Is it possible to predict neurosensory alterations in impacted lower third molar removal based on preoperative imaging procedures? A prospective cohort study.

BACKGROUND: Surgical extraction of the lower third molar (LTM) may trigger neurosensory injury of the inferior alveolar nerve, making extraction a real challenge. This study set out to assess whether is it possible to predict neurosensory alterations from preoperative imaging. MATERIAL AND METHODS: A total of 99 patients underwent 124 impacted lower third molar (ILTM) surgeries. Prior to surgery, panoramic and CBCT images were evaluated in an attempt to predict a neurosensory disturbance. Preoperative data (ILTM position, panoramic radiograph signs, inferior alveolar nerve (IAN) location and its contact with the ILTM roots) and intra/postoperative findings (extraction difficulty and sensitivity alterations) were recorded. Descriptive and bivariate data analysis was performed. Statistical comparison applied the chi-square test, Fisher test, and one-way ANOVA test. Statistical significance was established with a confidence interval (CI) of 95%. RESULTS: In 4.03% of cases, patients experienced neurosensory alterations. Of 124 ILTM positions in panoramic radiographs, 76 cases were considered to exhibit a potential neurosensory risk as they presented two or more types of superimposed relationships between ILTM and mandibular canal. Of these, alterations were reported in only three cases (3.95%). Of the 48 remaining ILTM images presenting only one sign, neurosensory alterations were observed in two cases (4.17%). No permanent alterations were recorded in any of the five cases observed. CONCLUSIONS: Within the limitations of the present study, prediction of neurosensory alterations prior to ILTM extraction by means of preoperative imaging did not show a significant statistical correlation with post-surgical incidence. Nevertheless, interruption of the canal´s white line (ICWL) or a diversion of the canal (DC) may predict an increased risk of IAN injury.

Perceived surgical difficulty of mandibular third molar extraction. A comparative cross-sectional study of dentists with postgraduate qualification in oral surgery and maxillofacial surgeons in a Spanish subpopulation.

BACKGROUND: Mandibular third molar (MTM) extraction is one of the most frequently performed surgeries in the oral cavity. Establishing the level of surgical difficulty pre-operatively is an essential step to ensure correct treatment planning. In Spain, MTM extraction - especially in cases presenting greater difficulty - is normally performed by doctors specializing in oral and maxillofacial surgery, or by dentists with postgraduate qualifications in oral surgery. The present work set out to analyze the extent to which perceptions of surgical difficulty of the said intervention vary in relation to professional training. MATERIAL AND METHODS: This cross-sectional, descriptive, observational study took the form of a survey. Using a visual analog scale (VAS), participants evaluated both the perceived difficulty of 30 cases of MTM extraction described by means of digital panoramic radiographs and the perceived difficulty deriving from a series of factors conditioning MTM extraction. The results underwent statistical analysis with SPSS Statistics 28.0 software. Non-parametric tests (Mann Whitney test for independent samples and the Kruskal-Wallis test) were applied. RESULTS: A total of 213 surveys were available for analysis. Both groups awarded the greatest importance to clinical experience, followed by anatomical and radiographic factors, root morphology obtaining the highest score among anatomical factors (9.01±1.42), while proximity of the MTM to the inferior alveolar nerve was regarded as the least important anatomical factor (8.11±2.54). Significant differences were only found for patient age, whereby maxillofacial surgeons awarded this factor more importance than dentists. CONCLUSIONS: The different training received by dentists specialized in oral surgery and maxillofacial surgeons did not influence either perceptions of surgical difficulty of MTM extraction, or opinions as to the factors influencing surgical difficulty.

Assessment of clinical outcomes and histomorphometric findings in alveolar ridge augmentation procedures with allogeneic bone block grafts: A systematic review and meta-analysis.

