Figure 1. Photomicrographs of longitudinal sections of mandibular first molar teeth, stained with hematoxylin and eosin, from three lines of mice genetically engineered to produce alterations in the growth hormone (GH) axis. Magnification (19x) is the same for all images. (A) A section displaying a complete cross-section of both mesial (Mesial) and dorsal (Dorsal) roots. Black lines identify radicular cementum: line * to # is acellular cementum; line to * is cellular cementum; area C is apical cellular cementum. (B,C) Sections of mesial tooth roots of littermate mice of a GH excess (giant) mice line. (B) Wild-type (Wt) phenotype. (C) Giant (GHXs) phenotype. (D,E) Sections of mesial tooth roots of littermate mice of a GH antagonist excess (dwarf) mice line. (D) Wild-type (Wt) phenotype. (E) Dwarf (GHAnt) phenotype. (F-H) Sections of mesial tooth roots of littermate mice of a GH receptor-deleted (GHR-KO) (dwarf) mice line. (F) Wild-type (Wt) phenotype. (G) Heterozygous (Het) for the GHR-KO mutation. (H) Dwarf (KO) phenotype.