【洪郡謙】評論

Contemporary Orthodontics 6 edition P.220,438(A) Mandibular transverse expansion was impossible until distraction osteogensis became available.從這裡可以知道下顎的橫向擴張是十分困難的。(B)The 2-mm limitation for forward movement of the lower incisors obviously is subject to considerable individual variation but makes sense in light of the observation that lip pressure increases sharply 2 mm out into space usually occupied by the lip.簡短來說就是，如果大於2mm，來自於嘴唇的壓力就會急劇升高。(C)(D) Expansion across the premolars and molars is much more likely to be maintained, presumably because of the relatively low cheek pressures.220頁那邊也有提到，下顎犬齒的橫向擴張基本上是沒辦法維持的！而且小臼大臼來自於臉頰的壓力明顯小很多，所以(C)的小臼大臼穩定度高於犬齒是對的！