Risk of pulp necrosis and related complications in the permanent anterior teeth with lateral luxation: A systematic review and meta-analysis

This systematic review aimed to evaluate the evidence related to the occurrence of pulp necrosis and related complications in permanent anterior teeth with lateral luxation. It was envisaged to address the ambiguity related to the recommendation for pulp extirpation in teeth with mature root apex. An a priori protocol was formulated as per the best practices of evidence-based medicine and registered in PROSPERO. A comprehensive search was performed electronically in PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane on July 10,2023 without any restriction of language or year of publication. The screening of titles and abstracts and later the full-text articles were performed. Later, the data extraction was performed by using a self-designed sheet, risk of bias (ROB) assessment was done, meta-analysis was performed, and the GRADE approach was used to assess the quality of evidence. The qualitative synthesis was performed on 13 studies done from 1985 to 2020 in hospital settings. There was variability in the minimum and total observation periods, sample sizes, and characteristics of the sample population. The overall pooled prevalence of pulp necrosis was found to be 57% (95% CI: 42, 72%). It was 12% (95% CI: 8%, 18%, I2 = 0%) in immature teeth, and 58% (95% CI: 42, 73%, I2 = 86%) in mature teeth. The pooled prevalence of EIRR was found to be 11% (95% CI: 4, 27%, I2 = 95%) with greater risk in teeth with mature root apex (RR: 1.26, 95% CI: 1.12, 1.42, I2 = 0%). The ROB was moderate or high in nine studies and the GRADE of evidence was very low in 14 of 15 outcomes. There are greater chances of pulp necrosis in teeth with lateral luxation, especially with mature apex. However, it can still be less than 60% in most cases with the prevalence of EIRR less than 20%. Hence, an absolute recommendation for endodontic intervention in mature teeth with lateral luxation must be interpreted with slight caution.

Research Note: Phenotypic trends for the multigenerational advanced intercross of the Virginia body weight lines of chickens

Random samples from generation S41 of the Virginia high and low 8-week body weight lines formed the base population for producing a multigenerational reciprocal intercross population. Although genetic mapping from this intercross has been reported, lacking are phenotypic trends across multiple generations. Here, we provide phenotypic information for the parental base population, the F1 reciprocal cross, and subsequent segregating recombinant generations F2 to F17. Heterosis for the selected trait in the F1 was negative for both reciprocal crosses. Phenotypic correlations for the selected trait in the recombinant generations were essentially nil for both males and females as was percent sexual dimorphism and coefficients of variation.

Risk of ankylosis of avulsed teeth immediately replanted or stored under favorable storage conditions before replantation: A long-term clinical study

BACKGROUND/AIM

There are few long-term clinical follow-up studies on human teeth replanted immediately or after storage in a suitable storage medium prior to replantation. This study aimed to assess the risk of ankylosis in avulsed human teeth replanted immediately or after storage in physiological media for a short time.

MATERIAL

Data from 116 patients with 145 replanted avulsed permanent teeth were selected from a comprehensive dental trauma database in Copenhagen University Hospital. The following teeth were selected: Group 1 comprised 36 teeth replanted immediately (dry time <6 min; wet time <6 min). Group 2 comprised 61 teeth replanted after physiologic storage media (saliva and saline) (dry time <6 min; wet time >5 min; wet time ranged from 7 to 170 min, and mean wet time was 59 min). Group 3 (control) included 48 teeth replanted after dry storage (dry time > 60 min).

METHOD

Clinical and radiographic registrations were carried out according to a standardized protocol; follow-up ranged from 7 months to 23 years. Ankylosis was diagnosed by percussion test and radiographs and related to the conditions prior to replantation and stage of root development.

RESULTS

The overall risk of ankylosis was 17.2% [95% CI: 4.61; 29.79] for immediately replanted teeth, 55.3% [95% CI: 42.54; 68.00] for teeth stored in physiologic media before replantation, and 85.7% [95% CI: 75.70; 95.73] for teeth stored dry more than 1 h. Mature teeth showed a significantly higher risk of ankylosis than immature teeth.

CONCLUSION

This clinical long-term study has verified earlier experimental studies showing that immediate reimplantation has the lowest risk of ankylosis. Physiologic storage media are good alternatives that also reduce the risk of ankylosis compared to dry storage, where ankylosis is more likely although not always seen. Mature teeth are significantly more likely to develop ankylosis.

The risk of healing complications in primary teeth with root fractures: A retrospective cohort study

BACKGROUND/AIM

Primary teeth are frequently affected by traumatic dental injuries. Root fractures are rare and have a reported incidence of 2% in the primary dentition. Hence, there is limited evidence on this topic. This study aims to evaluate the risk of healing complications in primary teeth with root fracture and to identify possible sequelae in the permanent dentition following root fracture in the primary dentition.

MATERIALS AND METHODS

A retrospective analysis of a cohort of 53 patients with 74 root fractured primary teeth. The standard follow-up program included clinical and radiographic examination after 4 weeks, 8 weeks, 6 months, and 1 year after the trauma and when the patient was 6 years of age. The following complications were registered: pulp necrosis (PN), pulp canal obliteration (PCO), ankylosis with replacement root resorption (ARR), infection-related root resorption (IRR), premature tooth loss (PTL), and repair-related resorption (RRR).

STATISTICS

The Kaplan-Meier and Aalen-Johansen estimators were employed. The level of significance was 5%.

RESULTS

A total of 74 teeth were included. 42 teeth were extracted at the initial examination. Risks estimated after 3 years: PTL 45.9% [95% CI: 28.8-63.0], PCO 12.9% [95% CI: 2.3-23.4], PN 14.9% [95% CI: 3.9-25.9], RRR 2.6% [95% CI: 0.0-7.5]. No teeth showed ARR or IRR. All complications were diagnosed within the first year. Most common sequelae in the permanent dentition was demarcated opacities, with an estimated risk of 20% [95% CI: 8.2-41.3].

CONCLUSIONS

There is a low risk of healing complications following a root fracture in the primary dentition. Root fractures often result in early extraction of the coronal fragment. The remaining apical fragment will undergo a physiological resorption. Aside from opacities, there is a low risk of sequelae in the permanent dentition.

Long-term functional consequences of cranial nerve injuries after carotid endarterectomy

BACKGROUND

The aim of the study was to investigate long-term patient consequences of cranial nerve injury (CNI) caused by carotid endarterectomy (CEA) in patients with identified CNI at the 30-day follow-up.

