Amanda Carneiro da Cunha

Bone mineral density

OBJECTIVE To verify whether bone mineral density (BMD) of cortical bone, trabecular bone, and total bone influence the primary stability of orthodontic miniscrews and to verify whether there is a correlation between the measurement of BMD by cone-beam computed tomography (CBCT) and central dual-energy x-ray absorptiometry (DEXA). MATERIALS AND METHODS Twenty bovine bone sections were extracted from the pubic and iliac bones from regions with cortical thicknesses of approximately 1 mm. The BMD of the total bone block was evaluated using two methods: CBCT and DEXA. The BMD of cortical, trabecular, and total bone in the region of interest (ROI) were also evaluated by CBCT. After scanning the bone blocks, 20 self-drilling miniscrews (INP®) 1.4 mm in diameter and 6 mm long were inserted into them. The peak implant insertion torque (IT) was registered. After this, the pull-out test (PS) was performed and the maximum force registered. The Pearson correlation test was applied to verify the correlations between variables. RESULTS The BMD of the total bone block verified by CBCT and DEXA showed a positive and strong correlation (r  =  0.866, P  =  .000). The BMD of the ROI for cortical bone influenced the IT (r  =  0.518, P  =  .40) and the PS of miniscrews (r  =  0.713, P  =  .001, Table 2). However, the total bone BMD (verified by CBCT and DEXA) and trabecular bone BMD presented weak and not statistically significant correlations with primary stability. CONCLUSIONS There was a positive correlation between total bone block BMD measured by DEXA and CBCT. The cortical BMD influenced the IT and PS.

Influence of bone architecture on the primary stability of different mini-implant designs.

INTRODUCTION Mechanical interlocking between a mini-implant (MI) and the bone substrate reflects directly on the primary stability achieved. The purposes of this study were to evaluate MI design performance in distinct bone substrates and correlate geometric characteristics with insertion site quality. METHODS Two types of self-drilling MIs (1.6 × 8 mm) were allocated to 2 groups according to their geometric designs: Tomas system (Dentaurum, Ispringen, Germany) and Dual-Top (Rocky Mountain Orthodontics, Denver, Colo). Forty sections (8 × 10 mm) were taken from bovine pelvic ilium and pubic bone. Geometric design characteristics were evaluated using scanning electron microscope imaging and Image-Pro Insight software (Media Cybernetics, Rockville, Md). Bone quality parameters were assessed with a microcomputed tomography system, and primary stability was evaluated by insertion torque and pull-out strength. Intergroup comparisons were performed with analysis of variance and Tukey tests, and the Pearson correlation test was carried out (P <0.05). RESULTS No significant difference was observed in the comparisons of the groups (Tomas: insertion torque, 12.87 N·cm; pull-out strength, 181 N; and Dual-Top: insertion torque, 9.95 N·cm; pull-out strength, 172.5 N) in the ilium. However, the Tomas group had a marked increase in insertion torque (25.08 N·cm; P <0.05) in the pubic bone. CONCLUSIONS MI mechanical performance differed according to bone quality parameters, indicating that certain geometric parameters may be set depending on the insertion substrate.

Mechanical influence of thread pitch on orthodontic mini-implant stability

The aim of this study was to evaluate the effect of pitch distance on the primary stability (PS) of orthodontic mini-implants (MIs) in artificial bone. Twenty experimental MIs were allocated to two groups, according to their geometric design: G1 (30o X 0.6 mm) and G2 (45o X 0.8 mm), and inserted into artificial bone of different densities: D1 (0.32 g/cm3) and D2 (0.64 g/cm3). The maximum insertion torque (IT) and removal torque (RT) values were recorded in N.cm. Loss of torque (LT) values were obtained by calculating the difference between the IT and RT. MI mobility was measured by means of a Periotest assessment. Normality and homogeneity were determined by means of the Kolmogorov-Smirnov and Shapiro-Wilk tests, respectively. A two-way ANOVA was used to detect differences between the mini-implant design and density factors. The ANOVA/Tukey tests were used to determine the intergroup difference. Higher IT values were observed for G2 (p ≤ 0.05) in D2. No statistical difference for RT was observed between the groups, whereas G2 presented higher values only for LT (p ≤ 0.05). The Periotest values (PTV) were higher for G1, in comparison with G2, in D1. G1 presented better PS in D2 (IT, RT and LT), whereas G2 was found to be more stable in D1, after evaluation with Periotest.

