Aliki Rontogianni
Short CV
Dr. Aliki Rontogianni is an Assistant Professor of Orthodontics in the Division of Dental Technology, Department of Biomedical Sciences, at the University of West Attica, Athens, Greece, since 2023. Dr. Rontogianni completed her Dental Degree at the National and Kapodistrian University of Athens, Greece (1997-2002). She continued her studies in the specialty of Orthodontics at Tel Aviv University, Maurice and Gabriela Goldschleger School of Dentistry, Israel (2003-2007), where she graduated with a Diploma in Orthodontics (Dipl. Orthod.) and a Master’s in Orthodontics (MOrth). She also completed a postgraduate program at the same university and obtained a Master’s in Biomaterials. Her research interest focused on the effect of time on the strength and mechanical properties of orthodontic elastics.
Since 2007, she has been a Research Associate in the Department of Orthodontics at the University of Athens, where she completed her PhD as a fellow of the Special Account for Research Grants. Her PhD topic was the study of mandibular growth in growing rats that had been modified and born with intrauterine growth restriction. Her main research interests include craniofacial development, biomaterials, osteoporosis, and forensic dentistry. Dr. Rontogianni also maintains a private clinical orthodontic practice in Athens, Greece.
Lecture: Study of mandibular growth in growing rats that had been modified and born with intrauterine growth restriction
We have intrauterine growth restriction (IUGR) when there is an inability of the newborn to reach the predetermined (expected) growth potential. These children are smaller in size than their normal counterparts. The presence of microcephaly at birth and the limited increase in head size are the most important factors of adverse neurodevelopmental outcome.
The aim of this study was to compare the qualitative and quantitative characteristics of the mandible in rats that have undergone IUGR with control groups of normal rats.
Materials and Methods: Twelve male rats were born IUGR by mothers sustaining 50% food restriction during pregnancy. Dual-energy X-ray absorptiometry of the tibia, proximal tibial metaphysis and the mandible, biochemical markers, histology and histomorphometrical analysis on the mandibular and subchondral bone of the condyle were performed. Lateral and anterior-posterior cephalometric radiographs were also taken in each animal.
Results: IUGR affected Bone Mineral Density of long bones significantly (p<0.005), even though a standard diet was available ad libitum to the offspring. BMD of the mandibular bone was also affected significantly in IUGR-born rats compared to the Controls in the antigonial notch was p<0.0005 and at the most inferior point of the mandibular symphysis was (p=0.003). IUGR rats had significantly lower osteocalcin values (p=0.021) and phosphorus (p=0.028) but not 25-OH vitamin D (p=0.352). Bone area percentage in the mandible was significantly lower (51.21±5.54) in IUGR compared to controls (66.00±15.49) and for subchondral bone of the condyle for IUGR (47.01±6.82) compared to controls (68.27±13.37). IUGR had a significant reduction in the fibrous layer but not the proliferating layer, with the hypertrophic layer significantly increased.
The IUGR group showed lower values for most lateral and anterior-posterior radiographs cephalometric measurements (p <0.05) at both 2 and 5 months, compared to controls.
Conclusion: Maternal restricted nutrition during gestation can affect bone density of the mandible and the tibia of the offspring. The mandibular bones are smaller compared to normal rats but the neurocranium was not affected.