Maternal factors in the origin of cleft lip/cleft palate: A population-based case-control study

OBJECTIVES

Orofacial clefts are among the most common birth defects, with an estimated worldwide incidence of around 1.5-1.7 per 1000 live-born babies. The most frequent form of orofacial clefts is cleft lip with or without cleft palate (CL ± CP). The role of environmental factors in the development of clefts is unclear in most patients, thus the aim of this study was to estimate possible maternal risk factors in the origin of CL ± CP.

MATERIALS AND METHODS

1648 CL ± CP cases, 2654 matched controls and 57 231 population controls were evaluated from The Hungarian Case-Control Surveillance of Congenital Abnormalities. Maternal factors during the critical period in cases and controls were compared. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated in a multivariable conditional logistic regression model.

RESULTS

Among socio-demographic data, we have found significant differences between maternal employment. The proportion of unskilled mothers (6.5%) were higher in the CL ± CP group than in controls (3.5%). Medically recorded maternal anaemia, excessive vomiting and threatened abortion were associated with a higher risk of CL ± CP. An elevated risk was also found in various acute illnesses such as influenza (OR: 2.4, 95% CI: 3.0-5.8), acute bronchitis (OR: 4.5, 95% CI: 1.6-12.6) and urinary tract infections (OR: 3.5, 95% CI: 2.0-6.0). Maternal migraine and essential hypertension occurred more frequently in the mothers of cases than in controls.

CONCLUSION

The findings of this study suggest that maternal diseases and lifestyle factors during the first trimester play a significant role in the development of CL ± CP.

A novel image processing procedure for the quantitative evaluation of dental enamel prism arrangement

Enamel prism is the main microstructural unit of mammalian enamel which composed of hundreds of bioapatite nanocrystals. Prism structure plays a key role in the excellent mechanical performance of dental enamel during millions of chewing cycles without significant remodeling. Thus, quantitative understanding of prism architecture is of utmost importance for biomechanical materials design. To characterize enamel prism orientation quantitatively, a novel image processing method has been developed. Our method is based on scanning electron microscopy images of etched enamel surface and consists of an ellipse fitting procedure, which provides a numerical approximation of prism shape and orientation in the studied cross section. The obtained analytical data allow to construct color coded orientation maps, which provide quick and useful insight into the microstructure of enamel. Besides striking visualization, orientation maps allow to extract and plot the rich information on the azimuthal and inclination angles of the prisms as function of location. Numerical data on prism arrangement can be analyzed using statistical tools over large areas, which paves the way towards quantifying comparative investigation of prism arrangement either in dentistry research or evolution biology. The application of the method is demonstrated for a distal-mesial cross-section of sound human tooth enamel. HIGHLIGHTS: Scanning electron microscopy images of etched enamel surface are analyzed using ellipse fitting. Geometrical parameters of the fitted ellipses provide numerical data of thousands of prisms. Prism arrangement is visualized on color coded orientation maps and analyzed using statistical tools.

Prosthetic rehabilitation of a patient with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome through a hybrid workflow: A case report with 2-year follow-up

AIM

Ectrodactyly-ectodermal dysplasia-cleft lip/palate (EEC) syndrome is a rare genetic disorder that affects ectodermal derived structures, including teeth, nails, hair, and sweat glands. Prosthetic rehabilitation of patients with EEC syndrome is essential towards improving their overall quality of life.

METHODS AND RESULTS

In the case shown, a telescopic retained overdenture was made on the lower jaw based on digital impression of a patient with EEC syndrome associated with cleft lip and cleft palate. Due to the congenital anomalies and limited mouth opening, the impression was taken with intraoral scanner, and after designing the telescopes on the digital model, the primary and secondary telescopes were confectioned by selective laser sintering.

CONCLUSION

Combining digital dental technology and conventional clinical prosthetic treatment methods, results in a well-functioning overdenture even in such complicated situations. The prosthodontic rehabilitation of patients with ECC helps to restore the masticatory and phonetic functions, increases the patient's self-esteem, and prevents further psychological trauma caused by hypodontia.

[The role of probiotics in oral health.]

