Novel multi-axial alveolar distractor - Part I: Design, manufacture, and mechanical/functional tests.

Purpose: This study developed a novel multi-axial alveolar distractor and evaluated its safety and effectiveness by performing various mechanical tests and finite element (FE) analysis.

Materials And Methods: A ball-and-socket joint with a high degree of freedom was proposed as the design concept to make the distractor produce a cone trajectory motion range of up to 60° with respect to the transport screw (central axis). This device was manufactured with Ti6Al4V alloy.

Broadband on-chip polarization mode splitters in lithium niobate integrated adiabatic couplers.

We report, to the best of our knowledge, the first broadband polarization mode splitter (PMS) based on the adiabatic light passage mechanism in the lithium niobate (LiNbO) waveguide platform. A broad bandwidth of ~140 nm spanning telecom S, C, and L bands at polarization-extinction ratios (PER) of >20 dB and >18 dB for the TE and TM polarization modes, respectively, is found in a five-waveguide adiabatic coupler scheme whose structure is optimized by an adiabaticity engineering process in titanium-diffused LiNbO waveguides. When the five-waveguide PMS is integrated with a three-waveguide "shortcut to adiabaticity" structure, we realize a broadband, high splitting-ratio (ηc) mode splitter for spatial separation of TE- (H-) polarized pump (700-850 nm for ηc>99%), TM- (V-) polarized signal (1510-1630 nm for ηc>97%), and TE- (H-) polarized idler (1480-1650 nm for ηc>97%) modes.

Asymmetric adiabatic couplers for fully-integrated broadband quantum-polarization state preparation.

Spontaneous parametric down-conversion (SPDC) is a widely used method to generate entangled photons, enabling a range of applications from secure communication to tests of quantum physics. Integrating SPDC on a chip provides interferometric stability, allows to reduce a physical footprint, and opens a pathway to true scalability. However, dealing with different photon polarizations and wavelengths on a chip presents a number of challenging problems.

Biomechanical evaluation of a novel hybrid reconstruction plate for mandible segmental defects: A finite element analysis and fatigue testing.

Purpose: This study develops a novel hybrid (NH) reconstruction plate that can provide load-bearing strength, secure the bone transplant at the prosthesis favored position, and also maintain the facial contour in a mandibular segmental defect. A new patient-match bending technique which uses a three-dimensional printing (3DP) stamping process is developed to increase the interfacial fit between the reconstruction plate and mandibular bone.

Materials And Methods: The NH reconstruction plate was designed to produce a continuous profile with non-uniform thickness and triangular cross-screw patterns with a locking-screw feature at the plate base.

A Revolving Temporary Anchorage Cap Connecting to an Orthodontic Miniscrew Using In Vitro Experimental Testing: Safety and Biomechanical Evaluations.

Purpose: This study is to develop a plastic revolving (translation and rotation) temporary anchorage cap (TAC) as the orthodontic anchor and evaluate its biomechanical safety and clinical used feasibility.

Materials And Methods: The TAC was designed to connect onto a mini-implant head with 45-degree switching unit and extended arm for tying an orthodontic elastic chain/coil spring. The removal force between the TAC and mini-implant head and torque resistance on the mini-implant/bone interface were performed to evaluate the biomechanical safety.

Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

Purpose: The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability.

Materials And Methods: Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.

Biomechanical evaluation of an orthodontic mini-implant with plastic removal cap: an in-vitro experimental testing.

This study evaluates the biomechanical interactions of a mini-implant using a plastic revolving cap (PRC) with translation/rotation features for optional orthodontic traction. An orthodontic mini-implant and the PRC consisting of a hexagon connection onto mini-implant with 60 degree switching unit and an extended arm to provide orthodontic wire tied at different positions. The PRC removal force was measured by pull-out testing.

Biomechanical evaluation of an orthodontic miniimplant used with revolving (translation and rotation) temporary anchorage device by finite element analysis and experimental testing.

Purpose: To evaluate the biomechanical interactions of a miniimplant using a temporary anchorage device (TAD) for orthodontic traction.

Materials And Methods: A miniimplant was designed with dual thread (DT) with a TAD that can be connected optionally onto the miniimplant with 60-degree switching unit and an extended arm for tying orthodontic wire. Finite element analysis was used to calculate the relative miniimplant displacement and bone strain under immediate load (500 gW) on behalf of the maximum lateral force during orthodontic treatment.

Biomechanical comparison of a single short and wide implant with monocortical or bicortical engagement in the atrophic posterior maxilla and a long implant in the augmented sinus.

Purpose: The present study investigated the biomechanical interactions of a monocortically or bicortically engaged short and wide implant in the atrophic posterior maxilla and compared them to those of a long implant in the augmented sinus under different loading conditions via a nonlinear finite element (FE) approach.

Materials And Methods: Nonlinear FE models of a single implant in the posterior maxilla were constructed for the following conditions: (1) A monocortically engaged 5-mm-long, 7-mm-wide implant with an internal tripodgrip abutment connection (SIT-1), (2) a bicortically engaged 6-mm-long, 7-mm-wide implant with internal tripod-grip abutment connection (SIT-2), and (3) a 13-mm-long, 4.5-mm-wide implant with an internal-hexagon abutment connection in an augmented sinus.

Biomechanical analysis of the effects of implant diameter and bone quality in short implants placed in the atrophic posterior maxilla.

Short dental implant (SDI) placement has been proposed as an alternative to reduce the surgical risks related to the advanced grafting procedures. The aim of this study was to simulate the biomechanical behaviors and influences of SDI diameters under various conditions of bone quality by using a validated finite element (FE) model for simulation. The CT image and CAD system were combined to construct the FE models with 6 mm length SDIs for 6, 7 and 8 mm diameters under three types of bone qualities, from normal to osteoporotic.

Evaluation of contributions of orthodontic mini-screw design factors based on FE analysis and the Taguchi method.

This study determines the relative effects of changes in bone/mini-screw osseointegration and mini-screw design factors (length, diameter, thread shape, thread depth, material, head diameter and head exposure length) on the biomechanical response of a single mini-screw insertion. Eighteen CAD and finite element (FE) models corresponding to a Taguchi L(18) array were constructed to perform numerical simulations to simulate mechanical responses of a mini-screw placed in a cylindrical bone. The Taguchi method was employed to determine the significance of each design factor in controlling strain.

Evaluation of the relative contributions of multi-factors in an adhesive MOD restoration using FEA and the Taguchi method.

Objectives: This study determines the relative contribution of changes (design factors) in cavity dimension, restorative material, adhesive layer modulus and thickness and loading condition on the biomechanical response of a premolar adhesive Class II MOD restoration.

Methods: A validated finite element (FE) model was used to simulate the mechanical responses. The Taguchi method was employed to identify the significance of each design factor in controlling the stress.