chǐ / liè / jiǎo / zhèng / tōng / cháng / xū / yào / jiào / cháng / shí / jiān / huàn / zhě / bì / xū / dìng / qī / fù / zhěn

齿列矫正通常需要较长时间，患者必须定期复诊。

Orthodontic treatment usually takes a long time, and patients must attend regular follow-up appointments.