Department for Oral and Maxillofacial Plastic Surgery, Rostock University, Germany.
J Craniomaxillofac Surg. 2013 Sep;41(6):450-6. doi: 10.1016/j.jcms.2012.11.025. Epub 2013 Jan 3.
A very famous paper by Sam Pruzansky, published in 1969, was entitled "Not all dwarfed mandibles are alike". This is the topic of this paper: to describe the shape and discuss the possible pathogenesis of an extremely rare congenital dysplasia found in a unilaterally hypoplastic mandible, namely the isolated mandibular ramus.
A unique malformation of the lower jaw was found in more than 75 patients with developmental abnormalities of the mandible diagnosed and treated by the two authors in two different university hospitals over the last 40 years. We performed the following teratological experiments with laboratory rodents in order to try to understand the pathogenesis of this special dysplasia (and others): at first the normal development of the lower jaw was studied in rat and mouse foetuses. Then a variety of teratogenic drugs were applied to pregnant females and then the foetuses of these pregnancies were studied following Caesarian section.
One rat foetus was identified which presented the identical dysplasia that had been noted in the patient described here. The dam pregnant with this foetus had been given 25 mg/kg bodyweight of 6-mercaptopurine on day 12 of pregnancy. The explanation found for the pathogenesis of this anomaly was deducted from the scientific literature regarding normal development of the mandibular condyle.
The nucleus of the so-called secondary cartilage that will produce the ascending ramus (plus condyle and coronoid) is a separate growth centre which fuses a short time later with the dental bone which becomes the mandible proper by this fusion.
1969 年，Sam Pruzansky 发表了一篇非常著名的论文，题为“并非所有矮小的下颌骨都一样”。本文的主题是描述一种非常罕见的先天性发育不良的形状，并探讨其可能的发病机制，这种畸形仅发生于单侧下颌骨发育不全，即孤立的下颌升支。
两位作者在过去的 40 年中，在两家不同的大学医院诊断和治疗了 75 例以上下颌骨发育异常的患者，发现了一种独特的下颌畸形。我们对实验室啮齿动物进行了以下致畸实验，以试图了解这种特殊发育不良（和其他发育不良）的发病机制：首先研究了大鼠和小鼠胎鼠下颌骨的正常发育。然后将各种致畸药物应用于妊娠雌性动物，然后通过剖腹产研究这些妊娠的胎鼠。
在一只大鼠胎鼠中发现了与这里描述的患者相同的畸形。这只胎鼠的母体在妊娠第 12 天接受了 25mg/kg 体重的 6-巯基嘌呤。从关于下颌骨髁突正常发育的科学文献中推断出这种异常的发病机制。
所谓的次级软骨核，将产生升支（加上髁突和喙突），是一个单独的生长中心，通过融合与牙骨融合，牙骨随后通过融合成为真正的下颌骨。
