Private Practice, Cedar Hill, TX, USA.
Am J Orthod Dentofacial Orthop. 2010 Mar;137(3):324-33. doi: 10.1016/j.ajodo.2009.05.018.
There are disparities in access to orthodontic treatment for children from low-income families. Systematic programs of limited-care interceptive and preventive orthodontics have been proposed as a solution. The purpose of this randomized clinical trial was to compare dental outcomes and funding eligibility from a group of Medicaid patients randomized to receive interceptive orthodontics (IO) in the mixed dentition or observation (OBS).
One hundred seventy Medicaid-eligible children were randomized to receive IO or OBS and followed for 2 years, when complete data were available on 72 and 74 children, respectively. The 2-year changes in the peer assessment rating (PAR) were compared using the Student t test. The proportions of children no longer eligible for Medicaid funding as defined by handicapping labiolingual deviation (HLD) scores less than 25 at the 2-year follow-up were compared with the chi-square test.
The IO patients had significantly greater decreases in the PAR scores--50%-compared with the OBS subjects, -6% (P <0.001). Negative and positive overjet and maxillary alignment were the components most affected by IO; they decreased by 11.0, 7.2, and 3.7 PAR points, respectively (P <0.001). Overbite showed little change. At the 2-year follow-up, 80% of the IO patients' malocclusions that qualified initially were no longer deemed medically necessary by the HLD index, compared with 6% in the OBS group (P <0.001).
IO significantly reduces the severity of malocclusions and moves most from the "medically necessary" category to elective but does not produce finished results for most patients. Overjet and alignment were most readily corrected by interceptive treatment. Deep overbites were the least susceptible to IO correction.
来自低收入家庭的儿童在获得正畸治疗方面存在差异。已经提出了有限护理的截骨和预防性正畸系统计划作为一种解决方案。本随机临床试验的目的是比较一组接受混合牙列截骨术（IO）或观察（OBS）的 Medicaid 患者的牙齿结果和资金资格。
170 名符合 Medicaid 条件的儿童被随机分为 IO 或 OBS 组，并分别随访 2 年，分别有 72 名和 74 名儿童获得完整数据。使用学生 t 检验比较 2 年时的同伴评估评分（PAR）变化。使用卡方检验比较 2 年随访时 HAND 评分<25 的残疾唇舌偏差（HLD）得分不再符合 Medicaid 资金资格的儿童比例。
IO 患者的 PAR 评分下降幅度明显大于 OBS 组，为 50%，而 OBS 组为-6%（P<0.001）。负性和正性覆合以及上颌对齐是受 IO 影响最大的组成部分；它们分别降低了 11.0、7.2 和 3.7 PAR 点（P<0.001）。覆盖变化不大。在 2 年随访时，80%的初始符合 IO 条件的患者的错牙合畸形不再符合 HLD 指数的医学必要性标准，而 OBS 组仅为 6%（P<0.001）。
IO 显著降低了错牙合畸形的严重程度，并使大多数错牙合畸形从“医学必需”类别转变为选择性，但对大多数患者来说并不能产生完整的结果。IO 最容易矫正覆合和对齐。深覆合对 IO 矫正的抵抗力最小。
