Dental and extra-oral clinical features in 41 patients with WNT10A gene mutations: A multicentric genotype-phenotype study.

WNT10A gene encodes a canonical wingless pathway signaling molecule involved in cell fate specification as well as morphogenetic patterning of the developing ectoderm, nervous system, skeleton, and tooth. In patients, WNT10A mutations are responsible for ectodermal-derived pathologies including isolated hypo-oligodontia, tricho-odonto-onycho-dermal dysplasia and Schöpf-Schulz-Passarge syndrome (SSPS). Here we describe the dental, ectodermal, and extra-ectodermal phenotypic features of a cohort of 41 patients from 32 unrelated families. Correlations with WNT10A molecular status (heterozygous carrier, compound heterozygous, homozygous) and patient's phenotypes were performed. Mild to severe oligodontia was observed in all patients bearing biallelic WNT10A mutations. However, patients with compound heterozygous mutations presented no significant difference in phenotypes compared with homozygous individuals. Anomalies in tooth morphology were frequently observed with heterozygous patients displaying hypodontia. No signs of SSPS, especially eyelids cysts, were detected in our cohort. Interestingly, extra-ectodermal signs consisted of skeletal, neurological and vascular anomalies, the latter suggesting a wider phenotypic spectrum associated with WNT10A mutations. Indeed, the Wnt pathway plays a crucial role in skeletal development, lipid metabolism, and neurogenesis, potentially explaining patient's clinical manifestations.

Difficulties experienced by dentists and orthodontists regarding ethical issues when announcing the diagnosis of a rare oral disease: a qualitative study in Marseille, France.

PURPOSE: It is traditionally considered that breaking bad news to patients does not represent a cause for concern for dental professionals. However, there are situations where they will be confronted with this task, as in the case of rare dental diseases. Little information is available regarding the feelings of healthcare professionals on this subject. There are no qualitative studies that explore how a diagnosis of oligodontia is announced to patients by dentists and orthodontists. The aim of our study is to explore the difficulties and ethical issues experienced by dental health professionals when they have to announce a diagnosis of oligodontia to a patient and their family. METHODS: This study relied on a qualitative research method using focus groups of dentists and orthodontists and a thematic analysis procedure. RESULTS: The difficulties experienced could be summarised within five topics: organisational difficulties, difficulties with the management of dental treatment and with the administrative management associated with this anomaly, difficulties with the content of the announcement, and relational difficulties. These could be grouped in two categories: practical difficulties and ethical difficulties. CONCLUSION: This survey allowed us to understand the difficulties encountered by dentists and orthodontists when announcing oligodontia. The participants felt uncomfortable with this task and were under stress. They reported difficulties in delivering the medical information and in adapting to the message. It is essential that dental professionals develop skills in medical communication.

Using e-learning to train dentists in the development of standardised oral health promotion interventions for persons with disability.

BACKGROUND: This study aims to evaluate whether an e-learning curriculum was sufficient to impart the necessary knowledge to dentists to allow them to implement an oral health promotion intervention in an institution for persons with disability. MATERIALS AND METHODS: Participants were asked to complete a 10-module online training course and to implement a standardised intervention in an institution. The outcome measures were as follows: online tracking of progress; multiple choice questionnaires completed at the end of most modules; self-efficacy questionnaire completed before and after online training; completion of training and calibration in the use of a standardised risk assessment form; initiation and full completion of an oral health promotion intervention in an institution; satisfaction of participants with the online training experience; and evaluation of the impact of the intervention by the institution staff. RESULTS: The study sample included 26 dentists. The 10 modules were passed by 24 dentists, and the mean value of the highest overall score recorded in the multiple questionnaires was 88.4% (± 4.0). Twenty participants completed the self-efficacy questionnaire before and after training; the mean values of scores after training were statistically different and higher than those at baseline. Questionnaire regarding satisfaction with the online training experience was completed by 22 participants; all of them stated that they were satisfied with the online training experience. CONCLUSIONS: The results indicate that the online training course helped participants to increase self-efficacy and to provide interventions in institutions. This study could have implications for both undergraduate and postgraduate dental education in France.

Impact of orthognathic surgery on the body posture.

