Non-randomized controlled prospective study on perioperative levels of stress and dysautonomia during dental implant surgery

PurposeThe purpose of this study was to compare pre- and postoperative autonomic activities and changes in salivary stress biomarkers between patients who received only local anesthesia and those who received local anesthesia together with intravenous sedation in dental implant surgery.MethodsA total of 21 patients were enrolled in this non-randomized controlled prospective study; 7 subjects underwent implant surgery under local anesthesia with intravenous sedation and 14 subjects underwent surgery under only local anesthesia. Stress was evaluated by measuring salivary levels of chromogranin A (CgA) and a spectral analysis of heart rate variability (HRV) at baseline (on a day other than the day of surgery), 1 h preoperatively, and 1 h postoperatively. HRV analysis yields low- (LF) and high-frequency (HF) components, the LF/HF ratio, and the component coefficient of variance (CCV[HF]), which provide indices of sympathetic and parasympathetic regulatory activity.ResultsCgA levels were significantly higher (p < 0.05) at baseline in patients who received sedation than those who did not, but CgA levels did not differ prior to surgery. Also, the values of most parameters, including LF, HF, LF/HF (L/H), and CCV(HF), did not significantly differ between groups or among the three time points. Only ΔL/H and ΔCCV(HF) were significantly lower (p < 0.05) at 1 h preoperatively in patients who received sedation than those who received only local anesthesia.ConclusionsCgA levels were high in both groups immediately before surgery, and thus CgA values immediately before surgery may not be a reliable indicator of the need for intravenous sedation. Also, spectral analysis of HRV, especially ΔL/H and ΔCCV(HF), could be useful for assessing tension and anxiety.     

Metástasis sacra simulando quiste óseo aneurismático

Cystic spinal lesions with characteristic patterns, such as the presence of haematic fluid-fluid levels (H-FFL), have been associated with many tumoral lineages, more frequently with aneurysmal bone cyst (ABC) and exceptionally with metastasis. We present the case of a 60-year-old man with the finding of a sacral cystic bone lesion with H-FFL, with initial suspicion of ABC and confirmed diagnosis of metastasis. The case presented is, to our knowledge, the second case published of spinal cystic bone metastasis with H-FFL pattern with unknown primary tumour at the time of diagnosis and the only one that received resective surgical treatment, achieving pulmonary and metastatic disease control with good quality of life after 1 year of follow up.     

Finite element contact analysis as a critical technique in dental biomechanics: A review

PurposeNonlinear finite element contact analysis is used to mathematically estimate stress and strain in a time- and status-dependent mechanical model. However, the benefits and limitations of this method have not been thoroughly examined.Study selectionThe current review summarizes the utility of contact analysis in characterizing individual stressors: (1) tooth-to-tooth contact, (2) restorative interface, and (3) bone–implant integration.ResultsOpposing tooth contact, friction, and sliding phenomena were simulated to estimate stress distribution and assess the failure risk for tooth enamel, composite, and ceramic restorations. Mechanical tests such as the flexural tests were simulated with the contact analysis to determine the rationale underlying experimental findings. The tooth–restoration complex was modeled with interface contact elements that simulate imperfect bonding, and the normal and tangential stresses were calculated to predict failure progression. Previous studies have used a friction coefficient to represent osseointegration adjacent to dental implants, but the relationship between interface friction and the bone quality is unknown. An understanding of the local stress and strain may better predict loss of osseointegration, however, the effective stress as a critical contributor to bone degradation and formation has not been established.ConclusionsContact analysis provides numerous benefits for dental and oral health sciences, however, a fundamental understanding and improved methodology are necessary.     

Volumetric comparison of autogenous bone and tissue-engineered bone replacement materials in alveolar cleft repair: a systematic review and meta-analysis

The goal of reconstruction of the alveolar cleft in patients with cleft lip and palate is to improve the quality of tissue, the structural stability, and increase the volume of bone. This study is a systematic review with meta-analysis of volumetric bony filling using autogenous bone and various tissue-engineered bone substitutes. We made an electronic search on MEDLINE, EMBASE, SCOPUS, WEB OF SCIENCE, “grey” publications (materials and research produced by organisations outside traditional channels for commercial or academic publishing and distribution), and relevant cross references according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that reported the outcomes of volumetric grafting were included in the meta-analysis. Of 1276 studies, 26 were included in the meta-analysis. Pooled analysis of 25 studies that used autogenous bone showed a significant reduction in the volume of the cleft equivalent to 62.0% bone fill (95% CI 54.3 to 69.6), in contrast to 10 studies that used a tissue-engineered material and reported bone filling of 68.7% (95% CI 54.5 to 82.8). The estimated sizes of pooled effects across studies showed that there was no significant difference between the two major intervention groups (p value 0.901). Our statistical analysis showed that autogenous bone grafts did not differ significantly from tissue-engineered materials in their ability to fill clefts.Systematic review registration: International Prospective Register of Systematic Reviews, PROSPERO (CRD42017065045).     

Quantification of Nucleated Cells,CD34-Positive Cells and CFU-GM Colonies in Single Bone Marrow Samples and Bone Marrow Harvests Derived from Healthy Children

Little is known regarding bone marrow (BM) cellularity, CD34+ fraction, and CFU-GM colony formation in relation to age and whether healthy children require a reference range distinct from healthy adults. We therefore analyzed a series of single BM aspirates from 45 healthy children who were evaluated as potential BM donors. Thirty-three of these children subsequently donated BM. We quantified the nucleated cell count, fraction of CD34+ cells, and number of CFU-GM colonies in single aspirates and BM harvests. Single aspirates displayed a mean nucleated cell count of 31.3 × 10⁶ cells/mL, a mean fraction of 1.17% CD34+ cells, and a mean colony forming potential of 66.6 CFU-GM/10⁵ cells. Harvests yielded the same number of nucleated cells but increased numbers of CD34+ cells and CFU-GM compared with single aspirates. The mean nucleated cell count in BM harvests was 31.1 × 10⁶ /mL with a mean fraction of 1.95% CD34+ cells and a mean of 112.4 CFU-GM colonies/10⁵ cells. The concentration of nucleated cells was elevated compared with reported adult counts, while CD34+ percentage and CFU-GM counts were similar. In this series of healthy children, the fraction of CD34+ cells, CFU-GM colonies, and nucleated cells decreased with age. We did not identify gender specific differences. To our knowledge, this represents the first comprehensive study of CD34+ cell fraction, CFU-GM counts, and nucleated cell numbers in the BM of healthy children. The findings provide valuable information for practical use for BM transplantation and contribute to the understanding of hematopoiesis from birth to adulthood.     

Case Study: An intraoperative finding of black bone disease in a podiatric surgery patient

Black bone disease has been recognised as a potential consequence of long-term treatment with tetracycline antibiotics. Largely documented affecting structures in the head and skull, there are few reported cases of black bone disease in the foot and ankle. The case of a 55 years old patient, who as a teenager, had undergone treatment with minocycline hydrochloride for chronic acne, and was found to have bone discolouration consistent with minocycline induced black bone disease (MIBBD) during the course of hallux valgus corrective surgery some 40 years later, is presented. In spite of the intraoperative findings, the patient’s post-operative recovery and bone healing was uneventful. The literature on minocycline induced black bone disease is reviewed.