Assessing the Relationship Between Anatomical Measurements and Nitrous Oxide Sedation Outcomes in Children: A Prospective Cross-Sectional Study

Background Nitrous oxide sedation is a widely used pharmacological behaviour management technique in pediatric dentistry. Despite its high success rate, variability in sedation outcomes is commonly observed. Anatomical factors may influence nitrous oxide requirements, yet they have not been well established. This study aimed to assess the relationship between body mass index (BMI), Mallampati score, and nasal index with sedation outcomes in children undergoing dental procedures. Methods A prospective cross-sectional study was conducted among 96 children aged 3–7 years requiring dental treatment under nitrous oxide (N ₂ O) sedation. Anatomical parameters, including BMI, Mallampati score, and nasal index, were recorded using a structured case record form. Sedation was administered via incremental titration, and the final N ₂ O concentration required for effective sedation was documented. Sedation effectiveness was evaluated using the Houpt Behaviour Rating Scale. Spearman’s rank correlation was used to assess the relation between anatomical parameters and N ₂ O sedation requirements. Results BMI demonstrated a significant positive correlation with Mallampati score and nitrous oxide concentration. The Mallampati score also showed a significant positive correlation with N ₂ O concentration. Nasal index showed a weak, non-significant positive correlation with N ₂ O concentration. Behavioural outcomes were favourable with 78.2% of children achieving good to excellent sedation ratings on the Houpt scale, and adverse events were minimal (2.1%). Conclusions BMI and Mallampati score were significant predictors of N ₂ O sedation requirements, while nasal index showed only a non-significant trend. Incorporating simple anatomical assessments into pre-sedation evaluation may help anticipate sedation needs, improve safety, and optimise treatment outcomes in pediatric dental patients. Further multicentre research is warranted to validate these findings. Trial registration: Clinical trial number: not applicable