The effects of the specific geometry of the magnetic field (such as fi
eld lines with torsion) on curvature emission and absorption in pulsar
magnetospheres are discussed. Curvature maser emission can arise from
two effects: the curvature drift, as has already been discussed in th
e literature, and field line torsion as discussed here in detail for t
he first time. Maser emission due to field line torsion can operate on
ly when the Lorentz factor is larger than a certain value. However, wh
en the Lorentz factor of electrons or positrons is sufficiently high,
curvature masering is due to both curvature drift and magnetic field l
ine torsion. The optical depth in the case of field line torsion is es
timated. It is shown that if torsion is due to rotation, the resultant
luminosity should be dependent on the rotation period in such a way t
hat shorter periods correspond to larger luminosities.