Case 1

A 13-year-old female patient attended the Periodontics and Implantology Clinic of the Division of Postgraduate Studies and Research of the Universidad Nacional Autónoma de México (DEPeI-UNAM), referred by the Department of Orthodontics with a diagnosis of impacted maxillary canine, tooth #13, sector III⁴ for surgical exposure.

Periodontally, her diagnosis was mild, generalized gingivitis induced by dental biofilm. After performing periodontal phase I, the tissue was in gingival health. Apical repositioning flap surgery was performed because, within the clinical periodontal parameters, a keratinized tissue width of 3mm was recorded in tooth 13. The tomography showed the impacted tooth #13, with the absence of cortical tissue in the labial region and at the level of the cementoenamel junction of tooth #11. These findings allowed us to determine the position of tooth 13 in sector III according to Lindauer’s diagnosis ⁴ and helped us in the selection of the surgical technique.

An apical repositioning flap was chosen to preserve as much keratinized tissue as possible⁸, and because of the apical position of the canine regarding the mucogingival line. In the surgical procedure, a partial thickness flap was designed, two-thirds of the coronal crown was exposed and the orthodontic button (Borgatta®) was attached as close as possible to the incisal edge using the 3M adhesive system®. The flap was then repositioned apically and sutured to the periosteum with single stitches and 6-0 polyglycolic acid suture so that it covered 2 to 3 mm of the crown (Figure 1. A-D).

Figure 1 Periodontal plastic surgery technique for the exposure of tooth #13. Case 1. A. Design of a partial thickness flap to be repositioned apically. B. Exposure of tooth #13. C. Placement of the orthodontic button. D. Apical repositioning of the flap using simple stitches and 6-0 polyglycolic acid suture. 

Traction of tooth #13 was activated at the time of orthodontic button placement with a second-generation Ormco closed elastic chain®, in the direction of tooth #14 to guide eruption (Figure 1. C-D). Traction was performed intermittently from tooth exposure until the ninth month of orthodontic follow-up where tooth positioning was achieved with light and continuous forces at one-year post-surgery.

Case 2

Female patient, 13 years old, attended the Periodontics and Implantology clinic of the DEPeI UNAM, referred by the Department of Orthodontics with a diagnosis of impacted maxillary canine teeth #13 and #23, sector IV⁴, for surgical exposure by apical repositioning flap for both teeth and a second flap surgery with lateral repositioning for tooth #13. Future extractions of teeth #11 and 21 were planned due to severe root resorption.

Periodontally, mild, generalized dental biofilm-induced gingivitis was diagnosed. After performing periodontal phase I the tissue was in gingival health. At the time of surgery, the width of keratinized tissue in teeth #13 and 23 was 3mm. The tomography allowed us to determine the position of teeth #13 and 23 in sector IV according to Lindauer’s diagnosis⁴ and it was observed that tooth #13 was in an apical position to tooth #23 and covered by labial cortical bone. These findings helped us to determine the surgical technique and we chose to perform an apical repositioning flap in both canines to preserve as much keratinized tissue as possible⁸, because of the apical position of the canines regarding the mucogingival line.

The surgical procedure was performed using the apical repositioning flap technique previously described in case 1, both for tooth 13 and tooth 23; with the only difference being that in tooth #13 cortical bone was removed before the removal of the connective tissue follicle (Figure 2. A-B). The traction of tooth #23 was activated at two weeks post-surgery from a closed metal ligature (TD) fixed from the orthodontic button (Borgatta®), attached by 3M adhesive system®, in the direction of tooth #21 to guide the eruption. Traction was performed intermittently for six months.

Figure 2 Periodontal plastic surgery techniques for exposure of teeth #13 and 23. A. Design of a partial thickness flap to be repositioned apically over both teeth. B. Placement of orthodontic buttons and apical repositioning of the flaps from simple stitches and 6-0 polyglycolic acid suture. 

Six months after surgery, it was observed that the keratinized tissue adjacent to the orthodontic button of tooth #13 was covering it and would not facilitate the placement of the bracket for future tooth traction, so it was decided to perform a second surgery with a lateral repositioning flap, after removing the orthodontic button (Figure 3. A-D).

Figure 3 Periodontal plastic surgery technique for exposure of tooth #13, 6 months after the previous surgery. A. Presence of keratinized tissue lateral to tooth #13. B. Design of a partial-thickness flap to be repositioned laterally. C. Exposure of tooth #13 and placement of the orthodontic button. D. Lateral repositioning of the flap using simple stitches and 6-0 polyglycolic acid suture. 

Seven months after the second surgery, the canines reached occlusion and the corresponding alveolar area of teeth #11 and 21, which were extracted because they had a hopeless prognosis due to complete root resorption and severe mobility.

At two years post-surgery, once the teeth reached occlusion and their position in the corresponding alveolar area, the clinical parameters were assessed in sequential order: PI, GI, PB, KT, RES, and same order with the tomographic parameters BH, BS, and BT (Figure 4 A-B).

