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Background/objectives: Based on the premise that tongue and lip force is affected in individuals with orofacial myofunctional disorders (OMDs), orofacial myofunctional therapy (OMT) programs typically include the strengthening of orofacial muscles through isometric and isotonic exercises. The purpose of this study is to examine whether there is indeed a measurable difference in maximum tongue and lip strength and endurance between subjects with and without OMDs, as well as to explore Oral Health-Related Quality of Life (OHRQoL) in this population., Methods: Sixty healthy young adults (mean age 18.9 years, SD 0.69 years, range 18.0-21.4 years) participated in this study. Perceptual evaluation of orofacial functions was conducted using the Orofacial Myofunctional Evaluation with Scores (OMES) protocol. Participants were divided into three groups, namely those with physiological orofacial functions (POF; n = 20), those with inconsistent orofacial functions (IOF; n = 11), and those with consistent OMDs (OMD; n = 29). Maximum isometric pressure and endurance of tongue and lips were measured using the Iowa Oral Performance Instrument (IOPI). OHRQoL was assessed using the Oral Health Impact Profile (OHIP-14)., Results: The OMES total scores did not differ significantly between the three groups, though the subscale 'function' showed significant differences (13.637; p = 0.001). No statistically significant differences in maximum isometric pressure or endurance for tongue and lips, nor for OHIP scores, were measured between the three groups., Conclusions: Although orofacial muscle strengthening is commonly part of OMT, current findings suggest the superfluity of these types of exercises in the treatment of OMDs in healthy young adults and may indicate the need to focus on awareness and rehabilitation of pathological functions in these individuals. Re-evaluation of the efficacy of OMT programs in different populations may be an important strategy going forward., (© 2024 John Wiley & Sons Ltd.)

Introduction: Children with malocclusion, combined with orofacial myofunctional disorders (OMDs), show increased risk of developing orthodontic problems and needs later in life. Speech-language therapists typically provide orofacial myofunctional therapy (OMT) after referral by dentists, orthodontists or ENT specialists. Interdisciplinary treatment is often advisable to prevent relapse after orthodontic treatment. OMDs and OMT are often found to be controversial topics by dentistry professionals. This study aimed to investigate self-reported knowledge and attitudes of Flemish dentists and orthodontists towards OMDs and OMT., Methods: A survey containing 32 items on demographics, self-reported knowledge of OMDs and OMT, attitudes towards OMDs, OMT, and its use in clinical practice, and referral behaviour was filled out by 48 general dentists (48/79, 61%) and 31 orthodontists (31/79, 39%). The impact of specialization, degree of experience and educational programme was also evaluated., Results: Fifty-six percent of all participants (44/79) reported insufficient to non-existent knowledge of OMT. Nevertheless, the general attitude towards the use of OMT was neutral (47%, 37/79) to (very) positive (48%, 38/79). Although they found correct, evidence-based knowledge on OMDs and OMT important, the majority indicated their formal training did not provide adequate information on OMDs (52%, 41/79) and OMT (62%, 49/79). Specialization showed significant effects, as orthodontists reported themselves knowledgeable on this topic significantly more often than general dentists (p < 0.001), and generally reported a more positive stance towards OMT (p = 0.022)., Conclusion: Dentists and orthodontists indicated a general interest in the topic of OMDs and OMT, alongside an overall lack of information provided by formal education. Current findings suggest the necessity of re-evaluating current curricula on OMDs and OMT., (© 2024 S. Karger AG, Basel.)

Background and Purpose: Venomous animals express numerous Kunitz-type peptides. The mambaquaretin-1 (MQ1) peptide identified from the Dendroaspis angusticeps venom is the most selective antagonist of the arginine-vasopressin V2 receptor (V2R) and the only unique Kunitz-type peptide active on a GPCR. We aimed to exploit other mamba venoms to enlarge the V2R-Kunitz peptide family and gain insight into the MQ1 molecular mode of action., Experimental Approach: We used a bio-guided screening assay to identify novel MQs and placed them phylogenetically. MQs were produced by solid-phase peptide synthesis and characterized in vitro by binding and functional tests and in vivo by diuresis measurement in rats., Key Results: Eight additional MQs were identified with nanomolar affinities for the V2R, all antagonists. MQs form a new subgroup in the Kunitz family, close to the V2R non-active dendrotoxins and to two V2R-active cobra toxins. Sequence comparison between active and non-active V2R Kunitz peptides highlighted five positions, among which four are involved in V2R interaction and belong to the two large MQ1 loops. We finally determined that eight positions, part of these two loops, interact with the V2R. The variant MQ1-K39A showed a higher affinity for the hV2R, but not for the rat V2R., Conclusions and Implications: A new function and mode of action is associated with the Kunitz peptides. The number of MQ1 residues involved in V2R binding is large and may explain its absolute selectivity. MQ1-K39A represents the first step in the improvement of the MQ1 design from a medicinal perspective., (© 2022 The British Pharmacological Society.)

