Asaumi J I, Shibata Y, Yanagi Y, Hisatomi M, Matsuzaki H, Konouchi H, Kishi K
Department of Oral and Maxillofacial Radiology, Field of Tumor Biology, Graduate School of Medicine and Dentistry, Okayama University, Japan.
Dentomaxillofac Radiol. 2004 Mar;33(2):125-7. doi: 10.1259/dmfr/68039278.
To examine mesiodens with regard to their status, their influence on adjacent teeth and their alteration during the follow-up period.
From retrospective reviews of all patients who visited our institution from 1990-2001, we identified 200 patients (256 mesiodentes) who were shown to have mesiodentes on the basis of a periapical radiograph, a panoramic radiograph or an axial radiograph.
The number of supernumerary teeth was one in 146 cases (73%), two in 52 cases (26%) and three in 2 cases (1%). Of 256 mesiodentes, the direction of the crown of the mesiodens was inverted in 172 (67%), in a normal direction in 69 (27%) and in a horizontal direction with regard to the tooth axis in 15 (6%). Of the 147 mesiodentes for which axial radiography was performed, 131 (89%) were located at a palatal site against the dental arch, 16 (11%) overlapped the dental arch and none were at a labial site. Of our 200 cases, a delay of eruption of the permanent central incisor was seen in 12 (6%), malposition or rotation of the central incisor in 5 (2.5%) and dentigerous cyst formation arising from mesiodens in 22 (11%). Marked movement of the mesiodens was seen in 10 cases during the follow-up period of 5-7 years. Some complication arising from mesiodens was seen in 19.5% of all cases in our research.
Although mesiodentes are not caused by malocclusion, they may cause it. A long period of impaction of mesiodentes may bring about dentigerous cyst formation or movement of the mesiodentes.
研究正中多生牙的状态、对相邻牙齿的影响以及随访期间的变化。
通过回顾性分析1990年至2001年期间来我院就诊的所有患者，我们根据根尖片、全景片或轴向片确定了200例患者（256颗正中多生牙）。
额外牙数量为1颗的有146例（73%），2颗的有52例（26%），3颗的有2例（1%）。在256颗正中多生牙中，牙冠方向倒置的有172颗（67%），方向正常的有69颗（27%），与牙轴呈水平方向的有15颗（6%）。在进行轴向片检查的147颗正中多生牙中，131颗（89%）位于腭侧，与牙弓相对，16颗（11%）与牙弓重叠，无一位于唇侧。在我们的200例病例中，恒中切牙萌出延迟的有12例（6%），中切牙错位或旋转的有5例（2.5%），由正中多生牙引起的含牙囊肿形成的有22例（11%）。在5至7年的随访期内，有l0例正中多生牙出现明显移动。在我们的研究中，所有病例中有19.5%出现了由正中多生牙引起的一些并发症。
尽管正中多生牙并非由错牙合引起，但它们可能导致错牙合。正中多生牙的长期阻生可能导致含牙囊肿形成或正中多生牙移动。
