Background/Objectives: This study investigates the etiology of enamel developmental defects, specifically Molar Incisor Hypomineralization (MIH), and explores correlations between MIH and dental anomalies such as hypodontia to improve interdisciplinary restorative and orthodontic treatments. Additionally, it assesses the influence of stress factors on the development of enamel defects. Methods: Conducted from July to September 2024, this study involved 57 patients aged 6 to 11 from an urban setting, divided into two groups: 32 with MIH and 25 controls, selected based on criteria of mixed dentition without systemic pathology or chronic medication. Clinical evaluations, including intraoral photographs and panoramic radiographs, were performed alongside a detailed questionnaire addressed to the mothers covering prenatal, perinatal, and postnatal factors. Results: The average age of children with MIH was 7.5 years, in contrast to 7.04 years in the control group (p = 0.17). Significant differences were noted in maternal age, with MIH mothers older (35.56 years) than controls (29.36, p = 0.0001). The prevalence of MIH was higher in boys (66.7%) compared to girls (38.1%, p = 0.036). Factors such as prolonged labor, medication during birth, and early postnatal medication were significantly linked to MIH. The study shows a strong correlation with hypodontia, with a significantly higher incidence of tooth number anomalies (p = 0.009) in the study group. Conclusions: Overall, the study emphasizes the association of MIH with various maternal and birth-related factors and with hypodontia, highlighting the need for a comprehensive, multidisciplinary approach to diagnosis and treatment. Further research is recommended to investigate the relationship between stress factors and MIH.