Do nasal and nasopharyngeal obstruction and their medical-surgical deobstruction significantly influence facial divergence? A concise review of major clinical studies with meta-analysis

Introduction: The term « adenoid facies » suggests a causal relationship between nasopharyngeal obstruction and facial hyperdivergence in growing subjects. The strength of this association is controversial and few « quantified » values exist.

Materials and methods: A rapid electronic search was conducted on PubMed and Embase to find the main cephalometric studies involving patients with nasal/nasopharyngeal obstruction compared to a control sample. A meta-analysis was carried out to quantify the effect of obstruction (1) and intervention to relieve the obstruction (2) on mandibular divergence (SN/Pmand angle), maxillo-mandibular divergence (PP/Pmand angle), inclination of the occlusal plane (SN/Poccl) and the gonial angle (ArGoMe).

Results: Qualitatively, the studies' bias level ranged from moderate to high. Results were concordant about the significant effect of the obstruction on facial divergence (1) with an increase in SN/Pmand (+3.6° on average, +4.1° in children <6 years), PP/Pmand (+5.4° on average, +7.7° <6 years), ArGoMe (+3.3°) and SN/Pocc (+1.9°). Surgical interventions to remove the respiratory obstacle in children (2) generally did not normalize the direction of growth, with the exception, with a very low level of evidence, of adenoidectomies/adeno-tonsillectomies, performed at an age less than 6-8 years.

Conclusion: Early detection of respiratory obstacles and postural abnormalities associated with oral breathing appears to be decisive in order to hope for management at a young age and normalization of the direction of growth. However, the effects on mandibular divergence remain limited, requiring caution, and cannot be considered a surgical indication.