Background: Relationships between malocclusion and orofacial myofunctional disorders (OMD), as well as malocclusions and articulation disorders (AD) have been described, though the exact relationships remain unclear. Given the high prevalence of these disorders in children, more clarity is needed., Summary: The purpose of this study was to determine the association between OMD (specifically, bruxism, deviate swallowing, caudal resting tongue posture, and biting habits), AD, and malocclusions in children and adolescents aged between 3 and 18 years. To conduct a systematic review, 4 databases were searched (MEDLINE, Embase, Web of Science, and Scopus). The identified articles were screened for the eligibility criteria. Data were extracted from the selected articles and quality assessment was performed using the tool of Munn et al. [Int J Health Policy Manag. 2014;3:123-81] in consensus. Using the search strategy, the authors identified 2,652 articles after the removal of duplicates. After reviewing the eligibility criteria, 17 articles were included in this study. One of the included articles was deemed to have an unclear risk of bias, whereas all other articles were considered to have a low risk of bias. The articles showed a relationship between anterior open bite and apico-alveolar articulatory distortions, as well as between anterior open bite and deviate swallowing. For the biting habits, bruxism, and low tongue position no clear conclusions could be drawn. Key Messages: The current review suggests a link between specific types of malocclusion and OMD and AD. However, more high-quality evidence (level 1 and level 2, Oxford Levels of Evidence) is needed to clarify the cooccurrence of other OMD, AD, and malocclusions., (© 2021 S. Karger AG, Basel.)

There is currently a lack of prognostic biomarkers to predict the different sequelae following traumatic brain injury (TBI). The present study investigated the hypothesis that subacute neuroinflammation and microstructural changes correlate with chronic TBI deficits. Rats were subjected to controlled cortical impact (CCI) injury, sham surgery, or skin incision (naïve). CCI-injured (n = 18) and sham-operated rats (n = 6) underwent positron emission tomography (PET) imaging with the translocator protein 18 kDa (TSPO) radioligand [ 18 F]PBR111 and diffusion tensor imaging (DTI) in the subacute phase (≤3 weeks post-injury) to quantify inflammation and microstructural alterations. CCI-injured, sham-operated, and naïve rats (n = 8) underwent behavioral testing in the chronic phase (5.5-10 months post-injury): open field and sucrose preference tests, two one-week video-electroencephalogram (vEEG) monitoring periods, pentylenetetrazole (PTZ) seizure susceptibility tests, and a Morris water maze (MWM) test. In vivo imaging revealed pronounced neuroinflammation, decreased fractional anisotropy, and increased diffusivity in perilesional cortex and ipsilesional hippocampus of CCI-injured rats. Behavioral analysis revealed disinhibition, anhedonia, increased seizure susceptibility, and impaired learning in CCI-injured rats. Subacute TSPO expression and changes in DTI metrics significantly correlated with several chronic deficits (Pearson's |r| = 0.50-0.90). Certain specific PET and DTI parameters had good sensitivity and specificity (area under the receiver operator characteristic [ROC] curve = 0.85-1.00) to distinguish between TBI animals with and without particular behavioral deficits. Depending on the investigated behavioral deficit, PET or DTI data alone, or the combination, could very well predict the variability in functional outcome data (adjusted R 2  = 0.54-1.00). Taken together, both TSPO PET and DTI seem promising prognostic biomarkers to predict different chronic TBI sequelae.