INTRODUCTION

The World Health Organization defines probiotics as: "Live microorganisms which when administered in adequate amounts confer a health benefit on the host." Probiotics maintain the balance of the normal intestinal flora and prevent the proliferation of pathogenic bacteria. Its therapeutic use in oral health is increasing. The literature reports successful results considering the treatment of caries and periodontal disease with probiotics. In these cases, probiotics effect the oral flora causing the disease. Our research investigates how caries and type I diabetes effect the normal oral flora.

OBJECTIVE

To summarize the literature on this topic and to present our research, which compares the oral microflora of children with or without caries and of healthy children with those having type 1 diabetes. Our research also determines the total oral bacterial and Lactobacillus count, and its species composition.

METHOD

A 0.5 ml saliva sample is collected from the participants (20 participants/group). The total bacteria count is determined on blood agar, the Lactobacillus is cultured on Rogosa agar. A MALDI-TOF (matrix-assisted laser desorption/ionization-time-of-flight) device is used to identify the different Lactobacillus species.

RESULTS

The total bacterial count of the two test groups did not show a significant difference compared to the control groups (109 vs. 108 CFU/mL). In the groups of children with caries and with diabetes, there was a significant difference in the Lactobacillus count compared to the control groups (102 vs. 103 CFU/mL). The species composition of the Lactobacillus differed in each group.

DISCUSSION

Cariogenic oral flora can displace the probiotic strains in the oral cavity. Diabetes in childhood can affect the composition of the oral flora.

CONCLUSION

Restoring the normal oral flora of the oral cavity with probiotics is a possible way of preventing the development of oral diseases. Further research is needed examining the function of individual probiotic strains. Orv Hetil. 2023; 164(24): 942-947.

Preoperative HbA1c and Blood Glucose Measurements in Diabetes Mellitus before Oral Surgery and Implantology Treatments

Diabetes mellitus has become a worldwide epidemic and is frequently accompanied by a number of complications proportional to the duration of hyperglycemia. The aim of this narrative review is to assess the most up-to-date guidelines on DM provided by both diabetes and dental associations. Furthermore, to gather evidence on the uni/bidirectional relationships of elevated HbA1c levels on dental surgery, implantology, bone augmentation, and periodontology and to demonstrate the importance of measuring HbA1c levels before invasive dental treatments. HbA1c and blood glucose measurements are a minimally invasive method for preventing complications in diabetes mellitus. The authors conducted a literature review to determine which oral conditions are affected by diabetes mellitus. MEDLINE served as a source with the use of a specific search key. Regarding oral complications of diabetes, prevention is the most vital factor. With this publication, we hope to assist physicians and dentists to make prompt diagnoses and to help in recognizing various oral manifestations of diabetes and follow the existing guidelines.

Patterns of Facial Profile Preference in a Large Sample of Dental Students: A Cross-Sectional Study

The objective of this study was to explore dental students’ facial profile preferences in a large sample of students. Nine hundred and nineteen dental students of four dental schools were involved. As part of a larger study on dentofacial esthetics, six photo series consisting of one unaltered and four altered variants of the same female profile were distributed among the students. The altered features were ones that are esthetically significant according to the literature. The students had to indicate the photo in each series that they preferred. The data were analyzed in a regression model in which preference in the given photo series was the dependent variable and gender, grade of studies, and dental school were the factors. Eight hundred and sixty-one students (93.7%) responded. Gender and dental school were not associated with the observed preferences, but the grade of studies was associated for three of the modified parameters: chin prominence, the sagittal position of the maxillary dental arch, and the simultaneous modification of the prominence of the chin and the nose. This study has confirmed several earlier observations, and new observations have also been made. We have demonstrated that the anteroposterior position of the maxillary incisors may be an important determinant of profile esthetics, even if this position does not influence the situation of the soft tissues and if the forehead cannot be used as a reference. We have also shown that the harmony between the nose and the chin overrides the importance of their individual dimensions.

