Batista, K. B., Thiruvenkatachari, B., Harrison, J. E., and O’Brien, K. D. (2018). Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children. Cochrane Database of Systematic Reviews, Issue 3, Art. No.: CD003452. DOI: 10.1002/14651858.CD003452.pub4 https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003452.pub4/full
This systematic review discusses the evidence behind the treatment of patients with increased overjets, and includes summaries of the best quality studies using functional appliances.
Nguyen, Q. V., Bezemer, P. D., Habets, L., and Prahl-Andersen, B. (1999). A systematic review of the relationship between overjet size and traumatic dental injuries. European Journal of Orthodontics, 21, 503–15. [DOI: 10.1093/ejo/21.5.503] [PubMed: 10565091]
These two papers discuss the increased risk of trauma to the incisors of patients with increased overjets.