Hussain Y. A. Marghalani

Background: Twin studies comparing craniofacial and dental characteristics in monozygotic and dizygotic twins help to differentiate genetic from environmental influences. This study assessed sella turcica morphology and taurodontism in relation to dental and skeletal relationships among twins in Saudi Arabia. Methods: A cross-sectional study was conducted among 64 twins (15 monozygotic pairs and 17 dizygotic pairs), aged 6–16 years, in Jazan, Saudi Arabia. Sella turcica morphology, size, and bridging were assessed using cephalometric images, while taurodontism was evaluated using panoramic radiographs. Skeletal and dental malocclusions were classified using established orthodontic criteria. Significant statistical analysis of comparisons and associations was set at p < 0.05. Results: No significant differences were observed between monozygotic and dizygotic twins regarding sella turcica size or morphology, skeletal and dental classifications, and first molar taurodontism indices. The sella turcica depth (p = 0.01) and anteroposterior width (p = 0.03) were positively associated with dental class III malocclusion, and sella depth (p = 0.02) was positively associated with age. Mandibular molar taurodontism (tooth #46) was positively associated with dental Class II and Class III malocclusions and negatively associated with age. Maxillary molar taurodontism (tooth #16) showed a significant positive association with dental Class III malocclusion. The sella bridging and sella shape categories showed low within-pair concordance ( 0.20). Conclusions: Zygosity was not significantly associated with sella turcica characteristics, taurodontism, or dental and skeletal relationships in this cohort. However, selected sella turcica dimensions and taurodontism indices were associated with malocclusion patterns and age, warranting further investigation.

Background: Preheating resin‐based composites (RBC) has been shown to enhance their mechanical and bonding properties. Nevertheless, the effect of preheating RBCs on the performance of orthodontic lingual fixed retainers has been scarcely reported. Objectives: The aim of this in vitro study was to investigate the effect of preheating flowable RBCs and the types of RBC and wire on the load at failure. Methods: A total of 64 blocks of resin‐embedded pairs of lower incisors were divided into four groups according to RBC/wire types (Tetric N‐Flow Bulk Fil restorative (TNF) vs. Transbond LR orthodontic (TRL) composites/Bond‐A‐Braid braided (B) vs. Ortho‐Flex‐Tech flexible (O) retainer wires). Each group was then subdivided into room temperature at 25°C (RT) and preheated temperature at 50°C (H) subgroups ( N = 16, n = 8). After bonding the wires, the test blocks were subjected to load‐to‐failure testing, and the maximum load was recorded (Lmax). Statistical analysis using 3‐way ANOVA with point‐biserial correlations was completed ( p < 0.05). Results: Temperature significantly increased L _max ( p < 0.001). Mean L _max of TRL/B was greater than TNF/O but was not statistically significant ( p > 0.05). There was no statistically significant interaction between the variables: RBC, wires, and/or temperature ( p > 0.05). Conclusion: The study shows preheating RBCs improves their load capacity, reducing lingual retainer adhesive debonding. Therefore, preheating flowable RBCs is effective for retention. Future research should explore different preheating temperatures and long‐term outcome conditions.

Background Assessing the relationship between the condyle and mandible volume and the various skeletal classes is essential in orthodontic diagnosis. The current study evaluated this relationship using volumetric cone-beam computed tomography (CBCT), cephalometric methods, and the correlations between them. Materials and Methods The study examined 37 full-head CBCTs (74 condyles) from adults in the Saudi population. The condyle and mandible were separated from within the CBCT images. The volume of each segment was compared to measurements from multiple cephalometric analyses. Results The combined total condylar volume has a moderate correlation with the maxillomandibular differential in each of the genders and in the total sample. Mandibular volume has a significant correlation with the Wits appraisal (sagittal classification) in males. It was also significantly correlated with the vertical classification using gonial angles in females and in the total sample. Conclusion The relationship between mandible and condyle volume and cephalometric measurements is both dimensional and within the maxillomandibular complex rather than positional or related to the cranial base. Also, the correlation between the condylar and mandibular volumes and the sagittal and vertical dimensions in the orthodontic skeletal classes provides better insight into the mandibular complex.

