Position Anomalies Research Articles

Prevalence and Patterns of Positional Dental Anomalies in First Permanent Molars: Insights from a Study in Oradea, Romania.

Tooth position anomalies, influenced by both genetic and environmental factors, can significantly impact oral health and play a critical role in establishing proper occlusion. The aim of this study was to identify the most prevalent tooth position anomalies in first permanent molars among Romanian patients and to evaluate additional variables as well. This retrospective study utilized digital study models to identify all existing tooth position anomalies. The study included patients aged 12 to 40 years with complete permanent dentition. Axial changes (buccal tilting, oral tilting, mesial tilting, and distal tilting) as well as rotational changes (mesio-buccal rotation and disto-buccal rotation) were investigated. After applying the exclusion criteria, 103 patients remained in the study. Our findings revealed a notable prevalence of positional anomalies, with disto-buccal rotations being most common in upper molars (tooth 1.6-22.3%, tooth 2.6-31.1%) and oral tilting predominating in lower molars (tooth 3.6-6.8%, tooth 4.6-14.6%). Interestingly, neither gender nor malocclusion type significantly influenced the occurrence of tooth position anomalies. Symmetrical patterns in positional changes were observed, with patients having tooth position anomalies at 1.6 significantly more frequently associated with anomalies at 2.6. Similarly, anomalies at 3.6 were significantly more frequently associated with anomalies at 4.6. Additionally, for molars 2.6 and 3.6 on the left side, the differences were statistically significant, with patients having anomalies at 2.6 significantly more frequently associated with anomalies at 3.6. This pattern was not observed for the molars situated on the right side of the dental arches. While this study provides insights into positional anomalies in first permanent molars among the Romanian population, its retrospective design and focus on a specific demographic may limit generalizability. In conclusion, the study underscores the significant prevalence of positional anomalies in first permanent molars among adolescents and adults in Oradea, Romania. Early detection and targeted interventions are crucial to address these anomalies and improve orthodontic outcomes. Comprehensive assessment and treatment planning are essential to achieve optimal dental harmony and function. Further research is needed to elucidate the underlying factors contributing to these positional changes and their long-term impact on oral health and occlusal stability.

Distribution of dental anomalies in panoramic radiography at RSGMP Universitas Airlangga

Objectives: This research was aimed to determine the distribution of dental anomaly cases on panoramic radiographs at Universitas Airlangga Dental Hospital (RSGMP). Materials and Methods: This research used a descriptive observational design with a total sampling technique from panoramic radiographic data at the Radiology Clinic of RSGMP Universitas Airlangga during 2018–2020, which had cases of dental anomalies. Results: The result showed 116 cases of dental anomalies, with more incidence in female (64%) than in male (36%). The most common dental anomaly category was the number of teeth anomalies (47.41%), followed by tooth size anomalies (29.31%), tooth shape anomalies (23.28%), and there were no cases of anomalies in tooth structure and position. The most common types of dental anomalies were microdontia (27.59%), missing teeth/agenesis (25%), supernumerary teeth (22.41%), dilaceration (16.38%), talon cusp (3.45%), taurodontism (2.59%), macrodontia (1.72%), gemination (0.86%). Conclusion: The most common cases of dental anomalies were based on their categories, namely anomalies in the number of teeth, followed by tooth size, and tooth shape.

Duodenal duplication cyst at the second part of the duodenum with congenital duodenal position anomaly completely resected by laparoscopic partial duodenectomy: a case report

BackgroundDuodenal duplication cysts (DDC) are rare duplications of the alimentary tract. Their treatment depends on their size and location. A radical treatment is total resection, if possible. However, partial excision, puncture, and marsupialization can be selected to prevent surgical injury to the pancreaticobiliary tract despite the risk of recurrence. There are some reports of pancreaticoduodenectomy for DDC because of the risk of recurrent symptoms and malignancy. However, this is considered excessively invasive for DDC, particularly in pediatric cases, because of its extremely low rate of malignancy and high morbidity and mortality rates. We encountered a case of DDC with a congenital duodenal position anomaly occurring in the second part of the duodenum. Taking advantage of the congenital duodenal position anomaly, the DDC was completely resected without injuring the pancreaticobiliary duct.Case presentationA 6-year-old boy was diagnosed with a duodenal duplication cyst with obstruction. There was a congenital duodenal position anomaly. The distal second part of the duodenum was the dorsal side of the proximal second part of the duodenum and ascended upward from the proximal second part of the duodenum. The third and fourth parts of the duodenum ran downward to the left and posterior parts of the portal vein, forming the ligament of Treitz. Complete laparoscopic resection of the duodenal duplication cyst and the second to fourth parts of the duodenum, and duodenojejunostomy with retrocolic reconstruction was performed because the duodenum was easily mobilized to the ligament of Treitz owing to the duodenal position anomaly. The duodenojejunostomy with retrocolic reconstruction achieved a more physiologically normal appearance compared to what would have been achieved with a Roux-en-Y reconstruction. The patient was discharged on postoperative day 12 without any complications.ConclusionsThe procedure used in this case might not be easily applied in all laparoscopy cases. However, it could be an option for duodenal duplication cysts with congenital duodenal position anomalies.