BACKGROUND: This systematic literature review aimed to evaluate the efficacy of allogeneic bone blocks for ridge augmentation by assessing block survival rates and subsequent implant survival, including post-surgical complications and histomorphometric analysis. MATERIAL AND METHODS: An electronic and manual search among references, was conducted up to April 2019 by two independent authors. Inclusion criteria were: human clinical trials in which the outcomes of allogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant success rates. RESULTS: Seven articles fulfilled the inclusion criteria and were analyzed. A total of 323 allogeneic block grafts were monitored for a minimum of 12 months follow-up after surgery, of which thirteen (4.02%) failed. Regarding the cumulative implant survival rate, the weighted mean was 97.36%, computed from 501 implants. Histologic and histomorphometric analysis showed that allogeneic block grafts presented some clinical and microstructural differences in comparison with autologous block grafts. CONCLUSIONS: Atrophic alveolar crest reconstruction with allogeneic bone block grafts would appear a feasible alternative to autologous bone block grafts, obtaining a low block graft failure rate, similar implant survival rate and fewer postoperative complications. Further investigations generating long term data are needed to confirm these findings.

Clinical repercussions and epidemiological considerations of supernumerary canines: A 26 case series.

BACKGROUND: To establish the prevalence of supernumerary canines (SNC) in a sector of the population of Madrid (Spain), as well possible complications associated with this unusual developmental variation. STUDY DESIGN: This observational study was performed between 2005 and 2017, among 21,615 patients seeking dental treatment at the Faculty of Dentistry, Complutense University of Madrid (Spain), and at the Virgen de la Paloma Hospital, Madrid (Spain); 22 patients with 26 SNCs were diagnosed. These 22 patients underwent clinical and radiological exploration, registering patient data. RESULTS: SNCs presented a prevalence of 0.10% of the study population. The supernumerary teeth (SNT) were located in the upper maxilla more frequently (61.54%) than the mandible (38.46%). 69.23% were found to be impacted, also causing the impaction of the permanent canine in 53.85% of these cases. In 15.38%, follicular expansion > 3mm was observed. SNCs were associated with other SNT in only four patients. CONCLUSIONS: Despite of the fact that the SNCs are usually diagnosed casually in the course of radiological exploration, in the present study over half of them (53.85%) caused impaction of the permanent canine. Early diagnosis allows optimal patient management and treatment planning, with intervention at an appropriate time to prevent complications in development and so reduce later treatment need.

Masseter and temporalis muscle electromyography findings after lower third molar extraction.

BACKGROUND: The main clinical application of electromyography is to detect abnormalities in muscle function, to assess muscle activity for purposes of recruitment, and in the biomechanics of movement. OBJECTIVES: To analyze electromyography (EMG) findings for masticatory muscles during chewing following surgical extraction of lower third molars, and to determine any correlation between pain, inflammation, trismus, and the EMG data registered. MATERIAL AND METHODS: This prospective study included 31 patients. Surface EMG was used to study masseter and temporalis muscle function before lower third molar extraction and 72 hours and seven days after surgery. Clinical variables, pain, inflammation, and trismus were registered before and after surgery. RESULTS: Studying the area and size of the masticatory muscles, higher values were found for temporalis than masseter muscles, regardless of the surgical side, which points to the greater involvement of the temporalis muscle in mastication. Comparing the side where surgery had been performed with the non-surgical side, a sharp and statistically significant reduction in amplitude and area were noted on the surgical side reflecting major functional affectation. One week after surgery, amplitude and area had almost returned to base-line values, indicating almost complete recovery. While pain decreased progressively after surgery, inflammation peaked at 72 hours, while mouth opening reached a minimum at this time, returning to normality within the week. CONCLUSIONS: Surgical extraction of lower third molars produces changes to electromyography activity that are more evident during the first hours after surgery and closely related to the intensity of pain suffered and the patient's inflammatory responses, although they are not related to mouth opening capacity.

Genetic variability of the equine casein genes.

The casein genes are known to be highly variable in typical dairy species, such as cattle and goat, but the knowledge about equine casein genes is limited. Nevertheless, mare milk production and consumption is gaining importance because of its high nutritive value, use in naturopathy, and hypoallergenic properties with respect to cow milk protein allergies. In the current study, the open reading frames of the 4 casein genes CSN1S1 (αS1-casein), CSN2 (ß-casein), CSN1S2 (αS2-casein), and CSN3 (κ-casein) were resequenced in 253 horses of 14 breeds. The analysis revealed 21 nonsynonymous nucleotide exchanges, as well as 11 synonymous nucleotide exchanges, leading to a total of 31 putative protein isoforms predicted at the DNA level, 26 of which considered novel. Although the majority of the alleles need to be confirmed at the transcript and protein level, a preliminary nomenclature was established for the equine casein alleles.