BACKGROUND: Postural control is classically described as being based on the visual, vestibular, and proprioceptive musculo-articular sensory systems. The influence of mandibular proprioception on postural stabilization remains controversial. Most previous studies analyzed how postural stability is influenced by partial changes in mandibular proprioception (dental occlusion and jaw position). RESEARCH QUESTION: In the present experiment, we asked whether drastic mandibular changes, resulting from orthognathic surgery (including dental, joint and muscular efferents), modify postural control. METHODS: The analyzes were performed in 22 patients tested before, and 2.5 months, after orthognathic surgery for treatment of dysmorphic jaws. Experiments were performed under 4 experimental conditions: 2 visual conditions: Eyes Open (EO) and Eyes Closed (EC), and 2 occlusal conditions: Occlusion (OC: mandible positioned by the contact of the teeth), and Rest Position (RP: mandible positioned by the muscles without tooth contact). The analyses focused on head orientation in the frontal plane and on postural stabilization in a static task, consisting of standing upright. RESULTS: The results show that, 2.5 months after orthognathic surgery, head orientation in the frontal plane was improved, since patient's external intercanthal lines became closer to the true horizontal line when they were tested EC and in OC condition. Postural responses, based on the wavelet transformation data, highlight an improvement in maintaining an upright stance for all the tested sensory conditions. However, such improvement was greater in the EC and RP conditions. SIGNIFICANCE: These results show, for the first time, that after drastic mandibular changes, the weight of proprioceptive cues linked to the mandibular system may be so enhanced that it may constitute a new reference frame to orient the head in space, in darkness, and improve static postural stabilization, even in the presence of visual cues.

[Two key describers of the sacro-acetabular relationships: the angles of sacral and acetabular incidence]. / Deux descripteurs clé des relations sacro-cotyloïdiennes : les angles d'incidence sacrée et cotyloïde Mise en évidence par le logiciel De-Visu.

PURPOSE OF THE STUDY: Implantation of total hip arthroplasties raises several important questions concerning the relationship between the orientation of the lumbosacral joint and the acetabular-femoral joint; in other words, between the position of the patients trunk and the orientation of the acetabula. To elucidate better these complex relationships, we conducted a morphometry study on a sample of 51 dry pelves: pelv 26 female and 25 male specimens. MATERIAL AND METHODS: Three-dimensional coordinates of 47 homologous points were recorded for each pelvis. Data were then processed with De-Visu, a graphic visualization software. Seven parameters were compared: sacral slope, sacral incidence, and five parameters quantifying the three-dimensional orientation of the acetabula. RESULTS: The graphic modelization enabled an integral 3-D visualization of each pelvis. The sagittal view enabled simultaneous visualization of the sacrum, the sacroiliac joints, the acetabula, and their alignments, as well as the variability of their spatial relation. The position reference chosen to simulate the upright position aligned the anterior iliac spines and the superior pubic point. This position was found pertinent because the mean value of the sacral slope (41.8) and the sacral incidence (54) were not different from published series. The sacral slope was the most strongly correlated with the acetabular parameters. It exhibited a positive correlation with sagittal acetabular slope (r=0.59) and acetabular inclination (r=0.59). It exhibited a negative correlation with acetabular anteversion (R=0.45). The correlation with the sagittal acetabular slope was very strong for anteversion (r=0.92), and rose with acetabular inclination (r=-0.66). The angle formed by the two acetabular axes was highly variable (37). The correlation between this angle and inclination was very high in males (r=-0.88) and non-significant in females. There was however a very strong correlation with anteversion in females (r=-0.74) which was non-significant in males. This contrasting finding was related to the wide spread of the inclination values in males and anteversion values in females. DISCUSSION: We demonstrated a new sagittal parameter: the acetabular incidence. The summit of this angle is the center of the acetabulum. The sides are the pelvic thickness and the acetabular axes. This parameter was negatively correlated with the sacral incidence. It account simultaneously for the sagittal position of the sacrum in relation to the acetabula and for the degree of acetabular anteversion and inclination. We have demonstrated that the geometric sum of these two angles, sacral incidence and acetabular incidence, is equivalent to the sacro-acetabular angle demonstrated by Lazennec and Saillant. These authors showed that the sacro-acetabular angle is the sum of two positional parameters, the sacral slope and the sagittal acetabular tilt (or slope). The three angles -- sacral incidence, acetabular incidence, sacro-acetabular angle -- are anatomic angles which do not vary with the pelvic position.

[Sleep bruxism in children]. / Le bruxisme du sommeil chez l'enfant.

Bruxism is defined as repetitive activity of the masticatory muscles, characterized by clenching the teeth or teeth grinding and/or by tapping and swaying. This study investigated sleep bruxism. The etiology is multifactorial: mainly central (neuropathic disorder, anxiety) but also genetic and local (posture, mouth breathing). The diagnosis is based primarily on the anamnesis and examination of dental wear and progression over time (photos and dental castings). A diagnostic guide is proposed in this article. Frequently found in children, bruxism is not always considered pathological. The severity criteria relate intensity (number of dental attrition facets) as well as the context found in children: anxiety, ventilation disorders, and fragile dental structures. Management is multidisciplinary and depends on the etiologic diagnosis.

