Vitamin D Supplementation in Primary Hyperparathyroidism: Analysis of Benefits and Hazards.

A gummy smile, or excessive gingival display, occurs when more than 3–4 mm of gingiva is visible during smiling.[] This condition can affect self-confidence, often prompting individuals to seek treatment. Etiological factors include a short or hypermobile upper lip, vertical maxillary excess, dentoalveolar extrusion, gingival hyperplasia, and altered passive eruption (APE).[] Among these etiologies, APE is frequently encountered in clinical practice and is characterized by a gingival margin positioned coronally to the height of the crown contour or 3–4 mm coronal to the cementoenamel junction (CEJ). This results from incomplete apical migration of the epithelial attachment during passive eruption.[] Contributing factors may include a genetically determined phenotype, orthodontic tooth movement, and endocrine system abnormalities.[] The prevalence of APE has been reported to range from 12.1%[] to as high as 42.1%[] in patients with a history of orthodontic treatment. The correction of APE typically involves periodontal surgery or esthetic crown lengthening to expose more of the anatomical crown and enhance the smile, including gingivectomy alone or in combination with osseous surgery.[] While smile analysis is crucial for surgical planning, accurate identification of the CEJ defines the maximum crown length that can be safely exposed, thereby preventing excessive gingivectomy and its associated risks, such as root recession, sensitivity, and esthetic concerns.[] Common techniques for locating the CEJ include tactile sensing with an explorer or probe, estimation from clinical crown length using gutta-percha on periapical radiographs, cone-beam computed tomography, and ultrasound.[] Although these techniques provide accuracy, they require skilled operators and may be costly. In addition, proposed average width-to-length ratios of the anatomical crown, measured directly on extracted teeth or plaster models of maxillary anterior teeth, have been used to estimate gingival overlap in APE cases. However, discrepancies in these ratios have been reported, which could be attributed to differences in ethnicity, tooth wear, and sex among study populations.[] Hence, a simple and clinically applicable landmark for estimating the anatomical CEJ in patients with APE remains lacking.