Cellular proliferation in the nasal septal cartilage of juvenile minipigs

Abstract

The growth of the nasal septal cartilage is believed to be a driving force of midfacial growth. Cellular proliferation is an important contributor to growth of the cartilage, but this factor has been rarely investigated. The current study was undertaken to assess the proliferation and cellular density in the septal cartilage of fast-growing juvenile minipigs. Six minipigs averaging 4.4 ± 1 months old were injected with 5′-bromo-2′-deoxyuridine (BrdU), a thymidine analog, 24 h before death. The septal cartilage was sectioned in the coronal plane and reacted for BrdU. The proliferative index (number of BrdU-positive chondrocytes/total number of chondrocytes) and cellular density (number of cells mm−2) of various locations of the septum were measured and compared in order to determine overall proliferation rate and whether regional variations in proliferative activity and cellular density are present. To provide a time perspective to the problem of midfacial growth, the lengths of the nasal bone and the palate were measured in a collection of 61 dry skulls of minipigs aged 1–8 months. Results showed that the septal chondrocytes were proliferating at a surprisingly high rate (~21%). The proliferative index was higher in the ventral and middle compared with the dorsal locations, and in the central cartilage compared with the perichondrium. No difference in proliferative index was found between the anterior and posterior parts of the septum. Cellular density was higher in the perichondrium than in the central cartilage. Within the central cartilage there was a trend for higher cellular density anteriorly. In conclusion, the rapidly growing midface of juvenile minipigs is associated with a high rate of septal proliferation, especially in the ventral half of the cartilage.

Growth and Development at the Sphenoethmoidal Junction in Perinatal Primates

“…Their evidence draws a distinction between septal growth relating to endochondral ossification at the PSept and ESept, which proceeds similarly to that of epiphyseal plates, and interstitial growth of cartilage more anteriorly. They concluded that the latter was more significant to septal length increase in young postnatal mice, and Al Dayeh and Herring () later confirmed the relationship of proliferation to midfacial growth in minipigs. Although we have no reason to discount the prolonged importance of interstitial cartilage growth at later ages, our findings suggest cartilage growth in the context of endochondral ossification is pronounced in the perinatal period of most if not all perinatal primates.…”

Betwixt and Between: Intracranial Perspective on Zygomatic Arch Plasticity and Function in Mammals

“…Degree of mineralization of cancellous and cortical bone in the mandibular condyle plateaus at 40–60 weeks (Willems et al, ), providing a general idea of peak skeletal growth in the skull. Despite these studies having been conducted on domesticated pigs, skull growth in minipigs generally tracks the trajectory of domesticated pigs (Al Dayeh and Herring, ). Thus, depending on the growth rates of the model organism, 8 weeks may be insufficient to detect an osteogenic response.…”

Septopremaxillary ligament traction system: a review

“…The seven studies 10,[16][17][18]20,22,23 included in this review are pertaining to the midfacial growth, septopremaxillary traction system and the SPL resection in experimental animal models. The included studies comprises of two observational and five interventional studies.…”

“…The included studies comprises of two observational and five interventional studies. 10,[16][17][18][20][21][22][23]…”

“…To answer these questions various experimental studies were conducted at first in nonprimates (rabbits, rats, pigs, dogs) and then more recently in primate subjects (Chimpanzee) for better extrapolation to human condition. [17][18][19][20][21][22][23] The main purpose of this review is to update and extend the knowledge of the role of septopremaxillary traction system on the midfacial growth by synthesizing the available literature that involves resection of the SPL in experimental animal models. If this review could systematically synthesize the results of relevant animal research, a change in the therapeutic notions can also be expected.…”