Clinical performance of tooth root blocks for alveolar ridge reconstruction.

This systematic literature review set out to investigate the clinical outcomes of autogenous tooth root blocks used for ridge augmentation: survival rates, block resorption, implant survival, post-surgical complications, and histology findings. This review followed PRISMA guidelines. An automated search was made in four databases, supplemented by a manual search for relevant articles published before December 2020. The quality of evidence provided was assessed with the Newcastle-Ottawa Quality Assessment Scale and the Joanna Briggs Institute Critical Appraisal tool. Seven articles fulfilled the inclusion criteria and underwent analysis. The articles included a total of 136 patients, who received 118 autogenous tooth root blocks and 26 autogenous bone blocks showing block survival rates of 99.15% and 100%, respectively. Tooth root blocks presented a mean bone gain that was similar to autologous bone blocks but showed less resorption. The implant survival rate was 98.32% for autogenous tooth root blocks. Reconstruction of alveolar crests by means of autogenous tooth root blocks appears to be a satisfactory option for single-tooth gaps and low grades of bone atrophy in terms of the survival of the bone block and the implants placed subsequently. More research providing long-term data is needed to confirm these findings.

The effects of farming systems (organic vs. conventional) on dairy cow welfare, based on the Welfare Quality® protocol.

Animal welfare in livestock production is of great interest to consumers. The organic farming approach strives to ensure animal welfare based on preventive measures, but there are very few scientific studies that compare the actual differences in animal welfare between organic and conventional farms. Those studies that have been carried out frequently focus on specific aspects of animal welfare, mostly health issues. The aim of the present study, therefore, was to investigate the effects of the farming system on the welfare of dairy cows in a more holistic way. Although this study was carried out in just two federal states of Germany, the results could serve as a suitable model for the whole country. We used the Welfare Quality assessment protocol to measure welfare for dairy cattle (Welfare Quality®, 2009) and the results showed significant differences (P < 0.05) between organic and conventional farms, but there was also considerable variance between individual farms of the same farming system. Organic farms scored higher in all four Welfare Quality® principles: "Good Feeding", "Good Housing", "Good Health" and "Appropriate Behavior" compared to conventional farms. In particular, organic farms obtained higher scores with respect to Welfare Quality® measures of resting comfort, which contributes to a lower percentage of lameness; organic farms also implemented less painful methods for disbudding, or indeed carried out no disbudding, and provided access to pasture and outdoor exercise. However, organic farms still have room for improvement, especially with respect to animal health. Therefore, outcome-based specifications should be included in the current (purely action-oriented) European regulation of organic production (EC, 2008; EU, 2018) to safeguard the health-related aspects of animal welfare.

Dental implant placement through impacted teeth or residual roots as an alternative to invasive extraction surgeries: a systematic literature review.

This work systematically reviews dental implant placement through impacted teeth or residual roots, as an alternative to invasive extraction surgeries, evaluated in terms of survival rates, marginal bone loss, surgical, and prosthetic complications. The authors conducted an electronic search of four databases up to September 2020; also a complementary handsearch was carried out. The quality of the included studies was assessed using a protocol for assessment of risk of bias in exposure studies. Ten studies fulfilled the inclusion criteria and were analysed. A total of 44 patients received 62 dental implants and were monitored for a minimum of 12-months follow-up. An overall mean implant survival rate was 90.32%, reporting 97.56 % for dental implants through impacted teeth and 76.19% through residual roots. No surgical or prosthetic complications were reported. Placing dental implants through impacted teeth may offer a valid therapeutic option for implant-supported restorations in patients for whom surgery and orthodontic traction are not possible, and/or patients who refuse to undergo more invasive extraction surgery. Moreover, additional caution is recommended when placing implants through retained root fragments, as this may involve long-term risk. Further research generating long-term data are needed to confirm these findings.

