Orthodontic Elastics: A Multivariable Analysis of YouTubeTM Videos.

Background/Purpose: Whether YouTube videos contain precise and adequate information on certain orthodontic procedures remains unclear. This study aimed to investigate the content and quality of YouTube videos on orthodontic elastics and identify the predictors of high-level content YouTube videos. Materials and Methods: Two hundred YouTube videos were screened for eligibility, and after applying the inclusion criteria, 133 videos were excluded. Student's t-test was used to compare the characteristics, quality parameters, and total content of the low-level and high-level content videos. Chi-square or Fisher's exact tests were implemented to identify the source and content element differences across low-level and high-level content videos. Pearson's correlation coefficients were used to determine the relationship between the total content score, video information and quality index (VIQI), and YouTube characteristics. Stepwise linear multiple regressions with forward selection were used to test the association of the YouTube characteristics and VIQI with the total content score. Results: Among 67 included videos, only 19.4% of videos were classified as high-level content videos. High-level content videos had significantly higher mean number of likes (MD = 4041.7; SD = 4680.7; P-value=0.0068), VIQI score (MD = 4.17; SD = 4.87; P-value=0.0073), and total content score (MD = 4.04; SD = 1.23; P-value=<0.0001). The adjusted linear regression model demonstrated a significant association between the total content score and VIQI, where 1 unit increase in the VIQI was significantly associated with a 0.16 increase in the total content score (B = 0.16; standard error [SE]=0.04; P = 0.0003). Further, a significant association was observed between the total content score and video duration, where 1 minute increase in the video duration was significantly associated with a 0.15 increase in the total content score (B = 0.15; SE = 0.05; P = 0.008). Conclusion: This study demonstrated that YouTube content quality concerning orthodontic elastics is poor. Thus, future implementation of online visual content provided by certified orthodontists will ensure accurate and thorough information delivery.

Predictors of procedural errors in class II resin composite restorations using bitewing radiographs.

Objective: To identify the potential factors that induce procedural errors during posterior proximal resin composite restorations placed by dental students. Materials and Methods: This retrospective study evaluated 803 bitewing radiographs of posterior proximal resin composite restorations placed by dental students at Imam Abdulrahman bin Faisal University. Atypical radiographic signs of failure were screened, and different patient-, operator-, and clinical-related factors were recorded. Chi-square test was used to examine the relationship between procedural errors and recorded factors. Stepwise adjusted logistic regression model was performed to identify predictors of procedural errors. Results: The most observed errors were internal gaps at the bonding interface and internal voids. Molars had 0.39 the risk of internal voids (odds ratio [OR] = 0.39; confidence interval [CI] = 0.25-0.60; P = <0.0001), 0.41 the risk of sharp angle (OR = 0.41; CI = 0.24-0.68; P = <0.001), and 0.57 the risk of open contact (OR = 0.57; CI = 0.34-0.97; P = 0.04) compared to premolars. Those who were >40 years of age had 1.79 the risk of overhang compared to younger patients (OR = 1.79; CI = 1.04-3.11; P = <0.04). First molars and premolars had 0.64 the risk of overhang compared to second molars and premolars (OR = 0.64; CI = 0.41-1.00; P = 0.04). Junior students had 1.97 the risk of internal gap compared to their senior counterparts (OR = 1.97; CI = 1.20-3.21; P = 0.008). Mesial restorations had 0.38 the risk of external gap compared to mesio-occluso-distal (MOD) restorations (OR = 0.38; CI = 0.19-0.78; P = 0.003). Restorations with a margin coronal to the cemento-enamel junction (CEJ) had 0.44 the risk of external gap compared to those restorations with a margin apical to the CEJ (OR = 0.44; CI = 0.29-0.66; P = <0.0001). Conclusion: Our findings suggested a higher incidence of procedural errors in restoring premolars and MOD cavity preparations. Therefore, it is crucial to enhance the comprehensiveness of laboratory training and expose students to diverse clinical scenarios and various techniques.

Oral microbiota analyses of paediatric Saudi population reveals signatures of dental caries.