Prevalence of malocclusions requiring treatment according to the KIG classification : Amultipart cross-sectional study over a20-year period in the district of Viersen/North Rhine.

In Germany, the reimbursement of orthodontic treatment costs within the framework of the statutory health insurance (GKV) was restricted on 01January2002 by the introduction of the orthodontic indication groups (KIG). The aim of this study was to evaluate the prevalence of findings requiring treatment in aspecialist practice over a20-year period. The results were then compared with data from existing older studies. The distribution of treatment-eligible KIG (KIG classifications grades 3-5) among patients with statutory health insurance in an orthodontic practice in North Rhine was determined over a20-year period (2002-2021) after the introduction of the KIG system. This period was additionally scrutinized in four 5‑year periods according to the operating cycles of the practice. Findings were classified into the highest of 19 possible KIG treatment needs levels. Multiple classifications were not made. Orthodontic treatment was indicated in a total of4537 (2393 female, 2144 male) patients according to current statutory health insurance guidelines. The KIG classification "D" (increased overjet) was the most frequent within the observed 20years with 24.3%. Among 11 KIG classifications, 86.1% of the 6 most frequent and 13.9% of the 5 rarest findings were observed constantly over all periods. Of 19 possible indications, "D4" was the most frequent with 19.6%. Of 4537 patients, 20.7% had KIG grade3, 63.6% KIG grade4 and 15.7% KIG grade5. The prevalence of sagittal deviations "D" and "M" was 35.0%, transverse "B" and "K" 17.9% and vertical "O" and "T" 3.7%. Tooth position anomalies "E" and "P" had ashare of 24.6%. The present study confirms existing findings as well as the nationwide data of the National Association of Statutory Health Insurance Dentists (KZBV) from 2020: The sagittal deviations "D" (increased overjet) and "M" (negative overjet) represented the most frequent findings with KIG D4 as the most common classification. The prevalence and age distribution of KIG grades 3-5 requiring treatment corresponded to nationwide comparative data.

A study of tooth agenesis in a sample of Malagasy orthodontic patient

The aim of this study was to describe the specific features of dental agenesis in Malagasy people. A retrospective cross-sectional study was conducted in two private orthodontic clinics in the city of Antananarivo, Madagascar. A total of 72 panoramic radiographs of patients aged more than 7 years old and undergoing orthodontic treatment between January 2008 and September 2022 were examined. Dental agenesis was declared in the absence of crown mineralization on the radiograph. Wisdom teeth agenesis was not considered in this study. Data were collected, coded, processed, and analyzed using SPSS 20.0 software. Statistical significance was set at p < 0.05. A significant predominance of females (72.2% vs. 27.8%) was observed among subjects with tooth agenesis (p < 0.000). The mandible was the most affected arch (57%). The mandibular lateral incisor (83%) was the most frequently absent tooth, followed by the maxillary lateral incisor (69.3%) and the mandibular second premolar (12.2%). Dental position anomalies associated with agenesis included impacted tooth (41.7%) and tooth transposition (4.2%). The general characteristics of tooth agenesis in our study population did not show any major differences compared to previous researches in other countries. However, a difference linked to ethnic origin was observed regarding the type of tooth most frequently affected by agenesis.

Retrospective Analysis of the Airway Space Changes in Dentofacial Deformity after Two-Jaw Orthognathic Surgery Using Cone Beam Computed Tomography.

