Stojanović Zdenka, Nikolić Predrag, Nikodijević Angelina, Milić Jasmina, Stojanović Branislav
Clinic for Dentistry, Military Medical Academy, Belgrade, Serbia.
Vojnosanit Pregl. 2013 Jul;70(7):645-52. doi: 10.2298/vsp110224042s.
BACKGROUND/AIM: Malocclusion of skeletal class III is a complex irregularity of sagittal inter-jaw relationship, which is due to irregularities of sagittal position of one or both of the jaw bones, which is often associated with disproportionate ratio of their length. The aim of this study was to determine whether the length of the jaw of children with skeletal class III in the period of mixed dentition was changed.
Fifty children with skeletal class III and the same number of those with skeletal class I, of both sexes, have been selected on the basis of cephalometric analysis of profile tele-x-ray of the head. All the children aged 6-12 had mixed dentition, and were divided according to sex and age into three subgroups within each group. The length of maxilla, mandible and cranial base were measured. Proportions among the lengths measured within each group were found and difference significance in the measured lengths and their proportions among groups and subgroups were evaluated.
The children with skeletal class III, compared with the findings in the control group, had significantly lower values of maxillary length, total maxillary length, as well as lower values of their lengths in proportion to lengths of the front or the total length of cranial base and in proportion to mandibular lengths (p < 0.05). Among the patients of different sexes, both in the test and the control group, a significant difference in the values of the measured lengths was found.
The children with skeletal class III have significantly shorter maxilla than those with skeletal class I.
背景/目的：骨性III类错牙合是一种复杂的矢状颌间关系不调，是由于一块或两块颌骨矢状位置异常导致的，常伴有其长度比例失调。本研究的目的是确定混合牙列期骨性III类儿童的颌骨长度是否发生改变。
基于头部侧面远距X线片的头影测量分析，选取了50名骨性III类儿童以及相同数量的骨性I类儿童，男女均有。所有6至12岁的儿童均处于混合牙列期，并根据性别和年龄在每组内分为三个亚组。测量上颌骨、下颌骨和颅底的长度。计算每组内测量长度之间的比例，并评估测量长度及其在组间和亚组间比例的差异显著性。
与对照组结果相比，骨性III类儿童的上颌骨长度、上颌骨总长度显著更低，其长度与颅底前部长度或总长度以及与下颌骨长度的比例也更低（p < 0.05）。在试验组和对照组的不同性别患者中，测量长度值均存在显著差异。
骨性III类儿童的上颌骨明显比骨性I类儿童短。
