Strategic management of altered passive eruption in anterior implant therapy: A case report.

Abstract

Background: A clinical scenario in the esthetic zone is the presence of short clinical crowns, which, in the absence of occlusal wear and other injuries, is referred to as altered passive eruption (APE). The presence of APE can lead to esthetic issues, which can impact the patient's smile harmony. In esthetically demanding cases, APE must be addressed prior to or in conjunction with implant therapy, and failure to do so can result in esthetic complications and failure in prosthetic planning. This case report exhibits a digital workflow in treating such patients to achieve optimal outcomes.

Methods: A 67-year-old female presented with a missing tooth #7 and APE of #6-11. Treatment included esthetic crown lengthening, guided bone regeneration (GBR) at site #7, followed by gingivectomy, implant placement, connective tissue graft (CTG), and provisionalization using lab-milled crowns to allow soft tissue maturation.

Results: Osseous crown lengthening with simultaneous GBR corrected altered bony architecture and reconstructed the implant site. Horizontal bone width increased from 4.99-6.71 to 6.39-9.74 mm at 6 months, with cone-beam computed tomography confirming 1-1.5 mm of ostectomy per tooth. Gingivectomy, implant placement, and CTG yielded a mean clinical crown height increase of 1.07 ± 0.19 mm and 13.4% improvement in width-to-length ratio, with favorable peri-implant parameters at final evaluation.

Conclusion: Preoperative analysis of patients' esthetics is important when implants are considered in the anterior segment. Recognition and treatment of APE can have significant effects on the 3D positioning of dental implants and the desired esthetic outcome.

Key points: Altered passive eruption must be identified and corrected before implant osseointegration, as post-integration correction requires flapping and osseous recontouring around the fixture that compromises esthetic outcomes. Osseous crown lengthening should be performed concurrently with guided bone regeneration and gingivectomy deferred to implant placement, since the coronal flap advancement required for guided bone regeneration displaces the mucogingival junction and would negate any prior soft-tissue modification. Digital planning that merges the diagnostic wax-up with the preoperative scan allows a single guide to govern both ostectomy margins and prosthetically driven implant position, which is essential to producing stable peri-implant tissue and improved crown proportions.

Plain language summary: Placing a dental implant in the anterior region is one of the most demanding procedures in dentistry, because the result must look natural as well as function well. This case report describes a 67-year-old woman missing an upper front tooth who also had a condition called altered passive eruption, in which the gums sit too high on the teeth, producing short-looking teeth and a "gummy" smile. Because the bone at the area of the missing tooth had also shrunk after the earlier extraction, the clinicians faced two problems at once: too little bone to hold an implant, and gum and bone contours that would have made any new tooth look out of proportion. The team used digital scans and a 3D-printed surgical guide, planned from a model of the ideal final smile, to reshape the bone around her front teeth at the same time as rebuilding bone at the implant site. Gum reshaping and implant placement followed, with a soft tissue graft to stabilize the gumline. The key lesson: these corrections must be completed before the implant fuses to bone, after which they become far harder to achieve.