The Impact of the COVID-19 Pandemic on Israeli Orthodontic Practice: A Clinic's Activity and Patients' Attitudes.

The current study aimed to characterize the activity in orthodontic clinics during the COVID-19-induced lockdown and the inter-lockdown periods, as well as to evaluate patients' perspectives with respect to their fears, their extent of cooperation with treatment, and their emergency needs during the lockdown. The data were gathered from 11 private orthodontic clinics from 1 January 2020 to 8 March 2021, which included three lockdowns and inter-lockdowns. Information specifying the number of admissions, missed appointments, and emergency visits was gathered. Four hundred and twenty-nine orthodontic patients treated in those clinics agreed to complete a questionnaire that evaluated their concerns and expectations, the treatment emergency issues, implementation of the orthodontist's instructions, and contact with the clinical staff during lockdowns. There was a significant increase in the number of scheduled appointments during the inter-lockdown periods, compared with the pre-pandemic period (p = 0.001). No difference in the number of missed/canceled or emergency appointments was found between the different periods (p > 0.420). The majority (89.6%) of the emergency visits involved issues with appliances; 68.7% of the subjects were advised to present themselves at clinics. During the peaks of the waves of the COVID-19 pandemic, a sharp rise in the number of missed and urgent appointments was not found. Reducing the number of orthodontic emergencies may assist in reducing patient fears.

Three-Dimensional Surface Texture Analysis of Fluoride's Effect on Enamel Erosion.

Enamel erosion has become a common clinical finding that often impairs dental esthetics and function. In the current study, we aimed to implement the three-dimensional surface texture analysis (3DST) method to explore the protective effect of fluoride on surface texture prior to erosive conditions. For each of the 50 teeth used in this study, the polished buccal enamel surface was divided into three separate areas: the first area was untouched polished enamel, the two other surfaces were immersed in 0.3% citric acid for 30 s. One was treated with high-concentration (19,000 ppm) sodium fluoride (NaF) solution prior to acid attack, and the other had no treatment prior to acid exposure. Enamel surface texture and step height measurements were obtained using a high-resolution disk scanning confocal microscope, and SEM images were also acquired. Surfaces treated with fluoride showed fewer variations in 3-D surface texture parameters than the eroded surface compared to the control group (p = 0.001). This was in accordance with the SEM descriptive images. The findings indicate that pre-fluoridated enamel areas were less affected by the acid and showed similar features to the untouched enamel. Moreover, a protective effect of the fluoride treatment against irreversible enamel damage was noted as the surface loss (step-height) was significantly reduced (p = 0.03). The study showed that 3DST analysis is a valuable methodology for detecting and quantifying subtle differences between the surfaces. When exploring the combination of all surface texture parameters, it was revealed that the pre-fluoridated eroded enamel surfaces showed considerable similarity to the untouched enamel.

Secondary Dentin Formation Mechanism: The Effect of Attrition.

Human dentin consists of a primary layer produced during tooth formation in early childhood and a second layer which first forms upon tooth eruption and continues throughout life, termed secondary dentin (SD). The effect of attrition on SD formation was considered to be confined to the area subjacent to attrition facets. However, due to a lack of three-dimensional methodologies to demonstrate the structure of the SD, this association could not be determined. Therefore, in the current study, we aimed to explore the thickening pattern of the SD in relation to the amount of occlusal and interproximal attrition. A total of 30 premolars (50-60 years of age) with varying attrition rates were evaluated using micro-computerized tomography. The results revealed thickening of the SD below the cementoenamel junction (CEJ), mostly in the mesial and distal aspects of the root (p < 0.05). The pattern of thickening under the tooth cervix, rather than in proximity to attrition facets, was consistent regardless of the attrition level. The amount of SD thickening mildly correlated with occlusal attrition (r = 0.577, p < 0.05) and not with interproximal attrition. The thickening of the SD below the CEJ coincided with previous finite element models, suggesting that this area is mostly subjected to stress due to occlusal loadings. Therefore, we suggest that the SD formation might serve as a compensatory mechanism aimed to strengthen tooth structure against deflection caused by mechanical loading. Our study suggests that occlusal forces may play a significant role in SD formation.