Magnesium incorporation into primary dental enamel and its effect on mechanical properties

Cross-sectional study of sound primary dental enamel revealed hardness zonation and, in parallel, significant change in the Mg content below the prismless layer. Mg content is known to play an important role in enamel apatite biomineralization, therefore, Mg ion exchange experiments were carried out on the outer surface of sound primary molars and on reference abiogenic Ca-phosphates using MgCl₂ solution. Effects of Mg incorporation on crystal/particle size, ionic ratio and morphology were compared and the observed changes were explained by parallel diffusion and dissolution/reprecipitation processes. Based on depth profile analysis and high resolution electron microscopy of the Mg-exchanged dental enamel, a poorly ordered surface layer of approximately 10-15 nanometer thickness was identified. This thin layer is strongly enriched in Mg and has non-apatitic structure. Below the surface layer, the Mg content increased only moderately (up to ~3 at%) and the apatite crystal structure of enamel was preserved. As a common effect of the Mg exchanged volume, primary dental enamel exhibited about 20% increase of nanohardness, which is intrepreted by strengthening of both the thin surface layer and the region below due to the decreased crystallite size and the effect of incorporated Mg, respectively. STATEMENT OF SIGNIFICANCE: Dental enamel is the most durable mineralized tissue in the human body, which, in spite to be exposed to extreme conditions like mastication and acidic dissolution, is able to fulfill its biological function during lifetime. In this study we show that minor component magnesium can affect hardness properties of human primary dental enamel. Then, through Mg incorporation experiments we provide an additional proof for the poorly ordered Mg-containing intergranular phase which has been recently observed. Also, we report that the hardness of dental enamel can be increased by ca. 20% by Mg incorporation. These results contribute to a deeper understanding of sound primary dental enamel structure and may inspire new pathways for assisted remineralization of enamel and regenerative dentistry.

Dentofacial mini- and microesthetics as perceived by dental students: A cross-sectional multi-site study

Background

How dental education influences students’ dental and dentofacial esthetic perception has been studied for some time, given the importance of esthetics in dentistry. However, no study before has studied this question in a large sample of students from all grades of dental school. This study sought to fill that gap. The aim was to assess if students’ dentofacial esthetic autoperception and heteroperception are associated with their actual stage of studies (grade) and if autoperception has any effect on heteroperception.

Methods

Between October 2018 and August 2019, a questionnaire was distributed to 919 dental students of all 5 grades of dental school at all four dental schools in Hungary. The questionnaire consisted of the following parts (see also the supplementary material): 1. Demographic data (3 items), Self-Esthetics I (11 multiple- choice items regarding the respondents’ perception of their own dentofacial esthetics), Self-Esthetics II (6 Likert-type items regarding the respondents’ perception of their own dentofacial esthetics), and Image rating (10 items, 5 images each, of which the respondents have to choose the one they find the most attractive). Both the self-esthetics and the photo rating items were aimed at the assessment of mini- and microesthetic features.

Results

The response rate was 93.7% (861 students). The self-perception of the respondents was highly favorable, regardless of grade or gender. Grade and heteroperception were significantly associated regarding maxillary midline shift (p < 0.01) and the relative visibility of the arches behind the lips (p < 0.01). Detailed analysis showed a characteristic pattern of preference changes across grades for both esthetic aspects. The third year of studies appeared to be a dividing line in both cases, after which a real preference order was established. Association between autoperception and heteroperception could not be verified for statistical reasons.

Conclusion

Our findings corroborate the results of most previous studies regarding the effect of dental education on the dentofacial esthetic perception of students. We have shown that the effect can be demonstrated on the grade level, which we attribute to the specific curricular contents. We found no gender effect, which, in the light of the literature, suggests that the gender effect in dentofacial esthetic perception is highly culture dependent. The results allow no conclusion regarding the relation between autoperception and heteroperception.

[Incidence of type 2 diabetes among oral cancer patients in Hungary]

INTRODUCTION

Data proves that Hungary has a leading role in the statistics of oral cancer and patients living with type 2 diabetes.

AIM

Our aim was to understand the statistical correlation between oral cancer and metabolic disorder (diabetes mellitus and impaired fasting glucose) due to the valuable data from the Semmelweis University.

METHOD

We analyzed the data of 835 patients diagnosed with malignant oral cancer and 587 tumor-free control patients. We investigated the incidence and location of oral cancer among patients living with diabetes, and compared these datasets with our previous data from 14 years earlier.

RESULTS

We found that in oral cancer patients, 26.1% had diabetes and 20.8% had impaired fasting glucose; in the control group these ratios were 10.8% and 11.1%. This difference is significant (p<0.05). 14 years ago in the tumor group 14.6%, in the control group 5.6% had diabetes, while 9.7% and 5.5% had impaired fasting glucose. Lip cancer had the biggest incidence.

