Tissue Dimensions Research Articles

The influence of fixation on the cardiac tissue in a 1-year observation of swine hearts.

The aim of this study was to investigate the influence of formaldehyde-based fixation on dimension, weight and shape of cardiac tissue during a 1-year observation. Seven measuring sites were permanently marked in 40 swine hearts prior to fixation. Four study groups (n=10 each) were assembled that differed only in concentration and the type of fixative. The fixatives were 2%, 4% or 10% formaldehyde phosphate-buffered solution (FPBS) and alcoholic formalin. The samples were measured before fixation and then after fixation at 1week, 3, 6 and 12months. At the 3-month point, the 10% FPBS had caused significant changes in the smallest number of parameters, while the 2% FPBS affected the greatest number of dimensions. The most significant changes included chordae tendineae shrinkage and an increase in muscle thickness. After 6months, the most significant changes were observed in 2% and 4% FPBSs and were also mainly associated with an increase in muscle thickness and chordae tendineae shrinkage. 1-year preservation compared to the baseline showed the most significant changes in muscle tissue thickness and hearth weight. The artery diameter decreased in long-term fixation in every tested solution. For atrial and angle measurements, 4% FPBS caused most significant changes among investigated fixatives. In all tested solutions, long-term fixation significantly changed cardiac tissue dimension compared to the nonpreserved samples. Short-term to 1-year fixation changes are smaller, but they should not be neglected. Different fixatives should be used depending on the character of the planned measurements.

Alveolar ridge regeneration of damaged extraction sockets using deproteinized porcine versus bovine bone minerals: A randomized clinical trial

BackgroundsClinical benefits in bone grafting of intact extraction socket have been widely known, but limited evidence is available for the procedure in damaged extraction sockets due to periodontal disease.PurposeThis study aimed to determine the dimensional alteration of alveolar ridge following bone grafting of damaged extraction sockets, and compare the outcomes of using deproteinized bovine (DBBM) versus porcine bone mineral (DPBM) in the damaged sockets.Materials and MethodsOne hundred patients (n = 50 for each group) with periodontitis‐induced damaged extraction socket were included in this randomized, single‐blind trial. After removal of tooth and granulation tissue, sites were grafted with either DBBM (DBBM group) or DPBM (DPBM group), and covered with collagen membrane. Linear/volumetric analyses of hard and soft‐tissue dimensions were performed on reconstructed/superimposed computed tomography and scanned cast images, taken immediately and 4 months after surgery.ResultsThe two groups showed comparable hard tissue augmentation with minimal reductions in the grafted volume, as well as in vertical (1.22 ± 2.16 and 1.45 ± 1.92 mm for DPBM and DBBM group, respectively) and horizontal (1.43 ± 3.40 and 1.83 ± 2.85 mm on the central section, respectively) dimensions at 4 months after surgery. However, several cases showed large variations in maintenance of the grafted volume. None of the measured parameters in hard and soft tissue dimensions differed significantly between DBBM and DPBM sites.ConclusionsDBBM and DPBM can comparably augment damaged extraction sockets with minimal postoperative reduction of the grafted volume. However, the large variations in the results should be further evaluated for application in routine dental clinics.

The Use of Cone Beam Computed Tomography to Assess Periodontal Biotype

Periodontal biotype is a concept with great relevance to clinical practice. Although numerous factors contribute to determining biotype, including soft/hard tissue thickness, soft/hard tissue contours, amount of keratinized tissue, and tooth shape, gingival thickness has been mostly utilized. The use of cone beam computed tomography (CBCT) has been recently proposed as a state-of-the-art approach for assessing periodontal biotypes because it provides information relative to both soft and hard tissue dimensions. When used in conjunction with lip retraction or a dual-scan technique, reliable and reproducible measurements of gingival and alveolar thickness can be made on CBCT scans, with the potential to aid in periodontal biotype assessment. While current data support the potential use of CBCT for periodontal biotype assessment, the technology in its current state should be used primarily for investigational purposes. The cost and radiation dose need to be considered and additional research is required before implementation into clinical practice.

Ultrasonography for noninvasive and real-time evaluation of peri-implant tissue dimensions.

