Tridimensional finite element analysis of teeth movement induced by different headgear forces.

Background: This study aimed to simulate the actions of low-pull (LP), high-pull (HP), and combined pull (CP) headgears (HGs) and to analyze tooth movement tendencies through finite element analysis.

Methods: Tomographic slices of a human maxilla with complete permanent dentition were processed by reconstruction software, and the triangular surface mesh was converted into non-uniform rational B-spline (NURBS) curves. An HG facial bow was also modulated in 3D.

Orthodontic intrusion of maxillary incisors: a 3D finite element method study.

Objective: In orthodontic treatment, intrusion movement of maxillary incisors is often necessary. Therefore, the objective of this investigation is to evaluate the initial distribution patterns and magnitude of compressive stress in the periodontal ligament (PDL) in a simulation of orthodontic intrusion of maxillary incisors, considering the points of force application.

Methods: Anatomic 3D models reconstructed from cone-beam computed tomography scans were used to simulate maxillary incisors intrusion loading.

Nicotine effect on bone remodeling during orthodontic tooth movement: histological study in rats.

Introduction: Nicotine is harmful to angiogenesis, osteogenesis and synthesis of collagen.

Objective: The aim of this study was to investigate the effect of nicotine on bone remodeling during orthodontic movement in rats.

Methods: Eighty male Wistar rats were randomly divided into three groups: Group C (control), group CM (with orthodontic movement) and group NM (nicotine with orthodontic movement) groups.

Insertion torque, pull-out strength and cortical bone thickness in contact with orthodontic mini-implants at different insertion angles.

This study aimed to evaluate biomechanical behaviour of inclined orthodontic mini-implants by analyzing its insertion torque (IT), axial pull-out strength (APS), and cortical bone thickness in contact with mini-implant (CBTC). A total of 102 mini-implants were inserted at 90 degree, 60 degree, and 45 degree to the surface of synthetic bone. Peak IT was measured, and the mini-implants were aligned with the mechanical testing machine to record the APS.

Digital signature of electronic dental records.

Introduction: The purpose of this article is to examine the feasibility of digital signature technology to guarantee the legal validation of electronic dental records.

Methods: The possible uses of digital signature technology, the actual use of digital signature technology to authenticate electronic dental records, the authentication of each part of the electronic dental record, the general legal principles involved, how to digitally sign electronic dental record files, and the limitations of this method are discussed.

Results And Conclusions: It is possible to obtain electronic dental records that carry the same legal certainty as conventional, nonelectronic records.

Treatment of an adult with several missing teeth and atrophic old mandibular first molar extraction sites.

This report describes the orthodontic treatment of a woman, aged 34 years 2 months, with several missing teeth and atrophic mandibular first molar extraction sites. We had planned to close the spaces from the missing maxillary canines with mesial movement of the premolars and molars. In the mandibular arch, protraction of the second molars into first molar extraction sites and reduction of the mandibular incisor protrusion were performed.

Biodegradation of orthodontic metallic brackets and associated implications for friction.

Introduction: This study aimed to assess the effect of clinical exposure on the surface morphology, dimensions, and frictional behavior of metallic orthodontic brackets.

Methods: Ninety-five brackets, of 3 commercial brands, were retrieved from patients who had finished orthodontic treatment. As-received brackets, matched by type and brand, were used for comparisons.

Mechanical evaluation of space closure loops in orthodontics.

This study evaluated the mechanical performance of teardrop-shaped loops and teardrop-shaped loops with helix used in orthodontic space closure. Sixty retraction loops made with 0.019" x 0.

Effect of etching and light-curing time on the shear bond strength of a resin-modified glass ionomer cement.

The aim of this study was to assess the influence of etching and light-curing time on the shear bond strength (SBS) and adhesive remnant index (ARI) of a resin-modified glass ionomer cement (RMGIC) upon debonding of orthodontic brackets. Sixty-eight bovine permanent incisors were obtained and embedded in acrylic resin. Edgewise metallic brackets were bonded to the teeth with Fuji Ortho LC RMGIC.

Orthodontic-prosthetic treatment of an adult with a severe Class III malocclusion.

This case report describes the treatment of a 37-year-old woman with multiple restored and missing teeth, a Class III subdivision malocclusion, and complete dental crossbite. Treatment options included orthognathic surgery and an orthodontic-prosthetic approach. The patient opted for nonsurgical treatment with space opening for prosthetic replacement of the first maxillary molars.

Influence of natural bovine enamel roughness on bond strength after etching.

Objective: To determine and compare the longitudinal and transverse roughness parameters of the enamel surface of bovine teeth and evaluate the influence of these parameters on bond strength.

Materials And Methods: Ninety bovine incisors were used. The surface roughness of enamel was measured with a profilometer.

Clinical challenges in treating a patient with deviated dental midlines and delayed root development of the mandibular left second premolar.

This case report describes the treatment of a girl, aged 13.3 years, with a concave face and a Class I relationship on the right and Class III on the left at the first molars. The left canines were in full Class II occlusion.

Metal and ceramic bracket effects on human buccal mucosa epithelial cells.

Objective: To test the null hypothesis that metal and ceramic brackets have no effect on the epithelial cells of the buccal mucosa.

Materials And Methods: Two metal and two ceramic brackets were bonded in 21 individuals of both sexes. With the use of liquid-based exfoliative cytology, morphometric and morphologic changes in buccal mucosa cells adjacent to these brackets were determined and were compared at three time points: baseline (T0), 60 days after placement (T1), and 30 days after removal of the brackets (T2).

Root formation of an autotransplanted tooth.

Traumatic injuries with loss of anterior teeth occur more frequently in children. Treatment of the dental trauma is complex and requires a comprehensive and accurate diagnostic and treatment plan. It is also important to consider the biological, functional, esthetic, and economic aspects.

The dilemma of the open gingival embrasure between maxillary central incisors.

Aim: The aim of this report is to present the etiology, diagnosis, and treatment planning strategy in the presence of an open gingival embrasure between the maxillary central incisors.

Background: The open gingival embrasure or "black triangle" is a visible triangular space in the cervical region of the maxillary incisors. It appears when the gingival papilla does not completely fill in the interdental space.

Insertional torque and axial pull-out strength of mini-implants in mandibles of dogs.

Introduction: The objectives of this study were to evaluate insertional torque of mini-implants (MI) for orthodontic anchorage, to compare their axial pull-out strength at 0 (T0), 15 (T15), and 60 (T60) days after placement, to determine initial and peri-implant cortical bone thickness, and to analyze the correlations among these variables.

Methods: Sixty MI were placed in the mandibles of 10 dogs. Peak insertional torque values were recorded, and, after the animals were killed, specimens were prepared.

Electromyographic activity evaluation and comparison of the orbicularis oris (lower fascicle) and mentalis muscles in predominantly nose- or mouth-breathing subjects.

Introduction: The objective of this study was to evaluate and compare the electromyographic (EMG) activity of the orbicularis oris--lower fascicle (LOO) muscle and the mentalis muscle (MT)--in predominantly nose-breathing (PNB) and mouth-breathing (PMB) subjects.

Methods: Thirty-four subjects, 22 PNB and 12 PMB, with Class II Division 1 malocclusions were evaluated in 2001 (T1) and again in 2004 (T2), 2 years 5 months later. The age ranges of the sample were 11 years to 14 years 11 months at T1, and 13 years 4 months to 16 years 6 months at T2.