Odajima T
SATO Institute of Dental Research, Tokyo.
Shikwa Gakuho. 1990 Mar;90(3):369-409.
In dental clinic for children, criteria for growth and developmental changes related to increases in the width and length of the dental arch at the primary, mixed, and permanent dentition stages are essential. This study was carried out to measure the width and the length of normal dental arch and to make detailed observations of growth and developmental processes in the dental arch at each dentition stage. Materials were serial study casts of the maxilla and the mandible taken every 2 month from 127 children (74 boys and 54 girls). The casts were made from 6 months after birth until the age of 15. Measurements of the width of the dental arch were made between bilateral teeth of the same tooth type, both deciduous and permanent. The length of the dental arch was measured on the basis of the perpendicular distance from the contact point of mesial surfaces of central incisors to a line between bilateral teeth of the same tooth type. Measured values were categorized according to either chronological age or tooth age on the basis of the eruption of the central permanent incisors. The indices of the dental arch with relation to the width and the length at each dentition stage were calculated for the sake of partial and total observations of alterations in dental arch form. The results were as follows: 1) In terms of chronological age, until 1 year before the eruption of permanent replacements, the width of the dental arch gradually decreased in both the maxilla and the mandible in the regions of the deciduous central and lateral incisors. Increasing slightly from about the age of 6 years and the period of mixed dentition, the width of the dental arch remained stable until the permanent dentition stage. From the primary dentition stage, the width of the dental arch in the region of the maxillary and mandibular canines and first and second molars gradually increased. Therefore it remained stable until the eruption of permanent dentition. The width in the region of the permanent maxillary and mandibular first molars gradually increased and attained a stable condition at about 12 years of age. In males, the width in the area of the maxillary secondary molars decreased slightly and tended to decrease in the mandible. In females, on the other hand, the width showed a tendency to increase with advancing ages. With the exception of the second permanent molars, the width between the distance of bilateral teeth were consistently larger in males than in females.(ABSTRACT TRUNCATED AT 400 WORDS)
在儿童牙科诊所，了解乳牙期、混合牙列期和恒牙列期牙弓宽度和长度增加所相关的生长发育变化标准至关重要。本研究旨在测量正常牙弓的宽度和长度，并详细观察每个牙列期牙弓的生长发育过程。材料为127名儿童（74名男孩和54名女孩）每2个月采集的上颌和下颌系列研究模型。模型制作时间从出生后6个月至15岁。牙弓宽度测量是在乳牙和恒牙的双侧同名牙之间进行。牙弓长度是根据中切牙近中面接触点到双侧同名牙连线的垂直距离来测量。测量值根据实际年龄或基于恒中切牙萌出情况的牙龄进行分类。为了部分和全面观察牙弓形态变化，计算了每个牙列期与宽度和长度相关的牙弓指数。结果如下：1）就实际年龄而言，在恒牙替换萌出前1年，上颌和下颌乳牙中切牙及侧切牙区域的牙弓宽度逐渐减小。从大约6岁混合牙列期开始略有增加，牙弓宽度在恒牙列期之前保持稳定。从乳牙列期开始，上颌和下颌尖牙及第一、二磨牙区域的牙弓宽度逐渐增加。因此在恒牙萌出前保持稳定。上颌和下颌第一恒磨牙区域的宽度逐渐增加，在大约12岁时达到稳定状态。在男性中，上颌第二磨牙区域的宽度略有减小，下颌有减小趋势。另一方面，在女性中，宽度有随年龄增长而增加的趋势。除第二恒磨牙外，男性双侧牙间距始终大于女性。（摘要截选至400字）
