Objectives Orthodontic relapse, the tendency of teeth to return toward their pre-treatment positions, remains a major challenge and has led to widespread use of fixed lingual retainers to preserve stability. However, conventional metal-wire retainers frequently exhibit high failure rates and limited longevity. Therefore, the aim of the study was to evaluate the shear bond strength (SBS) and failure pattern of a novel veneer-assisted fixed retainer compared with a conventional wire-only retainer design. Materials and Methods Seventy-six bovine incisors were allocated into 38 matched pairs (n = 19 per group). In the experimental group, multistranded wire was embedded within prefabricated composite shells (Filtek™ P60) and bonded using Transbond™ LR. Control specimens used conventional wire-only bonding. All samples underwent thermocycling (5,000 cycles, 5–55°C). SBS was measured with a universal testing machine, and failure modes were assessed using the Adhesive Remnant Index (ARI). Results Veneer-assisted retainers demonstrated significantly higher SBS compared with controls (2.89 ± 1.53 MPa vs. 1.99 ± 1.01 MPa; p = 0.036). ARI scores of 2–3, indicating that more than 50% of adhesive remained on the enamel surface, were significantly more frequent in the veneer group (p = 0.043). Conclusions Within the limitations of this in vitro study, the veneer-based fixed lingual retainer demonstrated improved bond performance and more favorable adhesive failure patterns compared with a conventional multistranded retainer. Clinical Relevance The novel design of the lingual retainer may improve bonding behavior at the adhesive interface; however, the underlying mechanisms were not directly evaluated.

Objectives:To compare orthodontic treatment cooperation between Generation Y and Generation Z teenagers and evaluate influence of age on compliance. Materials and Methods:This was a retrospective cohort study analyzing records of 124 patients (62 from each generation) treated at Tel Aviv University Dental School between 2007 and 2021. Patient cooperation was assessed through weighted noncompliance scores incorporating elastic or headgear wear, oral hygiene, appointment attendance, appliance breakage, and new caries development. Each noncompliance incident was weighted (1.0 point for major incidents, 0.5 for minor) and standardized by treatment duration. Multiple regression analysis accounted for age differences. Results:Mean age differed significantly between Generation Y (15.5 ± 1.7 years) and Generation Z (13.1 ± 1.6 years; P < .001). Initial noncooperation scores were similar (Generation Y: 36.8% ± 16.4%; Generation Z: 35.8% ± 15.8%; P = .732). After age adjustment, regression analysis revealed significantly higher noncooperation in Generation Y (B = 8.29; P = .014). Age independently influenced cooperation, with each year increase associated with a 3% decrease in noncooperation scores (B = -3.04; P < .001). Conclusions:Generation Z teenagers exhibited better orthodontic treatment cooperation than Generation Y after age adjustment. Age independently predicted cooperation, with older teenagers showing better compliance regardless of generation. Treatment planning should consider both generational differences and individual patient factors when selecting compliance-dependent treatment options.