CONCLUSIONS

The rise of type 2 diabetes in the tumor group was significant. This could be a burden for the health care system. We want to highlight the importance of interdisciplinary cooperation between health care professionals. Orv Hetil. 2018; 159(20): 803-807.

Effects of variable attachment shapes and aligner material on aligner retention

OBJECTIVE

To evaluate the retention of four types of aligners on a dental arch with various attachments.

MATERIALS AND METHODS

For this study, three casts were manufactured, two of which contained attachments (ellipsoid and beveled), and one without any attachments to serve as a control. Four types of aligners were thermoformed: Clear-Aligner (CA)-soft, CA-medium, and CA-hard, with various thicknesses, and Essix ACE. Measurements of vertical displacement force during aligner removal were performed with the Gabo Qualimeter Eplexor. Means and standard deviations were next compared between different aligner thicknesses and attachment shapes.

RESULTS

CA-soft, CA-medium, and CA-hard did not present a significant increase in retention, except when used in the presence of attachments. Additionally, CA-medium and CA-hard required significantly more force for removal. Essix ACE demonstrated a significant decrease in retention when used with ellipsoid attachments. The force value for Essix ACE removal from the cast with beveled attachments was comparable to that of CA-medium. Forces for aligner removal from the model without attachments showed a linear trend. Essix ACE did not show a continuous increase in retention for each model. Overall, ellipsoid attachments did not present a significant change in retention. In contrast, beveled attachments improved retention.

CONCLUSIONS

Ellipsoid attachments had no significant influence on the force required for aligner removal and hence on aligner retention. Essix ACE showed significantly less retention than CA-hard on the models with attachments. Furthermore, beveled attachments were observed to increase retention significantly, compared with ellipsoid attachments and when using no attachments.

Prevalence and distribution of permanent canine agenesis in dental paediatric and orthodontic patients in Hungary

Non-syndromic permanent canine agenesis, or combined with agenesis, or developmental absence of other tooth types, has occasionally been described in the literature, but isolated forms are rarely observed. The purpose of the present retrospective radiographic study was to provide data on the prevalence and distribution of permanent canine agenesis in the Hungarian population. Dental panoramic tomograms and the medical history data of 4417, 6- to 18-year-old children (average age 12 years, male-to-female ratio 1:1), who presented for treatment at the Department of Paediatric Dentistry and Orthodontics of the Semmelweis University Budapest, Hungary, were examined. Patients with systemic diseases were excluded. Chi-square and Fisher's tests were performed to determine statistical significance at a level of P < 0.05. Thirteen subjects had permanent canine agenesis. The overall prevalence was 0.29 per cent. The prevalence of permanent canine agenesis was 0.27 per cent in the maxilla and 0.09 per cent in the mandible (P < 0.01). The male-to-female ratio was 1:2.2. Dental anomalies associated with permanent canine agenesis were found: 11 patients had retention of the primary canines, 10 other types of agenesis of the permanent teeth, one a primary supernumerary tooth, one a supernumerary cusp, and nine occlusal disturbances.

Prevalence of accessory tooth cusps in a contemporary and ancestral Hungarian population

Dental morphological characteristics are useful for providing information for phylogenic and genetic studies and understanding variations within and among species. Carabelli and talon cusps are expressed in several degrees and different frequencies between humans, thus being useful in comparing and characterizing populations. The purpose of this study was to examine the incidence and degree of expression of a Carabelli tubercle and talon cusps in a contemporary Hungarian population compared with similar findings in the dentition of skulls dating from the 11th century, the so-called Arpád-era. The data were collected by examination of dental plaster casts of 600 children aged 7-18 years (304 males, 296 females) undergoing orthodontic treatment. The dentitions of 147 skulls, dating from the 11th century, from the ancient Halimba-Cseres cemetery stored at the Hungarian Natural History Museum were also examined. The incidence and degree of expression of a Carabelli cusp was investigated for the upper first permanent molars and scored according to an eight-grade classification system. The talon cusps on the upper permanent lateral incisors were also examined. A chi-square test was used for statistical analysis. The prevalence of Carabelli cusps was 65.34 per cent in the contemporary and 34 per cent in the 11th century population (P < 0.01). The contemporary group showed a prevalence of talon cusps of 2.5 per cent compared with 40.8 per cent for the skills from the Arpád-era, which was significant (P < 0.001). These findings demonstrate that the contemporary Hungarian population is a mixture of European and Mongoloid races. The data are in agreement with linguistic evidence that shows that distant Hungarian ancestors belonged to the Finno-Ugrian family of people, whose habitats extended from the Baltic to the middle Urals.

