The incidence of concha bullosa and its relationship to nasal septal deviation and paranasal sinus disease.

BACKGROUND AND PURPOSE: The incidence of middle turbinate pneumatization, or concha bullosa, has been well described in the literature. However, to our knowledge, no study has evaluated concha bullosa in relation to nasal septal deviation. We sought to analyze the incidence of concha bullosa and any correlation with nasal septal deviation and paranasal sinus disease. METHODS: Three neuroradiologists retrospectively reviewed findings of 1095 consecutive paranasal sinus CT studies conducted between 2001 and 2002. All examinations were performed for evaluation of a symptom referable to the sinonasal region. Paranasal sinus inflammatory disease was identified and graded as mild, moderate, or severe. Sphenoid, ethmoid, maxillary, and frontal sinuses were each graded separately on both sides. If a concha bullosa was present, it was graded in size as small, moderate, or large. If bilateral concha were present, sizes were compared and when one was larger, it was identified as dominant. When nasal septal deviation was present, it was graded as mild, moderate, or severe. The direction of nasal septal deviation was identified as the face of the convex surface. RESULTS: There was a clear association between the presence of a unilateral concha, or a dominant concha (in the case of bilateral concha), and the presence of nasal septal deviation (P < .0001). Moreover, there was a significant relationship between the presence of concha bullosa and deviation of the nasal septal to the contralateral side (P < .0001). This inverse association was present regardless of the size of the concha bullosa or degree of septal deviation. In every case, there was some preservation of air channels between the dominant concha and the nasal septum. Seventy-three percent of patients with concha bullosa had paranasal sinus inflammatory disease; 78% of patients without concha bullosa also had some form of inflammatory disease. CONCLUSION: Concha bullosa is a common anatomic variant. There is a strong association between the presence of a concha bullosa and contralateral deviation of the nasal septum. Nasal septal deviation away from the dominant concha, with preserved adjacent air channels, suggests that the deviation is not a direct result of mass effect from the concha. No increased incidence of paranasal sinus disease exists in patients with concha bullosa.