Orthognathic surgery is used to modify anomalies in maxillomandibular position; this process can significantly affect the anatomy of the airway and cause functional changes. This study aims to define the impact of mandibular maxillary movement on the airway of subjects with dentofacial deformity. A retrospective study was conducted on subjects with Angle class II (CII group) and Angle class III (CIII group) dentofacial deformities. The subjects were treated via bimaxillary surgery; for all of them, planning was performed with software and 3D printing. Cone beam computed tomography (CBCT) was obtained 21 days before surgery and 6 months after surgery and was used for planning and follow-up with the same conditions and equipment. Was used the superimposition technique to obtain the maximum and minimum airway areas and total airway volume. The data were analyzed with the Shapiro-Wilk test and Student's t-test, while Spearman's test was used to correlate the variables, considering a value of p < 0.05. Thus, 76 subjects aged 18 to 55 years (32.38 ± 10.91) were included: 46 subjects were in CII group, treated with a maxillo-mandibular advancement, and 30 subjects were in the CIII group, treated with a maxillary advancement and a mandibular setback. In the CII group, a maxillary advancement of +2.45 mm (±0.88) and a mandibular advancement of +4.25 mm (±1.25) were observed, with a significant increase in all the airway records. In the CIII group, a maxillary advancement of +3.42 mm (±1.25) and a mandibular setback of -3.62 mm (±1.18) were noted, with no significant changes in the variables measured for the airway (p > 0.05). It may be concluded that maxillo-mandibular advancement is an effective procedure to augment the airway area and volume in the CII group. On the other hand, in subjects with mandibular prognathism and Angle class III operated with the maxillary advancement and mandibular setback lower than 4 mm, it is possible to not reduce the areas and volume in the airway.

Modeled storm surge changes in a warmer world: the Last Interglacial

Abstract. The Last Interglacial (LIG; ca. 125 ka) is a period of interest for climate research as it is the most recent period of the Earth's history when the boreal climate was warmer than at present. Previous research, based on models and geological evidence, suggests that the LIG may have featured enhanced patterns of ocean storminess, but this remains hotly debated. Here, we apply state-of-the-art climate and hydrodynamic modeling to simulate changes in sea level extremes caused by storm surges, under LIG and pre-industrial climate forcings. Significantly higher seasonal LIG sea level extremes emerge for coastlines along northern Australia, the Indonesian archipelago, much of northern and eastern Africa, the Mediterranean Sea, the Gulf of Saint Lawrence, the Arabian Sea, the east coast of North America, and islands of the Pacific Ocean and of the Caribbean. Lower seasonal LIG sea level extremes emerge for coastlines along the North Sea, the Bay of Bengal, China, Vietnam, and parts of Central America. Most of these anomalies are associated with anomalies in seasonal sea level pressure minima and in eddy kinetic energy calculated from near-surface wind fields, and therefore seem to originate from anomalies in the meridional position and intensity of the predominant wind bands. In a qualitative comparison, LIG sea level extremes seem generally higher than those projected for future warmer climates. These results help to constrain the interpretation of coastal archives of LIG sea level indicators.

ALGORITHM OF RADIOLOGICAL EXAMINATION OF PATIENTS IN THE PLANNING OF ORTHODONTIC TREATMENT OF INTERARCH RELATIONSHIP OF TEETH AND TEETH POSITION ANOMALIES.

The aim: To increase the efficiency of diagnosis and planning of orthodontic treatment of patients with interarch relationship of teeth and teeth position anomalies by developing an optimal algorithm for radiological research using cone-beam computed tomography (CBCT), teleroentgenography (TRG), orthopantomography (OPG). Materials and methods: 1,460 patients with interarch relationship of teeth and teeth position anomalies were examined at the Department of Radiology of the P. L. Shupyk National Healthcare University of Ukraine. The cohort of 1460 examined patients was divided by gender: 600 men (41.1%) and 860 women (58.9%) aged 6 to 18 years and 18 to 44 years. Distribution of patients was held by the number of the primary pathology signs and the number of concomitant pathology signs. Results: The choice of the optimal radiological examination of patients is influenced by the number of signs of the main and accompanying pathology. The risk of secondary examination of the patient with a mathematical method of choosing the optimal diagnostic technique is determined.The risk of secondary radiological examination of the patient was determined at a marginal probability of 88% (at a higher value, the model predicts a repeat visit). Conclusions: The developed diagnostic model shows that when determining the Pr-coefficient of 0.79, it is recommended to carry out OPTG and TRG. With indicators of 0.88, the recommendation is to conduct CBCT in the age groups 6-18 and 18-44 years.