Existing methods for evaluating marginal bone loss and tissue biotype around dental implants present with many limitations. The aim of this study was to examine the accuracy of high-resolution, 3-dimensional ultrasound to measure peri-implant tissue dimensions. A 25-MHz ultrasound probe prototype was used to scan peri-implant tissues of 17 implants from seven fresh human cadavers. Four ultrasonic measurements were made as follows: the marginal bone level/thickness, and mucosal level/thickness. The readings were statistically compared to cone beam computed tomography (CBCT) and/or open bone measurements. The correlations (r) between the ultrasound and direct/CBCT readings of the four parameters ranged from 0.85 to 0.98 (p<0.0001). The mean absolute difference in the four parameters between ultrasound-direct and ultrasound-CBCT ranged from 0.033 to 0.24mm. Encouraging evidence is shown that ultrasound can accurately measure peri-implant tissue dimensions. Following clinical trial validations, ultrasound offers potential as a valuable tool to evaluate long-term peri-implant tissue stability without concerns of ionizing radiation and image artefacts around implants.

PR681: Dimensions of the periimplant soft tissues after surgical periimplantitis treatment, a retrospective clinical study

PR681: Dimensions of the periimplant soft tissues after surgical periimplantitis treatment, a retrospective clinical study

Peri-implant health.

The aim is to define clinical and histologic characteristics of peri-implant tissues in health and describe the mucosa-implant interface. An understanding of the characteristics of healthy peri-implant tissues facilitates the recognition of disease (i.e., departure from health). The healthy peri-implant mucosa is, at the microscopic level, comprised of a core of connective tissue covered by either a keratinized (masticatory mucosa) or non-keratinized epithelium (lining mucosa). The peri-implant mucosa averages about 3 to 4mm high, and presents with an epithelium (about 2mm long) facing the implant surface. Small clusters of inflammatory cells are usually present in the connective tissue lateral to the barrier epithelium. Most of the intrabony part of the implant appears to be in contact with mineralized bone (about 60%), while the remaining portion faces bone marrow, vascular structures, or fibrous tissue. During healing following implant installation, bone modeling occurs that may result in some reduction of the marginal bone level. The characteristics of the peri-implant tissues in health are properly identified in the literature, including tissue dimensions and composition. Deviation from the features of health may be used by the clinician (and researcher) to identify disease, including peri-implant mucositis and peri-implantitis.

PC246: Assessment of gingival tissue dimensions and relations of the dentogingival junction using soft tissue cone‐beam computed tomography before aesthetic crown lengthening surgery

PC246: Assessment of gingival tissue dimensions and relations of the dentogingival junction using soft tissue cone‐beam computed tomography before aesthetic crown lengthening surgery

Peri‐implant health

The aim is to define clinical and histologic characteristics of peri-implant tissues in health and describe the mucosa-implant interface. An understanding of the characteristics of healthy peri-implant tissues facilitates the recognition of disease (i.e., departure from health). The healthy peri-implant mucosa is, at the microscopic level, comprised of a core of connective tissue covered by either a keratinized (masticatory mucosa) or non-keratinized epithelium (lining mucosa). The peri-implant mucosa averages about 3 to 4mm high, and presents with an epithelium (about 2mm long) facing the implant surface. Small clusters of inflammatory cells are usually present in the connective tissue lateral to the barrier epithelium. Most of the intrabony part of the implant appears to be in contact with mineralized bone (about 60%), while the remaining portion faces bone marrow, vascular structures, or fibrous tissue. During healing following implant installation, bone modeling occurs that may result in some reduction of the marginal bone level. The characteristics of the peri-implant tissues in health are properly identified in the literature, including tissue dimensions and composition. Deviation from the features of health may be used by the clinician (and researcher) to identify disease, including peri-implant mucositis and peri-implantitis.

Dimensional Changes of the Soft Tissue after Alveolar Ridge Preservation with a Collagen Material. A Clinical Randomized Trial.