BACKGROUND: Oral microbiome sequencing has revealed key links between microbiome dysfunction and dental caries. However, these efforts have largely focused on Western populations, with few studies on the Middle Eastern communities. The current study aimed to identify the composition and abundance of the oral microbiota in saliva samples of children with different caries levels using machine learning approaches. METHODS: Oral microbiota composition and abundance were identified in 250 Saudi participants with high dental caries and 150 with low dental caries using 16 S rRNA sequencing on a NextSeq 2000 SP flow cell (Illumina, CA) using 250 bp paired-end reads, and attempted to build a classifier using random forest models to assist in the early detection of caries. RESULTS: The ADONIS test results indicate that there was no significant association between sex and Bray-Curtis dissimilarity (p ~ 0.93), but there was a significant association with dental caries status (p ~ 0.001). Using an alpha level of 0.05, five differentially abundant operational taxonomic units (OTUs) were identified between males and females as the main effect along with four differentially abundant OTUs between high and low dental caries. The mean metrics for the optimal hyperparameter combination using the model with only differentially abundant OTUs were: Accuracy (0.701); Matthew's correlation coefficient (0.0509); AUC (0.517) and F1 score (0.821) while the mean metrics for random forest model using all OTUs were:0.675; 0.054; 0.611 and 0.796 respectively. CONCLUSION: The assessment of oral microbiota samples in a representative Saudi Arabian population for high and low metrics of dental caries yields signatures of abundances and diversity.

Multinational study on profile preference of laypersons.

BACKGROUND: This study aimed to assess the facial profile preferences of lay people in seven locations from different countries and whether their place of residence, sex, age, race, education, or income influenced the decision. METHODS: After altering the lip and nose in 1 mm increments in the sagittal and sagittal/vertical directions, 50 profile silhouettes with white-like facial features were rated by evaluators. The soft tissue values were integrated into the profiles, and profile preferences were identified for each location. An ANOVA with post hoc Tukey test was used to compare the differences in mean preference in each location. A multivariable regression model was used to assess the effect of the demographics of the evaluator on preference. RESULTS: Thirteen profiles were ultimately analyzed. The mean for profile preference was significantly different across locations (P < 0.0001). For evaluators in the United States and Lebanon, the most preferred profile had the original lip and original nose. In Switzerland and South Africa, retrusive lips, and a small and less upturned nose was most preferred. In Japan and Saudi Arabia, the most preferred profile had the original lip and a protrusive nose that was less upturned. A protrusive lip with a small, upturned nose was preferred in Turkey. Profile change (P < 0.0001), location (P < 0.0001), sex (P < 0.0001), and race (P = 0.02) were significant confounders; in contrast, age, education, and income were not significant. CONCLUSIONS: Profile preference is different among the seven locations. For the most part, lay people prefer profiles within one SD from white norms. Also, an upturned nose is the least favored in most of the locations. Sex and race are also significant confounders. CLINICAL RELEVANCE: An orthodontic treatment plan decision is affected by an individual's preference for their facial appearance. This study helps clinicians understand how racial and regional differences may affect patients' preferences and, therefore, their expectations for orthodontic treatment results.

Influence of Denture Cleansers on the Retention Loss of Attachment Systems Retained Implant Overdenture.

Background: This study aimed to evaluate the effects of different denture cleansing solutions (DCSs) on the retention of Locator and Locator R-Tx attachment systems of implant retained overdentures (IRO). Methods: Two part acrylic resin blocks were fabricated, upper part contained metal housing and plastic inserts and lower part contained implant analogs and abutments. Eighty pink plastic inserts (40/attachment, 10/solution) were immersed in Corega, Fittydent, sodium hypochlorite, and water for a time simulating upto 1-year of clinical usage. Acrylic blocks were held on a universal testing machine for a pull-out test to record the dislodgement force. Measurements were conducted after 6 months (T1) and 12 months (T2). One-way ANOVA followed by Tukey's HSD test was used to analyze the results (α = 0.05). Results: For both attachments, retention significantly decreased after immersion in different solutions at T2 (P < 0.001). Locator R-Tx attachment in NaOCl showed a significant decrease in retention compared with other solutions at T1. At T2, there was a significant decrease in retention for all DCS compared with water (P < 0.001). Locator R-TX showed higher retention values per solution compared to Locator attachment (P < 0.001). In terms of retention loss %, NaOCl recorded the highest (61.87%) loss, followed by Corega (55.54%) and Fittydent (43.13%), whereas water demonstrated the best retention (16.13%) in both groups. Conclusion: Locator R-TX has better retention with different DCS immersion. The loss of retention varied with different types of DCS and NaOCl recorded the highest retention loss. Therefore, denture cleanser selection must be guided by the type of IRO attachment.

Three-dimensional morphometric analysis of anterior cranial base in growing patients.