Dental Anomalies' Characteristics.

The aim of this study was to characterize dental anomalies. The pretreatment records (photographs and radiographs) of 2897 patients (41.4% males and 58.6% females) were utilized to detect dental anomalies. The dental anomalies studied were related to number, size and shape, position, and eruption. A Chi-square test was carried out to detect associations between dental anomalies, jaw, and sex. A total of 1041 (36%) of the subjects manifested at least one dental anomaly. The prevalence of all dental anomalies was jaw-dependent and greater in the maxilla, except for submerged and transmigrated teeth. The most frequently missing teeth were the maxillary lateral incisor (62.3%) and the mandibular second premolars (60.6%). The most frequent supernumerary teeth were the incisors in the maxilla (97%) and the first premolars in the mandible (43%). Dental anomalies are more frequent in the maxilla and mainly involve the anterior teeth; in the mandible, however, it is the posterior teeth. These differences can be attributed to the evolutionary history of the jaws and their diverse development patterns.

Are chin and symphysis morphology facial type-dependent? A computed tomography-based study.

INTRODUCTION: The chin is a major determinant of the facial profile; hence, it plays a major role in orthodontics and orthognathic surgery. It is thus essential to follow and better understand its expression in different facial types. The major objectives of the current study were to characterize morphometrically the chin and symphysis and reveal their association with different facial types. METHODS: Computed tomography scans of the head and neck of 311 adults (163 males, 148 females; age range, 18-95 years) were classified into 3 facial types: short, average, and long. Height, width, projection, inclination, thickness, and area were measured on the chin and symphysis. RESULTS: The majority of the population (70%) manifested an average facial type; the other 30% were almost equally distributed between short and long facial types. The long facial type was more common among females and the short facial type among males. Chin projection, area, and size were significantly greater in short-faced patients. Chin width in males was similar for all facial types, whereas, in females, chin width was the widest in the short facial type and the narrowest in the long facial type. Symphysis height was significantly greater in long-faced patients in both sexes. The mandibular incisors' inclination relative to the mandibular plane was not significantly associated with the chin or symphysis morphology. CONCLUSIONS: Chin and symphysis morphology is facial type-dependent. Orthodontists and maxillofacial surgeons should be aware of the complex relationship between facial types and chin/symphysis size and shape when planning treatment.

The Prevalence of Temporomandibular Disorders and Dental Attrition Levels in Patients with Posterior Crossbite and/or Deep Bite: A Preliminary Prospective Study.

Background: The prevalence of various temporomandibular disorders (TMD) and the severity of attrition in patients with either bilateral or unilateral deep bite and/or posterior crossbite has not been established, nor has the effect of one year of orthodontic treatment on TMD. Methods: Of 310 patients presenting with suspected TMD, 160 were diagnosed with various TMD and 150 were TMD-free. Diagnosis was according to the Axis I of the Diagnostic Criteria for TMD. All participants underwent a dental examination, and 100 patients were reevaluated after one year of orthodontic treatment. Fisher's exact test and the proportion test with Bonferroni's correction were used for the categorical univariate analysis. Results: There was a significant association (P < 0.001) between deep bite and dental attrition (wear), but not between crossbite and/or deep bite in patients diagnosed with either painful TMD or disc displacement. The risk of sustaining painful TMD when crossbite presented simultaneously on the anterior and the posterior dentition was 2.625-fold greater than when it presented with a normal bite, although this difference was not significant (P=0.286) due to the lack of statistical power. There was no significant sex-related association between the occurrence of either painful TMD or disc displacement. A reduction in TMD findings was demonstrated after one year of treatment, but no statistical power was reached due to the small sample size. Conclusions: Deep bite may be related to dental wear but not to pain from TMD and/or disc displacement. Only crossbite that presents simultaneously on the anterior and the posterior dentition (mixed X-bite) may have some effect on the level of pain in TMD, but not on in the prevalence of disc displacement. Confirmation of these conclusions by well-designed studies on larger patient groups is warranted. There was a clinically significant improvement in TMD findings after one year of treatment.

