Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis.

AIM: This study aimed to describe gender-specific three-dimensional morphology of the soft-tissue nose in Lebanese young adults and to explore the associations between nasal morphology with age and body mass index (BMI). MATERIALS AND METHODS: Three-dimensional photographs were captured for 176 young healthy Lebanese adults (75 males and 101 females) aged 18.1-37.68 years. Linear and angular nasal measurements were computed and compared between genders, in addition to other established norms. Associations with age and BMI were also assessed. RESULTS: All linear measurements were greater in males than in females, and only the nasolabial angle was significantly larger in females by 2.97 degrees on average. Most of the measurements were found to be larger than the Caucasian norms. A few significant correlations were found between the measurements and age or BMI. CONCLUSION: This study is the first to present the sex-specific norms for nasal morphology in the Lebanese population and highlights the presence of gender dimorphism in the majority of measurements. Additional studies are needed to validate our data and expand the associations with age and BMI. CLINICAL SIGNIFICANCE: The data offered in this study could help enhance the accuracy of facial reconstructive surgery and aid in personalized treatment planning for both medical and cosmetic nasal interventions. How to cite this article: Saadeh M, Shamseddine L, Fayyad-Kazan H, et al. Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis. J Contemp Dent Pract 2024;25(3):199-206.

Composition's effect of Origanum Syriacum essential oils in the antimicrobial activities for the treatment of denture stomatitis.

This research has several purposes: First to assess the bacterial and fungal minimum inhibitory concentration of Origanum Syriacum essential oil. Second to quantify its bactericidal and fungicidal minimal concentration against S. aureus, S. mutans, and C. albicans found in denture stomatitis. The third purpose is to look at the influence of three different soils (Annaya, Bhanin and Michrif) on the essential oils composition. Three essential oils were extracted by hydro-distillation from three different Origanum Syriacum plant origins. Bioassays were conducted using a broth microdilution methods. Gas Chromatography analysis was used to calculate the abundance of most components in each essential oil. Post hoc tests assessed antimicrobial effects between ecotypes while Pearson's test correlated the different components and their antimicrobial efficiency (α < 0.05). All tested essential oils were efficient against all microorganisms. Origanum Syriacum essential oils derived from Annaya and Bhanin soils showed a superior antimicrobial activity compared to the Michrif one. The most abundant component and most efficient among all essential oils constituents was carvacrol. It can be concluded that Origanum Syriacum essential oils have an antimicrobial activity, which depends on the ecotype, its origin and its composition. They might be used to start a clinical trial for the treatment of denture stomatitis.

Relative Translucency of a Multilayered Ultratranslucent Zirconia Material.

AIM: The aim of this study was to compare the translucency parameter (TP) of ultratranslucent multilayered (UTML) zirconia according to thickness and layer level. MATERIALS AND METHODS: Rectangles of UTML zirconia with four layers [dentin layer (DEL), first transitional layer (FTL), second transitional layer (STL), and enamel layer (ENL)] and four different thicknesses (0.4, 0.6, 0.8, and 1 mm) were milled from blanks. Digital images were taken in a dark studio against white and black backgrounds under simulated daylight illumination and international commission on illumination (CIE) Lab* color values recorded using Photoshop Creative Cloud software. The TP was computed and compared according to thickness and layer level using analysis of variance (ANOVA) followed by Bonferroni post hoc analysis for multiple comparisons. Significance was set at p < 0.05. RESULTS: In each thickness, TP values were similar between any two layers. The significant effect of thickness on the TP was observed only in the first two layers. In the DEL, translucency was significantly greater at 0.4 mm than all other thicknesses. In the FTL, differences were significant between 0.4 and 0.8 mm and between 0.4 and 1 mm. CONCLUSION: The investigated zirconia does not seem to show gradational changes in relative translucency from dentin to enamel levels regardless of the thickness used. Thickness affected the TP only in the first two layers with better translu-cency at 0.4 mm. CLINICAL SIGNIFICANCE: Since relative translucency does not seem to be significantly different between layers, clinicians can modify the apicocoronal positioning of the UTML layers within the restoration according to the desired Chroma without any implications on the clinically perceived translucency. While the thickness of 0.4 mm may be suggested for anterior esthetic veneers because of its higher translucency, the other thicknesses of 0.6 to 1 mm can be used to mask colored abutments in full contour restorations.

Fit of pressed crowns fabricated from two CAD-CAM wax pattern process plans: A comparative in vitro study.

STATEMENT OF PROBLEM: Subtractive and additive computer-aided design and computer-aided manufacturing (CAD-CAM) wax pattern processing are 2 methods of fabricating a pressed ceramic crown. Whether a subtractive milled wax pattern or a pattern from the micro-stereolithography additive process produces lithium disilicate crowns with better marginal and internal fit is unclear. MATERIALS AND METHODS: Ten silicone impressions were made for a prepared canine tooth. Each die received 2 lithium disilicate (IPS e.max) copings, 1 from milled wax blocks and 1 from additive wax. The replica technique was used to measure the fit by scanning electron microscopy at ×80 magnification. Collected data were analyzed using the paired Student t test for the marginal and internal fit. For the occlusal fit, the difference in scores did not follow a normal distribution, and the Wilcoxon signed rank test was used (α=.05). RESULTS: The mean marginal, axial, and occlusal fit showed no significant differences when the 2 CAD-CAM manufacturing processes were compared (P>.05). For the marginal fit, the mean (±SD) values were 105.1 µm ±39.6 with the milled process and 126.2 µm ±25.2 for the additive process. The mean values were 98.1 µm ±26.1 for the axial fit in the milled process and 106.8 µm ±21.2 in the additive process. For the occlusal fit, median values (interquartile interval) were 199.0 µm (141.5 to 269.9) for subtractive manufacturing and 257.2 µm (171.6 to 266.0) for micro-SLA manufacturing. CONCLUSIONS: No significant difference was found between the fit of the 2 techniques. The mean values of axial and occlusal median values were 10 and 5 to 6 times greater than machine's nominal values.

