Search results for "mandible"
showing 10 items of 351 documents
Speed of sound measurements in mandibular and phalangeal bone during growth
2001
The micromechanical and elastic properties of bone, its structural maturity and, indirectly, mineral density are important factors for the planning and assessment of orthodontic and/or jaw orthopaedic treatment. This clinical study was undertaken to evaluate age-related changes in the anterior mandibular body. The speed of sound (SOS) has demonstrated age dependency in various peripheral bones and has been proposed as an alternative method for investigating bone parameters without the use of radiation. The ultrasound transmission velocity was measured in 184 healthy subjects (93 females, 91 males; mean age 17.6 +/- 13.7 years). According to the statistical analysis, the data did not reveal …
Mandibular connective tissue pedicle flaps in implant dentistry: report of three cases.
2007
Abstract An increase in soft tissues and alveolar bone in the anterior mandibular area between the canines is necessary to achieve a good esthetic result. The present article describes a technique for gaining bone volume and soft tissue to cover bone defects that would otherwise compromise the final result of prosthetic implant restoration in the anterior mandible. Three patients with anterior mandibular atrophy caused by loss of the mandibular incisors are presented. Particulate autologous bone grafting, the raising of a pediculate connective tissue flap to increase soft tissue, and implant placement were carried out simultaneously. After 2 years of follow-up, the implants were in good cli…
Vertical guided bone regeneration with bioabsorbable barriers.
2007
Guided bone regeneration (GBR) is a very useful surgical technique to increase limited alveolar bone for implant placement. The use of non-resorbable barriers is well established; however, bioabsorbable collagen membranes may simplify the surgical technique and make it more predictable.Vertical ridge augmentation was performed on 11 patients at the time of implant placement. The part of the implant out of bone was covered with autogenous bone/graft, and a slow-resorption collagen membrane was placed on top. Gingival tissues were closed with horizontal mattress and interrupted sutures. Second-stage surgery was performed 4 to 6 months later, and healing abutments were placed. The length of th…
Influence of bone parameters on peri-implant bone strain distribution in the posterior mandible
2014
Objectives: The success rate of dental implants depends on the type of bone at the implant site. The purpose of the present study was to investigate the effects of the bone parameters at the implant-placement site on peri-implant bone strain distributions. Study Design: The morphologies and bone densities of seventy-five potential implant sites in the posterior man - dible were measured using computed tomography (CT). Based on the CT data, we defined bone parameters (low and high in terms of cancellous-bone density and crestal-cortical bone density, and thin and thick in terms of crestal-cortical bone thickness), and we constructed finite-element models simulating the various bone types. A …
Cross-sectional human study of soft tissue chin (STC) thickness in adult patients in relation to sex, facial pattern and skeletal class
2017
Abstract Purpose The aim of this study was to study the relations between the soft tissue chin (STC) and sex, skeletal class, and facial pattern; and to describe the shape and behavior of the STC. Methods 385 non-growing patients were selected, 206 women and 179 men, with a mean age of 28.8 years (SD 4.2). Patients were divided into groups by skeletal class (class I, II or III) and facial pattern (brachyfacial, mesofacial or dolichofacial). STC thicknesses were measured at pogonion (Pg), soft pogonion (Pg′), gnathion (Gn), soft gnathion (Gn′), menton (Me) and soft menton (Me′) in the CBCTs. Results Sexual dimorphism was observed at Pg-Pg′ and Me-Me′. STC thickness was not related to skeleta…
Virtual Planning and 3D printing modeling for mandibular reconstruction with fibula free flap
2017
Background This study was to evaluate the use of virtual planning and 3D printing modeling in mandibular reconstruction and compare the operation time and surgical outcome of this technique with conventional method. Material and Methods Between 2014 and 2017, 15 patients underwent vascularized fibula flap mandibular reconstruction using virtual planning and 3D printing modeling. Titanium plates were pre-bent using the models and cutting guides were used for osteotomies. 15 patients who underwent mandibular reconstruction using fibula flap without aid of virtual planning and 3D printing models were selected as control group. The operation time was recorded and compared in two groups. Accurac…
Accuracy between virtual surgical planning and actual outcomes in orthognathic surgery by iterative closest point algorithm and color maps: A retrosp…
2018
Background To evaluate the accuracy between actual outcomes and virtual surgical planning (VSP) in orthognathic surgery regarding the use of three-dimensional (3D) surface models for registration using iterative closest point (ICP) algorithm and generated color maps. Material and Methods Construction of planning and postoperative 3D models in STL files format (M0 and M1, respectively) from CBCT of 25 subjects who had been submitted to bimaxillary orthognathic surgery was performed. M0 and M1 were sent to Geomagic software in semi-automatic alignment surface mesh order of M0 and M1 for registration using ICP algorithm to calculate mean deviation (MD, MD+, MD-, SD) and root mean square (RMS –…
Study between anb angle and Wits appraisal in cone beam computed tomography (CBCT)
2013
Objectives: To analyse the ANB and Wits values and to study correlations between those two measurements and other measurements in diagnosing the anteroposterior maxilo-mandibular relationship with CBCT. Study Design: Ninety patients who had previously a CBCT (i-CAT®) as a diagnostic register were selected. A 3D cephalometry was designed using one software package, InVivo5®. This cephalometry included 3 planes of reference, 3 angle measurements and 1 linear measurement. The means and standard deviations of the mean of each measurement were assessed. After that, a Pearson´s correlation coefficient has been performed to analyse the significance of each relationship. Results: When classifying t…
Anatomical characteristics and visibility of mental foramen and accessory mental foramen: Panoramic radiography vs. cone beam CT.
2015
Background: The mental foramen (MF) is a small foramen located in the anterolateral region of the mandible through which the mental nerve and vessels emerge. The knowledge on the anatomic characteristics and variations of MF is very important in surgical procedures involving that area. The aim of this study was two-fold: firstly, to analyze the anatomic characteristics of MF and the presence of accessory mental foramen (AMF) using CBCT and, secondly, to compare the capability of CBCT and PAN in terms of MF and AMF visualization, as well as influencing factors. Material and Methods: A sample of 344 CBCT scans was analyzed for presence and characteristics (i.e. diameter, area, shape, exit ang…
Influence of skeletal class in the morphology of cervical vertebrae: A study using cone beam computed tomography
2016
ABSTRACT Objectives: To quantify the prevalence of cervical vertebrae anomalies and to analyze any association between them and skeletal malocclusions or head posture positions in the same study. Materials and Methods: Two hundred forty patients who were attending the Department of Orthodontics of the University of Valencia for orthodontic treatment were selected and divided into three groups: skeletal Class I (control group, 0° <ANB < 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°) according to ANB Steiner angle. The morphology of the first five cervical vertebrae was analyzed with cone beam computed tomography to identify any anomalies. Intra- and interobserver error meth…