While social media offer great communication opportunities, they also increase the vulnerability of young people to threatening situations online. Recent studies report that cyberbullying constitutes a growing problem among youngsters. Successful prevention depends on the adequate detection of potentially harmful messages and the information overload on the Web requires intelligent systems to identify potential risks automatically. The focus of this paper is on automatic cyberbullying detection in social media text by modelling posts written by bullies, victims, and bystanders of online bullying. We describe the collection and fine-grained annotation of a cyberbullying corpus for English and Dutch and perform a series of binary classification experiments to determine the feasibility of automatic cyberbullying detection. We make use of linear support vector machines exploiting a rich feature set and investigate which information sources contribute the most for the task. Experiments on a hold-out test set reveal promising results for the detection of cyberbullying-related posts. After optimisation of the hyperparameters, the classifier yields an F1 score of 64% and 61% for English and Dutch respectively, and considerably outperforms baseline systems., Competing Interests: The authors have declared that no competing interests exist.

Labial adhesion is a preliminary surgical lip approximation used in the early management of unilateral and bilateral cleft lip and palate. Our objective was to evaluate its effects on the maxillary arch dimensions and nasolabial esthetics by means of a systematic review. The literature search (1955-2016) was based on MEDLINE via PubMed, Web of Science, EMBASE, and the Cochrane Library. Studies with labial adhesion as a single preliminary step for definitive lip closure, in combination with nasoalveolar molding or in combination with infant orthopedics were considered eligible. Fifteen articles were identified (1978-2015), including 587 patients who underwent labial adhesion. Reduction in alveolar cleft width was between 60.9% and 100% in unilateral cases and between 47.5% and 100% in bilateral cases. Reduction in palatal cleft width was between 28.4% and 59.8% in unilateral cases and between 37.5% and 50.5% in bilateral cases. No conclusive results could be drawn about the effect on nasolabial esthetics. This systematic review comprises the available literature of the last 50 years about labial adhesion. It showed reduction of alveolar and palatal cleft width after a treatment with labial adhesion with or without infant orthopedics. The treatment effect on nasolabial esthetics, especially in the long term, remains unclear., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: The purpose of this controlled study is to document articulation and oromyofunctional behavior in children seeking orthodontic treatment. In addition, relations between malocclusions, articulation, and oromyofunctional behavior are studied., Materials and Methods: The study included 56 children seeking orthodontic treatment. The control group, consisting of 54 subjects matched for age and gender, did not undergo orthodontic intervention. To determine the impact of the occlusion on speech, the Oral Health Impact Profile was used. Speech characteristics, intelligibility and several lip and tongue functions were analyzed using consensus evaluations., Results: A significant impact of the occlusion on speech and more articulation disorders for/s,n,l,t/were found in the subjects seeking orthodontic treatment. Several other phenomena were seen more often in this group, namely more impaired lip positioning during swallowing, impaired tongue function at rest, mouth breathing, open mouth posture, lip sucking/biting, anterior tongue position at rest, and tongue thrust. Moreover, all children with a tongue thrust showed an anterior tongue position at rest., Conclusions: Children seeking orthodontics have articulatory and oromyofunctional disorders. To what extent a combined orthodontic and logopaedic treatment can result in optimal oral health (i.e. perfect dentofacial unit with perfect articulation) is subject for further multidisciplinary research., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: (1) To determine whether immediate loading of orthodontic bone anchors (OBAs) generates more failures than delayed loading and (2) to evaluate the impact of different variables on the success rate of the use of OBAs as temporary anchorage devices in orthodontic treatment., Materials and Methods: In a prospective registry, consecutive patients were treated with OBAs by one experienced maxillofacial surgeon. An independent evaluator compared and analyzed different prospectively determined parameters: gender, age (young [< 16 years] versus mature [≥ 16 years]), time of loading (delayed versus immediate), jaw, location, fixation screw length, complications, and orthodontic indications. Success with the OBA was defined as the capacity to maintain anchorage throughout treatment. Premature removal of an OBA because of infection, serious mobility, or persistent pain was considered a failure. Fisher exact tests for analysis of associations between the categorical variables, with the patient as independent variable, were performed. Success and complications were evaluated using multivariate logistic regression., Results: Sixty-one patients (37 male, 24 female) were treated with 106 OBAs over a 5-year period (2001 to 2006). The reported success rate in this study was 88.3%. In seven patients (11.7%) an OBA was removed prematurely. Age, gender, time of loading, jaw, and location did not influence the failure rate. In 25% of patients, at least one screw failure was noted. A statistically higher screw failure rate was noted in female patients, and the younger group presented more complications than the mature group., Conclusion: According to the results of this study, OBAs are a reliable means to obtain absolute orthodontic anchorage. Immediate loading of an OBA did not generate more failures than delayed loading. Age, jaw, and position did not seem to play important roles in success. Age and gender were important parameters in fixation screw failure rate.