Association between posterior crossbite and/or deep bite and temporomandibular disorders among Palestinian adolescents: A sex comparison.

Objective: To assess the prevalence of temporomandibular disorders (TMDs) and posterior crossbite and/or deep bite and any possible association between them. Methods: One thousand-nineteen adolescents responded to a questionnaire regarding oral habits and TMD symptoms. Afterwards, they were diagnosed according to the Axis I of the DC/TMD and underwent a dental examination. The chi-square test was used for statistical analysis. Results: A significant association  was found between posterior crossbite and some TMD diagnosis, but no association was found between deep bite and TMD, nor between occlusal diagnosis and bruxism. TMDs were more prevalent in girls. There was a significant sex difference (more among females) in the prevalence of painful TMDs. Conclusion: Posterior crossbite in the adolescent population analyzed may be related to TMDs, in contrary to deep-bite. The presence of posterior crossbite may have different impact on TMD findings between the sexes.

The prevalence of posterior crossbite, deep bite, and sleep or awake bruxism in temporomandibular disorder (TMD) patients compared to a non-TMD population: A retrospective study.

Objective: To assess the prevalence of posterior crossbite and/or deep bite among patients diagnosed with temporomandibular disorders (TMD) compared to a non-TMD population.Methods: Four hundred ninety-four patients were enrolled: 345 with TMD according to the diagnostic criteria for TMD and 149 without TMD (control group). The chi-square test was used for statistical analysis.Results: A statistically significant association was found between sleep and awake bruxism and painful TMDs (p < .001 for both), but not with disc displacement. There was no association between posterior crossbite and/or deep bite with either painful TMD or disc displacement.Conclusion: Within the study limitations, sleep bruxism and awake bruxism may be related to pain in the TMD, and the severity of a deep overbite and presence of a unilateral or bilateral posterior crossbite should not be considered risk factors or as having any effect on the pain associated with TMD and/or disc displacement.

Canine Transposition - Prevalence, Distribution and Treatment Considerations among Orthodontic Patients.

Tooth transposition is a relatively rare dental anomaly of interchange in position of two adjacent teeth. AIM: To determine the prevalence and distribution of canine transposition in a sample of orthodontic patients and present treatment alternatives and outcome. STUDY DESIGN: The records of 3000 consecutively treated orthodontic patients from a university clinic were surveyed to detect canine transposition in both dental arches. The data was recorded according to gender, age, number and location. RESULTS: Canine transpositions were detected in 15 subjects, 3 (20%) males and 12 (80%) females presenting a prevalence of 0.5%. Of them, 6 were between the maxillary canine and first premolar, 7 between the maxillary canine and lateral incisor, 2 transpositions were between the mandibular canine and the lateral incisor. A female to male ratio of 4:1 with left side predominance was found. Treatment options include extracting the transposed teeth, maintaining them in their transposed position, or repositioning them in their normal place within the dental arch. CONCLUSION: The prevalence of canine transposition in the present sample was found to be 0.5% with a greater frequency in the maxilla. Treatment options include extraction of one of the transposed teeth, alignment of the teeth in their transposed position or correction of the anomaly. The latter gives the best esthetic outcome.

Upper Lip Horizontal Line: Characteristics of a Dynamic Facial Line.

Background: Upper lip appearance received major attention with the introduction of diverse treatment modalities, including lip augmentation, rhinoplasty surgery, and dental treatment designed to support the upper lip. Our objectives were to define the prevalence and characteristics of the upper lip horizontal line (ULHL), which is a dynamic line appearing during a smile, in relation to gender, malocclusions, aging, and facial morphology. Methods: First, the prevalence and gender distribution of ULHL was examined from standardized en-face imaging at full smile of 643 randomly selected patients. Second, cephalometric and dental cast model analyses were made for 97 consecutive patients divided into three age groups. Results: ULHL appears in 13.8% of the population examined, and prevailed significantly more in females (78%). The prevalence of ULHL was not related to age nor to malocclusion. Patients presenting ULHL showed shorter upper lip and deeper lip sulcus. The skeletal pattern showed longer mid-face, shorter lower facial height and greater prevalence of a gummy smile. Conclusions: Female patients with short upper lip, concavity of the upper lip, and gummy smile are more likely to exhibit ULHL. The ULHL is not age-related and can be identified in children and young adults. Therefore, it should be considered when selecting diverse treatment modalities involving the upper lip.