METHODS

Consecutive patients operated for symptomatic carotid artery stenosis 2015-2019 with a documented CNI at the 30-day follow-up after CEA were recruited to this cross-sectional survey. Telephone interviews were conducted >1 year after CEA utilizing survey instruments developed to uncover CNI symptoms. Patients graded their symptoms on a 4-point scale: 1) no symptoms; 2) mild symptoms; 3) moderate symptoms; and 4) severe symptoms.

RESULTS

Altogether, 477 patients underwent CEA, of which 82 were diagnosed with CNI; 70/82 patients remained alive at the time for the survey and 68 patients completed the interview. The mean follow-up time was 3.7 years. Severe persistent CNI symptoms were reported in 2/68 (2.9%), moderate symptoms in 1/68 (1.5%) and mild symptoms in 14/68 (21%) whereas 51/68 patients (75%) reported no residual symptoms. When extrapolating these findings to all patients, approximately 4.4% reported persistent symptoms at the long-term follow-up and only 0.8% reported moderate or severe symptoms.

CONCLUSIONS

The long-term consequences of CNI following CEA are benign in most patients, with a high rate of symptom resolution and a very low rate of persistent clinically significant symptoms.

Nonlinear Radiation Gauge for Near Kerr Spacetimes

In this paper, we introduce and explore the properties of a new gauge choice for the vacuum Einstein equation inspired by the ingoing and outgoing radiation gauges (IRG, ORG) for the linearized vacuum Einstein equation introduced by Chrzanowski in his work on metric reconstruction (Chrzanowski in Phys Rev D 11:2042-2062, 1975) on the Kerr background. It has been shown by Price et al. (Class Quantum Gravity 24:2367-2388, 2007) that the IRG/ORG are consistent gauges for the linearized vacuum Einstein equation on Petrov type II backgrounds. In (Andersson et al. Stability for linearized gravity on the Kerr spacetime, 2019), the ORG was used in proving linearized stability for the Kerr spacetime, and the new non-linear radiation gauge introduced here is a direct generalization of that gauge condition, and is intended to be used to study the stability of Kerr black holes under the evolution generated by the vacuum Einstein equation.

Effects of 3 months of detraining following cardiac rehabilitation in patients with atrial fibrillation

Background

Atrial fibrillation negatively impacts physical fitness and health-related quality of life. We recently showed that 3 months of physiotherapist-led exercise-based cardiac rehabilitation improves physical fitness and muscle function in elderly patients with permanent atrial fibrillation and concomitant diseases. Little is, however, known about the consequences for physical fitness, physical activity level, and health-related quality of life after ending the rehabilitation period.

Methods

Prospective 3 months follow-up study of 38 patients out of 40 eligible (10 women) who, as part of a randomized controlled trial, had completed a 3 months physiotherapist-led cardiac rehabilitation resulting in improved physical fitness,. In the current study, the participants were instructed to refrain from exercise for 3 months after completion of the rehabilitation period. Primary outcome measure was physical fitness measured as highest achieved workload using an exercise tolerance test. Secondary outcome measures were muscle function (muscle endurance tests), physical activity level (questionnaire and accelerometer), and health-related quality of life, (Short Form-36), as in the preceding intervention study. We used the Wilcoxon Signed Rank test to analyse differences between the end of rehabilitation and at follow-up. The effect size was determined using Cohen’s d .

Results

Exercise capacity and exercise time significantly decresead between end of rehabilitation and at follow-up (p < .0001 for both). A significant reduction in shoulder flexion repetitions (p = .006) was observed as well as reduced health-related quality of life in the Short Form-36 dimensions Physical Function (p = .042), Mental Health (p = .030), and Mental Component Score (p = .035). There were, however, no changes regarding objective and subjective physical activity measurements.

Conclusion

In older patients with permanent atrial fibrillation, previously achieved improvements from physiotherapist-led exercise-based cardiac rehabilitation in physical fitness and muscle function were lost, and health-related quality of life was impaired after ending the rehabilitation period. A strategy for conserving improvements after a rehabilitation period is essential.

NA0D - The new Traumatic Dental Injury classification of the World Health Organization

An accurate, clear, and easy-to-use traumatic dental injury (TDI) classification and definition system is a prerequisite for proper diagnosis, study, and treatment. However, more than 50 classifications have been used in the past. The ideal solution would be that TDIs are adequately classified within the International Classification of Diseases (ICD), endorsed by the World Health Organization (WHO). TDI classification provided by the 11th Revision of the ICD (ICD-11), released in 2018, and previous Revisions, failed to classify TDIs satisfactorily. Therefore, in December 2018, a proposal was submitted by Dr's Stefano Petti, Jens Ove Andreasen, Ulf Glendor, and Lars Andersson, to the ICD-11, asking for a change of the existing TDI classification. Proposal #2130 highlighted the TDI paradox, the fifth most frequent disease/condition neglected by most public health agencies in the world, and the limits of ICD-11 classification. Namely, injuries of teeth and periodontal tissues were located in two separate blocks that did not mention dental/periodontal tissues; infraction, concussion, and subluxation were not coded; most TDIs lacked description; and tooth fractures were described through bone fracture descriptions (e.g., comminuted, compression, and fissured fractures). These limitations led to TDI mis-reporting, under-reporting, and non-specific reporting by untrained non-dental healthcare providers. In addition, no scientific articles on TDIs, present in PubMed, Scopus, and Web-of-Science, used the ICD classification. Proposal #2130 suggested to adopt the Andreasen classification, the most widely acknowledged classification used in dental traumatology. The Proposal was reviewed by two WHO teams, two scientific Committees, one WHO Collaborating Center, and the Department of Non-Communicable Disease Prevention at WHO headquarters, and it underwent two voting sessions. In March 2022, the Andreasen classification was accepted integrally. A new entity was generated, called NA0D, "Injury of teeth or supporting structures" (https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f1413338122). Hopefully, this will contribute to increasing the public awareness, and the dental profession's management, of TDIs.

