A systematic review to assess the anatomical correlates of the notches in acoustic rhinometry

Background:  The graph obtained by Acoustic Rhinometry in most studies of normal adult Caucasian individuals clearly shows two notches at the beginning of the rhinogram. However, we found different opinions in the literature regarding the anatomical correlation of the anterior notches.Objective of review:  The aim of this study was to identify and to discuss papers providing objective evidence of anatomic correlation of two anterior notches.Type of review:  A systematic review of the literature using a defined search strategy. Papers were included based on pre‐defined criteria, which included standardization of techniques.Search strategy:  Systematic literature searches of MEDLINE and SCIELO (1989–2008).Evaluation method:  Review of all randomized controlled trials by two authors and grading of articles for quality. A meta‐analysis of data was attempted.Results:  21 articles were identified. Five of which were prospective studies with randomized controlled trials.Conclusions: The majority of Acoustic Rhinometry studies affirm that the first notch is the nasal valve and the second is the anterior end of the inferior turbinate. These findings were based on papers that had not studied the anatomical correlation of these notches. Other studies claim that the first notch is the nostril and the second is the nasal valve as a whole. The conclusion that can be drawn concerning anatomic correlation of the first two notches is that there are conflicting opinions about this correlation in the literature and that more studies are needed to provide more convincing data.