A gravitationally lensed quasar with quadruple images separated by 14.62 arcseconds.

Gravitational lensing is a powerful tool for the study of the distribution of dark matter in the Universe. The cold-dark-matter model of the formation of large-scale structures (that is, clusters of galaxies and even larger assemblies) predicts the existence of quasars gravitationally lensed by concentrations of dark matter so massive that the quasar images would be split by over 7 arcsec. Numerous searches for large-separation lensed quasars have, however, been unsuccessful. All of the roughly 70 lensed quasars known, including the first lensed quasar discovered, have smaller separations that can be explained in terms of galaxy-scale concentrations of baryonic matter. Although gravitationally lensed galaxies with large separations are known, quasars are more useful cosmological probes because of the simplicity of the resulting lens systems. Here we report the discovery of a lensed quasar, SDSS J1004 + 4112, which has a maximum separation between the components of 14.62 arcsec. Such a large separation means that the lensing object must be dominated by dark matter. Our results are fully consistent with theoretical expectations based on the cold-dark-matter model.

Complications associated with inferior alveolar nerve reposition technique for simultaneous implant-based rehabilitation of atrophic mandibles. A systematic literature review.

INTRODUCTION: Surgical inferior alveolar nerve (IAN) reposition techniques offer an alternative approach to implant-based rehabilitation in patients with severe mandibular atrophy The aim of this systematic review, was to determine the complications associated with the technique and to determine which of two variants (lateralization or transposition) is less invasive. MATERIALS AND METHODS: An electronic search was conducted in databases complimented by a manual search to identify clinical studies investigating complications derived from these surgical techniques. Only studies of adult humans, published in English during the last seven years were included. The initial search located 78 articles, of which seven were included in analysis on the basis of the following characteristics: four investigated inferior alveolar nerve lateralization (IANL), one inferior alveolar nerve transposition (IANT), and two investigated both reposition techniques. RESULTS: This review included data from 289 patients who were recruited for lateralization (N=319) or transposition surgery (N=33) making a total of 352 reposition procedures. Five patients (1.73%) suffered persistent damage to the IAN at the end of the follow-up periods. The overall implant survival rate was 99.26% of a total of 817 implants. The most common complications were neurosensory problems, mandibular fracture, infection, implant loss, and insufficient anatomical reconstruction of the atrophic mandible; neurosensory complications (hypoesthesia, paraesthesia, and hyperesthesia caused by traumatic damage to the nerve) were the most prevalent. CONCLUSIONS: Lateralization of the inferior alveolar nerve would appear to be less invasive as it produces lower percentages of persistent neurosensory disorders (1.56%) than transposition (12.12%). Nevertheless, both techniques offer a viable approach to implant placement in edentulous atrophic mandibles, obtaining predictable clinical and radiological results after 5 years implant loading.

Risk factors for lameness in freestall-housed dairy cows across two breeds, farming systems, and countries.

Lameness poses a considerable problem in modern dairy farming. Several new developments (e.g., herd health plans) strive to help farmers improve the health and welfare of their herd. It was thus our aim to identify lameness risk factors common across regions, breeds, and farming systems for freestall-housed dairy cows. We analyzed data from 103 nonorganic and organic dairy farms in Germany and Austria that kept 24 to 145 Holstein Friesian or Fleckvieh cows in the milking herd (mean = 48). Data on housing, management, behavior, and lameness scores for a total of 3,514 cows were collected through direct observations and an interview. Mean lameness prevalence was 34% (range = 0-81%). Data were analyzed applying logistic regression with generalized estimating equations in a split-sample design. The final model contained 1 animal-based parameter and 3 risk factors related to lying as well as 1 nutritional animal-based parameter, while correcting for the significant confounders parity and data subset. Risk for lameness increased with decreasing lying comfort, that is, more frequent abnormal lying behavior, mats or mattresses used as a stall base compared with deep-bedded stall bases, the presence of head lunge impediments, or neck rail-curb diagonals that were too short. Cows in the lowest body condition quartile (1.25-2.50 for Holstein Friesian and 2.50-3.50 for Fleckvieh) had the highest risk of being lame. In cross-validation the model correctly classified 71 and 70% of observations in the model-building and validation samples, respectively. Only 2 out of 15 significant odds ratios (including contrasts) changed direction. They pertained to the 2 variables with the highest P-values in the model. In conclusion, lying comfort and nutrition are key risk areas for lameness in freestall-housed dairy cows. Abnormal lying behavior in particular proved to be a good predictor of lameness risk and should thus be included in on-farm protocols. The study is part of the European Commission's Welfare Quality project.

