Alippi R M, Meta M D, Boyer P M, Bozzini C E
Department of Physiology, Faculty of Odontology, University of Buenos Aires, Argentina.
Eur J Oral Sci. 1999 Aug;107(4):260-4. doi: 10.1046/j.0909-8836.1999.eos107405.x.
Catch-up growth has been defined as growth with a velocity above the statistical limits of normality for age during a defined period of time which follows a period of impaired growth. Since no data are available on catch-up in mandibular growth, the present study was designed to estimate the dynamics of the mandibular size after short-term dietary protein restriction in rats during the post-weaning period. Weanling male rats, 22 d of age, were divided into two groups, control (C) and experimental (E). E rats were fed a protein-free diet during the first 10 d; from this time on, they were placed on a 20% protein diet, as were C rats during the entire experimental period, which lasted 70 d. Five rats from both groups were randomly selected every 10 d and sacrificed. Mandibular growth was estimated directly on the right mandible by measuring several dimensions (mandibular area, base length, mandibular height, mandibular length, alveolar length and incisor alveolar process length). Alveolar and incisor alveolar process lengths did not change with age or dietary protein. All other dimensions increased with age and were thus negatively affected by protein restriction. After growth restriction ceased, the rate of increase of all affected dimensions was above normal values and deficits were swiftly eliminated. Since age-independent dimensions compose roughly the anterior portion of the mandible, this portion of the bone was not affected by protein restriction. It was, thus, the posterior part of the mandible which stopped growth during the nutritional insult and showed catch-up during nutritional rehabilitation. In summary, the rat mandible has a high potential for catch-up during the post-weaning period, showing the ability to achieve complete catch-up in about 30 d.
追赶生长被定义为在一段生长受损期之后的特定时间段内，生长速度高于同年龄正常生长统计范围的生长情况。由于目前尚无关于下颌生长追赶的数据，本研究旨在评估断奶后大鼠短期饮食蛋白质限制后下颌大小的动态变化。22日龄的雄性断奶大鼠被分为两组，对照组（C）和实验组（E）。E组大鼠在最初10天喂食无蛋白饮食；从那时起，它们被给予20%蛋白质饮食，C组大鼠在整个为期70天的实验期间也给予相同饮食。每隔10天从两组中随机选取5只大鼠并处死。通过测量几个维度（下颌面积、基部长度、下颌高度、下颌长度、牙槽长度和切牙牙槽突长度）直接评估右侧下颌骨的生长情况。牙槽和切牙牙槽突长度不随年龄或饮食蛋白质变化。所有其他维度随年龄增加，因此受到蛋白质限制的负面影响。生长限制停止后，所有受影响维度的增加速率高于正常值，且缺陷迅速消除。由于与年龄无关的维度大致构成下颌骨的前部，这部分骨骼不受蛋白质限制的影响。因此，是下颌骨的后部在营养损伤期间停止生长，并在营养恢复期间表现出追赶生长。总之，大鼠下颌骨在断奶后具有很高的追赶生长潜力，显示出在约30天内实现完全追赶的能力。
