Dimensions of the dentogingival unit in the anterior maxilla – A study with CBCT

Background

The dentogingival unit (DGU) is the anatomical complex formed by the gingival membrane, gingival sulcus, junctional epithelium and connective tissue insertion, also known as the ìbiological spaceî. It is very important, and its invasion may cause the collapse and apical migration of the fixation apparatus. Biological space is essential for the success of various dental procedures and maintenance periodontal health. There are numerous methods to measure the dimensions of the DGU studies using CBCT are still very scarce.

Aim/Hypothesis

To characterize the gingival phenotype by determining the dimensions of the dentogingival unit in the anterior maxilla with CBCT analysis.

Material and Methods

The total study population consists of 50 elements, from which a preliminary random sample of 20 was collected. A CBCT of the anterior maxilla of each participant was done with Planmeca ProMax® 3D MID equipment with the same specifications conditions. All used a lip retractor to create a space between the soft and hard tissues, as well as cotton rolls between the teeth to allow a separation of the upper and lower jaws. The characterization of the dentogingival unit was performed by measuring the following parameters on teeth 21 and 11- Thickness of Free Gingiva (TFG) + Thickness of Attached Gingiva (TAG) + Gingiva Thickness in Supracrestal Insertion (GTSI) + Alveolar Bone Thickness (ABT) + Distance from the Amelo-Cementum Line to the Alveolar Crest (DACAC) + Distance from the Amelo-Cementum Line to the Free Gingival Margin (DACFGM) + Alveolar Height (AH) + Alveolar Width (AW) + and Mesio-distal diameter of incisional foramen (DIF)

Results

Measurements collected on teeth 11 and 21 are presented as follows-Tooth 11 MEASUREMENT MEAN VALUE SD Thickness of Free Gingiva 1.02 mm 0.16 mm Gingiva Thickness in Supracrestal Insertion 1.36 mm 0.28 mm Thickness of Attached Gingiva 0.86 mm 0.21 mm Alveolar Bone Thickness 0.82 mm 0.18 mm Distance Amelo-Cementum line to Alveolar Crest 1.57 mm 0.49 mm Distance Amelo-Cementum line to Free Gingival Margin 2.81 mm 0.71 mm Alveolar Height 18.96 mm 1.91 mm Alveolar Width 8.86 mm 0.93 mm Diameter of Incisal Foramen 2.53 mm 0.74 mm Tooth 21 MEASUREMENT MEAN VALUE SD Thickness of Free Gingiva 1.05 mm 0.25 mm Gingiva Thickness in Supracrestal Insertion 1.32 mm 0.32 mm Thickness of Attached Gingiva 0.90 mm 0.30 mm Alveolar Bone Thickness 0.87 mm 0.30 mm Distance Amelo-Cementum line to Alveolar Crest 1.67 mm 0.46 mm Distance Amelo-Cementum line to Free Gingival Margin 2.80 mm 0.69 mm Alveolar Height 19.12 mm 1.86 mm Alveolar Width 8.81 mm 0.96 mm Diameter of Incisal Foramen 2.54 mm 0.74 mm

Conclusion and Clinical Implications

According to the evaluation of the preliminary sample, we concluded that the CBCT allows measurements with high precision, without bias of subjectivity or necessity of invasion. It is, therefore, a method with high efficacy and low intolerance. However, the evaluation of the total sample will give a more representative picture of the Portuguese population.