Nyström M, Ranta R
Department of Pedodontics and Orthodontics, University of Helsinki, Finland.
Scand J Dent Res. 1988 Oct;96(5):393-8. doi: 10.1111/j.1600-0722.1988.tb01573.x.
The aims of this investigation were: 1) to study the effects of zygosity and the type of cleft on dental age in pairs of twins concordant or discordant for oral clefts, 2) to compare dental age in the twins with that in a population of normal Finnish children, and 3) to study asymmetry in the formation of mandibular teeth with regard to zygosity and the type of cleft. Twenty-two pairs of twins (8 mono- and 14 dizygotic) and one set of monozygotic triplets concordant or discordant for cleft lip (CL), cleft palate (CP), or both (CLP) were investigated. Four of eight mono- and 12 of 14 dizygotic pairs were discordant for clefts. An orthopantomogram of both twins was taken on the same day. In 7 of the 8 monozygotic (88%) and in 4 of the 14 dizygotic (29%) pairs, the dental age was the same in both twins. Of the 12 pairs discordant for clefts, the dental age of the twin with cleft was delayed in 5, advanced in 3, and the same in 4 compared with that of the twin without a cleft. The means of chronologic age and dental age were counted separately for the cleft subgroups and the non-cleft (NONC) group. The dental age was advanced in the CL twins and in the NONC twins, and was the same as chronologic age in the CP twins, but it was delayed in the CLP twins. Asymmetric formation of the 14 mandibular teeth (mostly the second premolars) was encountered in 3 of 8 CLP, in 3 of 18 CP, in 1 of 16 NONC, and in none of 5 CL children. The great similarity in tooth formation among the monozygotic twins indicates strong genetic control of dental maturation in twins concordant and also discordant for cleft.
1）研究同卵或异卵双胞胎中，唇腭裂的一致性或不一致性以及腭裂类型对牙龄的影响；2）比较双胞胎与芬兰正常儿童群体的牙龄；3）研究同卵或异卵双胞胎以及腭裂类型对下颌牙齿形成不对称性的影响。对22对双胞胎（8对单卵双胞胎和14对双卵双胞胎）以及一组唇裂（CL）、腭裂（CP）或两者皆有（CLP）的单卵三胞胎进行了研究。8对单卵双胞胎中有4对、14对双卵双胞胎中有12对唇腭裂情况不一致。在同一天为双胞胎双方拍摄曲面断层片。8对单卵双胞胎中有7对（88%）、14对双卵双胞胎中有4对（29%）双方牙龄相同。在12对唇腭裂情况不一致的双胞胎中，与未患唇腭裂的双胞胎相比，患唇腭裂的双胞胎牙龄延迟的有5对，提前的有3对，相同的有4对。分别计算唇腭裂亚组和非唇腭裂（NONC）组的实际年龄和牙龄均值。CL双胞胎和NONC双胞胎的牙龄提前，CP双胞胎的牙龄与实际年龄相同，但CLP双胞胎的牙龄延迟。14颗下颌牙齿（主要是第二前磨牙）形成不对称的情况在8例CLP中有3例、18例CP中有3例、16例NONC中有1例出现，5例CL儿童中均未出现。单卵双胞胎牙齿形成的高度相似性表明，唇腭裂一致和不一致的双胞胎中，牙齿成熟受强大的遗传控制。