Prevalence of hypodontia and hyperdontia in paedodontic and orthodontic patients in Budapest

Various publications have reported the prevalence of accessory teeth to be between 1 and 3%. In contrast, hypodontia has a much higher prevalence. In the current work, the authors studied OP radiographs on 2,219 patients aged 6 to 18 years who presented at the Department of Paedodontics and Orthodontics at Semmelweis University in Budapest (patients with systemic disease were excluded). The examined radiographs revealed a prevalence of accessory teeth of 1.53%. The sequence of prevalence was as follows: mesiodens > second incisor > first incisor. 77.5% of the accessory teeth were located in the upper jaw, with 97.5% of those being present in the incisor region. Hypodontia was detected in 326 patients (14.69%); missing wisdom germs were not considered. The sequence of prevalence of missing germ was as follows: upper second incisor > lower second premolar > upper second premolar > lower first incisor. Hypodontia in the molar region was observed in 15 cases (0.68%). The prevalence of oligodontia was 1.04%.

Tuberculate and Odontoma Type Supernumerary Teeth

An 8-and-a-half-year-old girl with supernumerary teeth of tuberculate and odontoma type is described. Treatment of the patient is carried out on conventional lines with a combination of surgical and orthodontic methods. The upper tuberculate type supernumerary teeth were extracted and, after surgical exposure, the upper permanent first incisors were aligned with removable appliances. After secondary dentition was completed, the lower odontoma type supernumerary tooth was removed surgically, and also the maxillary and mandibular first premolars were extracted because of severe crowding, and fixed orthodontic appliances were used to align the permanent dentition. Early diagnosis and treatment of this anomaly is necessary to avoid more serious consequences and to prevent severe orthodontic disturbances.

[Retention of Ultra Seal XT third generation fissure sealant in systematic pedodontic care]

The aim of the present study was to clinically evaluate Ultra Seal XT third generation light cured fissure sealant on the occlusal pits and fissures of permanent first and second molars for a period of two years. The examined population consisted of 112 Hungarian school-children, aged 8 to 14 years who presented for treatment at the Department of Dentistry for Children and Orthodontics in Budapest. The 1120 participants had a total of 247 permanent molars sealed. All teeth were monitorized and controlled after 6 months, 1 year and 2 years. Retentivity of fissure sealants were after 6 months 92.7%, one year 87.8%, two years 79.9%. These results are in accordance with data of literature. This longitudinal study showed that modern pit and fissure sealants can be applied during childhood in systematic pedodontic care. It has high retentivity and a directly proportional optimal caries-preventive effect.

[Prevalence of impacted permanent upper canine and its treatment in 11-18-year-old orthodontic patients]

Data of literature show very high prevalence of impacted upper permanent canine. The aim of the present study was to evaluate prevalence of retentioned or impacted upper permanent canines and to present their therapy. Data on 11-18-year-old children presented for treatment at the Department of Dentistry for Children and Orthodontics in Budapest over a period of 10 years (between 1990 and 2000) were analysed. OP X-ray films of 1858 children and adolescents--1102 female and 756 male--were examined and the data of anamnesis and the administered therapy were considered. Results revealed 101 cases of impacted cuspids, the male:female ratio was 46:55. Considering the totality of administered treatment methods, both surgical exposure and orthodontic treatment of the affected canines were needed in a high rate, i.e. 96.92% of the analysed cases. In 40.91% of the cases extraction of the correspondent upper first premolar was needed. Following the premolar extraction spontaneous occlusions of the impacted canine was established in 3.03%. Authors present the complex therapy of one case of palatally impacted upper permanent canine.

