Experimental gingivitis in patients with and without altered passive eruption

Clinical and radiographic assessment of gummy smile patients with altered passive eruption: a cross-sectional study in a Thai population

OBJECTIVES

The study aimed to evaluate the clinical crown length (CCL) among patients diagnosed with altered passive eruption (APE), the causes of a gummy smile, the prevalence of APE, and the correlation between parameters.

MATERIALS AND METHODS

A total of 86 gummy smile patients (516 teeth) underwent clinical examination and assessment using cone-beam computed tomography (CBCT), photography, and intraoral scanning.

RESULTS

Significantly shorter CCL and distance between the cementoenamel junction and bone crest (CEJ-BC) were observed among APE-affected teeth (p < 0.05). Among the patients, 56.1% of patients were diagnosed with APE, and most of them were affected by a combination of APE and hypermobile upper lip (HUL). Based on 183 APE-affected teeth, the prevalence of APE types and subtypes was as follows: APE1A (96; 19.3%), APE1B (78; 15.9%), APE2A (8; 1.6%), and APE2B (1; 0.2%). Positive correlations were found between keratinized gingival width (KGW) and bone thickness (BT), while negative correlations were observed between gingival thickness (GT) and BT.

CONCLUSION

Shorter CCL and CEJ-BC were the highlighted features of APE. APE affected approximately half of the gummy smile patients, with most of them presenting with a combination of HUL. Almost teeth affected by APE were classified as Type I, with a nearly equal distribution between subtypes A and B.

CLINICAL RELEVANCE

The clinical and radiographic features of APE contribute to a better understanding of this condition and facilitate the management of patients affected by APE. Approximately half of gummy smile patients will require multidisciplinary treatment.

Assessment of Negative Gingival Recession: A Critical Component of Periodontal Diagnosis

Accurate measurement of negative gingival recession (GR) is essential to accurately determine the clinical attachment loss, which leads to an accurate diagnosis and optimal therapy of periodontal disease. However, the accuracy of measuring the negative GR has been shown to be low and highly variable between examiners. The position of the gingiva margin in relation to the cemento-enamel junction (CEJ) varies among different stages of passive eruption. The amount of negative GR is about 2 mm on average at the mid-facial sites and ranges from 2 to 3.5 mm at interproximal sites in periodontally healthy patients. Some other clinical conditions may change the gingival dimension coronal to the CEJ, such as altered passive eruption and gingival enlargement. In addition to the traditional approach using a periodontal probe to assess the negative GR, nowadays dental ultrasound imaging may be able to assist in accurately measuring the amount of negative GR. This narrative review will discuss the existing evidence of the dimension of dentogingival tissue and the clinical assessment of negative GR using different clinical tools.

Histologic Analysis of Clinically Healthy Human Gingiva in Patients with Altered Passive Eruption

The purpose of this study was to histologically examine the clinically healthy gingiva of patients with altered passive eruption (APE). Five patients with type 1 APE were enrolled. They underwent scaling and polishing and received oral hygiene instructions. After 6 months of supervised plaque control and uninterrupted gingival clinical health (Gingival Index (GI) = 0 and no Bleeding on Probing (BoP)), upper anterior teeth were surgically treated. During the surgical procedure, the excised gingival margin was collected to be histologically examined. In four out of five patients, signs of inflammation including spongiosis and neutrophil exocytosis could be found in the epithelium of the gingival sulcus. Ulceration with exposure of the lamina propria and inflammatory granulation tissue were evident in the most severe cases. Normal density and orientation of collagen fibers could be seen within the superficial and the deep portions of connective tissue, with an increase in size and number of the deep collagen fibers and a reduced laxity of the superficial ones. In conclusion, the clinically healthy gingiva of APE patients showed features compatible with persistent inflammation, possibly due to recurrent traumatisms caused by an incisally placed gingival margin.