This study analysed the effects of cryopreservation on periodontal regeneration of autotransplanted rat molars. First and second maxillary molars (n=92) of 24 four-week-old Wistar rats were gently extracted and autotransplanted into the abdominal tissue immediately (control group n=44) or after cryopreservation in liquid nitrogen for 7 days (experimental group n=48). At 1, 2, 4 and 10 weeks after transplantation, the transplanted molars were excised and regeneration of the periodontal tissues was analysed on histological sections stained with routine H&E and Goldner method. Different tissue responses were scored on a tooth basis: inflammation, regeneration of the periodontal ligament, resorption/apposition of cementum, and alveolar bone formation. Sixty-two teeth were available for histological evaluation, including 30 experimental and 32 control samples. One week after transplantation, both control and test teeth were surrounded by granulation tissue and some areas of root resorption could be seen. After 2 weeks, signs of regeneration of the periodontal ligament, cementum apposition, and new bone formation roughly coincided in both groups, however markedly retarded in the experimental group. After 4 weeks, regeneration progressed equally in both groups, presenting fewer areas of cementum apposition in experimental samples. Finally, 10 weeks after baseline transplantation, no significant differences between both groups could be observed. Cryopreservation followed by autotransplantation of extracted teeth in rats appears to have minimal detrimental effects on regeneration of periodontal tissues after integration periods of 1-10 weeks. However, the present findings indicated that the regeneration process in general is retarded for cryopreserved teeth, as compared to their immediately transplanted homologues., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: The main aim of this experiment was to investigate the perception of Foreign Accent Syndrome in comparison to speakers with an authentic foreign accent., Method: Three groups of listeners attributed accents to conversational speech samples of 5 FAS speakers which were embedded amongst those of 5 speakers with a real foreign accent and 5 native speaker controls. The listening panels differed in their familiarity with foreign accented speech and speech pathology., Results: The findings indicate that listeners' perceptual responses to the three groups of speakers were essentially different at all levels of analysis. The native speaker controls were unequivocally recognized as native speakers of Dutch while the speakers with a real foreign accent were very reliably assessed as non-native speakers. The speakers with Foreign Accent Syndrome, however, were in some sense perceived as foreign and in some sense as native by listeners, but not as foreign as speakers with a real foreign accent nor as native as real native speakers. These results are accounted for in terms of a misinterpretation of markers of speech pathology as markers regional affiliation., Conclusions: The findings of the experiment are consistent with the idea that the very nature of the foreign accent is different in both groups of speakers, although it cannot be fully excluded that the foreign impression in the two groups is one of degree., Learning Outcomes: Readers are able to: (1) define Foreign Accent Syndrome as a motor speech disorder and identify the different subtypes of FAS, (2) describe the most important differences in listeners' perceptual reactions to FAS and real foreign accents, and (3) discuss the findings of the present study in relation to other studies investigating accent attribution in FAS., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The aim of this study was to evaluate the changes in incisor inclination following orthodontic treatment in Class II division 2 patients, and to assess the long-term stability after retention. Dental casts and cephalograms of 61 Class II division 2 patients (31 males and 30 females, mean age 13.4 years) with a closed lip seal were available before (T1), at the end of treatment (T2), and 3.5 years (mean) post-treatment (T3). A method of measuring upper incisor inclination on dental casts was developed for the purpose of the investigation. This involved placing markers on the study casts and then taking radiographs which were measured to establish the upper incisor inclination. Statistical analysis of the data included the calculation of mean values, standard deviation, standard errors, and ranges for each variable. Spearman ranked correlation coefficients were computed for selected model variables and scattergrams plotted. To investigate the influence of the chosen retention therapy, a Mann-Whitney U-test was used. The mean change in incisor inclination during orthodontic treatment was 15.2 degrees. There was a mean relapse of 2.2 degrees between T2 and T3, but this was not considered clinically relevant. The amount of relapse was independent of the type of the retention appliance (Hawley type retainer or lingual retainer). The relationship between long-term stability of the incisor inclination and between the lip line relative to the upper incisors was also investigated, based on cephalometric data. A mean decrease in lip line height of 0.6 mm was seen at T2 and, although the observed change was statistically significant, it would not be clinically relevant.

