Burke S, Burch J G, Tetz J A
College of Dentistry, Ohio State University, Columbus.
Am J Orthod Dentofacial Orthop. 1994 May;105(5):506-11. doi: 10.1016/S0889-5406(94)70013-3.
Five hundred sets of orthodontic diagnostic records of patients (age 15 years +/- 3) (228 males, 272 females) whose six maxillary anterior teeth had erupted were studied. Incidence of overlapped and crowded maxillary central incisors and magnitude of that crowding were determined, also the incidence of postorthodontic open gingival embrasures (black triangles) and width of those triangular spaces between maxillary central incisors were determined. Of the 500 patients 185 (37%) had preorthodontic crowding of maxillary central incisors. Magnitude of crowding was 1.08 mm +/- 0.94, n = 185. One hundred twenty-nine of these patients were treated. Their postorthodontic records were studied. Of the 129 cases 54 (41.9%) had a black triangular gingival embrasure space between the two maxillary central incisors postorthodontically. Width of the triangular space was 0.43 mm +/- 0.32, n = 54. One third of a similar population of orthodontic patients can be expected to have crowded central incisors. Two-fifths of those can be expected to have a postorthodontic black triangle when treated similarly.
对500例上颌六颗前牙已萌出的患者（年龄15岁±3岁，男性228例，女性272例）的正畸诊断记录进行了研究。确定上颌中切牙重叠和拥挤的发生率以及拥挤程度，同时确定正畸治疗后牙龈间隙（黑色三角区）的发生率以及上颌中切牙之间这些三角形间隙的宽度。在500例患者中，185例（37%）上颌中切牙存在正畸治疗前拥挤。拥挤程度为1.08mm±0.94，n = 185。其中129例患者接受了治疗，并对其正畸治疗后的记录进行了研究。在129例病例中，54例（41.9%）正畸治疗后上颌两颗中切牙之间出现黑色三角形牙龈间隙。三角形间隙宽度为0.43mm±0.32，n = 54。预计三分之一的类似正畸患者群体中会出现中切牙拥挤。当进行类似治疗时，预计其中五分之二的患者会出现正畸治疗后的黑色三角区。