ПРАКТИЧЕСКОЕ ПРИМЕНЕНИЕ АДДИТИВНЫХ ТЕХНОЛОГИЙ ПРИ ОРТОДОНТИЧЕСКОМ ЛЕЧЕНИИ, КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

A new method for positioning mini-implants in orthodontic patients with tooth position anomalies (ICD-10 K07.3) using a navigation surgical template is proposed. The template is used to position a mini-implant precisely based on the visualization results of cone beam computed tomography (CBCT), which facilitates safe and dynamic orthodontic tooth movements. CBCT visualization during the initial placement of mini-implants in the most stable position has significantly reduced the risks of premature loss of stability. Proper placement, in turn, leads to the successful completion of treatment using cortical bone support. Keywords: Mini-implants, digital planning, orthodontics, navigational surgical template, interdisciplinary interaction, dental surgery, case presentation

Prevalence of Developmental Dental Anomalies Using Digital Panoramic Radiographs in Libyan Dental Patients

Dental anomalies may occur due to the complex interactions among genetic, epigenetic, and environmental factors during dental development. The current study aimed to determine the prevalence and gender significance of developmental dental anomalies (DDA) in dental patients. This was a cross-sectional study of 260 subjects (123 males and 137 females) with an age range of 6–35 years old. Clinical and radiographic examinations were performed to determine the prevalence of anomalies in tooth number, shape, size, position, and structure. Descriptive statistics was performed, the chi-square test was used for analysis and p-value was set at 0.05. The findings showed that 203 subjects (78.1%) had DDA, which included 86 males (33.1%) and 117 females (45%). A significant gender difference was found regarding the prevalence of two anomalies (p &lt; 0.05). The most prevalent anomaly was displacement 51.2%, followed by dilaceration 24.2%. A significant gender difference (p &lt; 0.05) was found regarding hypodontia 16.5% and impaction 14.6%, with more predominant in females. Some anomalies were not observed such as microdontia, dentin dysplasia, ectopic eruption, gemination, and taurodontism. The study concluded that displacement and dilacerations were the common abnormalities. These findings may lead to various dental complications. Therefore, early diagnosis and follow-up observation are required to reduce the potential dental problems. In addition, it is helpful to increase the knowledge of practitioners with regards to DDA and its occurrence. Furthermore, it is good to highlight the importance of early diagnosis of DDA, especially in the mixed dentition, which can lead to reducing the complication of an orthodontic treatment plan.

Evaluating the Prevalence and Distribution of Dental Anomalies in the Permanent Dentition of Patients Seeking Dental Care.

Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity.These anomalies manifest as discrepancies in the number, color, size, and shape of the teeth. These dental anomalies can either be acquired, congenital, or developmental. Their early detection and management are necessary as they affect aesthetics and occlusion. The study had the aim of gauging the prevalence of developmental anomalies in the permanent dentition of Indian subjects. A total of 1192 participants recruited from the institute for study purposes, comprising males and females, were examined clinically and radiographically, and their dental casts were also evaluated. These subjects were assessed for anomalies in position, structure, number, and/or shape. Anomalies in the position include transmigration, transportation, and/or ectopic position; anomalies in the structure, including dentinogenesis imperfecta or amelogenesis imperfecta; anomalies in number, including hyperdontia or hypodontia; and anomalies in shape, including peg laterals, taurodontism, fusion, dens evaginatus, talon cusp, and/or microdontia. A statisticallysignificantdifference was seen in unilateral microdontia and dentinogenesis imperfecta between males and females, with attained p-values of 0.003 and 0.06, respectively. The results of the present study showed that 9.89% (n = 118) study subjects, whereas 1% (n = 12) study subjects had two dental anomalies in their permanent dentitions, with no subject presenting more than two dental anomalies, showing that various dental anomalies have a low prevalence in the Indian population. The present study has led to the conclusion that the prevalence of dental anomalies is low in Indian subjects. However, these anomalies should be detected and treated early to prevent them from causing further complications.

