Impacted Teeth

Dr. Bowman has invented several auxiliaries to assist in the correction of
impacted teeth including the Monkey Hook,
Kilroy Springs, and the Molar Jack


Dr. Bowman has designed and developed some orthodontic auxiliaries to assist in the correction of impacted teeth, one of the most problematic dilemmas in our specialty. As a play on one of several terms for “eye teeth,” Dr. Bowman has taught the technique of incorporating these auxiliaries as “canine obedience training,” with an eye to providing more versatile and predictable biomechanics. The key to dealing with impacted canines or cuspids is to provide specific directional forces to insure these teeth are moved down from the point where they are “stuck” in jaw.

Dr. Bowman has had several articles published and has lectured in many countries, describing these devices and the techniques he has developed for directing the eruption of impacted teeth.

Canine Ortho Tribune
Canine Obedience


image of a monkey hook and loop

The first device that Dr. Bowman created for impacted teeth was the very simple Monkey Hook and Loop. These small segments of orthodontic wire are formed into hooks that are inserted onto tiny “braces” or loop buttons that are held to the surface of the affected canine by orthodontic bonding adhesive. The Monkey Hook and Loop are most often placed onto the impacted tooth by an oral surgeon after they make a tiny window in the gum tissue to expose the surface of the impacted tooth. Forces to direct the eruption of the impacted tooth are then applied to one or more Monkey Hooks, linked like keys on a keychain, or linked together in a chain.

kilroy spring logo


image of a kilroy spring

Kilroy Springs are more elaborate spring auxiliaries that are added to orthodontic braces and wires to provide forces to impacted teeth to direct their eruption downwards and towards the dental arch. Dr. Bowman designed two different Kilroys: Kilroy I is the most commonly used as it is for cuspids that are impacted or stuck in the palate or roof of the mouth. Over 75% of impacted canines are found there and the cause appears to be primarily genetic in origin. In perhaps half of these instances, the canines have already caused some damage to the roots of other front teeth; however, this process often stops after the cuspid is moved away from those roots and into its correct position.

The Kilroy II spring is a more complex, cantilevered spring that is used for “eye teeth” that are impacted on the labial or “cheek side” of the jaw. This spring is designed to provide a more vertical force to direct the eruption of the canine downward with some milder direction into the arch form.

A combination of Monkey Hooks and Kilroy Springs are typically used with full braces, like the Butterfly System® (also designed by Dr. Bowman), for directing the eruption of impacted canines.

kilroy spring article in ortho tribune

Kilroy Springs
Kilroy Ad in Ortho Tribune