Table 1.
Sample Details.
Table 2.
Cephalometric Measures.
Fig 1.
Effects of nicotine exposure during gestation and lactation or only lactation on developing murine craniofacial form.
Representative 3D reconstructions from each exposure group highlight the subtle changes due to different nicotine exposures. Left lateral (left) and superior (right) images are presented from left to right for control, Peg + Lac, and Lac Only exposures. Scale = 9 mm (A). Cephalometric analysis showing significant statistical differences between groups are indicated by a black line and asterisk(s). Depictions of each measure are shown inset to the upper right of each plot. Cranial length (B) and craniofacial length (C) indicate a potential lag in growth due to nicotine exposure postnatally (Lac Only, Grey bars). No significant differences were detected in the calvarial height or width (D-E). The lactation only nicotine exposure resulted in a significant reduction in facial width when compared to the pregnancy and lactation exposure (Preg+Lac, Black bars, F-H). The pregnancy and lactation nicotine exposure resulted in a significant increase in anterior facial width (F) when compared to the unexposed control and lactation only groups (Preg+Lac, Black bars). The cranial base length was also significantly shorter in the lactation only exposed pups as compared to control pups (I). n = 24 Control, 25 Preg + Lac, 26 Lac Only *p ≤ 0.05 **p ≤ 0.01 ***p ≤ 0.001.
Fig 2.
Effects of nicotine exposure during gestation and lactation or only lactation on cranial suture patency.
3D renderings of representative mouse sutures from each exposure group. White arrowheads indicate coronal sutures, black right facing arrow identifies sagittal suture, and red left facing arrow indicates posterior interfrontal suture (A). Mean width (patency) of posterior interfrontal suture (B), sagittal suture (C), and coronal suture (D) indicates a high degree of variability and no statistically significant differences across or between groups. n = 24 Control (White bars), 25 Preg + Lac (Black bars), 26 Lac Only (Grey bars).
Fig 3.
Effects of nicotine exposure during gestation and lactation or only lactation on cranial synchondrosis form.
Micro-CT midline sections display ISS (red downfacing arrow) and SOS (white upfacing arrow) in three exposure groups. Analysis did not show any changes in the width or height of the ISS (B-C) or the SOS (E-F). The antero-posterior (patency) showed significant difference across the 3 groups in the SOS (G) and between the pregnancy and lactation and lactation only exposures in the ISS (D). n = 24 Control (White bars), 25 Preg + Lac (Black bars), 26 Lac Only (Grey bars) *p ≤ 0.05 **p ≤ 0.01.
Fig 4.
Effects of nicotine exposure during gestation and lactation or only lactation on cellular content of the cranial synchondroses.
Representative H&E-stained ISS (left) and SOS (right) with polarized PSR stained images inset (Scale Bar = 200 µm) (A). The analysis of chondrocyte counts per square mm in the ISS showed a significant reduction in chondrocytes in the pups exposed to nicotine during pregnancy and lactation (B). No significant differences were noted in the ISS for total collagen content, however more immature fibers were observed in nicotine exposed pups (C-D). Significantly reduced chondrocyte counts were found in the SOS of pups exposed to nicotine (E). Picro Sirius Red stained section analysis indicated reduced collagen content in the lactation only exposed group SOS. Our analysis also showed a significant reduction in intermediate collagen but a significant increase in mature collagen in the lactation exposed group when compared to the other 2 groups (G). n = 7 Control (White bars), 5 Preg + Lac (Black Bars), 5 Lac Only (Grey Bars) *p ≤ 0.05 **p ≤ 0.01 ***p ≤ 0.001.