In Situ Measurements of Thermal Ion Temperature in the Martian Ionosphere

In situ measurements of ionospheric and thermospheric temperatures are experimentally challenging because orbiting spacecraft typically travel supersonically with respect to the cold gas and plasma. We present O 2 + temperatures in Mars' ionosphere derived from data measured by the SupraThermal And Thermal Ion Composition instrument onboard the Mars Atmosphere and Volatile EvolutioN spacecraft. We focus on data obtained during nine special orbit maneuvers known as Deep Dips, during which MAVEN lowered its periapsis altitude from the nominal 150 to 120 km for 1 week in order to sample the ionospheric main peak and approach the homopause. We use two independent techniques to calculate ion temperatures from the measured energy and angular widths of the supersonic ram ion beam. After correcting for background and instrument response, we are able to measure ion temperatures as low as 100 K with associated uncertainties as low as 10%. It is theoretically expected that ion temperatures will converge to the neutral temperature at altitudes below the exobase region (∼180-200 km) due to strong collisional coupling; however, no evidence of the expected thermalization is observed. We have eliminated several possible explanations for the observed temperature difference between ions and neutrals, including Coulomb collisions with electrons, Joule heating, and heating caused by interactions with the spacecraft. The source of the energy maintaining the high ion temperatures remains unclear, suggesting that a fundamental piece of physics is missing from existing models of the Martian ionosphere.

Introduction of an interactive tool (the Dental Trauma Guide) in the undergraduate dental teaching to manage traumatic dental injuries

BACKGROUND/AIMS

Traumatic dental injuries (TDI) are complex problems where lack of proper care may result in serious complications. The need to improve the management of TDI is a frequently addressed concern. Methods of improvement in their diagnosis and management are continuously evolving. The interactive Internet tool, the Dental Trauma Guide (DTG), helps to simplify diagnostic and management dilemmas. However, it is not a freely available tool. The aim of the current study was to assess the knowledge and diagnostic skills of undergraduate dental students with access to the DTG compared with students without such access, in order to validate and promote this tool in dental education.

MATERIALS AND METHODS

Two groups of students were randomly selected where one group of final year dental undergraduate students were exposed to lectures, demonstrations, discussions and tutorials on the management of TDI according to the standard undergraduate curriculum in Sri Lanka. Another test group of 21 students were provided with access to DTG during their training in paediatric dentistry. At the end of the study period, students were assessed on their knowledge of TDI using MCQs (Multiple Choice Questions) and OSCEs (Objective Structured Clinical Examination), based on the DTG.

RESULTS

The students with access to the DTG were more knowledgeable in providing the correct answers to three out of the seven OSCE questions. Evaluation based on the MCQs did not reveal a significant difference (p = .913). However, users of the DTG showed a statistically significant difference with better overall knowledge based on their answers (p = .028). Following this period of evaluation, all of the students were provided with access to the DTG to supplement their learning experience.

CONCLUSION

The Dental Trauma Guide is a useful supplementary tool for undergraduate students to arrive at a correct diagnosis and treatment plan for TDI.

Comparison between Topical and Injection Anesthetics on Pain Related to Orthodontic Miniscrew Placement: A Split-mouth Study

AIMS AND OBJECTIVES

The aims of this study were to compare the anesthetic effect of a lidocaine/prilocaine (L/P) topical anesthetic with placebo on pain from needle sticks and to compare the anesthetic effect of the L/P topical anesthetic with an infiltrative anesthetic on pain from orthodontic miniscrew placement.

MATERIALS AND METHODS

Pain elimination was analyzed from two interventions: (a) needle stick and (b) miniscrew insertion. When assessing pain from needle stick, one side of the mandible received 2.5% lidocaine/2.5% prilocaine topical anesthetic, and the other side received placebo. When evaluating pain from miniscrew placement, one side of the mandible received L/P topical anesthetic and the other side received infiltrative anesthetic. The findings were recorded on a Visual Analogue Scale after needle stick and after miniscrew placement. Subjective assessment was analyzed by a questionnaire.

RESULTS

The L/P topical anesthetic significantly eliminated the pain from needle stick (Mann-Whitney test of medians, 29.0 vs 0.0, respectively, p<0.001). However, the injection anesthetic eliminated the pain from the miniscrew placement better than the L/P topical anesthetic (Mann-Whitney test of medians, 0.0 vs 5.5, respectively, p<0.001). Eighty percent of the subjects felt more comfortable with L/P topical anesthetic than injection anesthetic. Pain from needle stick pain was reported to be the most uncomfortable part of the study.

CONCLUSION

The L/P topical anesthetic efficiently eliminated pain from needle stick. The L/P topical anesthetic did not completely eliminate pain from miniscrew placement as the injection anesthesia, but it did reduce pain to tolerable levels.

CLINICAL SIGNIFICANCE

L/P topical anesthetics can significantly eliminate pain from needle stick injections, and L/P topical anesthetics can reduce pain from orthodontic miniscrew placement to tolerable levels.

The risks of ankylosis of 89 avulsed human teeth stored in saliva prior to replantation-A re-evaluation of a long-term clinical study

BACKGROUND/AIM

The survival of an avulsed tooth highly depends on the emergency management. The aim of this study was to evaluate the risk of ankylosis for avulsed human teeth stored in saliva preceded by various dry storage conditions prior to replantation.

MATERIAL AND METHODS

Data include 74 patients (54 male and 20 female) with 89 avulsed and replanted teeth (16 immature teeth, 73 mature teeth). Patient ages ranged from 6 to 36 years (median: 13.0 years). All teeth were stored in saliva before replantation. Treatment and follow-up were performed according to a standardized procedure. Follow-up periods ranged from 7 months to 20 years (mean 5.3 years). The risk of ankylosis over time was estimated by the Aalen-Johansen method in relation to the length of dry storage and the stage of root development. The effect of risk factors (root development and length of dry time) on the risk of ankylosis was analysed by Cox regression analysis.

RESULTS

For mature teeth, dry storage for 5 min or less before saliva storage resulted in a 47.4% (95% confidence interval (CI): 32.8-60.7) ankylosis rate. When dry storage was >5 min and <20 min, the risk of ankylosis was 76.8% (95% CI: 45.7-91.5). When dry storage exceeded 20 min prior to saliva storage, ankylosis increased to 89.3% (95% CI: 68.0-96.7). Ankylosis also increased with increasing saliva storage time. Specifically, one additional minute of wet time increased the ankylosis hazard rate (HR) by approximately 1% (CI = [0%, 2%], p = .052). Teeth with mature root development were significantly more frequently affected by ankylosis than teeth with immature root development (HR: 2.4 (95% CI: 1.0-5.5), p = .04).

CONCLUSION

Temporary storage in saliva should be encouraged if an avulsed permanent tooth cannot be immediately replanted or a suitable storage medium such as milk or saline is not immediately available at the place of the accident.