Unicystic Ameloblastoma: Rehabilitation with Chin Graft Harvested and Implant-Supported Fixed Prosthesis.

OBJECTIVE: The objective is to present a clinical case of a 38-year-old male with a maxillary unicystic ameloblastoma treated by means of tumor block resection followed by chin-harvested graft placement in order to place two dental implants for esthetic and functional rehabilitation. METHODS: Ameloblastoma is a benign odontogenic tumor characterized by local aggression and a high rate of recurrence; the latter partly depends on how it is treated. Complete resection of the tumor, which usually prevents recurrence, produces bone defects of varying size that must be reconstructed later on. In most cases this is done using bone grafts and implant-supported prostheses. Grafts harvested from the chin are relatively easy to obtain and enjoy a fairly uneventful post-operative with few complications; they are suitable for cases in which the defect generated by resection is of small size. RESULTS: Functional and esthetic rehabilitation and the tumor has not relapsed during a 7-year follow-up. CONCLUSION: Tumor block resection followed by chin-harvested graft placement and dental implants is a safe treatment for patients with unicystic ameloblastoma.

Investigating integument alterations in cubicle housed dairy cows: which types and locations can be combined?

In this study, a data set of 2922 lactating dairy cows in a sample of 64 conventional and organic dairy farms with Holstein Friesian cows in Germany and 31 conventional dairy farms with the dual purpose breed Fleckvieh in Austria was used to screen for correlations between the occurrences of different integument alterations. All cows were housed in cubicle systems. Alterations were classified as hairless areas (H), scabs or wounds (W) or swellings (S) and assessed at 15 locations of the cows' body. Highest median farm prevalences were found at the joints of the legs, which are already commonly included in studies on integumentary alterations: median farm prevalence was 83% for S and 48% for H at the carpal joints, followed by H (38%) and S (20%) at the lateral tarsal joints and H at the lateral calcanei (20%). Additional body parts with notable median prevalences for H were the hip bones (13%), pin bones (12%) and sacrum (11%). Three cluster models, with 2, 5 and 14 clusters, were built by hierarchical clustering of prevalences of the 30 most relevant alteration location combinations. Clustering revealed that location overruled type of lesion in most cases. Occasionally, clusters represented body segments significantly distant from each other, for example the carpal joints and lateral and dorsal calcanei. However, some neighbouring areas such as the medial and lateral hock area should be analysed separately from each other for causal analysis as they formed distinct clusters.

Implant survival and complications in cases of inferior alveolar nerve lateralization and atrophied mandibles with 5-year follow-up.

The objectives of this study were to evaluate the survival after 5 years of implants placed using inferior alveolar nerve (IAN) lateralization in cases of mandibular atrophy and to determine the incidence of complications. Twenty-seven patients received 74 implants by means of the IAN lateralization technique. Implant survival after 5 years of loading was 98.6%. Eighteen months after surgery, the recovery of sensitivity was complete in 26 cases. Implant placement with IAN lateralization was seen to be a satisfactory and predictable technique. IAN lateralization requires a high level of technical skill, and strict criteria should be applied when prescribing this treatment.