REVISITING ANOMALIES IN THE POSITION OF THE MAXILLARY CANINES DURING THE PERIOD OF PERMANENT OCCLUSION (ANALYTICAL SCIENTIFIC LITERATURE REVIEW)

The purpose of this work was to analyze current literature on the epidemiology, etiology, pathogenesis and clinical manifestations of anomalies in the position of the maxillary canines' crowns during the period of permanent occlusion. Research papers were studied, opinions and clinical findings of modern domestic and foreign authors were clarified. A systematic review of literature and studies published in the Russian and the English languages in the period from 2000 to 2021 with predominant including data for the last 10 years was carried out. The literature review includes review articles, clinical studies, dissertation research abstracts, retrospective and prospective studies. The use of literary sources published in the period up to 2011 may be justified, since scientific works do not lose their completeness and informativeness against the background of modern scientific literature. The article discusses current views on epidemiology, etiology, development of pathogenesis and clinical differences in anomalies of canine crowns' position in young patients. The lack of homogeneous data on the problem, diagnostic algorithms and approaches to the treatment of patients with anomalies in canine crowns' position in the period of permanent occlusion determines the relevance of further studying the issue.

Prevalence and distribution of selected developmental dental anomalies in Taif, Saudi population.

Background: Developmental dental anomalies are seen as abnormalities in tooth size, shape, position, and structure due to multiple reasons during various stages of tooth development. These anomalies can create disturbances in dental arch lengths and occlusions. Hence, it is very important to treat, recognise and perform proper treatment. The purpose of this study was to find out the prevalence and distribution of selected developmental anomalies in shape, size and position of teeth in the Saudi population of Taif Region.Design and Methods: The study was based on the clinical examination of 2481 adults who are Saudi nationals came for dental treatment from September 2019 to February 2020, at Taif University Dental Hospital, Saudi Arabia. These patients were examined clinically for developmental dental anomalies affecting shape, size and position.Results:We found that a total of 512 individuals (20.63%) had developmental anomalies and out of which 386 persons (15.56%) had at least one developmental dental anomaly. The frequency and distribution of anomalies of shape and size, number and position were 46.8%, 26.9% and 42.9% respectively. In the present study, 15.56% individuals exhibited at least one anomaly, 8.54% subjects had more than one anomaly and 79.36%.did not any developmental anomaly. On comparison, statistically significant results were seen between different groups of anomalies.Conclusions: The present study had varying results for the prevalence rate of selected dental anomalies. This variation in results might be due racial differences or discrepancy in sample size or/and diagnostic or inclusion criteria. Treatment of developmental anomalies necessitates a multidisciplinary approach and mostly may comprise of orthodontic correction or prosthetic replacement. Significance for public health The assessment of prevalence and distribution of dental anomalies in the Kingdom of Saudi Arabia is very much required. These dental anomalies are significant and show no symptoms, seen on careful examination. These mostly result in malocclusion, change in eruption, increased vulnerability to caries, compromised esthetics and problems in permanent teeth, difficulties in endodontic or surgical procedure of the affected tooth, so on. It is very essential to take care of these anomalies, if not can produce disturbances in maxillary and mandibular dental arch and occlusions. Further, these might pose complication in planning the orthodontic treatment. Hence to know the prevalence rate and distribution of such anomalies will help various dental faculties/specialists to identify and recognize prevailing dental anomalies early and perform proper treatment planning. There are no such studies in adult populations of Saudi Arabia. This study has indicated that about 20% of the participants had dental anomalies and was observed more in males of about 63.3%.

Orthodontic Status and Orthodontic Treatment Need of 12- and 15-Year-Old Greek Adolescents: A National Pathfinder Survey.

The purpose of this research was to assess the orthodontic status and orthodontic treatment needs of 12- and 15-year-old schoolchildren in Greece, in relation to sociodemographic factors and parental education level. A total of 1102 12-year-old children and 1131 15-year-old adolescents across Greece were assessed using the Modified Dental Health component (DHC) of the Index of Orthodontic Treatment Need (IOTN). An amount of 38.7% of 12-year-olds and 33.7% of 15-year-olds were in definite need of orthodontic treatment. The most common etiologic factors were tooth eruption and position anomalies. A higher rate of orthodontic treatment need was recorded among subjects with lower parental education level. Class I malocclusion was found in 50.9%, Class II in 38.4% and Class III in 10.8% of the total sample. A higher incidence of dental trauma was found in the 12-year-olds presenting with a Class II molar relationship and >3 mm overjet. The need for orthodontic treatment in Greece was higher, in comparison to other European countries, with one out of two children presenting a severe overjet associated with a high incidence of dental trauma. One out of three adolescents were still judged as having a need for orthodontic treatment by the age of 15.