The influx of serum albumin to enamel matrix in rat incisors after trauma

The most frequent results of trauma to tooth germs are enamel hypoplasia and enamel hypocalcification. These differing results may be due to the stage of amelogenesis at which trauma occurs. The cellular and biomolecullar events involved in the genesis of these defects are poorly understood. We hypothesized that one factor involved is the possibility that relatively high levels of serum albumin enter the enamel matrix through the damaged enamel organ, and impair mineralization of the matrix. The present study was undertaken to immunohistochemically and autoradiographically localize serum albumin in the enamel organs of rat incisors after trauma was inflicted to the mandibular incisor region of 4-day-old rats. Hemorrhage was seen surrounding the enamel organ and between the detached secretory-stage ameloblasts. One day after trauma, the most intense immunohistochemical (IHC) staining for albumin was localized in the outer layer of the enamel matrix adjacent to the detached secretory-stage ameloblasts. Albumin was also detected autoradiographically in the secretory-stage ameloblasts layer and enamel matrix. These findings indicate that serum albumin can leak between the detached ameloblasts and penetrate the enamel matrix after trauma. Leaked albumin was still present in the matrix during the maturation stage. Leaked albumin in the developing enamel could inhibit crystal growth and result in hypocalcification.

[Prevalence of congenital hypodontia in the permanent dentition and its treatment]

Congenital aplasia (agenesis) is an important development dental anomaly. There is a big discrepancy between the data on the prevalence of aplasia in dental literature. The authors analyzed orthopantomograms of 1875 children and adolescents at the Department of Dentistry for Children and Orthodontics of Semmelweis University. The prevalence of congenital aplasia was found 15.68% (294 subjects). There was no difference between the sexes. The most frequently missing teeth were the upper lateral incisors, the lower second premolars, the upper second premolars and the lower central incisors. The highest number of aplasia was detected in the second premolars (330 teeth). The frequency of aplasia of the molars was 0.74%. Oligodontia was found in 1.12%. The authors present two patients with aplasia and the successful treatment of the cases.

[Effect of experimentally induced trauma to the incisors in rats]

The purpose of this study was to produce developmental lesions of enamel in rats by a quick and simple method and to examine the enamel hypoplasia caused by trauma. 4-day-old and 3-week-old Wistar rats were used. Trauma was produced by needle pricking and hitting on the mandibula. After one week incisors were removed together with jaws and prepared for microradiography, X-ray diffraction, light microscope and transmission electron microscope examination. Microradiographic findings in the needle pricking group revealed hypocalcified and hypoplastic enamel. The incidence was 73.7%. In the hitting group of 4-day-old rats the incidence was lower, 70.0%. Microradiographic findings in this group were diffuse hypoplasia in the surface enamel. Hitting of 3-week-old rats produced no enamel hypoplasia. Crystallinity of hypoplastic enamel was reduced in both a-axis and c-axis direction. Histological findings in 4-day-old rats revealed disarranged and detached ameloblasts at location trauma. These results indicate that a needle pricking method involving secretory stage ameloblasts of 4-day-old rat incisors can induce a considerable amount of enamel hypoplasia.

Dental trauma in children presenting for treatment at the Department of Dentistry for Children and Orthodontics, Budapest, 1985-1999

Data on children with dental trauma who presented for treatment at the Department of Dentistry for Children and Orthodontics in Budapest over a period of 15 years were analysed. The WHO guidelines were used to classify the traumatic injuries. A total of 590 children were involved, 810 teeth being affected. Children aged 7-14 years made up 88% of the cohort. The male:female ratio was 58:42. The permanent:primary ratio for the affected teeth was 90:10. The teeth most commonly affected were the maxillary central incisors. In 70% of the cases, only one tooth was traumatised. The incidence of dental trauma peaked at 10 years of age. The most common injury type observed was enamel-dentin crown fracture. The decreasing sequence of frequency of etiological factors was playing, sports, falls, cycling, road accidents and fighting. Of the accidents, 65% occurred at school or at home. Seventy seven per cent of the patients presented for medical care in the first 3 days after the accident.

Endodontic treatment of immature tooth with dens invaginatus: a case report

The endodontic treatment of a dens invaginatus in an immature permanent upper lateral incisor of a 9-year-old boy is presented. Root canal treatment was performed using calcium hydroxide paste as a temporary root canal filling in order to achieve apexification. This was replaced after closure of the apex with a final root canal filling using gutta-percha and AH 26 as the sealer. The follow-up radiographic control demonstrated the effectiveness of nonsurgical treatment in a case of incomplete root formation in a tooth with dens invaginatus.