OBJECTIVE:This study aimed to provide a comprehensive case analysis from a single center, with the objective of clarifying the optimal timing and recommendations for a preferred treatment strategy customized to the specific presentation of each type of supernumerary tooth identified in the research. METHOD AND MATERIALS:A retrospective study was conducted on patients who presented with a supernumerary tooth and were treated interdisciplinarily at the clinic. RESULTS:In total, 55 patients with 81 supernumerary teeth of the permanent dentition were analyzed, 30 males and 25 females. The dentition status of the patients was as follows: 31 patients with mixed dentition, no patients with primary dentition, and 24 patients with permanent dentition. The diagnosis of supernumerary tooth was primarily made by general or pediatric dental practitioners and/or orthodontists. Patients were then referred to maxillofacial surgeons for treatment decision. The timing of treatment was mainly determined by the oral surgeon, based on the recommendations of the other specialists involved. Cases involving maleruption or malalignment of permanent teeth required both surgical and orthodontic treatment. Patients over 9 years old were treated either under local anesthesia or sedation, whereas those under 9 years old were treated under deep sedation or general anesthesia. A comprehensive investigation of cases involved the utilization of CBCT at the supernumerary tooth site to facilitate treatment planning. There was a significant correlation between younger age and the preference for treatment under sedation or general anesthesia (P &#61; .01, t test). Similarly, a strong association was found between younger age and the need for additional orthodontic treatment (P &#61; .016, t test). Cases of surgical removal of a supernumerary tooth at a young age typically did not require orthodontic traction of the permanent tooth, in contrast to cases of late surgical intervention (patients over 11 years old), which often did necessitate such traction. There was a strong tendency for treating supernumerary teeth in the maxilla. The proximity of supernumerary teeth to vital anatomical landmarks significantly influenced treatment decisions. Patients with supernumerary teeth near the mental foramen or the inferior dental canal in the premolar area were exclusively placed under follow-up care (P &#61; .002, Pearson chi-square test). However, in the maxilla, the proximity of supernumerary teeth to vital structures such as the floor of the nose and the incisive nerve did not affect the treatment approach, and those supernumerary teeth were mostly removed. CONCLUSIONS:A team approach for managing supernumerary teeth is recommended. The timing of treatment should carefully consider the advantages and disadvantages of early versus late intervention. Early surgical treatment in cases where eruption is disturbed might result in spontaneous eruption, eliminating the need for orthodontic traction of the permanent teeth.

Reliability of the six-stage cervical vertebrae maturation method to evaluate skeletal growth was evaluated on the combined male and female samples and revealed diverse results. The current study aimed to determine the reliability of the modified three-stage cervical vertebrae maturation method for estimating the skeletal growth of males and females. Pretreatment lateral cephalometric radiographs of 137 orthodontic patients were utilized to evaluate the intra- and inter-observer reliability of a modified cervical vertebrae maturation method. Four independent examiners categorized each radiograph into one of the three skeletal growth stages according to the cervical vertebrae morphology: (1) a pre-peak group (combining the CS1 and CS2 stages), (2) a peak group (combining the CS3 and CS4 stages), and (3) a post-peak group (combining the CS5 and CS6 stages). The Kappa index and the Fleiss multirater Kappa test were carried out to determine the reproducibility of this method. The studied sample included cephalometric radiographs of 68 males (49.6

The innermost dental tissue, termed secondary dentin (SD), has been established as a valuable parameter for aging, as its thickness is highly correlated with age and can be viewed in a non-invasive manner using micro -computerized tomography (mu CT). Dental remnants show a high preservation rate in an archeological context and may be used as age indicators, thus possibly supplementing traditional skeletal-based demographics. As the SD age assessment method was based on unworn teeth, in the current study, we adjusted the approach to allow age estimation of highly worn teeth and later to explore prehistoric samples. In order to do so, 90 lower pre-molars from known age and gender individuals with various degrees of occlusal attrition were included. The teeth originated from the Hamann-Todd Osteologic Collection (Cleveland, OH, USA) and from the Tel Aviv University collection (Israel). Combining SD measurements and occlusal Attrition slightly improved the standard error of age estimate from +/- 7.7 years based on SD and +/- 9.5 years based on Attrition to a range of +/- 6.5 years.The SD-age method was used to evaluate the age of individuals from three Natufian and Neolithic sites using dental remains (Hayonim Cave, Ein Mallaha 14,900-11,750 cal BP, and Kfar Hahoresh similar to 12,175-8250 cal BP). Population coverage increased substantially with the addition of forty-eight premolars to previous skeletal age assessments to create new life tables. The addition of dental age assessments, representing unaccounted in-dividuals, shifted the age distributions and increased the expected lifespan between 4.7 and 1.8 years. Using the SD-age analysis, isolated, fragmented teeth can be included in the paleodemographic study, thus broadening the coverage of samples and providing better insight into archaic populations' structure.

