Periodontal mechano-sensory responses following trauma to permanent incisor teeth in children

Abstract –  The aim of this study was to investigate mechano-sensory responses of injured and uninjured incisor teeth. Twenty-five children who had experienced dental trauma, together with age- and gender-matched controls, were studied prospectively. Touch thresholds of incisor teeth from both groups were determined using calibrated sets of von Frey hairs (force range 0.5–10.0 g in 0.5 g increments) using a forced choice staircase method. Forces were applied perpendicular to the buccal enamel surfaces along the midline, 2 mm from the incisal edge. Touch threshold was defined as the lowest force detected in three out of the five occasions. Following statistical analysis, P  < 0.05 was considered significant. At initial examination, the touch threshold values of 25 traumatised teeth were significantly greater than the untraumatised controls ( P  < 0.001), and these values approached those of the control teeth over 3–12 months ( P  > 0.05). Dental trauma was associated with increased touch thresholds in permanent incisor teeth, with recovery toward healthy control values usually occurring between 3–12 months.     

上前牙倒置阻生拔除后再植的临床体会

为探讨上前牙倒置阻生拔除后再植的可行性，选择上前牙倒置阻生病例15例，经正畸治疗扩展间隙，再经口腔外科手术拔除后再植。结果，86．7％的病例获得良好的治疗效果，无明显松动。认为用拔除后再植术治疗上前牙倒置阻生，能明显改善面形和咀嚼功能，避免了拔牙后再修复。     

Skewed sex ratios in familial holoprosencephaly and in people with isolated single maxillary central incisor

Autosomal dominant holoprosencephaly is a rare but well documented entity and it can be the result of mutations in the Sonic Hedgehog gene (SHH). The transmitting parent may be normal or have a single maxillary central incisor. We describe a skewed sex ratio among the transmitting parents with SHH mutations, with more mothers than fathers having the mutation (p=0.002). The mechanism underlying this skewed sex ratio is not clear; the SHH mutations do not involve triplet repeats, imprinting is plausible but untested, and there is no evidence that the risk of holoprosencephaly is greater among males carrying such a mutation (p=0.15). We considered the possibility that males with such a mutation are at greater risk of other malformations outside the central nervous system, which could reduce their reproductive fitness. To avoid ascertainment bias in identifying children with various malformations in kindreds with familial holoprosencephaly, we reviewed the reports of people with single maxillary central incisor and no other congenital malformations. Of the 16 cases identified, 13 were female (p=0.0085). We suggest that boys with mutations associated with autosomal dominant holoprosencephaly may be at greater risk of major malformations outside the central nervous system than girls.     

Fate of odontoblasts and blood capillaries in the incisal region of the rat incisor pulp

Transmission electron microscopy of thin sections of the rat incisor pulp revealed that in the middle region of the incisor there were fenestrated capillaries in the “predentinal plexus” and that this region contained the tallest odontoblasts. The odontoblasts gradually became shortened in the incisal part of this region: the fenestrated capillaries in the predentinal plexus changed to continuous type capillaries. Almost all the odontoblasts had degenerated near the incisal end of the tooth. The predentinal plexus disappeared in this region, but the “subodontoblastic capillary plexus” persisted. In a specific region just beneath the worn incisal end, numerous macrophages and polymorphonuclear neutrophils appeared and scavenged the degenerating cells, possibly including the odontoblasts. © 1993 Wiley-Liss, Inc.     