INTRODUCTION: The growth of the sphenoethmoidal and sphenofrontal suture in the anterior cranial base (ACB) terminates around 7 years old; therefore, ACB is used as a reference structure for superimposing radiographs in 2-dimensions (2D) and 3-dimensions (3D). The data in the literature regarding the cessation of growth of ACB in 3D is insufficient. The study aimed to evaluate the volumetric changes of ACB in growing patients on cone-beam computed tomography (CBCT) data in 3D. METHODS: The CBCT sample was obtained from a repository of scans of subjects (n = 30) aged 6-11 years with no craniofacial anomalies or growth-related disorders. CBCTs were taken at 2 time points (approximately 12 months apart). The mean age at the initial scan (T1) was 8.4 ± 0.89 years, and the follow-up scan (T2) was 9.6 ± 0.99 years. The bones of the ACB were segmented, and 3D models of the bones were generated using Mimics software. The volumetric measurement was performed on the 3D-rendered model. Linear measurements were performed on the slices. RESULTS: The volumetric analysis of the ACB between T1 and T2 showed a significant change (P <0.0001). There were no significant differences in volumetric changes of the ACB between the male and female subjects. The linear measurements on the right side of the cranial base showed continued growth between T1 and T2. CONCLUSIONS: In the studied sample, growth-related changes of ACB were observed through volumetric analysis after 7 years old.

Sickle Cell Disease Knowledge and Reproductive Decisions: A Saudi Cross-Sectional Study.

Background and Aim: Sickle cell disease (SCD) is an autosomal recessive disorder. Decisions following premarital screening results might be influenced by several factors. Thus, this study aims to assess the knowledge and beliefs toward SCD and reproductive decisions. Material and Methods: A cross-sectional study was conducted among adults in the eastern province of Saudi Arabia. Data was collected using a web-based questionnaire. Participants were divided into two groups based on their knowledge scores. Results: A total of 390 participants were recruited with a mean age of 28.6 years. The majority (90.5%) of participants had general knowledge about the disease mode of inheritance however, 66.9% had poor knowledge about the disease overall. Regarding knowledge level, there was no statistically significant difference between the non-healthy group (diseased and carrier) and healthy participants (P=0.304). Moreover, the participants' decisions about choosing future partners were more likely to be affected among those with prior knowledge about the disease (p=0.008). However, 152 (91.6%) male participants with prior knowledge would change their decision about selecting a future partner compared to 225 (92.4%) female participants. Regarding reproduction, only 38.5% of participants were aware of in vitro fertilization (IVF) as an assistive reproductive technology. Furthermore, female participants believed that IVF is a way to have healthy babies and would consider it despite the cost more than male participants (p=0.0001, p=0.007 respectively). Conclusion: SCD is an inherited disease with economic, physical, and psychological burdens. However, curative options are costly, and hence, prevention is key. Therefore, healthcare decision-makers should consider implementing policies to minimize the financial burden that may still affect society despite the availability of free medical care. This study warrants extensive community-based education programs that may contribute toward cost savings. It also highlights the importance of premarital counselling for disease and carrier people including alternative reproduction options.

Effects of counterclockwise bimaxillary advancement surgery and relapse on upper airway.

OBJECTIVE: The aim of this study was to evaluate the long-term volumetric changes of the upper airway compartments in response to counterclockwise bimaxillary advancement surgery with multi-piece maxillary osteotomy, and to analyse the relationship between the postoperative stability of the maxillomandibular skeletal complex, and the volumetric airway changes over-time. METHODOLOGY: Twenty-seven sets of pre (T0), post (T1) and follow-up (T2) (20.15 months) CBCT scans were used. The upper airway was isolated into five compartments: soft and bony nasal cavity (SNC, BNC), nasopharynx (NP), oropharynx (OP) and hypopharynx (HP) using Mimics V.22 software. The volumetric changes and the correlation between the airway change and the skeletal movements were analysed using repeated measure ANOVA, and Pearson's correlation coefficient, respectively. RESULTS: The results showed a significant decrease in SNC and BNC (10.94% and 7.69%, p < .05) at T1. However, SNC presented a significant recovery (11.73%, p < .05) at T2. NP, OP and HP segments presented significant and stable increases over time (10.41%, 53.62%, 24.70%, p < .05). CONCLUSIONS: This surgical approach produced a significant increase in OP and HP volumes in short and long term without a significant relapse, NP showed a significant increase in long term only, SNC and BNC volumes showed a significant decrease post-surgery which was only partially maintained for BNC.

Oral microbiota analyses of Saudi sickle cell anemics with dental caries.