Development of the femoral bicondylar angle in hominid bipedalism.

The bicondylar angle is the angle between the diaphysis of the femur and a line perpendicular to the infracondylar plane. The presence of a femoral bicondylar angle in Australopithecus afarensis indicates that these 3.5-million-year-old hominids were bipedal. Many studies have linked the formation of the femoral bicondylar angle with bipedality, but the mechanism for the formation of the angle is poorly understood. Mechanical factors, such as stresses and strains, influence the growth process. In particular, previous studies have demonstrated that hydrostatic compressive stress inhibits growth and ossification, and octahedral shear stress promotes growth and ossification. In this study we implemented these mechanobiological principles in a three-dimensional finite-element model of the distal femur. We applied loading conditions to the model to simulate loading during the single-leg stance phase of bipedal gait. The stresses in the physis of the distal femur that result from bipedal loading conditions promote growth and ossification more on the medial side than on the lateral side of the femur, forming the bicondylar angle. This model explains the presence of the bicondylar angle in hominid bipedalism and also the ontogenetic development of the bicondylar angle in growing children. The mechanobiological relationship between endochondral ossification and mechanical loading provides valuable insight into bone development and morphology.

Low energy Helium-Neon laser in the prevention of oral mucositis in patients undergoing bone marrow transplant: results of a double blind randomized trial.

PURPOSE: To evaluate the efficiency of Helium-Neon (He-Ne) laser in the prevention of oral mucositis induced by high dose chemoradiotherapy before autologous bone marrow transplantation (BMT). METHODS AND MATERIALS: Between 1993 and 1995, 30 consecutive patients receiving an autologous peripheral stem-cell or bone marrow transplant (BMT) after high dose chemoradiotherapy were randomized to possibly receive prophylactic laser to the oral mucosa after giving informed consent. Chemotherapy consisted of cyclophosphamide, 60 mg/kg intravenously (I.V.) on day (d)-5 and d-4 in 27 cases, or melphalan 140 mg/kg I.V. on d-4 in three cases. Total body irradiation (TBI) consisted of 12 Gy midplane dose in six fractions (4 Gy/day for three days). He-Ne laser (632.8 nm wavelength, power 60 mW) applications were performed daily from d-5 to d-1 on five anatomic sites of the oral mucosa. Oral examination was performed daily from d0 to d + 20. Mucositis was scored according to an oral exam guide with a 16 item scale of which four were assessed by the patients themselves. Mean daily self assessment scores for oral pain, ability to swallow and oral dryness were measured. A daily mucositis index (DMI) and a cumulative oral mucositis score (COMS) were established. Requirement for narcotics and parenteral nutrition was recorded. RESULTS: The COMS was significantly reduced among laser treated (L+) patients (p = 0.04). The improvement of DMI in L+ patients was also statistically significant (p < 0.05) from d + 2 to d + 7. Occurrence and duration of grade III oral mucositis were reduced in L+ patients (p = 0.01). Laser applications reduced oral pain as assessed by patients (p = 0.05) and L+ patients required less morphine (p = 0.05). Xerostomia and ability to swallow were improved among the L+ patients (p = 0.005 and p = 0.01, respectively). Requirement for parenteral nutrition was not reduced (p = NS). CONCLUSION: Helium-Neon laser treatment was well tolerated, feasible in all cases, and reduced high dose chemoradiotherapy-induced oral mucositis. Optimal laser treatment schedules still needs to be defined.

Trophic muscle regulation in children with congenital cerebral lesions.

A decrease in sarcomere number and hypoextensibility of ankle extensors was observed in certain children with congenital cerebral lesions. This phenomenon was reproducible and reversible in normal animals, i.e. trophic regulation adapted the muscle to the imposed length. The form of the torque-ankle angle curve was studied in 30 children. Its modification after treatment was considered as a sign of muscle adaptation. This adaptation was present in one group of 14 children. The steepness of the curve increased or diminished depending on the initial disorder and the treatment administered. In another group, treatment failed to modify the shape of the curve. In certain cases trophic regulation of the muscle appeared to be absent.

Decrease of muscle extensibility and reduction of sarcomere number in soleus muscle following a local injection of tetanus toxin.

