Orthodontists’ preferences regarding the difference of bracket bonding height between the maxillary incisors

ABSTRACT Introduction: The vertical position of orthodontic brackets in maxillary incisors may influence the incisal step between the anterior teeth and thereby interfere with the smile esthetics. Even so, esthetic standards have been modified over time and consistently required technical adjustments. Objective: This study analyzed orthodontists’ preferences regarding the difference of bracket bonding height between the maxillary central incisors (MCI) and maxillary lateral incisors (MLI), and further determined whether the orthodontist sex, age and time of specialization have association to their choices. Methods: This study collected data through an electronic form. Study participants analyzed a clinical case in which they indicated their preference for bracket bonding height. The placement height options ranged from 3.0 mm to 5.5 mm from the incisal edge, with 0.5-mm intervals, or at the clinical crown center (CCC). The difference in the bonding height between the MCI and MLI was analyzed, considering the formation of incisal steps between these teeth. Results: Participants indicated that the difference in bracket bonding height between the MCI and MLI should be as follows: 0 mm (3.9%); 0.5 mm (78.3%); 1 mm (7.6%); 1.5 mm (0.2%); and CCC (9.9%). There was no statistically significant correlation between the choice for bracket bonding height and sex, age and time since specialization. Conclusion: Most participating orthodontists choose the 0.5-mm difference in bracket placement height between the MCI and MLI. The variables sex, age and time since specialization did not influence this choice.

摘要
引言：上颌切牙的正畸托槽垂直位置可能会影响前牙间的切缘台阶，进而干扰微笑美学。即便如此，美学标准随时间不断演变，且始终需要技术调整。
研究目的：本研究旨在分析正畸医师对上颌中切牙（maxillary central incisors, MCI）与上颌侧切牙（maxillary lateral incisors, MLI）之间托槽粘接高度差的偏好，并进一步探究医师性别、年龄及从业时长与其选择是否存在关联。
研究方法：本研究通过电子问卷收集数据。研究对象需分析1例临床病例，并选择其偏好的托槽粘接高度。粘接高度选项范围为距切缘3.0 mm至5.5 mm，间隔0.5 mm，或以临床牙冠中心（clinical crown center, CCC）为参照。本研究针对上颌中切牙与上颌侧切牙间的托槽粘接高度差展开分析，同时考量两牙间形成的切缘台阶情况。
研究结果：参与调查的医师认为，上颌中切牙与上颌侧切牙的托槽粘接高度差应设置为：0 mm（3.9%）、0.5 mm（78.3%）、1 mm（7.6%）、1.5 mm（0.2%），或以临床牙冠中心为参照（9.9%）。正畸医师的托槽粘接高度选择与性别、年龄及从业时长均未呈现统计学意义上的显著相关性。
研究结论：多数参与本研究的正畸医师选择在上颌中切牙与上颌侧切牙间设置0.5 mm的托槽粘接高度差。性别、年龄及从业时长这三项变量并未对该选择产生影响。