Jens Ove Andreasen, 1935-2020 Father of Dental Traumatology

The life and professional contributions to dental traumatology of Dr. Jens Ove Andreasen are described in terms of his research, writing, teaching, and leadership.

Apolipoprotein B48 metabolism in chylomicrons and very low-density lipoproteins and its role in triglyceride transport in normo- and hypertriglyceridemic human subjects

BACKGROUND

Renewed interest in triglyceride-rich lipoproteins as causative agents in cardiovascular disease mandates further exploration of the integrated metabolism of chylomicrons and very low-density lipoproteins (VLDL).

METHODS

Novel tracer techniques and an integrated multi-compartmental model were used to determine the kinetics of apoB48- and apoB100-containing particles in the chylomicron and VLDL density intervals in 15 subjects with a wide range of plasma triglyceride levels.

RESULTS

Following a fat-rich meal, apoB48 appeared in the chylomicron, VLDL₁ and VLDL₂ fractions in all subjects. Chylomicrons cleared rapidly from the circulation but apoB48-containing VLDL accumulated, and over the day were 3-fold higher in those with high versus low plasma triglyceride. ApoB48-containing particles were secreted directly into both the chylomicron and VLDL fractions at rates that were similar across the plasma triglyceride range studied. During fat absorption, whilst most triglyceride entered the circulation in chylomicrons, the majority of apoB48 particles were secreted into the VLDL density range.

CONCLUSION

The intestine secretes apoB48-containing particles not only as chylomicrons but also directly into the VLDL₁ and VLDL₂ density ranges both in the basal state and during dietary lipid absorption. Over the day, apoB48-containing particles appear to comprise about 20-25% of circulating VLDL and, especially in those with elevated triglycerides, form part of a slowly cleared 'remnant' particle population, thereby potentially increasing CHD risk. These findings provide a metabolic understanding of the potential consequences for increased CHD risk when slowed lipolysis leads to the accumulation of remnants, especially in individuals with hypertriglyceridemia.

Craniofacial Height in Relation to Cross-Sectional Morphology of the Anterior Maxilla: An Anatomical Consideration in Implant Therapy

PURPOSE

Patients who have a vertical growth pattern are more prone to complete alveolar bone growth later and run a higher risk for inhibition of growth and infraposition after implants have been placed. Moreover, it has been suggested for the same category of patients that craniofacial height may influence the alveolar bone morphology of the anterior maxilla during growth. Hence, it is important to identify such patients early when considering implant treatment in young patients. The purpose of this study was to investigate the height and width of the alveolar bone in the anterior maxilla in subjects with different craniofacial heights to assess if there is a relation between craniofacial height and the dimensions of the alveolar bone in the anterior part of the maxilla.

MATERIALS AND METHODS

Measurements on cephalograms and cone beam computed tomography (CBCT) images of the maxilla from 180 fully dentate subjects were analyzed and categorized into three angle groups based on the craniofacial height: low-, normal-, and high-angle groups. Measurements of the alveolar bone were taken interradicular, at six reference points distributed between the first premolar regions in the maxilla. The height and width of the alveolar bone were measured with a standardized technique at 3, 6, 9, and 12 mm from the top of the alveolar process.

RESULTS

Significant differences were found regarding the height of the alveolar bone in all the subgroups and regarding the width in the 9- and 12-mm subgroups, and between low-/normal- and low-/high-angle groups, where the high-angle group represented the thinnest alveolar bone. A significant difference was found between male and female patients concerning all dimensions of the alveolar bone.

CONCLUSION

There is a relation between craniofacial height and the dimensions of the alveolar bone in the anterior part of the maxilla. Craniofacial height is an important factor to analyze when implant treatment is considered in the maxillary anterior region. This identification can preferably be carried out early in young patients who are still growing when various treatment options can still be considered.

Eden Baysal Dental Trauma Index: Face and content validation

BACKGROUND/AIM

Recording of traumatic dental injuries in the emergency situation with a simple and easily recordable index that will also enable computer registration is advantageous. The aim of this paper is to present a new index to facilitate recording traumatic dental injuries and assess its face and content validity.

MATERIALS AND METHODS

The index included information on the type of injury related to the affected structures (enamel, dentin, cement, pulp, periodontal ligament, and alveolar bone) in accordance with Andreasen's classification. In addition, injuries to the alveolar bone and the maturity of the root were included. Fifteen dental trauma experts from 11 different countries rated the codes and content of the "Eden Baysal Dental Trauma Index" using the RAND modified e-Delphi consensus method. A statement was considered valid after reaching 75% consensus among panel members. Two rounds were necessary for reaching consensus on seven statements and the definition. The last version of the index was then presented online to a feedback group that included 10 experts from five countries to determine the external validity by representative cases.

RESULTS

The wording of the definition showed 92.8% agreement in the first round. Statements 1 and 2 gave information about the structure of the index and both reached 90% agreement in the first round. Definition and statements from 1 to 7 reached agreement as 93.3%, 93.3%, 100%, 93.3%, 80%, 93.3%, 80%, and 93.3%, respectively, in the second round. Most of the experts in the feedback group reported that the index was useful and user-friendly.

CONCLUSION

After a total of two rounds with the panel members and one round with the feedback group, the "Eden Baysal Dental Trauma Index" was approved for face and content validity and external validity was obtained.

Effect of an Anesthetic Chewing Gum on the Initial Pain or Discomfort from Orthodontic Elastomeric Separator Placement

AIM

The aim of this study was to investigate the effect of a formulated anesthetic chewing gum (ACG) on the initial pain/discomfort resulting from the placement of orthodontic separators.

MATERIALS AND METHODS

The preparation of ACG formulation was investigated using food and drug administration (FDA)-certified ingredients. Sixty subjects were recruited and randomly allocated to three groups: (1) ACG, (2) chewing gum (CG) without anesthetics or (3) control (no CG) group. All subjects received an orthodontic elastomeric separator that was placed between the maxillary right or left first molar and second premolar. For all groups, the registration of pain/discomfort experienced immediately after separator placement (0 hour), then after 1, 4, and 8 hours was carried out using the visual analog scale.

RESULTS

Regarding the pain/discomfort perception, there was a statistically significant difference (p value <0.0001) between the three groups (ACG, CG, and controls) at each of the three-time points (1, 4 and 8 hours). There were no harms reported by both groups except for temporary mild muscle soreness from gum chewing that was reported by four subjects from the ACG group and two subjects from the CG group.

