has part has part has_part characteristic of abnormal submandibular gland morphology abnormal submandibular gland development MP:0013541 abnormal maxillary gland development abnormal submaxillary gland development aberrant formation or incomplete differentiation of either of the paired compound tubuloalveolar (aka tubuloacinar) major salivary glands composed of both serous and mucous secretory cells and situated beneath the mandible; in mice, submandibular gland development initiates as a thickening of the oral epithelium; around E12 an initial (single) epithelial bud on a stalk grows into a condensing neural crest-derived mesenchyme; clefts in the epithelium result in 3-5 epithelial buds at E13.5, and branching morphogenesis occurs with continued proliferation, successive rounds of cleft formation, duct elongation, and duct lumen formation, so that by E14 the gland is highly branched (multi-lobed); functional differentiation, with the appearance of proacinar cells and secretory products begins after E15 and continues to birth; acinar differentiation continues postnatally with final differentiation of the granular convoluted tubules at puberty submandibular gland