A cloud-fog software architecture for dental CBCT dose monitoring using the DICOM structured report: Automated establishment of DRL.

The diagnostic reference level (DRL) has been established to optimize the diagnostic methods and reduce radiation dose during radiographic examinations. The aim of this study was to present a completely new solution based on Cloud-Fog software architecture for automatic establishment of the DRL values during dental cone-beam computed tomography (CBCT) according to digital imaging and communications in medicine (DICOM) structured reports. A Cloud-Fog software architecture was used for automatic data handling. This architecture used the DICOM structured reports as a source for extracting the required information by fog devices in the imaging center. These devices transferred the derived information to the cloud server. The cloud server calculated the value of indication-based DRL in dental CBCT imaging based upon the parameters and adequate quantities of the absorbed dose. The feedback of DRL value was continuously announced to the imaging centers in 6 phases. In each phase, the level of the dose was optimized in imaging centers. The DRL value was established for 5-specific indications, including third molar teeth (511mGy.cm2), implant (719mGy.cm2), form and position anomalies of the tooth (408mGy.cm2), dentoalveolar pathologies (612mGy.cm2), and endodontics (632mGy.cm2). The determination of the DRL value in each phase revealed a downward trend until stabilization. The new solution presented in this study makes it possible to calculate and update the DRL value nationally and automatically among all centers. Also, the results showed that this approach is successful in establishing stabilized DRL values.

Analyzing the Role of Malnourishment in Malocclusion: A Cross-sectional Study.

Background:Malocclusion is defined as an occlusion in which there is malrelationship between the arches in any of the three planes or anomalies in tooth position beyond normal limits, the etiology being multifactorial. Malnutrition may also be allied to malocclusion, predominantly crowding, due to insufficient space for the teeth to erupt in the correct place.Objectives:The present study was conducted to investigate the role of diet as an etiological factor in the occurrence of malocclusion.Materials and Methods:Two hundred and twenty malnourished subjects were examined by a single experienced dental professional and the occlusal relationships were evaluated at a centric occlusion position by instructing the subject to swallow and then bite on the teeth together.Results:Ninety-eight subjects (44.54%) had Angle's Class I malocclusion with crowding: 18 (8.1%) presented with spacing. Angle's Class II division 1 malocclusion was evident in 52 subjects (23.63%), while Class II division 2 in 38 subjects (17.27%). Only 14 subjects (6.3%) presented with Angle's class III malocclusion.Conclusion:Dietary factors and dentition measures from a subset 220 malnourished subjects found that malnourished subjects with basal metabolic index <18.5 had statistically significant relationships with the crowding variables.

Prevalence of spacing and crowding in permanent dentition among patients visiting a private dental hospital

Malocclusion can be defined as an occlusion in which there is a mal relationship between the arches in any of the planes or one in which there are anomalies in tooth position beyond the normal limits. The literal meaning of malocclusion is a bad bite. People equate good dental appearance with success in many aspects. With the increasing demand for orthodontic treatment, the epidemiological data of malocclusion is essential in assessing the resources for orthodontic services. To assess the prevalence of spacing and crowding in the permanent dentition of patients visiting a private dental hospital. This study was based on data of patients who reported to the Department of Orthodontics, in a private teaching hospital in Chennai, India which was collected by reviewing patients records and analysing the data of 86000 patients. The data consisted of treatment done for spacing and crowding of permanent teeth in both arches in patients of age 12 to 25 years. Prevalence of crowding (64%) was more common than spacing (36%) indicating that crowding is the most common anomaly in both maxilla and mandible. Both maxilla and mandible showed statistical significance for age and gender. This study reveals that crowding is the most common anomaly in both arches.

Utility of intraoperative neuromonitoring in detecting recurrent nerve's anatomical anomalies during thyroidectomy.