Assessment of clinical outcomes and histomorphometric findings in alveolar ridge augmentation procedures with allogeneic bone block grafts: A systematic review and meta-analysis

BACKGROUND: This systematic literature review aimed to evaluate the efficacy of allogeneic bone blocks for ridge augmentation by assessing block survival rates and subsequent implant survival, including post-surgical complications and histomorphometric analysis. MATERIAL AND METHODS: An electronic and manual search among references, was conducted up to April 2019 by two independent authors. Inclusion criteria were: human clinical trials in which the outcomes of allogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant success rates. RESULTS: Seven articles fulfilled the inclusion criteria and were analyzed. A total of 323 allogeneic block grafts were monitored for a minimum of 12 months follow-up after surgery, of which thirteen (4.02%) failed. Regarding the cumulative implant survival rate, the weighted mean was 97.36%, computed from 501 implants. Histologic and histomorphometric analysis showed that allogeneic block grafts presented some clinical and microstructural differences in comparison with autologous block grafts. CONCLUSIONS: Atrophic alveolar crest reconstruction with allogeneic bone block grafts would appear a feasible alternative to autologous bone block grafts, obtaining a low block graft failure rate, similar implant survival rate and fewer postoperative complications. Further investigations generating long term data are needed to confirm these findings

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Guidelines for the use and performance of quantitative outcome measures in ALS clinical trials.

ALS is a motor neuron disease defined as a progressive, neurological disorder, resulting from variable and combined degeneration of upper and lower motor neurons. The heterogeneity of clinical involvement early in the course of the disease makes it difficult to diagnose, as well as to identify one unique outcome measure to quantify neurological changes in the course of the disease. Since clinical evidence of upper and lower motor neuron degeneration must exist in four anatomical regions (bulbar, cervical, thoracic, and lumbosacral), outcome measures should assess these regions. The WFN Airline House recommendations specify the purpose, properties, and the preferred parameters which serve as outcome measures in ALS clinical trials. The purpose of this document is to serve as a review of these outcome measures in terms of their advantages, disadvantages, sensitivity, reliability, and other characteristics, as well as their proper performance in ALS clinical trials. Generally these outcome measures are allocated to four areas: respiratory function, muscle strength, general function, and bulbar function. Our review leads us to believe that respiratory function and strength provide the most useful information, both for research and clinical purposes, and are essential as outcome measures. Inclusion of bulbar and general function parameters in trial design may increase the possibility of identifying a beneficial effect of therapeutic intervention. It is essential to note that the guidelines and recommendations put forth are intended to provide initial evaluation and critique of the proper employment and performance of these outcome measures in ALS clinical trials, based on the available literature and our experience.

Quantitative assessment of motor fatigue in amyotrophic lateral sclerosis.

Motor fatigue is a common complaint in patients with amyotrophic lateral sclerosis (ALS), but is often excluded, unlike weakness, from the clinical assessment of these patients. This could be due to the complexity and often painful assessment techniques of this motor deficit. This study examines the feasibility of quantitative assessment of motor fatigue by modifying presently available force measurements. The relationship between weakness and fatigue in ALS patients was also examined. Fifty-four ALS patients and 39 normal control subjects performed 30 s of sustained maximal voluntary isometric contraction (MVIC) of elbow flexors (EF), knee extensors (NE), and ankle dorsiflexors (DF), using a computerized force measurement system and standardized testing procedures. Fatigue index (FI) was digitally calculated, from the force-time curve, as the percentage of MVIC unable to be sustained over the 30-s period. Fatigue was greater in ALS patients than in normal control (mean=23% vs. 15%) in all muscles including muscles that were not clearly weak. Weakness and fatigue were poorly correlated in ALS patients and may be independent measures of the pathogeneses of ALS.

Rate and range of knee motion during ambulation in healthy and arthritic subjects.

The purpose of this study was to determine the relationship between gait velocity and rate and range of knee motion, during ambulation, for healthy and arthritic subjects. The arthritic subjects had either rheumatoid arthritis or osteoarthritis, and all were tested before and after total knee replacement. Healthy subjects ambulated at an average velocity of 80 m/min and demonstrated knee flexion and extension rates of 344 degrees/sec and a range of knee motion of 60 degrees. Gait velocity correlated with rates of knee flexion and extension and range of knee motion. Arthritic subjects ambulated at velocities less than those of healthy subjects ambulating at free speed. Arthritic subjects accordingly demonstrated reduced knee flexion and extension rates and range of knee motion. When compared with healthy subjects ambulating over a comparable gait-velocity range, the arthritic subjects demonstrated reduced rates and range of motion in most instances. We discuss implications for therapeutic intervention to increase gait velocity for arthritic subjects.