CONCLUSION

The ACG can significantly decrease and eliminate the initial pain/discomfort resulting from the placement of the orthodontic elastomeric separators. Furthermore, the ACG may decrease the need for a systemic analgesic.

CLINICAL SIGNIFICANCE

Orthodontic elastomeric separator placement can be uncomfortable. The ACG significantly decreased the initial pain/discomfort from orthodontic separators during the 8 hours. Therefore, the ACG can be used by the patients as needed whenever pain/discomfort is experienced from the placement of elastomeric separators. Consequently, this may reduce the need for systemic analgesics. How to cite this article: Al-Melh MA, Nada A, Badr H, et al. Effect of an Anesthetic Chewing Gum on the Initial Pain or Discomfort from Orthodontic Elastomeric Separator Placement. J Contemp Dent Pract 2019;20(11):1286-1292.

Investigation of human apoB48 metabolism using a new, integrated non-steady-state model of apoB48 and apoB100 kinetics

BACKGROUND

Triglyceride-rich lipoproteins and their remnants have emerged as major risk factors for cardiovascular disease. New experimental approaches are required that permit simultaneous investigation of the dynamics of chylomicrons (CM) and apoB48 metabolism and of apoB100 in very low-density lipoproteins (VLDL).

METHODS

Mass spectrometric techniques were used to determine the masses and tracer enrichments of apoB48 in the CM, VLDL₁ and VLDL₂ density intervals. An integrated non-steady-state multicompartmental model was constructed to describe the metabolism of apoB48- and apoB100-containing lipoproteins following a fat-rich meal, as well as during prolonged fasting.

RESULTS

The kinetic model described the metabolism of apoB48 in CM, VLDL₁ and VLDL₂ . It predicted a low level of basal apoB48 secretion and, during fat absorption, an increment in apoB48 release into not only CM but also directly into VLDL₁ and VLDL₂ . ApoB48 particles with a long residence time were present in VLDL, and in subjects with high plasma triglycerides, these lipoproteins contributed to apoB48 measured during fasting conditions. Basal apoB48 secretion was about 50 mg day^-1 , and the increment during absorption was about 230 mg day^-1 . The fractional catabolic rates for apoB48 in VLDL₁ and VLDL₂ were substantially lower than for apoB48 in CM.

DISCUSSION

This novel non-steady-state model integrates the metabolic properties of both apoB100 and apoB48 and the kinetics of triglyceride. The model is physiologically relevant and provides insight not only into apoB48 release in the basal and postabsorptive states but also into the contribution of the intestine to VLDL pool size and kinetics.

Mars's Dayside Upper Ionospheric Composition Is Affected by Magnetic Field Conditions

Previous observations have shown that electron density and temperature in the dayside ionosphere of Mars vary between strongly and weakly magnetized regions of the planet. Here we use data from the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to examine whether dayside ion densities and ionospheric composition also vary. We find that O+,O 2 + , andCO 2 + densities above ~200 km are greater in strongly magnetized regions than in weakly magnetized regions. Fractional abundances of ion species are also affected. TheO + / O 2 + ratio at 300-km altitude increases from ~0.5 in strongly magnetized regions to ~0.8 in weakly magnetized regions. Consequently, the plasma reservoir available for escape is fundamentally different between strongly magnetized and weakly magnetized regions.

Drugs in fall versus non-fall accidents with major trauma - A population-based clinical and medico-legal autopsy study

BACKGROUND

The main aim of the present population-based study was to compare drugs in fall versus non-fall accidents causing major trauma, including both clinical and medico-legal autopsy data.

METHODS

All individuals with accidents resulting in major trauma, a new injury severity score (NISS)>15 or lethal outcome was identified at hospital and/or the Department of Forensic Medicine between 2011 and 2013. Modified Downton Fall Risk Index ranged from 0 to 7, and was based on specific pharmaceuticals (max 5 points), previous fall (1 point) and cognitive impairment (1 point).

RESULTS

One hundred and four individuals with major traumatic accidents were identified, 38 (36.5%) died. The median modified Downton Fall Risk Index was 2 for fall accidents and 0 for non-fall accidents (p < 0.001). Modified Downton Fall Risk Index was an age-independent factor associated with fall accident (p < 0.001). The medico-legal autopsy rate for in-hospital patients was 50% (6/12) for fatal fall accidents in comparison with 92.3% (12/13) for fatal non-fall accidents (p = 0.03). In individuals undergoing medico-legal autopsy, the proportion of individuals with any detected drug was 77% in fall accidents compared to 39% in non-fall accidents (p = 0.036). The presence of sedatives (p = 0.002) and bensodiazepines (p = 0.023) were higher for fall accidents compared to non-fall accidents.

CONCLUSION

This population-based study on accidents with major trauma showed that drugs had high impact on fall accidents with major trauma. It seems warranted from a public health perspective to study if implementation of medication review guidelines at hospital managing polypharmacy issues may prevent fall accident recidivism.

The Space Physics Environment Data Analysis System (SPEDAS)

With the advent of the Heliophysics/Geospace System Observatory (H/GSO), a complement of multi-spacecraft missions and ground-based observatories to study the space environment, data retrieval, analysis, and visualization of space physics data can be daunting. The Space Physics Environment Data Analysis System (SPEDAS), a grass-roots software development platform (www.spedas.org), is now officially supported by NASA Heliophysics as part of its data environment infrastructure. It serves more than a dozen space missions and ground observatories and can integrate the full complement of past and upcoming space physics missions with minimal resources, following clear, simple, and well-proven guidelines. Free, modular and configurable to the needs of individual missions, it works in both command-line (ideal for experienced users) and Graphical User Interface (GUI) mode (reducing the learning curve for first-time users). Both options have "crib-sheets," user-command sequences in ASCII format that can facilitate record-and-repeat actions, especially for complex operations and plotting. Crib-sheets enhance scientific interactions, as users can move rapidly and accurately from exchanges of technical information on data processing to efficient discussions regarding data interpretation and science. SPEDAS can readily query and ingest all International Solar Terrestrial Physics (ISTP)-compatible products from the Space Physics Data Facility (SPDF), enabling access to a vast collection of historic and current mission data. The planned incorporation of Heliophysics Application Programmer's Interface (HAPI) standards will facilitate data ingestion from distributed datasets that adhere to these standards. Although SPEDAS is currently Interactive Data Language (IDL)-based (and interfaces to Java-based tools such as Autoplot), efforts are under-way to expand it further to work with python (first as an interface tool and potentially even receiving an under-the-hood replacement). We review the SPEDAS development history, goals, and current implementation. We explain its "modes of use" with examples geared for users and outline its technical implementation and requirements with software developers in mind. We also describe SPEDAS personnel and software management, interfaces with other organizations, resources and support structure available to the community, and future development plans.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s11214-018-0576-4) contains supplementary material, which is available to authorized users.

