RESUMEN
INTRODUCTION: We aimed to investigate the morphometric development of the cranial base and its related structures, and their growth rate changes from the ninth gestational week to full term in a large group of human fetuses. METHODS: We selected 203 (109 male, 94 female) fetuses between 9 and 40 weeks of gestation and without any external anomalies. From each fetus, standard lateral and posteroanterior cephalometric images were taken using a dental digital panoramic and cephalometric x-ray machine. Fourteen linear and 9 angular parameters were measured. RESULTS: The cranial base angle showed a statistically significant increase between the groups from only the second to the third trimester periods. The sagittal translation of the maxilla increased during the prenatal period, whereas the mandibular sagittal relation grew at a steady rate. The vertical plane angles of the maxilla and the mandible did not show any significant changes. The maxillary length to mandibular length ratio remained stable. CONCLUSIONS: The cranial base angle increased, especially in the second through the third trimesters. The maxilla and the mandible demonstrated different growth patterns in the sagittal direction. The findings of this study could be a guide for interpreting the relationships among the craniofacial structures.
Asunto(s)
Cefalometría/métodos , Huesos Faciales/embriología , Desarrollo Fetal/fisiología , Cráneo/embriología , Cadáver , Mentón/embriología , Largo Cráneo-Cadera , Femenino , Fémur/embriología , Feto , Pie/embriología , Edad Gestacional , Humanos , Masculino , Mandíbula/embriología , Maxilar/embriología , Hueso Nasal/embriología , Organogénesis/fisiología , Hueso Parietal/embriología , Radiografía Dental Digital/métodos , Radiografía Panorámica/métodos , Silla Turca/embriología , Base del Cráneo/embriologíaRESUMEN
Objective : The aim of the present study was to compare the morphometrics of the craniofacial and alveolar arch structures of anencephalic fetuses with those of normal human fetuses without anencephaly or any other anomaly. Design : Original article. Methods : Standard lateral and posteroanterior cephalometric radiographs of 23 anencephalic and 33 normal human fetuses aged between 21 and 40 weeks of gestation were compared. These fetuses were divided into three periods based on gestational age, and vertical, sagittal, transverse, and angular measurements were taken in the cranial base and facial regions. Moreover, intraoral measurements from the maxillary and mandibular arches were also made to determine the width and depth. Results : N-S and S-Ba lengths and the N-S-Ba angle, measured on lateral cephalometric radiographs, were statistically smaller in anencephalic fetuses (p < .05). The S-N-ANS, S-N-Pg, and ANS-N-Pg angles and the Go-Me length were significantly greater in anencephalic fetuses (p < .05). Maxillary length, ramus length, and anterior facial heights were similar in both groups. On posteroanterior radiographs, all parameters except bigonial distance were found to be smaller in the anencephalic fetuses (p < .05). Maxillary alveolar width was small among anencephalic fetuses in all three periods; whereas, the mandibular alveolar width was narrow only in the third period. Conclusion : Cranial and facial structures were affected morphometrically to various degrees in anencephalic cases. The most significant alterations in anencephalic cases were related to measurements in the transverse direction. This indicated that cephalic tissue influenced not only the cranial base but also all facial structures.
Asunto(s)
Cefalometría , Feto , Anencefalia , Humanos , Mandíbula , MaxilarRESUMEN
OBJECTIVE: The objective of this study was to determine the developments, morphometric features, and shapes of the maxillary and mandibular arches during the prenatal period in a large series of fetal material. METHODS: The study was carried out on 225 human fetuses aged between 8 and 40 weeks of gestation. General, extraoral, and intraoral parameters were taken from each fetus. The width and depth measurements and the shapes of the maxillary and mandibular arches were achieved using the casts obtained. The arches were categorized according to the shapes of the anterior and posterior regions of the arches. RESULTS: Palatal and mandibular indices did not change during the prenatal period. Maxillary arch measurements were greater than the mandibular measurements. Moreover, width measurements of both arches were greater than the depth measurements during fetal life. We found that the frequencies of triangular maxillary and mandibular arches were highest in the first and second trimesters; whereas, the square model became more frequent in the third trimester and at full term. Classification of the arches according to their posterior regions showed that the tips of the arches shifted medially toward the term. There were significant correlations between width and depth parameters of the arches and extraoral parameters. CONCLUSION: Data obtained in the study would be useful for clinicians by presenting an objective scale related to the prenatal period as well as being helpful in assessing the development of this region, identifying the anomalies and pathologies, and assisting treatment.