group). The first group involved skeletal class 1, the second group involved skeletal class 2, and the third group involved skeletal class 3 patients. In all, 14 permanent teeth and interdental regions in the maxilla and mandible were evaluated. Root length and root width were measured on each tooth. Buccal cortical bone thickness, cancellous bone thickness, and lingual cortical bone thicknesses were measured in each interdental region. Analysis of variance, Kruskall-Wallis H and Mann-Whitney U tests were used for statistical comparisons. RESULTS: No significant difference was found between the groups for root length, root width, buccal cortical bone and lingual cortical bone thickness. A significant difference was observed between the groups for cancellous bone thickness as it was thicker in skeletal class 2 group. Cortical bone was thicker in the mandible compared to maxilla on both buccal and lingual sides and it was thicker in the posterior region compared to the anterior region on the buccal side. CONCLUSIONS: Differences in cancellous bone thickness between different sagittal facial patterns and differences in cortical bone thickness between different alveolar regions should be taken into consideration when planning orthodontic tooth movements and anchorage mechanics.

Appraisal of the relationship between tooth inclination, dehiscence, fenestration, and sagittal skeletal pattern with cone beam computed tomography.

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.

Sagittal skeletal correction using symphyseal miniplate anchorage systems : Success rates and complications.

OBJECTIVES: Aim of this study is to evaluate success rates and complications related with symphyseal miniplate anchorage systems used for treatment of Class 2 and Class 3 deformities. METHODS: A total of 58 miniplates applied to 29 growing patients were evaluated. The first group comprised 24 symphyseal miniplates applied to 12 patients and Forsus Fatigue Resistant Devices were attached to the head of the miniplates for mandibular advancement. The second group consisted of 34 symphyseal miniplates applied to 17 patients and intermaxillary elastics were applied between acrylic appliances placed on the maxillary dental arch and the symphyseal miniplates for maxillary protraction. Success rate and complications of the symphyseal plate-screw anchorage system were evaluated. RESULTS: The overall success rate of symphseal miniplates was 87.9%. Six miniplates showed severe mobility and 2 miniplates broke during orthodontic treatment. Infection, miniplate mobility and mucosal hypertrophy were statistically different between the two groups. CONCLUSIONS: Symphyseal miniplates were generally used as successful anchorage units in most patients. Infection, mobility, and mucosal hypertrophy occurred more frequently in Class 2 deformity correction. However, the success rates regarding the two treatment modalities were comparable.

Cone Beam Computed Tomography in Orthodontics.

Orthodontists treat malocclusions by applying three-dimensional forces. For years, the diagnosis of this three-dimensional condition and the related treatment plan has been based on two-dimensional imaging. Lateral and anteroposterior cephalometric, panoramic, and periapical radiographs are some of the two-dimensional radiographs routinely used in orthodontics. Despite being highly beneficial in evaluating skeletal and dental relations, these radiographs fail to provide sufficient two-dimensional information in certain cases. The purpose of this compilation is to review the use of cone-beam computed tomography in orthodontics.

Extrusão cirúrgica de um dente com fratura coronorradicular: acompanhamento de 3.5 anos / Surgical extrusion of a crown-root fractured tooth: 3.5-year follow-up

Introdução: diferentes abordagens de tratamento sãoindicadas para dentes com fraturas coronorradiculares.A extrusão cirúrgica é um procedimento único, que envolveo reposicionamento imediato do dente à sua posiçãonormal. Objetivo: o objetivo deste relato de casofoi apresentar o tratamento multidisciplinar de um pré--molar superior com fratura coronorradicular. Métodos:neste caso, um pré-molar superior fraturado foi tratadopor meio da técnica de extrusão cirúrgica. Após aresolução da lesão periapical, o dente foi restauradocom coroa metalocerâmica. Resultados: após 3,5 anosde acompanhamento, o dente não apresentou sintomasou sinais clínicos e radiográficos de reabsorção radicularprogressiva, de perda óssea marginal ou de doença periapical.Conclusão: os resultados favoráveis do casodemonstram que a extrusão cirúrgica pode ser uma alternativade tratamento para os protocolos existentes.

Influence on smile attractiveness of the smile arc in conjunction with gingival display.

INTRODUCTION: Many variables affecting smile esthetics and attractiveness have been evaluated. However, the influence of the interaction of several variables is not as well known. Furthermore, patients and dental professionals might view smile esthetics differently. Therefore, the purpose of this research was to evaluate the influence of the smile arc in conjunction with the amount of maxillary gingival display on the perception of smile attractiveness by orthodontists, dentists, and laypersons. METHODS: A frontal intraoral photograph of ideally aligned teeth was modified using image-processing software. Photos showing 7 smile arcs, from flat to vaulted, were obtained, and these were combined with photos showing 4 different amounts of maxillary gingival display. The attractiveness of the 28 images of different smiles was evaluated by 3 groups of raters (orthodontists, dentists, and laypersons), each consisting of 70 persons. RESULTS: Both smile arc (P <0.05) and gingival display amount (P <0.001) had statistically significant influences on the perception of smile attractiveness. Smile attractiveness scores with reference to gingival display amount showed a statistically significant (P <0.001) difference between the rater groups. A significant (P <0.05) interaction between smile arc and gingival display amount was observed. CONCLUSIONS: Examining other components influencing the perception of smile attractiveness might help clinicians develop more satisfying treatment plans for their patients.

Comparison of two implant-supported molar distalization systems.