Development, validity and reliability testing the Swedish Ethical Climate Questionnaire

BACKGROUND

An ethical climate has been described as a working climate embracing shared perceptions about morally correct behaviour concerning ethical issues. Various ethical climate questionnaires have been developed and validated for different contexts, but no questionnaire has been found concerning the ethical climate from an inter-professional perspective in a healthcare context. The Swedish Ethical Climate Questionnaire, based on Habermas' four requirements for a democratic dialogue, attempts to assess and measure the ethical climate at various inter-professional workplaces. This study aimed to present the construction of and to test the psychometric properties of the Swedish Ethical Climate Questionnaire.

METHOD

An expert group of six researchers, skilled in ethics, evaluated the content validity. The questionnaire was tested among 355 healthcare workers at three hospitals in Sweden. A parallel analysis (PA), an exploratory factor analysis and confirmatory factor analysis were performed.

ETHICAL CONSIDERATIONS

The participants included in the psychometric analysis were informed about the study, asked to participate in person and informed that they could withdraw at any time without giving any reason. They were also assured of confidentiality in the reporting of the results.

FINDINGS

The parallel analysis (PA) recommended one factor as a solution. The initial exploratory factor analysis with a four-factor solution showed low concordance with a four-factor model. Cronbach's alpha varied from 0.75 to 0.82; however, since two factors only consisted of one item, alpha could not be reported. Cronbach's alpha for the entire scale showed good homogeneity (α = 0.86). A confirmatory factory analysis was carried out based on the four requirements and showed a goodness-of-fit after deleting two items. After deletion of these items, Cronbach's alpha was 0.82.

DISCUSSION

Based on the exploratory factor analysis, we suggest that the scale should be treated as a one-factor model. The result indicates that the instrument is unidimensional and assesses ethical climate as a whole.

CONCLUSION

After testing the Swedish Ethical Climate Questionnaire, we found support for the validity and reliability of the instrument. We found the 10-item version of Swedish Ethical Climate Questionnaire satisfactory. However, we found no support for measuring different dimensions and, therefore, this instrument should be seen as assessing ethical climate as of whole.

Genomic signatures of 60 years of bidirectional selection for 8-week body weight in chickens

Sixty years, constituting 60 generations, have passed since the founding of the Virginia body weight lines, an experimental population of White Plymouth Rock chickens. Using a stringent breeding scheme for divergent 8-week body weight, the lines, which originated from a common founder population, have responded to bidirectional selection with an approximate 15-fold difference in the selected trait. They provide a model system to study the genetics of complex traits in general and the influences of artificial selection on quantitative genetic architectures in particular. As we reflect on the 60th anniversary of the initiation of the Virginia body weight lines, there is opportunity to discuss the findings obtained using different analytical and experimental genetic and genomic strategies and integrate them with a recent pooled genome resequencing dataset. Hundreds of regions across the genome show differentiation between the 2 lines, reinforcing previous findings that response to selection relied on standing variation across many genes and giving insights into the haplotype complexity underlying regions associated with body weight.

Guidelines for the Management of Traumatic Dental Injuries: 1. Fractures and Luxations of Permanent Teeth

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and followup are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented.

Soil water potential and temperature sum during reproductive growth control seed dormancy in Alopecurus myosuroides Huds

The sustainable management of unwanted vegetation in agricultural fields through integrated weed control strategies requires detailed knowledge about the maternal formation of primary seed dormancy, to support the prediction of seedling emergence dynamics. This knowledge is decisive for the timing of crop sowing and nonchemical weed control measures. Studies in controlled environments have already demonstrated that thermal conditions and, to some extent, water availability during seed set and maturation has an impact on the level of dormancy. However, it is still unclear if this applies also under field conditions, where environmental stressors and their timing are more variable. We address this question for Alopecurus myosuroides in south-western Sweden. We quantified the effects of cumulated temperature and precipitation as well as soil water potential during the reproductive growth phase of A myosuroides on primary seed dormancy under field conditions. Empirical models differing in focal time intervals and, in case of soil water potential, focal soil depths were compared regarding their predictive power. The highest predictive power for the level of primary dormancy of A. myosuroides seeds was found for a two-factorial linear model containing air temperature sum between 0 and 7 days before peak seed shedding as well as the number of days with soil water potential below field capacity between 7 and 35 days before peak seed shedding. For soil water potential, it was found that only the top 10 cm soil layer is of relevance, which is in line with the shallow root architecture of A. myosuroides. We conclude that for this species the level of dormancy depends on the magnitude and timing of temperature and water availability during the reproductive growth phase. Water availability appears to be more important during maternal environmental perception and temperature during zygotic environmental perception.

A call for action: Improve reporting of research studies to increase the scientific basis for regulatory decision-making

This is a call for action to scientific journals to introduce reporting requirements for toxicity and ecotoxicity studies. Such reporting requirements will support the use of peer-reviewed research studies in regulatory decision-making. Moreover, this could improve the reliability and reproducibility of published studies in general and make better use of the resources spent in research.

RETRACTED: Increased incidence of cervical cancer in Sweden: Possible link with HPV vaccination

The Centre for Cervical Cancer Prevention in Sweden has noted in its annual report a substantial increase in the incidence of invasive cervical cancer, especially during the two years 2014 and 2015. I have sub-grouped the data according to age, using the same statistical database of the National Board of Health and Welfare as used by the authors of the above-mentioned report. The increase in the incidence of cervical cancer was shown to be most prominent among women 20-49 years of age while no apparent increase was observed among women above 50. The FDA has noted in the clinical trials referred to it for marketing approval that women exposed to the human papilloma virus (HPV) prior to vaccination had an increase in premalignant cell changes compared with placebo controls. I discuss the possibility that HPV vaccination could play a role in the increase in the incidence of cervical cancer by causing instead of preventing cervical cancer disease in women previously exposed to HPV. A time relationship exists between the start of vaccination and the increase in the incidence of cervical cancer. The HPV vaccines were approved in 2006 and 2007, respectively and most young girls started to be vaccinated during 2012-2013.

