[Note on the variability of the basicranial axes].

On 114 lateral radiographies of skulls, we looked for the best basicranial axis, i.e. the least variable, the most stable. One should discard the foramen magnum plane (too variable due to the basion lack of precision); the same is true for the axes passing through the sellion point, because the Sella turcica center is situated relatively lower in women and in toothless persons (at least in our series); the studies on the sphenoidal angle are thus tainted with error, the jugum and clivus planes being still more unprecise. Incidentally, let us report the little value of the palatine plane (but not of the nasal plane). The positive results are as follows: compared to the bregma-lambda axis, the nasion-opisthion axis is less variable than the auriculo-orbitary Francfort plane. But this last plane contracts higher correlations with the bregma-nasiolambda angle. Thus Francfort and nasion-opisthion axes both look equally good.