Slow soleus muscle in guinea pig developed within 4--6 days after local injection of a sublethal dose of tetanus toxin and 2--4 days after the first signs of local tetanus, a myostatic contracture characterized by a change in the passive tension--lengthening curve associated with a considerable decrease of the sarcomere number. It was demonstrated by clinical and EMG investigations that the soleus did have a tetanic spasm at least within the 2--4 day period of observation. When local tetanus was confined to slow soleus by functional suppression of rapid gastrocnemius and ankle flexor muscles, the decrease of the sarcomere number still persisted. This decrease failed to occur after section of the nerve supplying the soleus when associated with an injection of the tetanus toxin, and was much greater than when the soleus was passively shortened for the same period of time by plaster cast.

Comparison of the intraosseous biocompatibility of Dyract and Super EBA.

The purpose of this study was to compare the intraosseous biocompatibility of Dyract, a new hydrophilic glass-ionomer cement, to that of Super EBA. Twenty-four New Zealand rabbits were anesthetized, one leg was shaved, the femur exposed, and two holes were drilled through the cortical plate. The materials were loaded into silicone carriers and inserted into the femur. Half of the rabbits were killed 4 weeks after implantation and the other half at 12 weeks and the femurs were prepared using standard histological procedures. The tissue reactions were graded from none to severe. At 4 weeks both materials showed slight to moderate reactions, characterized by the presence of fibrous tissue interposition and inflammatory cells. At 12 weeks, bone healing had occurred, despite the persistence of some fibrous tissue interposition, and the reactions were classified as slight. At both observation periods, statistical analysis failed to show any difference between the two materials indicating that Dyract and Super EBA had similar intraosseous biocompatibility.

Toe-walking in children with cerebral palsy: contributions of contracture and excessive contraction of triceps surae muscle.

The study was designed to provide a quantitative analysis of toe-walking in children with cerebral palsy (CP). The total internal moment developed about the ankle joint during locomotion and the passive component of this internal moment were measured. The contributions of the active and passive components were expressed as the ratio (R) between the passive moment and the total internal moment. Measurements were compared for 13 children with CP and 5 healthy children. For the data analysis, the children with CP, exhibiting apparently similar toe-walking, were divided into two groups: 1) Group CPI and 2) Group CPII. Group CPI was characterized by a small ratio R value, which indicated the presence of excessive contractions of the triceps surae muscle during locomotion. In Group CPII, the ratio R value was abnormally high, which indicated that a contracture (ie, structural change of the muscle or the tendon) was entirely or at least partly responsible for toe-walking. Each group requires a different therapeutic strategy.

In vitro cytotoxicity of dental adhesive systems under simulated pulpal pressure.

OBJECTIVES: Most of the devices used to evaluate the cytotoxicity of resin-based composites in vitro use a dentin barrier test. However, it is difficult to obtain the number of freshly extracted teeth, all on the same day, that is necessary for powerful statistical analysis. Tooth cryopreservation provides a way to build up a supply of teeth. This in vitro study compared cryopreserved teeth and freshly extracted teeth in an evaluation of the cytotoxicity of resin-based composites. In addition, this study also evaluated the effects of pulsatile pressure and the importance of dentin permeability on the cytotoxic response to bonding resins. METHODS: Forty freshly extracted and forty cryopreserved third molars were used. A standardized Class I cavity was prepared within the dentin. The hydraulic conductance of each tooth was recorded. The cavities were filled either with Scotchbond Multi-Purpose Plus and Z 100 (3M Dental Products) or with Optibond and Herculite (Kerr). A plexiglas device was designed to permit 24 h long contact between culture medium and the roof of the pulp chamber while a pulsatile pulpal pressure was simulated. The viability of L 929 cells cultured with a control medium and evaluated by an MTT assay was compared to that of L 929 cells cultured with medium which remained for 24 h in contact with the pulp chamber of restored teeth. A three-way ANOVA was used to compare the cytotoxicity among the different groups. A simple least-squares linear regression was used to seek a relationship between the hydraulic conductance of dentin and the cytotoxicity of composite restorative materials. RESULTS: No significant differences in cytotoxicity were found between the freshly extracted teeth and the cryopreserved teeth (p = 0.53). The cytotoxicity of the resin adhesives was statistically higher when a pulsatile pulpal pressure was simulated (p = 0.04). A significant relationship was found between the hydraulic conductance of dentin and the cytotoxicity of resin-based composites (p = 0.02). SIGNIFICANCE: Cryopreserved teeth can be used for in vitro evaluation of the cytotoxicity of resin adhesives. Pulsatile pulpal pressure simulations increased the in vitro cytotoxicity of the tested materials.

