Use of Clark’s twin block for the treatment of angle class II malocclusion during development: retrospective study based on literature data

Purpose: The dentoskeletal Class II malocclusion is widespread and causes aesthetic, phonetic and functional problems, increasing the risk of trauma for upper incisors and an incorrect craniofacial development of children. The aim of this retrospective study is to assess Class II malocclusions and evaluate, through cephalometric analysis, skeletal and dentoalveolar changes after treatment using Clark’s Twin Block appliance. Methods: The authors carried out three different searches on the MEDLINE database (through PUBMED), the ScienceDirect database and the Cochrane Library using selected MeSH keywords. The studies obtained were filtered based on an evaluation on quality and type of data provided. Once data was obtained, it was used to determine whether the changes in cephalometric measures after treatment with Clark’s Twin Block appliance suggest a positive effect of the appliance on patients. Results: Functional appliances causing a mandibular advancement show similar effects on craniofacial structures, as shown by cephalometries. Data shows that the maxilla (SNA) tends to restrict sagittally (head gear effect) and the mandible has a significant sagittal advancement (SNB) and length increase. Both the profile and facial esthetics of patients improved due to the reduction of the maxillomandibular skeletal relation (ANB and WITS appraisal). A noticeable correction of overjet and overbite was also measured. Clinical Significance: In order to treat Class II malocclusion caused by a retrognathic mandible, using Clark’s Twin Block is a viable option. The success of the treatment, however, depends on the patient’s individual cooperation.