This study was undertaken to determine the variation in crown-root angle (CRA) of the upper incisors and canines as well as the variation in their labial contour. In addition, the influence of the variability of the labial contour and of different bracket heights on torque was evaluated. Proximal radiographs were taken of 160 extracted maxillary teeth (81 incisors and 79 canines). They were digitized and analysed with Jasc Paint Shop Pro 7TM and Mathcad 2001 Professional. The incisal edge, the centre of the cemento-enamel junction (CEJ), and the root apex were digitized to define the crown and root long axis. For all teeth the CRA was measured. At several heights of the labial surface a tangent was determined, enabling measurement of the inclination of the labial surface. The CRA had great variability, ranging from 167 to 195 degrees for the canines (mean value 183 degrees) and from 171 to 195 degrees for the incisors (average 184 degrees). The mean inclinations of the labial surfaces for the incisors varied greatly. Between 4 and 4.5 mm from the incisal edge the standard deviations (SD) were the smallest and between 2 and 4.5 mm from the incisal edge the labial surface angle differed by approximately 10 degrees. For the canines the mean inclinations of the buccal surface also varied. This angle differed by around 10 degrees between 2 and 4.5 mm from the incisal edge, but the SD were much larger than for the incisors. It can be concluded that placement of a bracket on a tooth at varying heights, still within a clinically acceptable range, results in important differences in the amount of root torque.

As far as craniofacial development is concerned, the orthodontist is mainly interested in growth of the jaws, craniofacial growth patterns and physiologic backgrounds of bone remodelling after tooth displacement. In biomechanics, the principle "action is equal to reaction" is one of the most important issues to deal with. The art in orthodontics is to distribute the reaction forces or to use them on purpose in an attempt to achieve one of the treatment goals. Reaction forces can be neutralized intra-orally. In this respect the location of the center of resistance of the tooth or a group of teeth needs to be defined carefully in order to have a good understanding of the biomechanical principles of tooth displacement. The action forces can be neutralized extra-orally. When no reaction forces on other teeth are applied, there will be no side effects of the reaction forces on other teeth. Research on the biomechanical principles of the headgear does offer some clinical information. Recently in orthodontics, the use of implants has been introduced. It can be used to neutralize reaction forces intra-orally. Moreover, the implants can be used primarily as anchorage during orthodontic tooth movement and later on to replace missing teeth. Recent animal studies at our department have shown that non-axial loading of implants with forces higher than 5 Newton can be used.

Marfan syndrome (MFS) is a connective tissue disorder with autosomal dominant inheritance. Mutations in the FBN1 gene cause deficient processing of fibrillin-1, the main constituent of extracellular microfibrils, affecting tissues displaying elastic properties. Clinical manifestations are widespread and involve the skeletal, ocular, cardiovascular and pulmonary systems, skin and integumentum, and dura. A highly arched palate and retrognathia have been assigned to the symptoms with minor diagnostic specificity, although epidemiological data on prevalence are lacking yet. Twenty-six patients with MFS (n = 26) were studied for craniofacial characteristics using cephalometric measurements on lateral cranial radiographs. The purposes of this study were (1) to compare cephalometric variables of MFS group with age- and sex-matched population norms, and (2) to assess differences in palatal vault dimensions among adult MFS (n = 17) and matched controls (n = 32) by means of cephalometric measurements. Significant differences with population norms were found in the structures of the cranial base, the maxillary complex, the mandible body, and the relations of the jaws with respect to the cranial base and to each other. Palatal height and palatal length were significantly larger in MFS, and were significantly correlated to each other and to the height of the maxillo-alveolar processus. The present data disprove in part previously reported findings, possibly due to biased patient selection in these studies or demographic differences. However, a strong correlation was found between maxillary/mandibular retrognathia, long face, highly arched palate, and MFS. A combination of both intrinsic genetic factors and environmental factors is suggested as a possible explanation for specific morphogenetic aspects of the craniofacial complex in MFS.

