2 Formation of face -five elevations / frontonasal prominence /maxillary prominence paired upper 上頜隆起 branches of first branchial arch /mandibular prominence paired lower 下颌隆起 branches of first branchial arch2. Formation of face ---five elevations /frontonasal prominence /maxillary prominence: paired, upper branches of first branchial arch /mandibular prominence: paired, lower branches of first branchial arch