This study compared tooth color and enamel and dentinal thickness between orthodontically treated and untreated individuals. (1) Methods: A matched case–control study was conducted. The sample included 26 patients who had received orthodontic treatment and 31 matched controls. The color assessment was performed subjectively using the VITA 3D-Master (VM) shade guide and objectively using the VITA Easyshade (VE) spectrophotometer. Differences in L*, a*, and b* (lightness, red/green, and blue/yellow) were calculated. The color change was evaluated using ΔE*ab and the whiteness index (WID). Tooth structure thickness (labiolingual, labial enamel, and labial dentin) was evaluated using cone-beam computerized tomography. The correlations between overall tooth color and tooth structure thickness were evaluated. (2) Results: A total of 228 teeth were evaluated. Color assessment using VM showed significant differences between orthodontically treated and untreated teeth (p < 0.001), while VE revealed no significant differences. Both groups showed no difference in tooth enamel and dentinal thickness. Significant differences in tooth color (p < 0.05) were observed between genders. Both VM and VE showed weak to moderate correlations with tooth color and enamel and dentinal thickness (p < 0.05). (3) Conclusions: Orthodontic treatment may demonstrate visually perceptible but acceptable and clinically undetectable tooth color alteration.

Objectives: To compare the maxillary sinus volume between both sides in adult patients with upper occlusal canting (>2 mm cant) and a control group (≤2 mm cant) using cone‐beam computed tomography scans.Materials and methods: This retrospective study included a total of 84 scans (42 scans per group) according to predetermined selection criteria. OnDemand 3‐D™ software was used for volumetric and linear measurements of the maxillary sinus. Maxillary occlusal canting was determined at the level of the maxillary first molars. It was defined as the vertical difference between right and left sides relative to the Frankfort horizontal plane. Non‐parametric tests were applied.Results: The median difference in the maxillary sinus volume between the sides was statistically significant between the control and cant groups (P < 0.001). Also, the median difference in the maxillary sinus craniocaudal height and apex sinus distance between the sides was statistically significant between the control and cant groups (P < 0.05 and P < 0.001, respectively).Conclusion: In adult patients, maxillary occlusal canting of more than 2 mm was associated with asymmetric maxillary sinus volumes. In the cant group, maxillary first molars on the canted‐down side were in close proximity to the sinus floor, which suggests a limited leeway for molar intrusion.

Background: The knowledge of dimensions of the symphysis is important for morphological and orthodontic studies. This research evaluates the association between mandibular symphysis dimensions and anteroposterior and vertical skeletal patterns in adults. Materials and methods: This cross-sectional cephalometric study included 90 lateral cephalograms of untreated subjects presenting for orthodontic treatment. The inclusion criteria were adults with lateral cephalograms showing the symphyseal region and anterior cranial base. One investigator traced and analyzed all cephalograms. Symphyseal height, thickness, and ratio between height and thickness were measured in relation to seven anteroposterior and vertical skeletal measurements in females and males. Results: Symphyseal measurements were associated with SNA^o (anteroposterior) in females and Gonial angle (vertical) in males. When analyzed by anteroposterior skeletal classification (ANB^o), no significant differences in symphyseal dimensions were found. Multiple linear regression analyses showed that Gonion-Nerve (mm) and Gonial angle were significantly associated with symphyseal height. Gonion-Nerve (mm), basal bone width (mm), and alveolar bone height (mm) were associated with symphyseal thickness. Basal bone width (mm) and alveolar bone height (mm) were associated with symphyseal ratio. Conclusions: Symphyseal dimensions were significantly associated with vertical but not anteroposterior skeletal patterns. Future studies are warranted to evaluate the Gonion-nerve measurements concerning the symphysis in relation to vertical and anteroposterior skeletal patterns. Background: The knowledge of dimensions of the symphysis is important for morphological and orthodontic studies. This research evaluates the association between mandibular symphysis dimensions and anteroposterior and vertical skeletal patterns in adults. Materials and methods: This cross-sectional cephalometric study included 90 lateral cephalograms of untreated subjects presenting for orthodontic treatment. The inclusion criteria were adults with lateral cephalograms showing the symphyseal region and anterior cranial base. One investigator traced and analyzed all cephalograms. Symphyseal height, thickness, and ratio between height and thickness were measured in relation to seven anteroposterior and vertical skeletal measurements in females and males. Results: Symphyseal measurements were associated with SNA^o (anteroposterior) in females and Gonial angle (vertical) in males. When analyzed by anteroposterior skeletal classification (ANB^o), no significant differences in symphyseal dimensions were found. Multiple linear regression analyses showed that Gonion-Nerve (mm) and Gonial angle were significantly associated with symphyseal height. Gonion-Nerve (mm), basal bone width (mm), and alveolar bone height (mm) were associated with symphyseal thickness. Basal bone width (mm) and alveolar bone height (mm) were associated with symphyseal ratio. Conclusions: Symphyseal dimensions were significantly associated with vertical but not anteroposterior skeletal patterns. Future studies are warranted to evaluate the Gonion-nerve measurements concerning the symphysis in relation to vertical and anteroposterior skeletal patterns.