(1) Introduction: Mandibular second molar (MM2) impaction is a relatively rare dental anomaly, but its early detection is imperative for orthodontic diagnosis and treatment. This study evaluates early radiographic characteristics of MM2 in the process of its impaction and the role of the third molar (MM3) in this process. (2) Materials and Methods: Panoramic radiographs of orthodontic patients of Chinese-American origin (n = 5575), age 9–15 years (mean 13.13) were examined for MM2 impactions and the presence of MM3. (3) Results: A total of 151 patients with 212 impacted MM2s were detected in the Chinese-American study group. Unilateral impactions were found more than bilateral and were distributed equally between the left and right sides. Mesial angulation of the impacted teeth was present in 92.7% of the cases, and MM3s were found adjacent to the impacted MM2s in 97.4% of the cases. (4) Conclusions: MM2 differential root developments with deficient mesial root lengths appeared to be the primary cause for MM2 impaction. Posterior crowding and arch length deficiency were contributing factors causing MM2 impaction. This impaction occurred early, before the third molar bud was developed. It sometimes occurred even when the third molar was congenitally missing. Nevertheless, the possible involvement of the third molar in MM2 impaction needs further investigation.

The research objectives were to determine the prevalence of impacted teeth in orthodontic patients in Israel, examining the epidemiological and genetic linkage. Methods: Data was collected from the cohort of patients treated in Tel-Aviv University between 2010–2017. Forty-five patients treated for impacted teeth were randomly selected, compared to 45 control patients, paired by age and sex. Collected data included: week of birth, type of birth, medical history, dental anomalies, treatment referee, chief complaint, treatment modalities and treatment duration. Results: The periodic prevalence of impacted teeth was 11.9%. There was a statistical tendency in the week of birth and type of birth (earlier birth week and more caesarean sections in the study group). Statistical significance was found for systemic disease, chief complaint, referee for treatment and treatment duration. Dental anomalies for the patient or first-degree relatives found odds ratio for the presence of an impacted tooth up to 6 times higher. Conclusions: There is epidemiological data related to impacted teeth, such as preterm births and caesarean sections, with the need for further research.

Introduction: The mass-harvesting of digitized medical data has prompted their use as a clinical and research tool. The purpose of this study was to compare the accuracy and reliability of artificial intelligence derived cephalometric landmark identification with that of human observers. Methods: Ten pre-treatment digital lateral cephalometric radiographs were randomly selected from a university post-graduate clinic. The x- and y-coordinates of 21 (i.e., 42 points) hard and soft tissue landmarks were identified by 6 specialists, 19 residents, 4 imaging technicians, and a commercially available convolutional neural network artificial intelligence platform (CephX, Orca Dental, Hertzylia, Israel). Wilcoxon, Spearman and Bartlett tests were performed to compare agreement of human and AI landmark identification. Results: Six x- or y-coordinates (14.28%) were found to be statistically different, with only one being outside the 2 mm range of acceptable error, and with 97.6% of coordinates found to be within this range. Conclusions: The use of convolutional neural network artificial intelligence as a tool for cephalometric landmark identification was found to be highly accurate and can serve as an aid in orthodontic diagnosis.

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.

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.

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.

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.

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.

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.

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.

Introduction: The chin isa 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. (Am J Orthod Dentofacial Orthop 2021;160:84-93)

Introduction: Early diagnosis and referral is essential in order to provide the best orthodontic care. Paediatric specialists (PSs) and general dental practitioners (GDPs) are usually the first dental professionals to diagnose a malocclusion. Aim: To evaluate the knowledge and approach of PSs and GDPs in the management of children in reference to the timing of referral and early orthodontic intervention. Methods: A survey assessed referral patterns and the respondents' orthodontic knowledge regarding treatment timing and indications for early treatment in the early and late mixed dentition. Results: One hundred and seventeen dentists participated in the study, of whom 79 were GDPs and 38 were PSs. The average total accuracy score in a 27-knowledge questionnaire was 68.6%, resulting in a statistically significant difference between the PSs and the GDPs. This difference arose from confusion regarding the prevention of maxillary permanent canine impaction and the need for a leeway space maintainer. Conclusions: The GDPs and the PSs had a sound knowledge of orthodontics and a reasonable referral pattern, although the knowledge of PSs was significantly higher than that of the GDPs. There is a need for further education regarding orthodontic treatment needs and timing both in undergraduate/postgraduate training as well as in professional continuing education programs.

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.

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.

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.