OBJECTIVES: The objectives of this study were to identify the composition of oral microbiota in a cohort of patients with sickle cell anemia (SCA) and a high mean number of decayed, missing, and filled permanent teeth (DMFT) and compare it to a cohort of patients with SCA and a low number of DMFT and elucidate the effect of fetal haemoglobin levels on the oral microbiota composition. METHODS: Patients who had been diagnosed with SCA, who were homozygous for sickling ß-globin mutation (ßS/ßS), who had Arab-Indian haplotype, and who ranged in age from 5 to 12 years were included in this study. Oral saliva from each participant (n = 100) was collected in GeneFiX™ Saliva DNA Microbiome Collection tube and DNA was extracted using GeneFiX™ DNA Isolation Kits. The composition of oral 16S rRNA from patients with SCA and high dental caries (n = 27, DMFT ≥5) and low dental caries (n = 73, DMFT ≤4) was analysed. Sequencing was performed on an Ion Personal Genome Machine using, Ion PGM Hi-Q view Sequencing 400-bp kit. RESULTS: We observed an overall increase in abundance of Proteobacteria, Chloroflexi, and Bacteroidetes in the high DMFT index group compared to those with a low DMFT index. In addition, there was an overall increased abundance of microbiota from Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes in the patients with SCA with low fetal haemoglobin compared to those with high fetal haemoglobin (P < .05). Enterobacteriaceae species were the most significant abundant species of bacteria found in both the high DMFT index group and low fetal haemoglobin cohort (P < .05). CONCLUSIONS: Our data indicate that SCA in Saudi patients with high DMFT have a higher predominance of pathogenic bacteria compared to those with low DMFT. Furthermore, SCA in Saudi patients with low fetal haemoglobin have a higher predominance of pathogenic bacteria compared to those with higher fetal haemoglobin.

Longitudinal changes in the dental arch width and symmetry in identical and fraternal twins.

INTRODUCTION: This study aimed to assess growth-related dental and symmetry changes in the dental arch within and between identical and fraternal twins in mixed and permanent dentition. METHODS: Three-dimensional scanned dental models of eligible subjects were selected from the Forsyth-Moorrees Twin Study sample. This retrospective cohort study was carried out on 36 identical (18 pairs) and 28 fraternal (14 pairs) twins in mixed dentition and 36 identical (18 pairs) and 38 fraternal (19 pairs) twins in permanent dentition stages on the basis of the availability of the dental casts scanned each year from each group (Table I). Linear measurements from dental casts were performed in patients aged 8-16 years. Student t test and Pearson's correlation were used to compare the symmetry between and within the identical and fraternal twins. The resemblance and heritability patterns were retrospectively obtained from the Pearson correlation coefficient and Falconer's heritability test (H2 = 2 × b). Adjusted mixed-effects estimates and 95% confidence intervals were calculated to test the association between age and dental parameters for both mixed and permanent dentition groups. RESULTS: Intercanine and intermolar widths significantly increased (P <0.05) during the mixed dentition but became stable after 13 years old. No statistically significant differences were found in arch symmetry between the 2 groups (ie, identical and fraternal) in any of the included measurements. Evaluation of the resemblance and heritability pattern showed nonsignificant results for all variables measured (H2 range, -0.67 to 0.56). CONCLUSIONS: The dental arch becomes wider at a higher rate in the canine region than the molar region in both the mixed and early permanent dentition. The dental arches of twins develop symmetrically, and their growth is not mainly affected by genetics. Asymmetrical teeth will maintain their relative position to reference planes throughout growth.

Risk Assessment of Varicose Veins Among Teachers in Al-Ahsa, Saudi Arabia.

Background Varicose veins (VV) are abnormally swollen, tortuous, and prominent veins caused by insufficient venous valves leading to venous congestion and elevated venous pressure. Prolonged standing at work has been proposed to be an important risk factor for varicose veins. Teachers are prone to have varicose veins due to prolonged standing. The aim of this study was to assess the risk of varicose veins among teachers in Al-Asha, Saudi Arabia. Method This was a cross-sectional study conducted among teachers of primary, secondary, and high schools in Al-Ahsa, of both genders, between April 2022 and June 2022. The participants were interviewed and examined for the presence of signs and symptoms of the disease. Finally, the collected data were analyzed using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 26.0 for Windows) software. Result Out of 399 participating teachers with a mean age of 43.2 ± 12.9 years, 216 (54.1%) were males and the remainder were female. The commonest symptom was pain in the legs, which was exacerbated by work (43.1%). Most of the participants were working for more than 16 years (43.6%) and standing for less than six hours per day (72.7%). The most pointed sign was spider legs-shaped veins (23.8%). However, the least collective sign was paleness in the ulcer area after healing (1.8%). A total of 140 teachers had a family history of varicose veins, 74 of them (18.5%) were diagnosed with varicose veins previously. We summarize our result as female teachers who have a family history of VV have more risk to develop the disease. Conclusion The prevalence of varicose veins was high among teachers in Al-Ahsa, Saudi Arabia. According to our study, teachers have a significant chance of developing the condition since their working style contributes to its progression. Further actions need to be made in order to increase awareness and prevent its complications.