Age estimation of fragmented human dental remains by secondary dentin virtual analysis.

Unlike bones, teeth are remarkably resilient and can withstand severe trauma, making age assessment based on the dentition essential for forensic analysis. Modern techniques for age estimation focus on pulp-chamber volume measurements using radiographs and computerized tomography (CT); however, these are applicable only for complete teeth (i.e., with intact crown and root). In the current study, we developed a new approach using high-resolution micro-computerized tomography (µCT) to visualize the secondary dentin (SD), an inner layer surrounding the pulp which accumulates with age, thus facilitating age estimation of fragmented and broken teeth.The growth pattern of the SD with age was analyzed for 77 lower premolars from two anthropological collections. A comparison of SD virtual segmentation and histological measurement was highly correlative (ICC = 0.95). SD was measured per volume (mm3) of a 1 mm thick slice directly below the cemento-enamel junction. Regression analysis using SD measurements increased the success rates of age estimation (82%) compared with the "gold-standard" pulp/dentin method (54%) in the range of ± 10 years. The accuracy of age estimation based on SD analysis was improved to a range of 7-8 years.The SD method thus allows age estimation with greater prediction rates and better accuracy based on only a small fragment of a tooth in a non-invasive manner. This novel methodology is easy to use, accessible, and bears implications in various fields such as forensic sciences and anthropological research.

Variation in Chin and Mandibular Symphysis Size and Shape in Males and Females: A CT-Based Study.

The chin is a unique anatomical landmark of modern humans. Its size and shape play an important role from the esthetic perspective. However, disagreement exists in the dental and anthropological literature regarding the sex differences in chin and symphysis morphometrics. The "sexual selection" theory is presented as a possible reason for chin formation in our species; however, many other contradictory theories also exist. This study's aims were therefore to determine how chin and symphysis size and shape vary with sex, and to discuss "sexual selection" theory as a reason for its formation. Head and neck computed tomography (CT) scans of 419 adults were utilized to measure chin and symphysis sizes and shapes. The chin and symphysis measures were compared between the sexes using an independent-samples t-test, a Mann-Whitney test, and the F-statistic. The chin width was significantly greater in males than in females (p < 0.001), whereas the chin height, area, and size index were significantly greater in females (p < 0.001). Symphysis measures did not differ significantly between the sexes. Size accounted for 2-14% of the chin variance and between 24-33% of the symphysis variance. Overall, the chin was found to be a more heterogeneous anatomical structure than the symphysis, as well as more sexually dimorphic.

Prevalence and Characteristics of Supernumerary Teeth in Israeli Orthodontic Patients.

BACKGROUND: Supernumerary teeth are one of the most common anomalies in the human dentition, found most frequently in the maxillary anterior region causing impaction or displacement of the adjacent permanent teeth. AIM: The purpose of this retrospective study was to determine the prevalence and characteristics of supernumerary teeth in orthodontically treated patients. STUDY DESIGN: Pre-treatment facial and intraoral photographs, study models, panoramic and periapical radiographs of 3,000 consecutively treated orthodontic patients (mean age 12.2 years) from the Department of Orthodontics Tel Aviv University, were examined to detect supernumerary teeth in both arches. They were recorded according to gender, age, number, location, position and morphology. RESULTS: Thirty-six patients, 22 (61%) males and 14 (39%) females with 50 supernumerary teeth, of which 42 (84%) were found in the maxillary anterior region, and 8 (16%) in the mandible, presenting a prevalence of 1.2%. CONCLUSIONS: A prevalence of 1.2% was found in our study. The most common supernumerary tooth is mesiodens located at the maxillary anterior region. The characteristics of supernumeraries were based on their morphology, location and position. The most frequent complications caused were rotations, displacement and arrested eruption of maxillary incisors.