Background:Reduction of the soft tissue is an unavoidable consequence of tooth extraction without appropriate measures of Alveolar Ridge Preservation (ARP).Objectives:The objective of this study is the volumetric investigation of the dimensional change of the soft tissue post tooth extraction to compare an Alveolar Ridge Preservation (ARP) measure with the insertion of a combination material with a collagen cone to fill the alveolus, combined with a collagen membrane, with untreated extraction alveoli.Methods:In the context of a randomized clinical trial, 31 patients were treated with the combination material directly post tooth extraction in the maxilla (ARP). In 29 further patients, the extraction alveoli were left without further measures (control group).The changes of the soft tissue contour were measured 6 (+/- 1) weeks post extraction. The measurements were performed by superimposing digital models. The groups were compared using the Wilcoxon rank-sum-test.Results:The premolar subgroup revealed a significant difference of the soft tissue dimension post insertion of a collagen material into the alveolus in comparison to untreated alveoli. In these cases, the mean loss of soft tissue volume after use of the collagen material was significantly lower.Conclusion:The proposed hypothesis that there is a difference of the soft tissue preservation between alveoli with and without the use of a collagen material can be accepted with restrictions to the premolar region. A statistically significant lower volume reduction of the soft tissue by implantation of the collagen material could be detected with premolars.

Influence of implant neck surface and placement depth on crestal bone changes and soft tissue dimensions around platform-switched implants: A histologic study in dogs.

To analyse bone remodelling and peri-implant soft tissues around platform-switching implants with and without a machined collar placed at different levels in relation to bone crest. All mandibular premolars and the first molars were extracted in five dogs. At 6months, six implants with and without a machined neck (MACH and GBAE implants, respectively) were randomly inserted in each hemimandible positioning the implant-abutment interface in either a supracrestal (+1.5mm), equicrestal, or subcrestal (-1.5mm) position. After 6months, animals were killed for histomorphometric analysis. When net bone loss (primary outcome variable) was compared between MACH and GBAE groups, the multivariable regression analysis revealed no significant differences between implants inserted at the same vertical position. The dimensions of the peri-implant mucosa were greater in MACH implants compared with GBAE implants; however, these differences failed to reach statistical significance. Regarding the number of inflammatory cells and collagen fibre orientation, no statistically significant differences were found between MACH and GBAE groups. The surface treatment of the implant neck does not seem to have an influence on net bone loss, and there were no statistically significant differences in the peri-implant soft tissues between platform-switching implants with and without a machined neck.

The Relationship Between Hard Tissue and Soft Tissue Dimensions of the Nose in Children: A 3D Cone Beam Computed Tomography Study.

This study using three-dimensional cone beam computed tomography (CBCT) images of children determined relationships between nasal skeletal and soft tissue measurements and assessed the association with sex, age, and skeletal maturation stage. Following reliability studies, skeletal and soft tissue parameters were measured on coded CBCTs of 73 children (28M:45F;6-13yoa). Pearson and Mantel correlations were used to analyze associations between skeletal and soft tissues. Partial Mantel correlations were used to study the associations between skeletal and soft tissue, adjusting for sex, age, and skeletal maturation. Linear regression analyses were used to predict soft tissues sizes. Logistic regression was used to study the relationships between soft and skeletal tissue symmetry. Except for nasal aperture width and interalar width, skeletal landmarks best predicted corresponding soft tissue landmarks. Significant positive associations existed between skeletal and soft tissues after adjusting for sex, skeletal maturation, and age. Children's nasal skeletal tissues predicted nasal soft tissue reasonably well.

Effect of platelet-rich fibrin palatal bandage on pain scores and wound healing after free gingival graft: a randomized controlled clinical trial.

This prospective randomized clinical trial was conducted to determine whether the application of a platelet-rich fibrin (PRF) palatal bandage after harvesting free gingival grafts (FGG) would improve healing of donor sites and decrease pain scores and patient discomfort. Twenty-four patients received FGG to augment keratinized tissue dimensions. The application of a PRF bandage was decided randomly (n = 12 in each group). Patients reported their pain levels for the first 7days of healing using the visual analog scale (VAS), 101-point numerical rating scale (NRS-101), and 4-point verbal rating scale (VRS-4). The patients' pre-operative anxiety levels were measured using three anxiety scales. The healing of the donor sites was evaluated and compared to preoperative records. Data were assessed and recorded before surgery and at 1, 2, 3, 4, and 8weeks postoperatively. Dental anxiety and state-trait anxiety were evaluated at baseline and correlated to the postoperative pain scores. There were no significant differences in anxiety levels between the two groups; yet, they could potentially influence the outcome of any surgery and were included as covariates. The patients in the PRF group reported significantly lower pain scores and their pain levels returned to baseline levels earlier, compared to the control group. PRF palatal bandages significantly reduced postoperative pain and discomfort and facilitated wound healing after harvesting FGG. The study provided evaluation of patient-centered outcomes, which is timely, significant, and could benefit both periodontists and patients.