North European invasion by common ragweed is associated with early flowering and dominant changes in FT/TFL1 expression

During the last two centuries, the North American common ragweed (Ambrosia artemisiifolia L.) invaded a large part of the globe. Local adaptation of this species was revealed by a common garden experiment, demonstrating that the distribution of the species in Europe could extend considerably to the North. Our study compares two populations of common ragweed (one from the native range and one from the invaded range) that differ in flowering time in the wild: the invasive population flowers earlier than the native population under non-inductive long-day photoperiods. Experiments conducted in controlled environments established that the two populations differ in their flowering time even under inductive short-day photoperiods, suggesting a change in autonomous flowering control. Genetic analysis revealed that early flowering is dominantly inherited and accompanied by the increased expression of the floral activator AaFTL1 and decreased expression of the floral repressor AaFTL2. Early flowering is also accompanied by reduced reproductive output, which is evolutionarily disadvantageous under long vegetation periods. In contrast, under short vegetation periods, only early-flowering plants can produce any viable seeds, making the higher seed set of late-flowering plants irrelevant. Thus, earlier flowering appears to be a specific adaptation to the higher latitudes of northern Europe.

Effect of periodontal ligament removal with gauze prior to delayed replantation in rabbit incisors on rate of replacement resorption

BACKGROUND/AIM

Delayed (dry storage > 60 minutes) replantation results in ankylosis and replacement resorption. It has been suggested to remove the non-viable periodontal ligament before replantation to possibly reduce the rate of replacement resorption. However there has been no study on the rate of replacement resorption after such measures. The aim of this study was to investigate if there was any difference in the rate of replacement resorption by either removing the periodontal ligament (PDL) with gauze or not removing PDL in teeth subjected to delayed replantation followed by healing for 2 or 6 weeks.

MATERIALS AND METHODS

Maxillary central incisors were extracted in 8 rabbits. In the right central incisors, the necrotic PDL was removed by dry gauze over the root surface. In the left eight extracted teeth PDL was left on the root surface. All extracted teeth were left to dry for 60 minutes. Extra-oral root canal treatment was performed before replantation. The rabbits were sacrificed after 2 weeks and 6 weeks respectively. Histologic processing and evaluation was done.

RESULTS

In the 2 weeks group, all teeth showed ankylosis. The cementum was intact, and fusion of the bone and root was generally seen without resorption of the root, whereas in the 6 weeks group regardless of whether PDL had been kept or not, ankylosis and osseous replacement of the dentin was seen. There was no evidence of inflammatory infiltrate in the sections examined.

CONCLUSION

Removal of PDL prior to delayed replantation may result in some initial protection of the cementum during the first few weeks. However, over longer times there seems to be neither protection of the dentin from ankylosis and osseous replacement, nor any influence on the rate of replacement resorption.

World traumatic dental injury prevalence and incidence, a meta-analysis-One billion living people have had traumatic dental injuries

Traumatic dental injuries (TDIs) account for a considerable proportion of bodily injuries. Nevertheless, global TDI frequency is unknown, probably because TDI diagnosis is not standardized. This study estimated world TDI frequency. A literature search (publication years 1996-2016) was aimed at covering as many countries, communities, ethnic groups as possible, thus achieving high generalizability. In particular, non-specific keywords, no language restrictions, and large databanks were used. Observational studies reporting proportions of individuals with at least one TDI (prevalence) and who developed TDI (incidence rate) were considered. Prevalence rates to permanent dentition, primary dentition and in 12-year-olds, incidence rate to any tooth for any age, male-to-female prevalence ratio (PR) in 12-year-olds, with 95% confidence intervals (95 CIs), were extracted/calculated. Study quality, Z-score distribution, funnel plot symmetry analysis, between-study heterogeneity, sensitivity, and subgroup analyses were performed. Selected primary studies were 102 (permanent dentition; 268 755 individuals; median age, 13.8 years), 46 (primary dentition; 59 436 individuals; median age, 3.4 years), 42 (12-year-olds; 33 829 individuals), 11 (incidence rate; 233 480 person-years; median age, 7.8 years), and 31 (PR; 16 003 males, 16 006 females). World TDI frequency resulted as follows: permanent dentition prevalence 15.2% (95 CI, 13.0%-17.4%); primary dentition prevalence 22.7% (95 CI, 17.3%-28.7%); 12-year-olds prevalence 18.1% (95 CI, 15.3%-21.0%); incidence rate, 2.82 (95 CI, 2.28%-3.42%) per 100 person-years; PR, 1.43 (95 CI, 1.34%-1.52%). Differences between WHO Regions were found. This study shows that more than one billion living people have had TDI. TDI is a neglected condition which could rank fifth if it was included in the list of the world's most frequent acute/chronic diseases and injuries.

Asymmetries, heterosis, and phenotypic profiles of red junglefowl, White Plymouth Rocks, and F1 and F2 reciprocal crosses

During the domestication of farm animals, humans have manipulated genetic variation for growth and reproduction through artificial selection. Here, data are presented for growth, reproductive, and behavior traits for the red junglefowl, a line of White Plymouth Rock chickens, and their F₁ and F₂ reciprocal crosses. Intra- and intergenerational comparisons for growth related traits reflected considerable additive genetic variation. In contrast, those traits associated with reproduction exhibited heterosis. The role of sexual selection was seen in the evolution of prominent secondary sexual ornaments that lend to female choice and male-male competition. The large differences between parental lines in fearfulness to humans were only mitigated slightly in the intercross generations. Whereas, overall F₁ generation heterosis was not transferred to the F₂, there was developmental stability in the F₂, as measured by relative asymmetry of bilateral traits. Through multigenerational analyses between the red junglefowl and the domestic White Plymouth Rocks, we observed plasticity and considerable residual genetic variation. These factors likely facilitated the adaptability of the chicken to a broad range of husbandry practices throughout the world.

Long-term predictors of loneliness in old age: results of a 20-year national study

OBJECTIVES

The understanding of social phenomena is enhanced if individuals can be studied over longer periods. Regarding loneliness in old age, there is a general lack of longitudinal research. The aim of this study was to examine whether there is an association between loneliness in old age and social engagement 20 years earlier, as stated by life course theory and the convoy model.

METHOD

Data from the nationally representative Swedish Panel Study of Living Conditions of the Oldest Old (2002 and 2011 data collection waves) and the Swedish Level of Living Survey (1981 and 1991 data collection waves) were used. The sample included 823 individuals with an average age of 62.2 years at baseline and 82.4 years at follow-up.

