Ankylosed teeth as abutments for palatal expansion in the rhesus monkey.

The maxillary permanent lateral incisors of three rhesus monkeys were intentionally ankylosed by a replantation and splinting technique. A 1-pound expansion force was applied to the ankylosed teeth for 5 to 15 weeks. The intermaxillary and interpremaxillary sutural expansion was monitored radiographically during the experimental period. Two animals were killed for histologic examination after 13 and 23 weeks, and the third animal was monitored radiographically for 21 weeks. Skeletal expansion of the maxilla was achieved without concomitant buccal tipping of the abutment teeth. Osteoid tissue was deposited on localized areas of the resorbed cementum and dentin of the ankylosed teeth. The periodontal ligament showed atrophic and degenerative changes similar to those found with increased age in human beings.