The effect of birth weight on tooth development by Demirjian's method.

OBJECTIVES: The aim of this study was to investigate the impact of birth weight on tooth development in children aged 7-8 years. MATERIALS AND METHODS: This retrospective cohort study comprised 75 children born at Bint Al-Huda Hospital, Bojnurd, in 2013-2014. The children were categorized into three groups based on their birth weight: Normal Birth Weight (NBW), Low Birth Weight (LBW), and Very Low Birth Weight (VLBW). Panoramic radiographs were taken for orthodontic examination, and Demirjian's 8-teeth method was employed to determine dental age. The study compared dental and chronological age within each group. Data analysis utilized SPSS software version 26, employing One-way ANOVA and chi-square tests. Statistical significance was set at P ≤ 0.05. RESULTS: The mean difference in dental and chronological age for Very Low Birth Weight (VLBW) children was 0.22 ± 0.44 years, for Low Birth Weight (LBW) children it was 0.19 ± 0.45 years, and for Normal Birth Weight (NBW) children, it was 0.08 ± 0.46 years. Although the mean difference decreased with increasing birth weight, this trend did not achieve statistical significance (P = 0.55). Furthermore, no significant differences were observed between the weight groups (P = 0.529) or genders (P = 0.191).

Evaluation of Zygomaticosphenoidal Angle in Patients With Unilateral Zygomaticomaxillary Complex Fracture.

ABSTRACT: This study aimed to assess the zygomaticosphenoidal (ZS) angle in patients with reducted unilateral zygomatico-maxillary complex (ZMC) fracture and compare it with the normal control group. This study was performed on CT images of 60 cases and 60 controls with a mean age of 35.1 ±â€Š14.6. The ZS angle was measured on axial images containing the equator of the eyeball. Moreover, the mean absolute difference value and asymmetry index were calculated. Chi-square test, independent-sample t test, 1-way ANOVA, paired-sample t test, and ROC curve analysis were applied. The mean ZS angle in the control group was 46.6°â€Š±â€Š3.5°. Considering laterality, the mean of ZS was not significant in the control group. However, after reduction of unilateral ZMC fracture, there was a significant difference between the mean ZS angle in right and left sides. The mean absolute difference between right and left ZS angles was significantly higher in the case group. A threshold number of 0.9° is established in the mean absolute difference value which is the difference between the right and left ZS angles in an individual for detecting asymmetry. The ZS angle can be a useful anatomical aid to guide surgeons in achieving facial symmetry in ZMC fractures.

Evaluating the presence of IAN injury in patients with juxta-apical radiolucency after third molar surgery: a retrospective cohort study.

BACKGROUND: Juxta-apical radiolucency (JAR) has been presented as a radiographic sign, suggestive of the IAN injury through third molar surgery. This study aimed to evaluate the relation of JAR with IAN injury in cone-beam computed tomography (CBCT) images and to determine whether the presence of JAR is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates. METHODS: Of an initial sample of 545 mandibular third molars, a total of 75 JAR+ and 75 JAR- teeth were evaluated by CBCT. We assessed the relationship between the presence of JAR in cone-beam computed tomography (CBCT) images and the presence of IAN injury after mandibular third molar surgeries. Moreover, we investigated whether the presence of IAN injury is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates. Descriptive statistics, Chi-square test, and Fisher's exact test were performed for statistical analysis. RESULTS: A significant relationship was found between JAR and temporary IAN injury (P = 0.036). However, there was no case of permanent IAN injury. IAN injury showed no significant relationship with the tooth angulation, position to IAN and proximity to the mandibular canal, lingual cortical plate thinning, sex, and age. CONCLUSIONS: JAR is generally in contact with the mandibular canal, and some degree of cortical thinning can be found in most cases. In this study, JAR was significantly related to temporary IAN injury. JAR may increase the risk of nerve injury during the surgical removal of third molars.