Zachrisson B U, Skogan O, Höymyhr S
Am J Orthod. 1980 Mar;77(3):307-19. doi: 10.1016/0002-9416(80)90084-6.
Using fiber-optic transillumination, a clinical assessment was made of enamel cracks (prevalence, localization, expression, direction) in three groups of adolescents representing debonded, debanded, and orthodontically untreated teeth. The findings indicated that enamel cracks were extremely common in all three groups. Most cracks were not very prominent and could easily be overlooked on routine clinical examination. The majority of cracks were vertical and, with the exception of the mandibular incisors, were most frequently localized in the gingival two-thirds of the facial tooth surfaces. The marked cracks were observed mostly on maxillary canines and central incisors in all groups. Of the few horizontal cracks noted, most were located in maxillary and mandibular central incisors. Clinical implications of the observations are (1) careful bonding and debonding do not result in a significant increase of enamel cracks; (2) whenever pronounced vertical cracks occur on other teeth than maxillary central incisors and canines or many horizontal cracks are observed, the bonding/debonding technique should be re-evaluated; (3) it seems advisable to notify parents/patients of marked cracks before orthodontic treatment is started, in order to avoid problems later when it is difficult or impossible to document their pretreatment existence.
采用光纤透照法，对三组青少年牙齿（分别代表已脱粘接剂、已除带环和未经正畸治疗的牙齿）的釉质裂纹（发生率、位置、表现、方向）进行了临床评估。结果表明，釉质裂纹在所有三组中都极为常见。大多数裂纹不太明显，在常规临床检查中很容易被忽视。大多数裂纹是垂直的，除下颌切牙外，最常见于牙面部牙龈三分之二处。在所有组中，明显的裂纹大多见于上颌尖牙和中切牙。观察到的少数水平裂纹大多位于上颌和下颌中切牙。这些观察结果的临床意义在于：（1）仔细的粘接和脱粘接不会导致釉质裂纹显著增加；（2）当上颌中切牙和尖牙以外的其他牙齿出现明显的垂直裂纹或观察到许多水平裂纹时，应重新评估粘接/脱粘接技术；（3）在正畸治疗开始前告知家长/患者明显的裂纹似乎是可取的，以避免以后难以或无法记录其治疗前存在情况时出现问题。