Impact of a Core Ferrule Design on Fracture Resistance of Teeth Restored with Cast Post and Core.

Objectives. To investigate the influence of a contra bevel on the fracture resistance of teeth restored with cast post and core. Materials and Methods. Sixty plastic analogues of an upper incisor were endodontically treated and prepared with 6° internal taper and 2 mm of ferrule in order to receive a cast post and core. The prepared samples were divided into two groups (n = 30); the first group serves as control while the second group was prepared with an external 30° bevel on the buccal and lingual walls. All samples crowned were exposed to a compressive load at 130° to their long axis until fractures occurred. Fracture resistance loads were recorded and failure modes were also observed. Mann-Whitney test was carried out to compare the two groups. Results. Mean failure loads for the groups were, respectively, 1038.69 N (SD ±243.52 N) and 1078.89 N (SD ±352.21 N). Statistically, there was no significant difference between the two groups (P = 0.7675 > 0.05). Conclusion. In the presence of a ferrule and a crown in the anterior teeth, adding a secondary ferrule to the cast post and core will not increase the resistance to fracture.

Marginal and internal fit of pressed ceramic crowns made from conventional and computer-aided design and computer-aided manufacturing wax patterns: An in vitro comparison.

STATEMENT OF PROBLEM: To our knowledge, no studies have evaluated the influence of the wax fabrication technique on the internal adaptation and marginal accuracy of pressed ceramic single crowns. PURPOSE: The purpose of this in vitro study was to compare the marginal and internal fit of a lithium disilicate crown fabricated either from conventional waxing or from a subtractive milled wax pattern. MATERIAL AND METHODS: Ten silicone impressions were made for a maxillary canine prepared to receive a complete crown. Two pressed lithium disilicate glass ceramic copings were made on the die poured from each impression. The first was from a conventional wax pattern and the second from milled wax blocks. The replica technique was used to measure the fit by scanning electron microscope at ×80 magnification. Collected data were analyzed with the paired Student t test for the marginal and wall fit. For the occlusal fit, the difference in scores did not follow a normal distribution, and the Wilcoxon signed ranks test was used (α=.05). RESULTS: The mean values +SD were 170.3 ±50.7 µm for the marginal fit and 130.3 ±21.6 µm for the internal fit with the conventional technique. For the computer-aided design and computer-aided manufacturing (CAD-CAM) technique, they were 105.1 ±39.6 µm and 98.1 ±26.1 µm. Statistical significance was found for the marginal and internal fit (P<.05). The occlusal fit median and interval interquartile scores were 305.0 µm (269.9 to 334.4) for conventional fabrication and 199.0 µm (141.5 to 269.9) for subtractive manufacturing. The differences were not statistically significant (P>.05). CONCLUSIONS: The subtractive CAD-CAM waxing technique resulted in the improved fit of a pressed lithium disilicate crown by decreasing the marginal discrepancies and internal adaptation.

Effect of tapering internal coronal walls on fracture resistance of anterior teeth treated with cast post and core: In vitro study.

When fabricating indirect post and core, internal coronal walls are tapered to remove undercuts and allow a better adaptation. To evaluate the fracture strength of anterior tooth reconstructed with post and core and crowned, with two different taper of internal coronal walls, 6° and 30° to the long axis, two groups of 30 clear plastic analogues simulating endodontically treated maxillary central incisors were prepared. The analogues crowned were subjected to a compressive load with a 1-kN cell at a crosshead speed of 0.05 mm/min at 130° to the long axis until fracture occurred. Data were analyzed by Lillifors and Mann-Whitney tests. Mean failure loads for the groups were as follows: group I 1038.69 N (standard deviation ±243.52 N) and group II 1231.86 N (standard deviation ±368.76 N). Statistical tests showed significant difference between groups (p = 0.0010 < 0.01). Increasing the taper of internal coronal walls appears to enhance the fracture resistance of anterior maxillary teeth post and core reconstructed.

Mandibular canine dimorphism in establishing sex identity in the lebanese population.

Background and Objective. In forensic investigations, mandibular canines provide excellent materials to identify gender since they are more likely to survive disasters. The objective of this study was to investigate gender dimorphism by comparing the mesiodistal width of mandibular permanent canines and intercanine distance in a group of Lebanese population. Methods. Participants consisted of undergraduate students from the School of Dentistry, Lebanese University, for two academic years who fulfilled the inclusion criteria. Canine widths and intercanine distance were measured by one operator directly on dental casts using a digital caliper. Results. One hundred thirty-three Lebanese dental students (54 males and 69 females) aged 18-25 were included in the study. The intercanine distance was significantly greater in males (P value < 0.0001). The right and the left canine widths were significantly greater in males than in females (P value < 0.0001). However, no significant difference was found between left and right canines for males (P value > 0.05) and females (P value > 0.05). The mean width of canine was greater than 7.188 mm for males. Conclusion. The parameters measured in the present study are of great help in sex identification in forensic investigations in the Lebanese adult population.