has part has part has_part characteristic of part of has modifier abnormal frontal bone morphology abnormal frontal bone orbital part morphology 2017-11-10T13:22:34Z abnormal frontal bone horizontal part morphology any structural anomaly of the horizontal part of the frontal bone composed of two thin triangular plates, the orbital plates, which form the vaults of the orbits and the ethmoidal sinuses, and are separated from one another by a median gap, the ethmoidal notch; this part also comprises the anterior and posterior ethmoidal foramina MPheno.ontology abnormal pars orbitalis ossis frontalis morphology abnormal pars orbitalis (os frontale) morphology MP:0030381 morphology abnormal orbital part of frontal bone