Epicrestal and subcrestal placement of platform-switched implants: 18month-result of a randomized, controlled, split-mouth, prospective clinical trial.

To evaluate the changes in marginal bone levels (MBL) and soft tissue dimension around platform-switched implants with the implant-abutment junction (IAJ) placed at the crest or 1.5-2mm subcrestally. In all, 96 platform-switched implants were placed in either the posterior maxilla or mandible in 48 partially edentulous patients in a split-mouth study. All implants were provisionally restored after 4-5months and definitively after 6months (T6). Radiographic assessment of MBL was assessed at implant placement (T0), T6, 12months (T12), and 18months (T18) after placement. Mid-buccal soft tissue and papilla measurements were performed at T6, T12, and T18. In all, 43 patients with 86 implants completed the study. The T18 examination showed an implant survival rate of 100% in both groups. Analysis showed that MBL varied as a function of IAJ location, which indicated more coronal bone levels with subcrestal (2.39±0.08mm) than with epicrestal placements (0.88±0.08mm) (p<.05). Greater average marginal bone loss was found in the subcrestal group (0.40±0.07mm) compared to the epicrestal group (0.13±0.08mm) although no statistically significant difference was found at T18 (p>.05). Levels of mid-buccal soft tissue had no significant changes over time, regardless of group (p>.05). There was a significant difference in increase in papilla between T6 and T12 and T18 (p=.005 and .001), but not between T12 and T18 (p=.61). These papilla levels and changes were similar between groups (p>.05). The MBL changes around platform-switched implants with same geometry were not affected by the epicrestal or subcrestal location of the IAJ. Furthermore, the location of the IAJ did not affect the implant survival and soft tissue dimensions. However, no bone loss was located apical to the IAJ when the implants were placed subcrestally.

Mechanical Properties of Arterial Elastin With Water Loss.

Elastin is a peculiar elastomer in that it requires water to maintain resilience, and its mechanical properties are closely associated with the immediate aqueous environment. The bulk, extra- and intrafibrillar water plays important roles in both elastic and viscoelastic properties of elastin. In this study, a two-stage liquid-vapor method was developed to investigate the effects of water loss on the mechanical properties of porcine aortic elastin. The tissue samples started in a phosphate-buffered saline (PBS) solution at their fully hydrated condition, with a gravimetric water content of 370±36%. The hydration level was reduced by enclosing the tissue in dialysis tubing and submerging it in polyethylene glycol (PEG) solution at concentrations of 10%, 20%, 30%, and 45% w/v, which reduced the water content of the samples to 258±34%, 224±20%, 109±9%, and 58±3%, respectively. The samples were then transferred to a humidity chamber to maintain the hydration level while the samples underwent equi-biaxial tensile and stress relaxation tests. The concentration of 10% PEG treatment induced insignificant changes in tissue dimensions and stiffness, indicating that the removal of bulk water has less effect on elastin. Significant increases in tangent modulus were observed after 20% and 30% PEG treatment due to the decreased presence of extrafibrillar water. Elastin treated with 45% PEG shows a very rigid behavior as most of the extrafibrillar water is eliminated. These results suggest that extrafibrillar water is crucial for elastin to maintain its elastic behavior. It was also observed that the anisotropy of elastin tends to decrease with water loss. An increase in stress relaxation was observed for elastin treated with 30% PEG, indicating a more viscous behavior of elastin when the amount of extrafibrillar water is significantly reduced. Results from this study shed light on the close association between the bulk, extra- and intrafibrillar water pools and the mechanics of elastin.

Non-interventional 1-year follow-up study of peri-implant soft tissues following previous soft tissue augmentation and crown insertion in single-tooth gaps.