An interventional study for improving the manual dexterity of dentistry students.

OBJECTIVES: Traditionally, the acquisition of manual skills in most dental schools worldwide is based on exercises on plastic teeth placed in a "phantom head simulator". No manual trainings are done at home. Studies revealed that preliminary training of one motoric task leads to significant improvement in performance of the required motoric task that has similar components. Performing tasks indirectly via a dental mirror are complicated for the young dental students. We hypothesized that instructed training of basic skills required in dentistry at home on a tool simulating the phantom laboratory will improve the capabilities of the students and will be reflected by their clinical grades. METHODS: We developed a portable tool PhantHome which is composed of jaws, gingival tissue, rubber cover and a compatible stand. Specific teeth produced by a 3D printer with drills in different directions were placed in both jaws. Students were requested to insert pins by using tweezers and dental mirror according to instructions initiating with easy tasks and continue to ones that are more complicated. 106 first clinical year dental students participated in the study; 65 trained only in the traditional phantom lab (control). 41 trained at home by the PhantHome tool two weeks before and 2 months during the initial stage of phantom lab. The students grades routinely provided in the phantom laboratory at different stages were compared. RESULTS: Students who trained with the portable tool performed better than the control group in the first direct and second indirect preparations (p<0.05). These exams were taken when the PhantHome was available to the students. Then, the tool was returned and the phantom course continued regularly. We believe that this is why no differences between the grades of the groups were observed further on. CONCLUSIONS: Training by the PhantHome improves motor skills and consequently the clinical performances.

Nonsyndromic orofacial clefts among Jews and non-Jews born in 13 hospitals in Israel during 1993-2005.

OBJECTIVES: Orofacial clefts are one of the most common birth malformations and represent a significant public health economic expenditure. The purpose of this investigation was to study the epidemiology of orofacial clefts in newborns from 1993 to 2005 in Israel. In addition, a comparison of data from the National Birth Defects Registry (NBDR) and Hospital records will be made. METHODS: A retrospective data review of reports to the Israeli NBDR on infants with orofacial clefts in comparison with records reviewed at 13 major hospitals, accounting for 60% of all births in Israel. RESULTS: Of 1334 newborns found to be with orofacial clefts all over Israel between 1993 and 2005, 1015 were reported to the NBDR and 319 were unreported but retrieved from hospital files. During this period, of the 976 578 live births found in the 13 participating hospitals, there were 866 newborns with orofacial clefts. Of those, 684 (79%) were nonsyndromic orofacial clefts and 182 (21%) had additional syndromes. The prevalence of nonsyndromic orofacial clefts was 7/10 000 live births, lower than reported outside Israel. Only 65% of orofacial clefts retrieved from the 13 hospitals were reported to the NBDR. A significantly higher orofacial cleft prevalence was found among non-Jews than Jews (11 and 6 of 10 000 live births, respectively), (P < .00 001). CL/P was found more frequently than isolated cleft palate (CP). More males had orofacial clefts than females, mostly unilateral with left side predominance. CONCLUSIONS: The prevalence of nonsyndromic orofacial clefts was found to be 7/10 000 live births. The higher orofacial cleft prevalence among non-Jews may be explained by the high prevalence of consanguinity and deprived maternal nutritional status in this population.

Parental Perceptions of Prosthetic Treatment for and Coping Abilities of Children with Ectodermal Dysplasia: A Pilot Study.

Purpose: Congenital absence of teeth (oligodontia) due to ectodermal dysplasia (ED) may impact children's emotional aspects and quality of life. The purpose of this study was to investigate parents' perceptions regarding the impact of ectodermal dysplasia and oligodontia on the self-confidence, self-esteem, self-image, and social life of their children. Methods: Ten parents of ED children were interviewed via semistructured questionnaire. Results: Parents reported that their children became aware of their oligodontia at kindergarten age and received dentures before starting school. The parents also reported that most of the children like going to school and are socially active. Most parents noted that dentures improved the esthetics, self-image, and self-esteem of their children as well as mastication abilities. Conclusions: According to the parents, dentures contribute to the esthetics, self-image, self-esteem, and mastication abilities of children with ectodermal dysplasia. Their appearance generally did not affect their ability to socialize with their peers.