Anatomical variations such as a non-recurrent laryngeal nerve (NRLN) are very rare (reported rates within 0.6-1% to the right side and only four cases to the left side) but they can lead to serious risk of nerve lesion during thyroidectomy. It is known that to prevent inferior laryngeal nerve lesions, it is mandatory to obtain a correct and wide exposure of the nerve during all kind of thyroid surgeries but in case of laryngeal nerve position anomalies, it is hard to achieve a safe nerve identification. Continuous intraoperative neuromonitoring (C-IONM) technology can detect the presence of NRLN. In this study we present seven cases of NRLN incidentally found during our last 10-year experience, in a total of 1074 procedures, including total thyroidectomy and lobectomy. Three out of seven cases were identified with the help of C-IONM. On the other hand, the other four cases of non-recurrent laryngeal nerve were identified during an extensive dissection of the thyroid lodge. We registered no nerve palsy in the group of patients who underwent surgery with the help of C-IONM, while we had two nerve palsies (out of four cases) in the group of patients without the help of C-IONM. In our experience we also registered a reduction of surgery time when we used the C-IONM. In our opinion C-IONM is a safe method to discover anatomical anomalies such as a non-recurrent laryngeal nerve and may help to reduce nerve palsy rate.

Establishment of national diagnostic reference levels in dental cone beam computed tomography in Switzerland.

Objectives:The aim of this study was to establish diagnostic reference levels (DRLs) in the field of dental maxillofacial and ear-nose-throat (ENT) practices using cone beam CT (CBCT) in Switzerland.Methods:A questionnaire was sent to owners of CBCTs in Switzerland; to a total of 612 institutions. The answers were analyzed for each indication, provided that enough data were available. The DRLs were defined as the 75th percentile of air kerma product distribution (PKA).Results:227 answers were collected (38% of all centers). Third quartile of PKA values were obtained for five dental indications: 662 mGy cm² for wisdom tooth, 683 mGy cm² for single tooth implant treatment, 542 mGy cm² for tooth position anomalies, 569 mGy cm² for pathological dentoalveolar modifications, and 639 mGy cm² for endodontics. The standard field of view (FOV) size of 5 cm in diameter x 5 cm in height was proposed.Conclusions:Large ranges of FOV and PKA were found for a given indication, demonstrating the importance of establishing DRLs as well as FOV recommendations in view of optimizing the present practice. For now, only DRLs for dental and maxillofacial could be defined; because of a lack of ENT data, no DRL values for ENT practices could be derived from this survey.

Inter-annual variability of shelf water volume on the northeastern Canadian and United States continental shelf, 1973–2013

Understanding the variability of waters confined to the northeastern United States and Canadian continental shelf is essential in determining factors that influence hydrographic patterns and structure, changes in fisheries stocks and planktonic assemblages, and the impact of Arctic warming. Shelf waters (SHW) located between Newfoundland and Cape Hatteras are characterized by lower salinity (<34 PSU) and lower temperatures than the generally warmer and more saline slope waters located farther offshore. Significant inter-annual variability of SHW volume has been noted from previous studies within the more limited Mid Atlantic Bight sub-region. Multiple factors may impact the volume of SHW, including local and remote river runoff and precipitation, release and equator-ward transport of fresh water from the Arctic and sub-polar gyre, ice melt from Greenland, cross-shelf removal, and both vertical and horizontal mixing processes. Here, we estimate inter-annual variability of SHW volume over the large shelf domain located between Newfoundland and Cape Hatteras from 1973 through 2013. Objectively-analyzed (OA) annual mean SHW thickness and error (as a percent of data variance) is computed for each of eleven sub-regions spanning our study domain for the 41-year period. Results show significant decreasing trends in SHW volume within 5 of the 11 sub-regions (The Grand Banks through the Eastern Scotian Shelf sub-regions) in agreement with previous work which has shown a decreasing trend of northern Labrador Current transport. OA annual mean SHW volume anomalies were cross-correlated with annual mean shelf slope front (SSF) position anomalies for corresponding sub-regions, displaying a highly significant relationship for the Georges Bank, the Mid Atlantic Bight, and the DelMarVa Hatteras shelf, with higher volumes corresponding to more offshore SSF positions. Annual mean near-surface salinity anomalies, when cross-correlated with OA annual mean SHW volume anomalies, displayed significant positive correlations from the Gulf of St. Lawrence northeast to the Newfoundland shelf and displayed primarily negative correlations from the Gulf of Maine to the DelMarVa Hatteras sub-region. The North Atlantic Oscillation annual indices displayed significant cross-correlations with annual mean OA SHW volume anomalies only for the Tail of the Grand Banks and Georges Bank., There were no significant cross correlations computed between the OA annual mean SHW volume anomalies and the NAO winter index for corresponding years.