This paper investigates speech rate in two standard national varieties of Dutch on the basis of 160 15 mins conversations with native speakers who belong to four different regions in the Netherlands and four in the Dutch-speaking part of Belgium (Flanders). Speech rate was quantified as articulation rate and speaking rate, both expressed as the number of syllables per second (syll/s). The results show a significant effect of speakers' country of origin: subjects in the Netherlands speak 16% faster than subjects in Belgium (articulation: 5.05 vs. 4.23 syll/s, speaking: 4.23 vs. 4.00 syll/s). In addition, the independent variable sex was also found to be significant: on average, men speak 6% faster than women (articulation: 4.79 vs. 4.50 syll/s, speaking: 4.23 vs. 4.01 syll/s). The independent variable age was significant too: younger subjects speak 5% faster than older ones (articulation: 4.78 vs. 4.52 syll/s, speaking: 4.23 vs. 4.01 syll/s). The findings of this study confirm the traditional view that speech rate is determined by extralinguistic variables, but also suggest that there may be intrinsic tempo differences between language varieties.

Force application on teeth and bone structures results in orthodontic and orthopaedic movements. The effect of force application during different time intervals (initial and longitudinal displacements) can be evaluated by describing the displacement vectors or by constructing the centres of rotation of the displacements. The aim of this investigation was to review different experimental studies to compare the position of the centre of rotation (CR) with the displacement vectors of the object (tooth or bone) after force application. The results indicate that the measuring procedure and the use of the CR to describe the displacement are very sensitive: a large discrepancy in the position of the CR does not necessarily lead to a major change in the displacement vector of the object. Displacement vectors seem to be more appropriate in describing both initial and longitudinal tooth or bone displacements.

The purpose of this study was to investigate the initial displacement of the upper dentition and the nasomaxillary complex as a result of different directions of force application, and to determine the initial centres of resistance for both the upper dentition and the nasomaxillary complex. A macerated human skull with a well-aligned upper arch was used as one experimental model and Araldit 208 as a substitute for the periodontal ligament (PDL). Specifically designed 'antenna-headgear' was developed in an attempt to create different points of force application to simulate high-pull and horizontal traction, and orthopaedic force magnitudes of 8 N were applied to the upper dentition and the nasomaxillary complex. Double exposure holography was used to measure the initial displacement. Reproducibility of the technique was tested and found to be reliable. According to the registered fringe patterns, the force application transmitted by the headgear resulted in complex displacement of facial bones. Pure translation of the maxilla and the upper dentition was observed when the force vector passed by in the area of the key-ridge. No obvious difference was found between the centre of resistance of the upper dentition and the nasomaxillary complex. The location of two different centres of resistance could not be confirmed by measuring initial displacements on this macerated human skull.

Removable orthodontic appliances have some limitations compared to fixed appliances. However, a removable appliance can be used during each period of craniofacial growth and dental development. A number of clinical applications for the removable appliance during the mixed and permanent dentition is explained. The use of functional orthopedic appliances and removable retention appliances are also described. It is concluded that the removable appliance can still play a favorable part in the treatment of malocclusions in each developmental stage.

From the rat intestinal microflora we isolated a gram-positive rod, termed HDCA-1, that is a member of a not previously described genomic species and that is able to transform the 3alpha,6beta, 7beta-trihydroxy bile acid beta-muricholic acid into hyodeoxycholic acid (3alpha,6alpha-dihydroxy acid) by dehydroxylation of the 7beta-hydroxy group and epimerization of the 6beta-hydroxy group into a 6alpha-hydroxy group. Other bile acids that were also transformed into hyodeoxycholic acid were hyocholic acid (3alpha, 6alpha,7alpha-trihydroxy acid), alpha-muricholic acid (3alpha,6beta, 7alpha-trihydroxy acid), and omega-muricholic acid (3alpha,6alpha, 7beta-trihydroxy acid). The strain HDCA-1 could not be grown unless a nonconjugated 7-hydroxylated bile acid and an unidentified growth factor produced by a Ruminococcus productus strain that was also isolated from the intestinal microflora were added to the culture medium. Germfree rats selectively associated with the strain HDCA-1 plus a bile acid-deconjugating strain and the growth factor-producing R. productus strain converted beta-muricholic acid almost completely into hyodeoxycholic acid.