OBJECTIVE: To examine skeletal, dental, and soft tissue effects of the Miniscrew Implant Supported Distalization System (MISDS) and the Bone-Anchored Pendulum Appliance (BAPA). MATERIALS AND METHODS: Among 28 patients displaying Angle Class II malocclusion, 14 patients with a mean age of 14.8 ± 3.6 years treated with MISDS were included in the first group, and 14 patients with a mean age of 14.5 ± 1.5 years treated with BAPA were included in the second group. The pretreatment and posttreatment lateral cephalograms were analyzed. Statistical evaluation was carried out using the paired Shapiro-Wilk test, the paired-sample t-test, and the unpaired t-test. RESULTS: Upper posterior teeth were distalized successfully in both groups. Nearly bodily distalization was seen in the MISDS group, whereas significant distal tipping of the upper first molars was observed in the BAPA group (P < .001). There were no statistically significant changes in the sagittal position of the maxilla and mandible and in the position of the upper incisors as a result of treatment in either group. CONCLUSIONS: Both methods provided absolute anchorage for distalization of posterior teeth; however, almost translatory distal movement was encountered in the MISDS group, and substantial distal tipping of the maxillary molars accompanied distalization in the BAPA group.

Palatal implant versus zygoma plate anchorage for distalization of maxillary posterior teeth.

This study aimed to examine the skeletal, dental, and soft tissue effects of the implant-supported pendulum (ISP) and the zygoma anchorage system (ZAS) used for the distalization of maxillary posterior teeth. Among 30 patients showing Angle class II malocclusion, 15 patients with a mean age of 14.3±1.6 years and treated with ISP were included in the first group; 15 patients with a mean age of 14.7±2.5 years and treated with ZAS were included in the second group. The predistalization and postdistalization lateral cephalograms were analysed. Statistical evaluation was carried out using SPSS. Point A and upper incisors protruded in the ISP group, retruded in the ZAS group. Upper posterior teeth were distalized in both groups, but more in the ZAS group. Significant differences were observed between the groups for the sagittal movements of Point A, incisors, and posterior teeth. Overbite decreased in the ISP group, overjet decreased in the ZAS group, upper and lower lips retruded only in the ZAS group. Both methods provided absolute anchorage for distalization of posterior teeth, but the skeletal and soft tissue outcome and distalization obtained was greater in the ZAS group. Both methods can be used as alternatives to extraoral traction and conventional molar distalization appliances with different patient requirements.

Effect of support materials on supported platinum catalyst prepared using a supercritical fluid deposition technique and their catalytic performance for hydrogen-rich gas production from lignocellulosic biomass.

A number of supported Pt catalysts have been prepared by supercritical carbon dioxide deposition technique using various supports. The reduction of Pt precursor to metal performed by heat treatment under nitrogen flow. The prepared catalysts were evaluated for gasification of wheat straw biomass hydrolysates and glucose solution for hydrogen-rich gas production. The activities of the catalysts were highly affected by distribution, amount and particle sizes of platinum on the support. In general carbon-based supported Pt catalysts exhibited better catalytic activity compared to other supports to be used. Compared to biomass hydrolysate feed, gasification of glucose always resulted in higher volume of gas mixture, however, hydrogen selectivity was decreased in all catalyst except multi-walled carbon nanotube. The deposition of Pt particles inner side of that support makes the large organic substrates inaccessible to reach and react with those metal particles.

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

OBJECTIVE: To examine remodeling in bone supporting mini-implants by comparing a no drug (ND) group with a group that received a potent intravenous bisphosphonate in a canine model. MATERIALS AND METHODS: Twelve skeletally mature (2- to 3-year-old) male dogs were divided into two groups. Seven dogs were administered 0.1 mg/kg/mo of zoledronic acid (ZA) for 16 weeks, while five age-matched dogs received no drug. Two mini-implants (Tomas, Dentaurum, Newton, Pa) were placed unilaterally in the maxilla and mandible (4 mini-implants per animal × 12  =  48). Serial fluorescent bone labels were administered in vivo. Postmortem, the bone blocks containing the mini-implants were harvested and used for histomorphometric analyses at two regions of interest (adjacent: within 1 mm of interface; distant: 1-4 mm from the interface) supporting the mini-implant. Data were analyzed using mixed models. RESULTS: In general, the ZA group had a significantly lower bone formation rate than the ND group (P < .05) for all jaws/regions except for the adjacent region in the maxilla, P  =  .12. Despite the reduction, mean intracortical remodeling in the ZA group ranged from 35%-42% per year in the implant adjacent bone. This rate is substantially higher than that reported for noninjured sites in the jaw. CONCLUSIONS: Bone remodeling is typically elevated in implant supporting bone. After ZA administration, the healing response represented by elevated turnover in implant supporting bone was diminished but was not abolished.

Success of zygomatic plate-screw anchorage system.

PURPOSE: To evaluate the success of zygomatic plate-screw anchorage and to define the key points that help to improve the success of this system. MATERIALS AND METHODS: A total of 74 zygomatic plate-screw anchors were applied to 37 patients from 2 groups receiving orthodontic treatment. The first group consisted of 19 patients, and the zygoma anchors were applied bilaterally to distalize the maxillary buccal segment. The second group consisted of 18 patients, and the zygoma anchors were applied bilaterally to stabilize the maxillary molars during maxillary canine retraction. The orthodontic force was applied 1 week after the insertion of the plates. In the first group, 450 g of direct force and in the second group 150 g of indirect force were applied to the zygomatic plates. The success rate of the zygomatic plate-screw anchorage system was evaluated. RESULTS: One plate was lost and the others remained stable all through the orthodontic treatment. Mild gingival inflammation was observed in 1 patient (2 plates), and pus formation was detected in 1 patient (2 plates). One plate was covered because of mucosal hypertrophy. CONCLUSION: Zygomatic plate-screw anchorage system is a reliable technique to obtain orthodontic anchorage and may eliminate the need for extraoral force. However, the surgical insertion technique, position of the plates, and oral hygiene status of the patients certainly influence the success of the system.