[The origin of femoral trochlear dysplasia: comparative anatomy, evolution, and growth of the patellofemoral joint]. / Origine des dysplasies de la trochlée fémorale: anatomie comparée, évolution et croissance de l'articulation fémoro-patellaire.

We performed a comparative analysis of the femoropatellar morphology examining the evolutionary aspects to search for the origin of trochelar dysplasia. Trochlear dysplasia is frequent in the human population and, when associated with morphological and positional abnormalities of the patella, can lead to patellar pain syndrome in minor cases or patellar dislocation in severe cases. There is no strict relationship between the observed anomalies and clinical expression. The shape of the articular surfaces is variable in mammals depending on their type of locomotion: unguligrade, digitigrade, plantigrade. In greater apes, the femoral diaphysis is straight and the trochlea is flat and symmetrical. The patella does not tend to dislocate laterally since the knee under load is always flexed. In human adults, the femoral diaphysis has a valgus obliquity angle of 8 degrees to 10 degrees. Consequently, the trochlea has a deepened sulcus and an elevated lateral lip, avoiding lateral patellar dislocation, especially during initial knee flexion. In the human newborn, the femoral diaphysis is vertical. As the child starts walking, the femoral obliquity angle develops between 1 and 7 years of age, inducing a secondary valgus of the extensor apparatus. This obliquity does not develop in non-walking children. Fossil femurs of australopithecus demonstrate that a high obliquity angle had appeared more than 3 million years ago, but also exhibit a poorly deepened trochlea and a slight elevation of the lateral facet. At 1.8 million years, the fossils have the oblique diaphysis, the strongly deepened sulcus and the strongly elevated lateral facet. The obliquity angle of the femoral diaphysis is the leading feature which initiated the later modifications of the patellofemoral joint that over 3 million years were never inscribed in the human genoma. Lateral trochleal lip and deep sulcus are features that were first acquired, then once selected, genetically assimilated, and now appear on the fetal cartilaginous epiphysis.

[Is surgery of the tendons of the knee flexor muscles justified in cerebral palsy?]. / La chirurgie tendineuse des fléchisseurs du genou est-elle justifiée chez l'infirme moteur cérébral?

The lengths of the tendons and muscle belly connective tissue envelopes of the knee flexor muscles of 6 healthy and 11 children with cerebral palsy were measured. The restricted passive knee extension was found to be associated with abnormally short tendons in all cases of contracture. This correlation provided an experimental support for the surgical lengthening of the tendon.

[Anatomic study of the anterior patellar groove in the fetal period]. / Etude anatomique du creusement de la trochlée fémorale chez le foetus.

PURPOSE OF THE STUDY: We performed a biometric analysis of the femoral trochlea in the fetus and compared our findings with those observed in adults in order to search for correlations with other biometric parameters of the femur. MATERIAL AND METHOD: Twenty-two fetuses (44 knees) conserved in formol and free of known orthopedic disease were studied. Fetal age ranged from 26 to 40 weeks. After anatomic dissection, digitalized images were used to obtain angle measurements with a dedicated software. Measurements made on the distal epiphyseal view were: anteroposterior dimension of the condyles, medial and lateral protrusion of the trochlear borders, difference in condyle height, length of the trochleal borders, alpha angle of the trochlear groove, trochlear slope. Measurements made on the AP femoral view were: femoral anteversion, length of the femoral neck, neck-shaft angle. Spearman's test was used to search for correlations. Results were compared with measurements obtained under the same conditions in a series of 32 adult knees published by Wanner. RESULTS: The trochlear alpha angle was 148 degrees (coefficient of variation 4%). The angle was greater than 150 degrees for 18 trochleae. The lateral border of the trochela was higher than the medial border in 37 of the 44 knees. There was no correlation with age and gender. Femoral anteversion was 27.01 degrees, with a high coefficient of variation (46%), and no correlation with the trochlear alpha angle. Comparison with measurements made on the adult knees revealed no significant difference. DISCUSSION: This is the first report of statistically significant biometric data of the fetal trochlea. The morphology of the lower femur observed during the third trimester of fetal live is the same as observed in adults. Morphological changes in the proximal femur occurring during growth do not appear to modify the morphology of the distal femur. The asymmetrical ingression of the patella into the trochlea, characteristic of modern man, is considered to result from bipedalism. Our study would suggest that the anatomic characteristics of the trochlea could have been integrated into the genoma during the course of evolution. This would be in favor of a genetic origin of trochlear dysplasia.