How do geometry-related parameters influence the clinical performance of orthodontic mini-implants? A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to investigate how parameters related to geometry influence the clinical performance of orthodontic mini-implants (MIs). Systematic searches were performed in electronic databases including MEDLINE, Scopus, Web of Science, Virtual Health Library, and Cochrane Library and reference lists up to March 2016. Eligibility criteria comprised clinical studies involving patients who received MIs for orthodontic anchorage, with data for categories of MI dimension, shape, and thread design and insertion site, and evaluated by assessment of primary and secondary stability. Study selection, data extraction, quality assessment, and a meta-analysis were carried out. Twenty-seven studies were included in the qualitative synthesis: five randomized, eight prospective, and 14 retrospective clinical studies. One study with a serious risk of bias was later excluded. Medium and short MIs (1.4-1.9mm diameter and 5-8mm length) presented the highest success rates (0.87, 95% CI 0.80-0.92). A maximum insertion torque of 13.28Ncm (standard error 0.34) was observed for tapered self-drilling MIs in the mandible, whereas cylindrical MIs in the maxilla presented a maximum removal torque of 10.01Ncm (standard error 0.17). Moderate evidence indicates that the clinical performance of MIs is influenced by implant geometry parameters and is also related to properties of the insertion site. However, further research is necessary to support these associations.

High-intensity laser application in Orthodontics

ABSTRACT Introduction: In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. Objective: The aim of this study is to discuss HILT applications in orthodontic treatment. Methods: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. Conclusion: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

Miniscrew-assisted rapid palatal expansion for managing arch perimeter in an adult patient

ABSTRACT Introduction: Etiology of dental crowding may be related to arch constriction in diverse dimensions, and an appropriate manipulation of arch perimeter by intervening in basal bone discrepancies cases, may be a key for crowding relief, especially when incisors movement is limited due to underlying pathology, periodontal issues or restrictions related to soft tissue profile. Objectives: This case report illustrates a 24-year old woman, with maxillary transverse deficiency, upper and lower arches crowding, Class II, division 1, subdivision right relationship, previous upper incisors traumatic episode and straight profile. A non-surgical and non-extraction treatment approach was feasible due to the miniscrew-assisted rapid palatal expansion technique (MARPE). Methods: The MARPE appliance consisted of a conventional Hyrax expander supported by four orthodontic miniscrews. A slow expansion protocol was adopted, with an overall of 40 days of activation and a 3-month retention period. Intrusive traction miniscrew-anchored mechanics were used for correcting the Class II subdivision relationship, managing lower arch perimeter and midline deviation before including the upper central incisors. Results: Post-treatment records show an intermolar width increase of 5 mm, bilateral Class I molar and canine relationships, upper and lower crowding resolution, coincident dental midlines and proper intercuspation. Conclusions: The MARPE is an effective treatment approach for managing arch-perimeter deficiencies related to maxillary transverse discrepancies in adult patients.

Camouflage of a high-angle skeletal Class II open-bite malocclusion in an adult after mini-implant failure during treatment

&NA; The treatment of skeletal anterior open‐bite malocclusion requires complex orthodontic planning that considers its multifactorial etiology, treatment limitations, and high relapse rates. This case report illustrates a successful treatment approach for a skeletal high‐angle Class II malocclusion in an adult with a severe open bite. The treatment consisted of a high‐pull headgear therapy after mini‐implants failure during fixed orthodontic therapy. Adequate esthetics and function were achieved. Despite its low probability, the unexpected event of mini‐implant loosening during complex treatments should be considered. Therefore, classic orthodontic mechanics should be established, especially when treating patients for whom invasive procedures such as miniplates or orthognathic surgery are not available options. HighlightsA dentoalveolar orthodontic camouflage of a severe open bite in an adult patient is described.A high‐pull headgear was implemented due to subsequent mini‐implants loosening episodes.Adequate esthetics and function were achieved.The 23‐month follow‐up showed the stability of this treatment modality.The treatment of skeletal anterior open-bite malocclusion requires complex orthodontic planning that considers its multifactorial etiology, treatment limitations, and high relapse rates. This case report illustrates a successful treatment approach for a skeletal high-angle Class II malocclusion in an adult with a severe open bite. The treatment consisted of a high-pull headgear therapy after mini-implants failure during fixed orthodontic therapy. Adequate esthetics and function were achieved. Despite its low probability, the unexpected event of mini-implant loosening during complex treatments should be considered. Therefore, classic orthodontic mechanics should be established, especially when treating patients for whom invasive procedures such as miniplates or orthognathic surgery are not available options.