The inherent difficulty to control growth vectors is caused by the forces applied to the growing bone mainly by the tongue and muscles of the oral cavity. As a result, direction of bone growth in the mandible changes, and rather than bone formation in the desired buccal aspect, the process ends with bone generation on the undesired lingual aspect. The same undesired process occurs in the maxilla, where although the directions of bone growth are opposite, bone is formed on the undesired aspect rather than on the desired one.

Most existing alveolar bone distractors do not provide control over the vectors during the distraction phase and the very few that do so are all extraosseous, bulky and, therefore, are far from being user-friendly or the practitioner's first choice.