Gastric Perforation as a Complication of COVID-19 Infection: A Case Report.

Pulmonary symptoms are the primary manifestation of the COVID-19 disease, which originated in Wuhan in China in December 2019. However, it is now established to show widespread extrapulmonary manifestations, including gastrointestinal involvement. Abdominal pain, diarrhea, nausea, and vomiting are considered the most common gastrointestinal symptoms. Gastric perforation in association with COVID-19 is rarely reported in the literature. Here, we report a case of a 71-year-old male COVID-19-infected patient, medically free, who presented to the emergency department complaining of severe abdominal pain for a one-week duration. He was diagnosed with a case of perforated viscus and septic shock. The patient was shifted to the operating room for exploratory laparotomy. We aim in this report to highlight this fatal complication of COVID-19 infection in order to improve patients' outcomes.

Treatment of bisphosphonate induced osteonecrosis of jaw in rats using an angiogenesis factor (A-Heal) and ABMDO (Autologous Bone Marrow Derived Osteoblasts).

BACKGROUND AND OBJECTIVE: The aims of this study were to create Bisphonates Related Osteonecrosis of the Jaw (BRONJ) in rats and treat them with an angiogenesis factor (A-Heal) and ABMDO (Autologous Bone Marrow Derived Osteoblasts). MATERIALS AND METHODS: Thirty female Wistar rats were procured. Rats were labeled as Group I to III. Group I = Osteoblast group, Group II = A-Heal and Group III Control group. In Groups I-III, BRONJ was created and treated in Group I with ABMDO, Group II with A-Heal and Group III was the control group. At the end of the four weeks post treatment, all the animals were humanely killed. The intact maxillae were removed in total. Histopathological and radiological examinations were carried out with physicians blinded to the groups. RESULTS: Computerized tomography revealed that Groups I and II demonstrated the presence of dense osteosclerosis, intralesional calcifications, and adequate healing of the overlying soft tissues compared to Group III, which showed the presence of bone erosions at the alveolar ridge with a lack of intralesional calcifications and ulceration of the overlying soft tissues. Histologically, H&E staining Group 1 and Group 2 both showed marked reactive bone formation. Group 2 additionally revealed the most prominent vascular proliferation (also highlighted by Factor VIII, an endothelial cell marker) among all groups. Group 3 showed cartilaginous proliferation with less reactive bone formation, implicating decreased endochondral ossification compared to Groups 1 and 2. CONCLUSION: This study shows that angiogenesis factor (A-Heal) and ABMDO were successful in the treatment of experimentally created BRONJ in an animal model.

Heritability of nasal characteristics assessed using lateral cephalograms.

INTRODUCTION: The midface and nasal bones have a significant influence on facial esthetics. Being able to predict the ultimate size of a growing patient's nose may influence the orthodontic treatment plan. Our study aimed to determine whether significant heritability exists between parents and children using multiple soft and hard tissue measurements of nasal dimensions. METHODS: This cross-sectional study comprised 47 Western European families from the Forsyth Moorrees Twin Study. The lateral cephalograms of each parent and postpubertal child were evaluated using 14 cephalometric variables. The resemblance and heritability patterns were estimated from the Pearson correlation coefficient and Falconer's heritability test (ie, h2 = 2 × ß estimate). RESULTS: We found significant heritability between 1 or both parents to sons, daughters, or both children for 11 measurements. Daughters were more strongly influenced by their mothers than fathers, and sons showed relatively few features strongly heritable from either parent. The nasal bone length and ANB were strongly heritable with the mother, and the nose length alone was strongly heritable with the father. In addition, 4 of the 6 measurements that were significantly heritable for daughters were horizontal measurements. CONCLUSIONS: Many nasal dimensions are significantly heritable. However, fathers more strongly influenced their daughters than sons, but mothers and daughters shared stronger and more numerous traits than fathers and daughters. Finally, horizontal traits were significantly more heritable between parents and daughters than sons.

