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

Abstract

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. 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). 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. 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.