Correction of Class II Skeletal Malocclusion with an Infra- Zygomatic Crest Bone Screw Approach

Introduction: This case report describes the treatment of a Class II skeletal malocclusion with a prognathic maxilla and retrognathic mandible with severely proclined maxillary incisors and lingually blocked mandibular right lateral incisor withentire maxillary arch distalization and use ofinfra-zygomatic crest bone screws devoid of extraction of premolars.

Method: Treatment involved strap-up of a pre-adjusted edgewise appliance, MBT technique (0.022 X 0.028 - inch slot). A non-extraction approach was recommended despite the case warranted premolar extractions. Infra-zygomatic bone screws of length 14mm and diameter 2mm was used for the distalization of the entire maxillary arch. The case was assessed at start of orthodontic treatment (T1) and end of orthodontic treatment (T2).

Results: At T2, the severe pre-maxillary prognathism and mandibular anterior crowding with lingually locked right lateral incisor was corrected with the canines and molars finished in Class I relationship. Normal overbite and overjet with a pleasing soft tissue profile was satisfactorily achieved.

Conclusion: Infra-zygomatic bone screws can be effectively used as absolute skeletal anchorage to correct Class II skeletal discrepancy with maxillary prognathism and severe proclination of maxillary incisorsdevoid of premolar extractions.