老年大鼠切牙造牙本质细胞的超微结构变化

应用透射电镜研究了老年大鼠切牙造牙本质细胞的超微结构变化。该细胞核出现凹陷和切迹，常染色质减少，异染色质增加。胞浆内粗面内质网扩张，变短，线粒体水肿，嵴断裂，最后空泡化，高尔基复合体由复杂到简单，最后消失。     

上颌中切牙倒置埋伏阻生不同术式的正畸治疗

目的 探讨上颌中切牙倒置埋伏阻生的矫治方法。方法 6对11例倒置阻生的上中切牙,先行开窗术式与翻瓣术式显露牙冠,然后在U型保护罩的运行下用固定正畸技术进行矫治。结果 翻瓣术式后固定矫正器经12－18个月,开窗术式后固定矫正器8－12个月使倒置埋伏阻生牙进入牙弓排齐。结论 倒置埋伏阻生的上颌中切牙,通过手术和正畸技术,完全能排入正常牙列,不需排除。     

应用微型种植体支抗压低犬切牙过程中牙周组织改建的实验研究

目的:应用微型种植体支抗压低犬切牙,观察此方法压低牙齿时牙周组织的改建情况,为种植体支抗压低牙齿的正畸临床应用提供理论依据和应用指导.方法:实验犬6只,在两侧上颌第二切牙与第三切牙颊侧牙槽中隔各植入一枚微型种植体,上颌6颗切牙通过个别带环焊接托槽与片段弓丝连扎,用镍钛拉簧每侧施加120 g力.分别于加力后0, 1, 3, 7, 14和30 d处死实验犬,取切牙及其牙周组织进行X光片检查,以及标本处理、组织切片、HE染色观察.结果:切牙根尖区与牙槽嵴顶部牙周组织改建最为活跃,主要表现为骨质吸收;此外切牙唇腭侧牙周组织也发生了明显的改建活动.结论:应用种植体支抗压低犬切牙时,切牙除了实现垂直向的压低移动以外,同时还发生了冠唇向根舌向的转动,这对于该方法的正畸临床应用具有一定的指导意义.若压低牙齿力值过大, 会导致牙根尖吸收,因此在临床应用中应重点注意力值大小的选择,并应尽可能使用持续性的力量压低牙齿.     

碘仿+碘酚治疗前牙慢性瘘管型根尖炎的疗效评价

目的 :碘仿[1] +碘酚治疗前牙慢性瘘管型根尖炎的疗效评价。方法 :随机分为两组 :采用碘酚瘘管通过术[2 ] 及碘仿根管封药治疗 10 2牙为治疗组 ;采用传统的“樟脑酚 (CP) +甲醛甲酚 (FC)”治疗 48牙为对照组 ,两组最终均作根管充填。结果 :治疗组痊愈 90牙 ,痊愈率 88% ;对照组痊愈 33牙。结论 :碘仿 +碘酚治疗前牙慢性瘘管型根尖炎 ,见效快 ,治愈率高 ,复发率低 ,值得临床推广使用     

正畸美学区的CBCT测量分析

目的探究正畸美学区,包括面下1/3前牙区牙槽骨、切牙位置以及唇部软组织在不同矢状面型、年龄及性别之间的差异性。方法 2012年6月至2013年5月间在山东大学口腔医院进行治疗的60例12~50岁汉族人,根据不同矢状骨面型、性别和年龄分组。根据头影测量ANB的角度分为3组:骨性Ⅰ类(1°5°,18例,30%),骨性Ⅲ类(ANB≤1°,19例,31.7%);根据性别分组:女性41例(68.3%),男性19例(31.7%);根据年龄分组:青少年组12~19岁22例(36.7%),青年组20~29岁20例(33.3%),中年组30~50岁18例(30%)。分别进行锥形束CT(CBCT)测量分析。骨性分组以及年龄分组采用方差检验和多个独立样本检验(Kruskal-Wallis检验),性别组间用独立样本t检验。结果 1不同矢状骨面型之间,骨性Ⅱ类患者前牙区牙槽骨及切牙过度萌出,骨性Ⅲ类患者下唇缘点的唇厚度最小;2不同性别之间,骨和软组织的各项测量值男性均大于女性;3随年龄增长,切牙区牙槽骨的高度、切牙的位置以及唇部软组织变化明显,而牙槽骨的宽度和骨皮质厚度基本稳定。结论正畸美学区在不同的矢状面型、性别和年龄间呈现一定的变化规律,有利于指导临床决策。