Can I intrude?

Studies were identified using Medline, PubMed, Medline In-Process and Other Non-Indexed Citations, all evidence-based medicine reviews (Cochrane Database of Systematic Reviews, ACP (American College of Physicians) Journal Club, Database of Reviews of Effectiveness (DARE) and CCTR (Cochrane Controlled Trials Register), Embase, Web of Science and LILACS(Latin American and Caribbean Health Sciences).

Studies included were clinical trials in humans where the intrusion of permanent incisors was determined using cephalometric radiograph superimpositions.

A qualitative synthesis of all included studies was conducted, along with a fixed-effects meta-analysis of two studies that employed the same treatment method.

Of 28 articles meeting the initial selection criteria, only four were included because of methodological issues with the others. Two studies that used the segmented arch technique were included in a fixed-effects meta-analysis to evaluate the amount of incisor intrusion. The combined mean estimates were 1.46 mm (95% confidence interval, 1.05-1.86) for the maxillary incisor and 1.90 mm (95% confidence interval, 1.22-2.57) of intrusion for the mandibular incisor.

True incisor intrusion is achievable in both arches, but the clinical significance of the magnitude of true intrusion as the sole treatment option is questionable for patients with severe deep bite. In non-growing patients, the segmented arch technique can produce 1.5 mm of incisor intrusion in the maxillary arch and 1.9 mm in the mandibular arch.