Overview
Altered passive eruption (APE) is a developmental condition characterized by an abnormal relationship between the tooth and its surrounding gingival tissues. This condition results in the gingival margin being positioned too high on the tooth crown, failing to approximate the cementoenamel junction (CEJ). Consequently, patients often present with excessive gingival display, short clinical crowns, and aesthetic concerns. APE can significantly impact both the functional and esthetic aspects of dental health, necessitating specialized diagnostic and therapeutic approaches. Understanding the pathophysiology, clinical presentations, and effective management strategies is crucial for clinicians aiming to optimize patient outcomes.
Pathophysiology
Altered passive eruption is fundamentally a disruption in the normal developmental and eruptive processes of teeth, leading to a dentogingival relationship where the gingival margin is positioned coronally on the anatomic crown rather than aligning with the CEJ [PMID:19655539]. This misalignment can stem from genetic predispositions, environmental factors, or a combination thereof, affecting the harmonious eruption of teeth and the establishment of the correct biologic width. The condition manifests differently across various subtypes, with type I subcategory B being particularly notable for its clinical implications, often characterized by excessive gingival display and short clinical crowns [PMID:36409356]. The underlying mechanisms involve disruptions in the balance between epithelial attachment and connective tissue attachment, leading to a compromised gingival architecture that fails to adapt appropriately to tooth eruption. This misalignment not only affects aesthetics but also predisposes teeth to functional issues and potential periodontal complications.
Clinical Presentation
Patients with altered passive eruption typically present with a hallmark clinical feature: excessive gingival display, which often results in short clinical crowns and compromised esthetic outcomes [PMID:19655539]. This presentation can significantly affect the smile line, leading to concerns about facial aesthetics and self-esteem. Studies involving 24 participants diagnosed with APE type I subcategory B have underscored the necessity for interventions such as esthetic crown lengthening to address these issues [PMID:36409356]. Monitoring parameters like gingival margin level (GML) at various time points—baseline, immediately postsurgery, and at 1, 3, and 9 months—has shown the effectiveness of crown lengthening procedures in achieving stable clinical outcomes [PMID:35060967]. Additionally, six young female patients with APE type 1B, characterized by excessive gingival display (EGD), benefited from comprehensive surgical approaches including crown lengthening and, when necessary, lip repositioning, highlighting the multifaceted nature of treatment required [PMID:31549103]. In some cases, incomplete passive eruption can lead to subgingival caries in maxillary anterior teeth, emphasizing the importance of early diagnosis and intervention to prevent further complications [PMID:10808344].
Diagnosis
Diagnosing altered passive eruption involves a combination of clinical examination and specific diagnostic techniques. Participants diagnosed with APE type I subcategory B typically undergo thorough clinical assessments, including transgingival probing, to accurately identify the extent of gingival displacement relative to the CEJ [PMID:36409356]. The assessment often reveals discrepancies between the expected gingival height and the actual position of the gingival margin, which is crucial for differentiating APE from other gingival conditions. Research has also highlighted the significance of considering patient-specific factors, such as periodontal phenotype, in diagnosis and treatment planning. For instance, thicker periodontal tissues may exhibit different patterns of gingival recovery post-surgery, influencing the choice of surgical techniques [PMID:35060967]. Utilizing advanced techniques like bipolar electrosurgical methods can enhance the clarity of the operative field, aiding in precise diagnosis and assessment of gingival architecture [PMID:18478898]. Clinical examination by experts like Hempton TJ and Esrason F further emphasizes the importance of recognizing the discrepancy between tooth eruption and gingival height, which is pivotal in confirming the diagnosis of incomplete passive eruption [PMID:10808344].
Management
The management of altered passive eruption primarily revolves around surgical interventions aimed at correcting the gingival architecture and restoring proper tooth exposure. A randomized controlled clinical trial demonstrated that both the guided dual technique and conventional crown lengthening significantly increased clinical crown length in patients with APE type I subcategory B, with stable results maintained over 12 months of follow-up [PMID:36409356]. Laser-assisted esthetic crown lengthening (ECL) using Er,Cr:YSGG lasers has shown comparable outcomes in terms of gingival margin recovery, whether performed with open-flap or flapless approaches, with minimal tissue rebound noted at 9 months post-surgery [PMID:35060967]. Surgical protocols involving gingivectomy, apically positioned flaps, and bone recontouring have been successfully employed in treating APE type 1B, resulting in a mean increase of 1.6 mm in tooth crown height one year post-surgery, with stable gingival margins [PMID:31549103]. Apically repositioned flaps combined with osseous recontouring are particularly effective in restoring both gingival health and aesthetic parameters, addressing excessive gingival display and short clinical crowns [PMID:19655539]. Techniques such as bipolar electrosurgery, as demonstrated by Kurtzman GM and Silverstein LH, offer precise control over gingival tissue, facilitating more aesthetically pleasing results [PMID:18478898]. In cases where subgingival caries complicate the presentation, crown lengthening surgery plays a critical role in facilitating necessary restorative procedures [PMID:10808344].
Prognosis & Follow-up
The prognosis for patients undergoing surgical interventions for altered passive eruption is generally favorable, with stable clinical outcomes observed over extended periods. Participants treated with the guided dual technique maintained a clinical crown length of 9.35 mm (± 0.80) at 12 months post-intervention, indicating robust and sustained results [PMID:36409356]. Studies have noted minimal tissue rebound differences between open-flap and flapless ECL techniques, with thicker periodontal phenotypes showing significantly higher supracrestal gingival tissue recovery [PMID:35060967]. Photographic analysis further supports the consistency of these improvements, demonstrating stable enhancements in crown length from baseline to one year post-surgery [PMID:31549103]. Proper follow-up is essential to monitor for any signs of regression or complications, ensuring that the biologic width is maintained and gingival health is preserved. By effectively remodeling the attachment apparatus and exposing the correct tooth dimensions, surgical treatments can lead to long-term improvements in both gingival health and aesthetic outcomes [PMID:19655539].
Key Recommendations
References
1 Carrera TMI, Freire AEN, de Oliveira GJPL, Dos Reis Nicolau S, Pichotano EC, Junior NVR et al.. Digital planning and guided dual technique in esthetic crown lengthening: a randomized controlled clinical trial. Clinical oral investigations 2023. link 2 Altayeb W, Arnabat-Dominguez J, Low SB, Abdullah A, Romanos GE. Laser-Assisted Esthetic Crown Lengthening: Open-Flap Versus Flapless. The International journal of periodontics & restorative dentistry 2022. link 3 Aroni MAT, Pigossi SC, Pichotano EC, de Oliveira GJPL, Marcantonio RAC. Esthetic crown lengthening in the treatment of gummy smile. The international journal of esthetic dentistry 2019. link 4 Rossi R, Benedetti R, Santos-Morales RI. Treatment of altered passive eruption: periodontal plastic surgery of the dentogingival junction. The European journal of esthetic dentistry : official journal of the European Academy of Esthetic Dentistry 2008. link 5 Kurtzman GM, Silverstein LH. Diagnosis and treatment planning for predictable gingival correction of altered passive eruption. Practical procedures & aesthetic dentistry : PPAD 2008. link 6 Hempton TJ, Esrason F. Crown lengthening to facilitate restorative treatment in the presence of incomplete passive eruption. Journal of the Massachusetts Dental Society 1999. link
6 papers cited of 7 indexed.