en Life Science Life Science مقاله پژوهشی Original Research Article <span style="line-height:2;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><b><span style="background:#2d7f8f"><span style="color:white">Background & Objective:</span></span><b> </b>&nbsp;</b><span style="color:black">Angiopoietin-1 (Ang-1) is a key regulator of angiogenesis and vascular maturation and may play an important role in tooth development. This histological study aimed to evaluate the effect of the local application of angiopoietin-1 on tooth development in the upper molar region of neonatal rats at postnatal day 16.</span><br> <b><span style="background:#2d7f8f"><span style="color:white"><span style="letter-spacing:-.1pt">&nbsp;Materials & Methods:</span></span></span></b> &nbsp;<span style="color:black"><span style="letter-spacing:-.1pt">Twelve neonatal rats weighing 3.5&ndash;4.0 g were maintained under controlled environmental conditions with free access to food and water. The animals were randomly allocated to either an experimental group (n = 6) or a control group (n = 6). The experimental group received a local injection of 10 &mu;L of angiopoietin-1 into the upper right molar region, whereas the control group received an equal volume of sterile saline. All animals were sacrificed on postnatal day 16, and histological analyses were performed to evaluate tooth development.</span></span><br> <b><span lang="EN-IN"><span style="background:#2d7f8f"><span style="color:white">Results: </span></span></span>&nbsp;</b><span style="color:black"><span style="letter-spacing:-.1pt">Local administration of angiopoietin-1 significantly accelerated tooth development in all animals of the experimental group. Histological examination demonstrated enhanced deposition of dental hard tissues, characterized by increased dentin and enamel thickness, together with significantly higher numbers of odontoblasts, fibroblasts, and blood vessels compared with the control group. All evaluated histological parameters differed significantly between the two groups (P < 0.05).</span></span><br> <b><span style="background:#2d7f8f"><span style="color:white">Conclusion: </span></span>&nbsp;</b><span style="color:black">Local application of angiopoietin-1 promoted and accelerated tooth development in neonatal rats, suggesting that angiopoietin-1 may enhance odontogenesis by stimulating angiogenesis and promoting the formation and maturation of dental tissues.</span></span></span></span><br> &nbsp; tooth development, angiopoietin 1, angiogenesis, VEGF, Enamel organ 261 268 http://journal.zums.ac.ir/browse.php?a_code=A-10-7469-1&slc_lang=en&sid=1 Al-Hussein Ali Mohammed Hussein alhusain@alameed.edu.iq 5200319475328460090749 0009-0006-1757-597X Yes College Of Dentistry, University Of Al-Ameed, kerbala, Iraq Enas Fadhil Kadhim dr.enas.fadhil4@codental.uobaghdad.edu.iq 5200319475328460090750 5200319475328460090750 No College Of Dentistry, University Of Baghdad, Baghdad, Iraq