  Tri-bimaximal neutrino mixing may arise from see-saw models based on family
symmetry which is spontaneously broken by flavons with particular vacuum
alignments. However recent analyses hint that tri-bimaximal mixing may be
insensitive to the precise form of vacuum alignment. In this paper we derive
approximate analytic results which express the deviations from tri-bimaximal
neutrino mixing due to vacuum misalignment. We also relate vacuum misalignment
to departures from form dominance, corresponding to deviations from the real
orthogonal $R$ matrix, where such corrections are necessary to allow for
successful leptogenesis. The analytic results show that the corrections to
tri-bimaximal mixing and form dominance depend on the pattern of the vacuum
misalignment, with the two effects being uncorrelated.