Background: Few studies have investigated the volumetric relationship between the condyles and the mandible bilaterally. Materials and methods: Condylar and mandibular segmentations from a sample of CBCTs for 37 individuals were selected. T-test, correlation and linear regression analyses were performed to assess the relationships between the volumes of the condyles and mandible. Results: The volume of the condyles and the mandible was significantly different between genders, p<.05. There was a significant but moderate correlation between the volumes of the condyle and the rest of the mandible on the same side (p<.01). A regression analysis model demonstrated that condylar volume is related to the volume of the mandible. Conclusions: The relationship between the condylar volume and the rest of the mandible was found to be moderate. The relation between the condylar volume and mandibular volume is described by the regression equations for each side of the jaw. Sexual dimorphism exists in condylar and mandibular volumes. Background: Few studies have investigated the volumetric relationship between the condyles and the mandible bilaterally. Materials and methods: Condylar and mandibular segmentations from a sample of CBCTs for 37 individuals were selected. T-test, correlation and linear regression analyses were performed to assess the relationships between the volumes of the condyles and mandible. Results: The volume of the condyles and the mandible was significantly different between genders, p<.05. There was a significant but moderate correlation between the volumes of the condyle and the rest of the mandible on the same side (p<.01). A regression analysis model demonstrated that condylar volume is related to the volume of the mandible. Conclusions: The relationship between the condylar volume and the rest of the mandible was found to be moderate. The relation between the condylar volume and mandibular volume is described by the regression equations for each side of the jaw. Sexual dimorphism exists in condylar and mandibular volumes.

Objectives: Many countries have enforced lockdowns on their populations due to the coronavirus disease 2019 (COVID‐19) pandemic. This study aimed to assess the effects of the lockdown on dental students.Methods: A longitudinal, repeated cross‐sectional study was conducted to evaluate psychological problems experienced by dental students during the COVID‐19 lockdown in Saudi Arabia. The dental students were selected from different universities using 2‐stage cluster sampling. The validated Arabic version of the 21‐item depression, anxiety, and stress scale questionnaire was distributed at the beginning and end of the lockdown. Mann–Whitney U and Kruskal–Wallis tests were used as appropriate. Chi‐square test was used to compare the proportions between the sociodemographic data, and logistic regression analysis was used to identify variables associated with the students’ responses.Results: A total of 1287 respondents participated in this study (695 first‐survey respondents, 592 second‐survey respondents). There were longitudinally significant differences in the students’ mental health outcomes based on gender, university, class year, and survey time during the COVID‐19 lockdown. The lockdown increased the likelihood of female, single, and junior students experiencing stress. The students who lived alone recorded a high chance of elevated levels of depression, anxiety, and stress, which showed a significant longitudinal reduction during the lockdown. Moreover, the lockdown increased the likelihood of mental health problems among the students staying in households of two persons or two‐five persons.Conclusions: This study indicates the importance of considering the detrimental mental health consequences on dental students in the event of future pandemics.

Introduction: Pursuing an esthetically-pleasing orthodontic outcome, orthodontic patients must consider and choose from the different available options of orthodontic appliance. Practitioners need to be better informed of their customers’ preferences to make better practice management decisions and satisfy their patients’ needs. Purpose: To explore adult laypeople’s perceptions of the attractiveness, acceptability, preference and economic value of different orthodontic appliances when they consider these appliances for themselves and for their children. Patients and methods: This cross-sectional survey included 199 adults (110 females). The average age of participants was 27.7 years. Participants answered a questionnaire evaluating and comparing multiple smiling images of an adult wearing different orthodontic appliances. Participants rated each appliance for: (1) attractiveness on a Likert scale; (2) acceptability of having the appliance placed for themselves and their children (with a yes/no response); (3) preference (by ranking all appliances in order); and (4) economic value (by providing the additional amount they are willing to pay for each appliance for themselves and their children). Results: We found a statistically significant difference in the attractiveness scores between the different orthodontic appliances (p< 0.0001). The most attractive appliances were clear aligners and lingual brackets. The least attractive appliances were colored o-tied-brackets followed by shaped-brackets. Clear aligners were the most acceptable appliances among our participants to have placed on themselves (86.9%) and their children (84.9%). Shaped brackets were the least acceptable appliances among our participants to have placed on themselves (24.1%) and their children (36.2%). The most preferred appliances were lingual brackets (39.2%), followed by clear aligners (34.17%). The least preferred appliances were colored o-tied-brackets (4%). Participants varied with regards to how much more they were willing to pay for each of the different orthodontic appliances. The majority were willing to pay more for clear aligners and lingual brackets to have them placed on themselves but not to have them placed on their children. Conclusion: Adults preferred more innovative esthetic appliances over traditional ones and were willing to pay more to have them placed on themselves but not on their children.

Facial growth in the vertical dimension is the last to be completed and can often be detrimental to the success of dental implants, orthodontic treatment, and orthognathic surgery that young individuals undergo.