To assess peri-implant soft tissue dimensions at implant sites, previously augmented with a collagen matrix (VCMX) or an autogenous subepithelial connective tissue graft (SCTG), between crown insertion and 1year. Twenty patients with single-tooth implants received soft tissue augmentation prior to abutment connection randomly using VCMX or SCTG. Following abutment connection 3 months later, final reconstructions were fabricated and inserted (baseline). Patients were recalled at 6 months (6M) and at 1 year (FU-1). Measurements included clinical data, soft tissue thickness, volumetric outcomes and patient-reported outcome measures (PROMs). The buccal soft tissue thickness showed a median decrease of -0.5mm (-1.0;0.3) (VCMX) and 0.0mm (-0.5;1.0) (SCTG) (p=.243) up to FU-1. The soft tissue volume demonstrated a median decrease between BL and FU-1 of -0.1mm (-0.2;0.0) (p=.301) for VCMX and a significant decrease of -0.2mm (-0.4; -0.1) (p=.002) for SCTG, respectively. Intergroup comparisons did not reveal any significant differences between the groups for peri-implant soft tissue dimensions and changes up to FU-1 (p>.05). PROMs did not show any significant changes over time nor differences between the groups. Between crown insertion and 1 year, the buccal peri-implant soft tissue dimensions remained stable without relevant differences between sites that had previously been grafted with VCMX or SCTG.

Dimensional Variations in the Soft Tissue Profile After Removal of Implant-Supported Fixed Interim Restorations: A Pilot Clinical Study.

To measure dimensional changes of the periimplant soft tissue profile after removal of a single implant fixed interim restorations using digital impression procedures. Ten participants presenting with single implant-supported fixed interim restorations (ISFIRs) on the maxillary esthetic zone. A 2-step silicone impression was made of the maxillary arch with the ISFIRs. The experimental procedure was obtained by making digital impressions of the gingival contours immediately after ISFIR removal. The control procedure was formed by fabricating definitive casts from the conventional impression using the ISFIRs as a customized impression transfer and making digital impressions of these definitive casts. Both images of paired groups were digitally overlapped on the computer, and their profiles were measured at the coronal, midlevel gingiva in the buccolingual and mesiodistal width. Statistically significant differences between the ISFIR emergence profile width and the unsupported soft tissue profile width were observed at the midlevel gingiva in the buccolingual dimension (1.35 mm) and at the coronal (0.51 mm) and midlevel gingiva (1.29 mm) in the mesiodistal dimension. A digital impression, as used in this pilot study, does not capture accurately the desired soft tissue dimensions immediately after removal of the ISFIR.

Measurement properties of gingival biotype evaluation methods

There are numerous methods to measure the dimensions of the gingival tissue, but few have compared the effectiveness of one method over another. This study aimed to describe a new method and to estimate the validity of gingival biotype assessment with the aid of computed tomography scanning (CTS). In each patient different methods of evaluation of the gingival thickness were used: transparency of periodontal probe, transgingival, photography, and a new method of CTS). Intrarater and interrater reliability considering the categorical classification of the gingival biotype were estimated with Cohen's kappa coefficient, intraclass correlation coefficient (ICC), and ANOVA (P < .05). The criterion validity of the CTS was determined using the transgingival method as the reference standard. Sensitivity and specificity values were computed along with theirs 95% CI. Twelve patients were subjected to assessment of their gingival thickness. The highest agreement was found between transgingival and CTS (86.1%). The comparison between the categorical classifications of CTS and the transgingival method (reference standard) showed high specificity (94.92%) and low sensitivity (53.85%) for definition of a thin biotype. The new method of CTS assessment to classify gingival tissue thickness can be considered reliable and clinically useful to diagnose thick biotype.

Endotracheal tube placement during computed tomography of brachycephalic dogs alters upper airway dimensional measurements.

Computed tomography (CT) is used to document upper airway lesions in dogs with brachycephalic obstructive airway syndrome. The presence of an endotracheal tube during CT scanning is often required for general anesthesia. We hypothesized that the endotracheal tube placement would change the soft tissue dimensions of the upper airway. The aims of this prospective, method comparison study were to evaluate the reliability of the previously reported upper airway CT measurements with endotracheal tube placement, and to propose measurements that are minimally affected by the endotracheal tube. Twenty brachycephalic dogs were included in this study. Each dog underwent head/neck CT with an endotracheal tube, followed by a second scan without the endotracheal tube. Ten measurements of the soft palate, nasopharynx, and trachea were performed. Tracheal dimension was significantly larger with the endotracheal tube compared to without, whereas the soft palate cross-sectional area was significantly smaller with the endotracheal tube than without the endotracheal tube. The influence of the endotracheal tube on the caudal nasopharynx cross-sectional (transverse-sectional) area varied with a mean proportional absolute difference of 35%. Rostral soft palate thickness, tracheal perimeter, and cross-sectional area of the rostral nasopharynx were the measurements least affected by the endotracheal tube (intraclass correlation coefficient = 0.964, 0.967, and 0.951, respectively). Therefore, we proposed that these three measurements may be most useful for future brachycephalic obstructive airway syndrome studies that require CT scanning of intubated animals. However, with endotracheal tube placement, measurements of soft palate length, caudal nasopharyngeal cross-sectional area, and trachea height and width may not be reliable.

