Taking the guesswork out of mandibular symphyseal distraction osteogenesis

Mandibular symphyseal distraction osteogenesis has recently been introduced as a means of resolving arch length deficiencies in the anterior segment a nd as a method of reducing large vestibular spaces related to a narrow mand ible. Accurately relating the required distraction for a given anterior too th mass and desired future anteroposterior location of the central incisors has not been possible until recently. The relationship between these 3 con trolling factors has been mathematically described by the hyperbolic cosine function and a computer program designed for easy use by the clinician. Tw o clinical cases illustrate the application of the program. A Web site wher e the program can be downloaded at no cost is mentioned.