RESULTS

Each form of social engagement in old age was significantly associated with the same form of social engagement 20 years earlier. Close forms of social engagement were associated with loneliness in old age; as were more distant forms of social engagement, but only when they were considered solely in old age.

CONCLUSION

Patterns of social engagement in old age were established at least 20 years earlier and close forms of social engagement are long-term predictors of loneliness, although current social engagement tended to be more influential on loneliness. The study underlines the importance of interventions targeted at close relationships that can provide social support in old age.

Bone regeneration using composite non-demineralized xenogenic dentin with beta-tricalcium phosphate in experimental alveolar cleft repair in a rabbit model

Background

Alveolar cleft repair is performed via bone grafting procedure to restore the dental arch continuity. A suitable bone substitute materials should possess osteoinductive and osteoconductive properties, to promote new bone formation, along with a slowly resorbable scaffold that is subsequently replaced with functionally viable bone. Calcium phosphate biomaterials have long proved their efficacy as bone replacement materials. Dentin in several forms has also demonstrated its possibility to be used as bone graft replacement material in several studies. The purpose of this study was to evaluate bone regeneration pattern and quantify bone formation after grafting pre-established experimental alveolar clefts defects model in rabbits using composite xenogenic dentin and β-TCP in comparison to β-TCP alone.

Methods

Unilateral alveolar cleft defects were created in 16 New Zealand rabbits according to previously described methodology. Alveolar clefts were allowed 8 weeks healing period. 8 defects were filled with β-TCP, whereas 8 defects filled with composite xenogenic dentin with β-TCP. Bone regeneration of the healed defects was compared at the 8 weeks after intervention. Quantification of bone formation was analyzed using micro-computed tomography (µCT) and histomorphometric analysis.

Results

µCT and histomorphometric analysis revealed that defects filled with composite dentin/β-TCP showed statistically higher bone volume fraction, bone mineral density and percentage residual graft volume when compared to β-TCP alone. An improved surgical handling of the composite dentin/β-TCP graft was also noted.

Conclusions

Composite xenogenic dentin/β-TCP putty expresses enhanced bone regeneration compared to β-TCP alone in the reconstruction of rabbit alveolar clefts defects.

What are the important outcomes in traumatic dental injuries? An international approach to the development of a core outcome set

BACKGROUND/AIMS

There are numerous treatment options following traumatic dental injury (TDI). Systematic reviews of different treatments are challenging owing to the diversity of outcomes reported between clinical studies. This issue could be addressed through the development and implementation of a agreed and standardized collection of outcomes known as a core outcome set (COS). The aim of this study was to develop a COS for TDI in children and adults. The secondary aim was to establish what, how, when and by whom these outcomes should be measured.

MATERIALS AND METHOD

The project was registered with Core Outcomes Measures in Effectiveness Trials (COMET). A web-based survey was developed to capture the opinions of dentists globally as to which outcomes should be recorded. A list of outcomes was entered into a Delphi Survey and scored by an Expert Working Group (EWG). The scoring was repeated, followed by conference calls to discuss, refine and finalize the COS. The EWG split into small groups of subject-specific experts to determine how, when and by whom each outcome would be measured.

RESULTS

The questionnaire was completed by 1476 dentists. The EWG identified 13 core outcomes to be recorded for all TDI's. An additional 10 injury-specific outcomes were identified. A table has been produced for each outcome detailing what, when, and how each outcome should be recorded.

CONCLUSIONS

A robust consensus process was used to develop an international COS for TDI in children and adults. This includes both generic and injury-specific outcomes across all identified domains.

Healing of soft tissue lacerations in diabetic-induced rats

BACKGROUND/AIM

Prevalence and incidence of diabetes are increasing and many dental trauma patients today have diabetes. The implications of delayed wound healing, associated with diabetes mellitus, on oral mucosal wound healing have not been investigated extensively. The aim of this study was to investigate the implications of diabetes mellitus on the cellular, vascular, and fibroblastic changes induced by laceration on the oral mucosa of Wistar rats.

MATERIALS AND METHODS

Sixteen female Wistar rats were randomly assigned into two groups: 1. Experimental Streptozotocin-induced diabetic group (8 rats). 2. Control group (8 rats). A standardized laceration injury was induced from the corner of the mouth to the mid-check penetrating through dermal and oral mucosal contaminated by saliva. Samples were taken from the rats after sacrificing them on days 1,3,7, and 10. Inflammation was evaluated both qualitatively and quantitatively. Two investigators evaluated samples in a blinded manner.

RESULTS

Histology reports indicated delayed wound healing patterns in diabetic rats through days 1, 3, 7, and 10 when compared to controls. Inflammation was also noted to be consistently present more often in diabetic rats. Furthermore, polymorphonuclear cell count was consistently higher in diabetic rats.

CONCLUSION

The results suggest that oral mucosa wound healing is delayed in diabetic Wistar rats compared to non-diabetic rats in terms of wound closure, angiogenesis, and polymorphonuclear cells number. Furthermore, it is also suggested that wound healing is impaired both in the early and late stages of soft tissue wound healing.

To pace or not to pace: a pilot study of four- and five-gaited Icelandic horses homozygous for the DMRT3 'Gait Keeper' mutation

The Icelandic horse is a breed known mainly for its ability to perform the ambling four-beat gait 'tölt' and the lateral two-beat gait pace. The natural ability of the breed to perform these alternative gaits is highly desired by breeders. Therefore, the discovery that a nonsense mutation (C>A) in the DMRT3 gene was the main genetic factor for horses' ability to perform gaits in addition to walk, trot and canter was of great interest. Although several studies have demonstrated that homozygosity for the DMRT3 mutation is important for the ability to pace, only about 70% of the homozygous mutant (AA) Icelandic horses are reported to pace. The aim of the study was to genetically compare four- and five-gaited (i.e. horses with and without the ability to pace) AA Icelandic horses by performing a genome-wide association (GWA) analysis. All horses (n = 55) were genotyped on the 670K Axiom Equine Genotyping Array, and a GWA analysis was performed using the genabel package in r. No SNP demonstrated genome-wide significance, implying that the ability to pace goes beyond the presence of a single gene variant. Despite its limitations, the current study provides additional information regarding the genetic complexity of pacing ability in horses. However, to fully understand the genetic differences between four- and five-gaited AA horses, additional studies with larger sample materials and consistent phenotyping are needed.