We examined the effect of the type of cholic acid conjugation (taurine-conjugated, glycine-conjugated, or unconjugated cholic acid) on cholic acid 7 alpha-dehydroxylation by intestinal flora. Cholic acid 7 alpha-dehydroxylation in fecal cultures, in cultures of a defined limited flora consisting of a mixture of seven bacterial species isolated from the intestinal tract, and in a binary culture of a 7 alpha-dehydroxylating Clostridium species plus a cholic acid-deconjugating Bacteroides species was studied. We found that tauroconjugation of cholic acid significantly (P < 0.05) increased bacterial 7 alpha-dehydroxylation of cholic acid into deoxycholic acid from 34 to 55% in fecal cultures, from 45 to 60% in defined limited fecal cultures, and from 75 to 100% in binary cultures. Equimolar concentrations of free taurine did not stimulate 7 alpha-dehydroxylation in fecal cultures or in the defined limited flora, but free taurine did stimulate 7 alpha-dehydroxylation in the binary culture. In the binary culture of Clostridium species strain 9/1 plus Bacteroides species strain R1, the minimal flora capable of increased 7 alpha-dehydroxylation of taurocholic acid, strain R1 deconjugated taurine and rapidly reduced it to H2S. Bacteroides species strain R1 did not grow unless taurine or another appropriate reducible sulfur source was present. Clostridium species strain 9/1 did not grow or 7 alpha-dehydroxylate unless H2S or another source of reduced sulfur was present. We conclude that the increased 7 alpha-dehydroxylation of tauroconjugated cholic acid depends on the reduction of taurine to H2S, which is a necessary growth factor for the 7 alpha-dehydroxylating bacteria.

The purpose of this study is to evaluate the dental and skeletal effect of the headgear activator according to Van Beek (1981). Special emphasis is put on the changes in vertical position of the incisors after treatment. The material for this study consists of pre- and post-treatment cephalograms of 43 girls and 35 boys with severe Class II malocclusions. Changes due to treatment were compared with two control groups: the series of Riolo et al. (1984), and 50 Austrian children with Class II malocclusions who did not receive treatment during the observation period. The headgear activator was found to be an effective treatment tool in the correction of Class II division 1 malocclusions. The observed skeletal changes were limited to minor growth stimulation of the mandible, while an orthopaedic effect on the maxilla could not be established. The dento-alveolar changes due to headgear activator treatment were most obvious in the upper incisor area resulting in an intrusion and a retroclination of these teeth. Moreover, vertical control of the lower anterior facial height in open bite growth patterns was observed in the sample investigated.

Three anaerobic bacteria, isolated from the ceca of rats and mice, converted, through a concerted mechanism, beta-muricholic acid, the predominant bile acid in germfree rats, into omega-muricholic acid. One isolate was a Eubacterium lentum strain; the second and third isolates were tentatively identified as atypical Fusobacterium sp. strains. The conversion of beta-muricholic acid into omega-muricholic acid proceeded in two steps: E. lentum oxidized the 6 beta-hydroxyl group of beta-muricholic acid to a 6-oxo group, which was reduced by either of the two other species to a 6 alpha-hydroxyl group, yielding omega-muricholic acid. This transformation occurred both in vitro and in gnotobiotic rats. Monoassociation of germfree rats with the E. lentum strain gave rise to an unidentified fecal bile acid, probably a derivative of beta-muricholic acid having a double bond in the side chain.

We isolated 12 strictly anaerobic steroid-3-sulfate-desulfating strains from the intestinal floras of rats and humans. Two strains (S1 and S2) of the same atypical Clostridium species and an atypical Lactobacillus strain (termed R9) were obtained from rats. The human isolates were identified as Eubacterium cylindroides (two strains, H1 and H2), Peptococcus niger (two strains, H4 and H89), and Clostridium clostridiiforme. We also isolated, from different human fecal samples, four strains of phenotypically similar asaccharolytic Bacteroides strains, H6.2a, H6.2b, H65, and H175. Aryl steroid sulfatase activity for estrogen sulfates was present in all isolates. Alkyl steroid sulfatase activity for both 3 alpha- and 3 beta-sulfates was found only in P. niger H4. The same P. niger strain and Clostridium strains S1 and S2 also possessed bile acid sulfatase activity.

This article deals with the possibilities and limitations of autogenous transplantations. In properly selected cases (trauma, missing teeth,...), this procedure might be a valuable alternative treatment. The indications for transplantation, the surgical technique, the recipient site and the choice of the transplant are discussed. The most important parameters which influence the success of a transplantation are: the stage of root formation, the atraumatic removal and insertion of the germ, the final position of the transplant and the post-operative fixation. Clinical examples will illustrate some indications.