Journal of Dental Medicine

Background and Aims: One of the concerns of dentists is selecting a suitable brand of stainless steel crowns with maximum dimensional adaptation with primary teeth. The aim of this study was to compare the primary molar crown dimensions with that of two brands of stainless steel crowns (SSCs) in a sample of Iranian children.
Materials and Methods:  In this study, 130 eligible children between 3 and 12 years (66 boys, 64 girls) were selected. After recording the demographic information, the mesiodistal, buccolingual and occluso-gingival dimensions of first (D) and second (E) primary molars were measured on dental casts and compared with the dimensions of KTR (MeiMeiMinBenjing, Benjing, China) and Shinghung (Shinhungcompany, Seoul, South Korea) SSCs. Data were assessed using chi-square test and Pearson correlation coefficient. P<0.05 was considered statistically significant.
Results: In this study, the most dimension matching of the teeth with that of SSCs were observed mesiodistally in upper D and lower D, buccolingualy in the upper D and lower D, and occluso-gingivaly in upper D and lower E. The most cases of mismatch in the mesiodistal dimensions of the teeth with that of SSCs were observed in the lower E and upper D. Also, the most cases of mismatch in the buccolingual dimension were found for upper E and lower E.
Conclusion: Both SSCs brands in this study showed significant dimensional adaptation with the primary teeth in Iranian children. The most dimensional adaptation was between KTR SSCs and maxillary primary molars, and between Shinhung SSCs and mandibular primary molars.

Background and Aims: The white color of teeth is one of the most essential factors in smile esthetics. Therefore, various whitening agents such as bleaching mouthwashes have been produced in response to the people’s high demand for having whiter teeth. The present study evaluated the efficacy of three whitening mouthwash products on tooth enamel whiteness.
Materials and Methods: In the present in vitro study, 32 bovine incisors were assigned to four groups in terms of the mouthwash used (n=8): control (C); Xenon Smart White (ZSW), containing pyrophosphate and triphosphate; Signal White Now (SWN), containing Blue Covarine; and Pasta Del Capitano whitening mouthrinse (PCW), containing Plasdone. Colorimetry was carried out using a spectrophotometer at the baseline and 2, 4, 8, and 12 weeks after treatment with mouthwashes. Data were analyzed using CIELab parameters with ANOVA, RM two-way ANOVA, and post hoc Tukey tests (α=0.05).
Results: The results showed that the whiteness created by the SWN mouthwash was clinically visible (ΔE>3.3). However, the functions of all the mouthwashes were statistically similar with no significant differences from the control group (P>0.05).
Conclusion: Although, Blue Covarine-containing mouthwash was somewhat effective in whitening of tooth enamel, none of the mouthwashes had significant efficacy compared to distilled water.

Background and Aims: Mandibular third molar is the most common impacted tooth and craniofacial morphology and facial parameters can be appropriate predictors of impaction of this tooth. The aim of this study was to evaluate the relationship between Gonial angle, mandibular plane inclination, and ramus height with the impaction of mandibular third molar.
Materials and Methods: This retrospective descriptive-analytical study was performed by analysis of lateral cephalometric radiographic images of 172 patients in city of Zahedan in 2020. The status of eruption of mandibular third molars was determined by clinical examination and assistance of panoramic radiographic images and samples were categorized into four groups: fully erupted (1), partially impacted (2), impacted (3), partially developed (4). Then, the Gonial angle, mandibular plane, and ramus height were measured on lateral cephalometric images of each group and collected data were analyzed by Chi-square test and analysis of variance (ANOVA).
Results: Among the patients, 68.02% were female and 31.97% were male. The difference between the mean values of Gonial angle of four groups was not statistically significant (P>0.05). In the fourth group, the mean value of mandibular plane inclination was significantly higher (29.74) and the mean value of the ramus height was significantly less (49.21 mm) than other groups.
Conclusion: According to the preformed analysis and obtained results, Gonial angle, mandibular plane, and ramus height were not accurate predictors for the impaction of mandibular third molar and further studies should be undertaken in this filed.

Background and Aims: Bimaxillary dentoalveolar protrusion (BDP) is a common orthodontic anomaly characterized by protrusive dental arches and lip prominence. Extraction of the first premolars is a frequently employed treatment approach in these patients. However, the effect of this intervention on Bolton ratios-particularly the overall and anterior ratios-remains unclear. This study aimed to evaluate the impact of first premolar extractions on Bolton ratios in patients with BDP.
Materials and Methods: This experimental study was conducted on archived physical models of 34 Class I patients with BDP and functional lip incompetency (>4 mm) accompanied by lip protrusion, available at the Orthodontics Department of School of Dentistry, Babol, in 2024. All patients had a full complement of teeth from the first incisor to the first molar in each quadrant. After digitizing the models, mesiodistal tooth widths and the overall and anterior Bolton ratios were calculated. Digital simulation of first premolar extraction was performed, followed by reassessment of Bolton ratios. Pre- and post-treatment values were statistically compared using paired t-tests in SPSS (significance level set at 0.05).
Results: Among 34 studied casts, 67.6 % belonged to females. The mean overall Bolton ratio decreased significantly from 90.33 ± 2.23% to 87.72 ± 2.39%, and the anterior ratio declined from 78.19 ± 2.96% to 77.85 ± 3.03% (P<0.001). Additionally, 15 patients exhibited residual space post-treatment, primarily in the mandibular arch.
Conclusion: Based on the results of the present study, first premolar extraction significantly reduced both the overall and anterior Bolton ratios in patients with bimaxillary dentoalveolar protrusion. However, the likelihood of residual space—particularly in the lower arch-should be carefully considered during orthodontic treatment planning to ensure long-term stability and success.