Delayed Primary Closure of Traumatic Tension Wounds Using Plastic Straps and Kirschner Wires.

Tension of the wound edges should be overcome with precise surgical planning, which is recognized as one of the major contributors to local complications by compromising circulation of the wound edges. In this article, it was aimed to present the clinical results of a surgical technique, in which the plastic straps and Kirschner wires are used for delayed primary closure of traumatic tension wounds. Depending on the assessment of the wound localization, wound dimension, and mobility of adjacent soft tissue, the technique was performed in 9 patients with a male to female ratio of 8:1. Gunshot injury was the leading cause (n = 5), and in most cases, the wounds were located at the lower extremities (n = 6). The mean time between performing the technique and closing the wound primarily and the mean hospitalization time were 4.8 ± 1.1 and 13.5 ± 3.9 days, respectively. In each case, wound closure and healing were achieved successfully without any serious complications. The presented technique provides advantages of using a low cost as well as a very simple equipment, improved and reliable stability during tightening process due to self-locking feature of the plastic straps, no donor site morbidity, short operating time with low rate of post-operative complications, and short hospitalization time. We recommend using this invaluable technique reliably for the treatment of traumatic tension wounds. However, further studies are needed for better evaluation of cosmetic and functional outcomes of the presented technique.

Influence of subcrestal implant placement compared with equicrestal position on the peri-implant hard and soft tissues around platform-switched implants: a systematic review and meta-analysis.

The aim of this article is to systematically review the effect of subcrestal implant placement compared with equicrestal position on hard and soft tissues around dental implants with platform switch. A manual and electronic search (National Library of Medicine and Cochrane Central Register of Controlled Trials) was performed for animal and human studies published up to December 2016. Primary outcome variable was marginal bone level (MBL) and secondary outcomes were crestal bone level (CBL), soft tissue dimensions (barrier epithelium, connective tissue, and peri-implant mucosa), and changes in the position of soft tissue margin. For primary and secondary outcomes, data reporting mean values and standard deviations of each study were extracted and weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated. A total of 14 publications were included (7 human studies and 7 animal investigations). The results from the meta-analyses have shown that subcrestal implants, when compared with implants placed in an equicrestal position, exhibited less MBL changes (human studies: WMD = - 0.18 mm; 95% CI = - 1.31 to 0.95; P = 0.75; animal studies: WMD = - 0.45 mm; 95% CI = - 0.66 to - 0.24; P < 0.001). Furthermore, the CBL was located at a more coronal position in subcrestal implants with respect to the implant shoulder (WMD = - 1.09mm; 95% CI = - 1.43 to - 0.75; P< 0.001). The dimensions of the peri-implant mucosa seem to be affected by the positioning of the microgap and were greater at implants placed in a subcrestal position than those inserted equicrestally (WMD = 0.60mm; 95% CI = 0.26 to 0.95; P < 0.001). While the length of the barrier epithelium was significantly greater in implants placed in a subcrestal position (WMD = 0.39mm; 95% CI = 0.19 to 0.58; P < 0.001), no statistical significant differences were observed between equicrestal and subcrestal implant positioning for the connective tissue length (WMD = 0.17mm; 95% CI = - 0.03 to 0.36; P = 0.10). This systematic review suggests that PS implants placed in a subcrestal position have less MBL changes when compared with implants placed equicrestally. Furthermore, the location of the microgap seems to have an influence on the dimensions of peri-implant soft tissues. Clinical relevance When compared with PS placed in an equicrestal position, subcrestal implant positioning demonstrated less peri-implant bone remodeling.