			Home About us Contact

Column Morphology (column + morphology)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Skeletal morphogenesis of the vertebral column of the miniature hylid frog Acris crepitans, with comments on anomalies

JOURNAL OF MORPHOLOGY, Issue 1 2009
L. Analía Pugener
Abstract Although the vertebral columns of anurans have received much study in the last 150 years, few detailed descriptions exist of the skeletal morphogenesis of this anatomical unit. Herein, the ontogeny of the vertebral skeleton of the hylid frog Acris crepitans is described based on cleared and double-stained specimens, radiographs, and 3D reconstructions generated from synchrotron microCT scans. The adult axial formula is 1-7-1-1, and the vertebral centra are epichordal and procoelous. The neural arches are nonimbricate, and there is a medial articulation between the laminae of Presacrals I and II. Free ribs are absent. The sacral diapophyses are uniform in width or slightly expanded distally. The urostyle is slender, round in cross section, and about equal in length to the presacral region. Presacral vertebrae are the first to form, developing in a cephalic-to-caudal sequence. However, development and growth are decoupled and growth is fastest initially in the posterior presacrals and sacrum. In addition, there is a time lag between the formation of the presacral/sacral region and the postsacral region. More than 8.5% of the specimens examined have vertebral anomalies, and about 50% display small variants from the typical vertebral column morphology. However, these malformations do not seem to have been so severe as to have affected survival. J. Morphol., 2009. © 2008 Wiley-Liss, Inc. [source]

Cervical column morphology in patients with skeletal open bite

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2008
L Sonnesen
Structured Abstract Authors,,, Sonnesen L, Kjær I Objectives,,, To examine and compare the cervical column morphology in adult patients with skeletal open bite with the cervical column morphology of an adult control group with neutral occlusion and normal craniofacial morphology. Design,,, A retrospective case,control study. Setting and Sample Population,,, Thirty-eight open bite patients, 27 women, aged 17,39 years, and 11 males, aged 18,40 years were compared with 21 controls, 15 females, aged 23,40 years, and six males aged 25,44 years from profile radiographs. Outcome measure,,, From each individual a visual assessment of the cervical column and angular measurements of the craniofacial dimensions were performed on profile radiographs. Results,,, In the open bite group 42.1% had cervical column body fusion, and 13.2% had posterior arch deficiency. The fusion always occurred between C2 and C3. Cervical column deviations occurred significantly more often in the open bite group compared with the control group (p < 0.05). Associations were found between fusions of the cervical column and maxillary retrognathia (p < 0.05), large maxillary inclination (p < 0.05) and large cranial base angle (p < 0.05). Associations were also found between posterior arch deficiency and maxillary retrognathia (p < 0.05) and cranial base angle (p < 0.05). The craniofacial parameter most important for the fusions and posterior arch deficiency was the maxillary retrognathia (p < 0.01, R,2 = 0.20; p < 0.05, R,2 = 0.26, respectively). Conclusion,,, New associations between skeletal open bite and cervical column deviations are described. It is suggested that this knowledge is incorporated in future diagnostic and orthodontic treatment planning. [source]

Vertebral anatomy in the Florida manatee, Trichechus manatus latirostris: A developmental and evolutionary analysis

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2007
Emily A. Buchholtz
Abstract The vertebral column of the Florida manatee presents an unusual suite of morphological traits. Key among these are a small precaudal count, elongate thoracic vertebrae, extremely short neural spines, lack of a sacral series, high lumbar variability, and the presence of six instead of seven cervical vertebrae. This study documents vertebral morphology, size, and lumbar variation in 71 skeletons of Trichechus manatus latirostris (Florida manatee) and uses the skeletons of Trichechus senegalensis (west African manatee) and Dugong dugon (dugong) in comparative analysis. Vertebral traits are used to define morphological, and by inference developmental, column modules and to propose their hierarchical relationships. A sequence of evolutionary innovations in column morphology is proposed. Results suggest that the origin of the fluke and low rates of cervical growth originated before separation of trichechids (manatees) and dugongids (dugongs). Meristic reduction in count is a later, trichechid innovation and is expressed across the entire precaudal column. Elongation of thoracic vertebrae may be an innovative strategy to generate an elongate column in an animal with a small precaudal count. Elimination of the lumbus through both meristic and homeotic reduction is currently in progress. Anat Rec, 290:624,637, 2007. © 2007 Wiley-Liss, Inc. [source]