The Depth of the Olfactory Sulcus in Normosmic Children and Adolescents

Aims: The depth of the olfactory sulcus can be reduced in patients with congenital anosmia or psychiatric disorders such as schizophrenia or psychosis. Standard values for the depth of the olfactory sulcus were published mostly for adults. Values under 8 mm were regarded as pathologic, probably indicating anosmia. There are no specific studies to standard values in children and adolescents. The aim of this study is to establish cutoff values for the pathologic depth of the olfactory sulcus in children.

Methods: We investigated 40 normosmic children at the age of 6 to 18 years. The depth of the olfactory sulcus was measured in MR images. The children were investigated with Sniffin Sticks, including discrimination, threshold, and identification tasks.

Results: On average, the depth of the olfactory sulcus on the right side was 10.1 mm and on the left side was 9.6 mm. The occurrence of a deeper right side is in accordance with the literature, All children at nine years of age or older showed sulci with a depth of 8 mm or more. Only children younger than 8 years had sulci under 8 mm. The results of the Sniffin Sticks displayed normosmia in all children.

Conclusion: In children, 9 years of age or older, the proposed cutoff value of 8 mm indicating anosmia can be used safely. In children, 8 years and younger different cutoff values should be considered.

Keywords: depth of the olfactory sulcus, children, anosmia.