{
  "abstract": "Introduction Hyperdivergent skeletal class II malocclusion in adolescents is characterised by mandibular retrognathia with excessive vertical growth and clockwise mandibular rotation, which can worsen facial profile and airway-related morphology. Although mandibular advancement approaches are commonly used, they may increase the vertical dimension and are suboptimal for patients with long-face patterns. This randomised controlled trial aims to evaluate a micro-implant-assisted protrusion correction technique designed to flatten the occlusal plane and promote counterclockwise mandibular rotation, thereby improving facial profile and pharyngeal space.Methods and analysis This trial is registered at the Chinese Clinical Trial Registry (ChiCTR; ChiCTR2100054105). This is a two-arm, multicentre, randomised, parallel-controlled trial. Ninety adolescents will be recruited from Shanghai Stomatological Hospital, Zhongshan Hospital (Fudan University), and Xinhua Hospital (Shanghai Jiao Tong University School of Medicine), and will be randomly allocated (1:1) to the test or control group. The control group will receive conventional anterior teeth retraction, whereas the test group will receive a micro-implant-assisted vertical control protocol with occlusal plane flattening. The primary outcome is the change in the A point–nasion–B point angle. Secondary outcomes include changes in the occlusal plane, incisor and molar heights, and facial height. Measurements will be assessed at baseline, at the end of treatment and at 12 months after treatment completion.Ethics and dissemination This study was approved by the Ethics Committee of the Shanghai Stomatological Hospital (approval no. (2022)006). The results of this study will be made available in peer-reviewed journals.Trial registration number ChiCTR2100054105.",
  "authors": [
    {
      "affiliations": [
        "Department of Orthodontics, Fudan University Shanghai, Shanghai, China",
        "Fudan University Shanghai, Shanghai, China"
      ],
      "name": "Shuangshuang Shi"
    },
    {
      "affiliations": [
        "Biomedical Informatics & Statistics Center, School of Public Health, Fudan University, Shanghai, China"
      ],
      "name": "Wei Zhang"
    },
    {
      "affiliations": [
        "Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatolog, Fudan University, Shanghai, China"
      ],
      "name": "Weihua Zhang"
    },
    {
      "affiliations": [
        "Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatolog, Fudan University, Shanghai, China",
        "Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China"
      ],
      "name": "Meixiu Lin"
    },
    {
      "affiliations": [
        "Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatolog, Fudan University, Shanghai, China",
        "Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China"
      ],
      "name": "Xu Chenyi"
    },
    {
      "affiliations": [
        "Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatolog, Fudan University, Shanghai, China",
        "Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China"
      ],
      "name": "Yun Lu"
    },
    {
      "affiliations": [
        "Department of Orthodontics, Shanghai Stomatological Hospital, Shanghai, China"
      ],
      "name": "Yuehua Liu"
    }
  ],
  "title": "Efficacy of anterior intrusion-based vertical control versus conventional sagittal retraction in adolescents with hyperdivergent mandibular retrognathia: study protocol for a randomised controlled trial",
  "uid": "0947c1ca-838b-51fa-bc16-575f3c04b373"
}