Figure 4 Tomographic analysis. Schematic drawing to calculate the labial and palatal bone height (BH) and bone support (BS) of the exposed canines at two years post-surgery. The green lines identify the cementoenamel junction-alveolar crest (CEJ-AC) distance in both the labial and palatal regions, the pink line identifies the apex-cementoenamel junction (A-CEJ) distance, the blue line marks the apex-labial alveolar crest (A-LAC) distance, and the dashed white line identifies the apex-palatal alveolar crest (A-PAC) distance. The bone percentage was calculated by dividing the apex-alveolar crest distance by the apex-enamel cementoenamel junction distance. Schematic drawing for calculating the labial and palatal bone thickness (BT) of exposed canines at two years post-surgery. Taking as reference the distance between the root surface and the cortex, perpendicular to the long axis of the tooth, at 3 mm S1), 6 mm (S2), and 9 mm (S3) (blue, green, and purple lines respectively) from the cementoenamel junction. 

Case 1

Tooth #13: In the clinical parameters, PI=0 showed the absence of plaque in the gingival area; GI=0, showed gingiva with the absence of inflammation, hemorrhage, and alteration of color change, PD<4mm, with the absence of periodontal pockets (Table 1), KT of 5mm (Figure 5 A-C).

Figure 5 Assessment of keratinized tissue obtained around tooth #13 after surgery. The tissue followed the tooth during its movements and is comparable to that of the adjacent teeth. A. 6 months post-surgery. B. One-year post-surgery. C. Two years after surgery. 

Table 2 shows the RES, where the score for the gingival margin level was 6, i.e., absence of gingival recession; for the marginal tissue contour the result was 1, showing a scalloped marginal contour; the variable of texture with a score of 0 showed the presence of a scar; for color, the score was 1, showing adequate integration with the adjacent soft tissues; for its part, the MGL was shown to be aligned with the adjacent teeth, obtaining a score of 1. A total score of 9 was obtained.

In the tomographic parameters the BH in the vestibular region was higher (3.96 mm) relative to the BH in the palatal region (1.42 mm); the percentage of labial BS was lower (71%) relative to the percentage of palatal BS (88%) (Table 1) (Figure 6 A). BT was lower at all three labial cortical sites (S1=0.53 mm) (S2=0.49 mm) (S3=0.58 mm) relative to BT at all three palatal cortical sites (S1=0.83 mm) (S2=1.87 mm) (S3=2.49 mm) (Table 1) (Figure 7A).

Figure 6 Tomographic image showing the measurements of the labial and palatal bone height (BH) and bone support (BS) of the exposed canines at two years post-surgery. A. Tooth #13, case 1. B. Tooth #13, case 2. C. Tooth #23, case 2. 

Figure 7 Tomographic image showing the labial and palatal bone thickness (BT) measurements of the exposed canines two years after surgery. A. Tooth #13, case 1. B. Tooth #13, case 2. C. Tooth #23, case 2. 

Case 2

Teeth #13 and 23. In the clinical parameters, PI=0 presented an absence of plaque in the gingival area, GI=0, showed gingiva with absence of inflammation, bleeding, and color change, PD<4mm with absence of periodontal pockets (Table 1), KT of 5mm and 3mm for teeth 13 and 23 respectively (Figure 8 A-C). The RES showed a score of 6 for the level of the gingival margin in the two canines, i.e., absence of gingival recession; for marginal tissue contour the score was 1 for both teeth, evidencing a scalloped marginal contour; the texture variable with a score of 0, showed the presence of a scar around the two canines; For color, the score was 0 for tooth #13, showing a color variation with the adjacent teeth, and 1 for tooth #23, showing an adequate integration with the adjacent soft tissues; for its part, the MGL was aligned with the adjacent teeth, obtaining a score of 1 for both teeth. A total score of 8 was obtained for tooth #13, and 9 for tooth #23 (Table 2).

Figure 8 Assessment of keratinized tissue obtained around teeth #13 and 23 after surgery. The tissue followed the tooth during its movements and is comparable to that of the adjacent teeth. A. 6 months post-surgery. B. One-year post-surgery. C. At two years post-surgery 

In the tomographic parameters for tooth #13, BH in the labial region was higher (4.80 mm) relative to the palatal AO (1.33 mm); the percentage of labial BS was lower (49%) relative to the percentage of palatal BS (87%). For tooth #23, BH in the labial region was higher (2.26 mm) relative to the palatal BH (1.31 mm); the labial BS percentage was lower (61%) relative to the palatal BS percentage (78%) (Table 1) (Figure 6 B-C).

It was observed that the BT for the labial cortex of tooth #13 was lower at the three points (S1=0.48 mm) (S2=0.74 mm) (S3=0.71 mm) relative to the BT at the three points of the palatal cortex (S1=2.49 mm) (S2=4.00 mm) (S3=2.67 mm). For tooth #23 the BT of the labial cortex was lower at the two points (S1=0.42 mm) (S2=0.60 mm) relative to the BT at the two points of the palatal cortex (S1=1.70 mm) (S2=3.93 mm), the third point (S3) could not be evaluated due to the decreased height of the labial and palatal cortices (Table 1) (Figure 7 B-C).