Agenesis of Permanent Canines in Orthodontic Patients: Prevalence, Location, Treatment Options and Outcomes.

Purpose: Tooth agenesis is one of the most common anomalies of the human dentition, found most often in the maxillary anterior region and in the mandibular and maxillary premolar regions. Little information is available on the prevalence and distribution of permanent canine agenesis. The purpose of this retrospective study was to evaluate the prevalence and distribution of permanent canine agenesis in orthodontic patients and describe treatment options and outcomes. Methods: The records of 3,000 consecutively treated patients in the Department of Orthodontics, Tel Aviv University, Tel Aviv, Israel were reviewed. The pre-treatment facial and intraoral clinical photographs as well as panoramic and periapical radiographs were used to detect permanent canine agenesis in both dental arches. The data were recorded according to sex, age, number of missing canines, and their location. Results: Twenty-three patients (0.76 percent), nine males (39 percent) and 14 females (61 percent) had 38 congenitally missing canines. Of these, 22 (58 percent) were missing in the maxilla and 16 (42 percent) were missing in the mandible. Conclusions: The overall prevalence of missing permanent canines in our population was 0.76 percent. The female-to-male prevalence ratio was approximately three to two and more canines were missing in the maxilla than in the mandible.

Supernumerary Teeth in the Maxillary Anterior Region: The Dilemma of Early Versus Late Surgical Intervention.

Supernumerary teeth are the most common developmental dental anomalies in the maxillary anterior region causing interference to the developing permanent incisors resulting in poor dental and facial esthetics. Two different opinions regarding the timing for surgical removal of the supernumerary teeth are presented. In this case report, three brothers with supernumerary teeth in the maxillary anterior region are presented, their surgical and orthodontic management and outcome are discussed.

The use of Bjork's indications of growth for evaluation of extremes of skeletal morphology.

BACKROUND: Morphological indicators within the cranium for prediction of mandibular growth patterns as reported by Bjork are: (1) inclination of the condylar head (ICH), (2) curvature of mandibular canal (CMC), (3) shape of the lower border of the mandible and specifically depth of the antegonial notch (AN), (4) inclination of the symphysis (ISY), (5) interincisal angle (IIA), (6) intermolar angle (IMA), and (7) lower anterior face height (LAFH). The purpose of this study was to examine the association of these indicators as they relate to extreme skeletal patterns observed in skeletally mature subjects. MATERIALS: The pre-treatment lateral cephalometric radiographs of 395 post-growth subjects were randomly selected from the archives of a university orthodontic department. These were divided in three groups according to their MP-SN angle [normal: 28-36degrees (G1), hypodivergent: ≤26degrees (G2), hyperdivergent: ≥38degrees (G3)]. RESULTS: It was found that only LAFH was correlated to age across all groups. However, within G1, G2, and G3, and between genders, it was found that there were statistically significant differences for all indicators in relation to age, except IMA (P > 0.05). In addition, ISY and IMA had a predictive value lower than the chance level (0.5). CONCLUSION: Bjork's implant studies have contributed much to understanding facial-skeletal growth; however, this study suggests that their utilization as a tool in classifying extreme skeletal patterns requires careful evaluation of all the parameters involved.

Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations.

Bilateral mandibular tooth transposition is a relatively rare dental anomaly caused by distal migration of the mandibular lateral incisors and can be detected in the early mixed dentition by radiographic examination. Early diagnosis and interceptive intervention may reduce the risk of possible transposition between the mandibular canine and lateral incisor. This report illustrates the orthodontic management of bilateral mandibular canine-lateral incisor transposition. Correct positioning of the affected teeth was achieved on the left side while teeth on the right side were aligned in their transposed position. It demonstrates the outcome of good alignment of the teeth in the dental arch.