Analysis of nasal airway symmetry and upper airway changes after rapid maxillary expansion.

INTRODUCTION: The objectives of this study were to assess the changes in right vs left nasal cavity volumes and minimum cross-sectional width, nasopharyngeal, and oropharyngeal volumes of the upper airway in response to rapid maxillary expansion (RME). METHODS: Pretreatment and posttreatment cone-beam computed tomography scans of 28 patients with a mean age of 9.86 ± 2.43 years and 20 age- and sex-matched controls were digitized and linear, angular, and volumetric measurements were obtained. RESULTS: Nasopharyngeal volume, right, and left nasal cavity volumes, and minimum cross-sectional widths increased significantly 2 years post RME (P <0.05). These measurements did not show any significant increase in the control group (P >0.05), whereas the oropharyngeal volume increase for both groups was comparable (P = 0.92). In the experimental group, the right and left nasal cavity volumes were not significantly different at baseline or posttreatment. However, the change that occurred was significantly larger for the left nasal cavity. This change for the control group was more significant for the right nasal cavity. Maxillary right and left molar inclinations were positively correlated to the nasal cavity volume, showing that the more buccally inclined the maxillary molars were, the smaller the nasal cavity volume. CONCLUSIONS: Nasopharyngeal and right and left nasal cavity volumes and minimum cross-sectional widths increase significantly after RME in young children. Expansion decreases the degree of difference in volume between the right and left nasal cavities. The buccal inclination of maxillary molars is correlated with nasal cavity volume.

An Evaluation of Microbial Flora, Alkaline Phosphatase and IL-8 Levels in GCF of Orthodontic Patients with Self-Ligating and Conventional Brackets.

PURPOSE: To compare the microbial flora, alkaline phosphatase (ALP) and interleukin-8 (IL-8) levels during orthodontic treatment with self-ligating brackets versus conventional brackets. PATIENTS AND METHODS: Forty patients were included in this study and distributed equally between two groups. One group received conventional edgewise brackets while the other group received DAMON self-ligating brackets. Periodontal parameters were recorded and biochemical and microbial analyses were conducted before bonding (baseline), and 14, 30, and 45 days after bonding. Paired t-test was performed to estimate the intergroup differences from the baseline at the various time points; unpaired t-test was used for intragroup comparisons. RESULTS: A significantly higher prevalence of gram-negative as well as gram-positive microorganisms was found in the group with conventional brackets than that with self-ligating brackets. Alkaline phosphatase (ALP) activity and interleukin-8 (IL-8) levels were significantly higher in the gingival crevicular fluid of the group with conventional brackets than that with self-ligating brackets. CONCLUSION: The conventional bracket-ligature technique exhibited an increase in IL-8 levels, ALP activity, and microbial colonization compared with that of the self-ligature technique. Accordingly, self-ligating brackets are recommended in orthodontic patients to improve periodontal health and minimize damage outcomes of periodontal tissue interventions.

Orthodontic Treatment as a Protective Factor for Dental Caries Experience and Severity: A Population-Based Study.

OBJECTIVE: The aim of this study was to assess the effects of orthodontic treatment on the experience, prevalence, and severity of dental caries later in life in a representative sample of U.S. adults. METHODS: Using a population-based study design, data from 9,486 participants in the third National Health and Nutrition Survey (NHANES), including self-reported information on the history of orthodontic treatment and its timing, were obtained. Caries experience and prevalence was assessed using the decayed (DT) and filled (FT) teeth indices (i.e., DT > 0, FT > 0, and their aggregate DFT > 0). Severe dental caries experience and prevalence was defined as DT > 2, FT > 11, and DFT > 12. Unadjusted and adjusted logistic regression models that accounted for the complex sampling design were used to assess the association between orthodontic treatment and dental caries experience, prevalence, and severity. Statistical significance was set at a P value of less than 0.05. RESULTS: The history of orthodontic treatment was reported in 19.62% of the adults. Around 94% of participants had at least one decayed or filled tooth (DFT > 0), and 21.09% met the aggregate DFT criterion for severe caries (DFT > 12). After controlling for confounding variables, a reported history of orthodontic treatment was found to significantly decrease the odds of DT > 0, DT > 2, FT > 11, and DFT > 12 (odds ratios (OR) = 0.41, 0.36, 0.74, and 0.60, respectively). CONCLUSION: A history of orthodontic treatment was a protective factor for untreated dental caries, in assessments of the severity and prevalence of dental caries experience.