1 Radiographic Evaluation of the Alveolar Ridge Splitting Technique Combined with Guided Bone Regeneration vs Guided Bone Regeneration Alone in the Anterior Maxilla: A Retrospective Controlled Study Lulu Zhang, MM1 After tooth extraction, bone loss Yuanding Huang, MD2 in the buccal aspect of the anterior maxilla is more severe, partially be- cause of tissue pressure from the labial side and bundle bone resorp- This study aimed to estimate the radiographic outcomes of the alveolar ridge tion.1 Therefore, the alveolar ridge splitting (ARS) technique combined with guided bone regeneration (GBR) and splitting (ARS) technique with simul- compare its efficacy with GBR alone in maxillary anterior narrow ridges. Forty taneous implantation has been in- patients with 51 implants in the ARS group and 40 patients with 49 implants in troduced to repair bone defects and the GBR group were included. The buccal bone thickness (BBT) at 0 to 4 mm 2 from the implant shoulder immediately and 6 months postoperative were facilitate implant installation. analyzed using cone beam computed tomography. The BBT at both time This method favors cases with points had no statistical disparities between the two groups (P > .05). However, an alveolar crest width of 3 to 5 mm, BBT changes indicated significant disparities, with more BBT preservation particularly in the maxilla, with thin- in the ARS group (P < .05). Compared with GBR alone, the ARS technique ner cortical bone and lower bone combined with GBR, despite obvious buccal bone diminution, could be a density.3 Nevertheless, due to surgi- reliable modality for treating ridge width deficiency in the anterior maxilla. Int J Periodontics Restorative Dent 2020 (9 pages). doi: 10.11607/prd.4512 cal trauma or inadequate blood sup- ply, buccal bone resorption could happen. Hitherto, prior investigations on the ARS procedure mostly dealt with the ridge width alteration and marginal bone loss after surgery4–6 but scarcely reported dimensional changes of the buccal bone during postoperative bone remodeling. Apart from that, the impact of orofa- cial implant angulation on the coronal buccal bone changes has sparsely been analyzed.7 Recently, however, 1Department of Oral Implantology, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, the popularity of cone beam com- Chongqing, China. puted tomography (CBCT) makes it 2Department of Oral Implantology, Stomatological Hospital of Chongqing Medical possible to observe the buccolingual University, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of bone configuration. To date, new Higher Education, Chongqing, China. insights advocate the application of Correspondence to: Dr Yuanding Huang, Department of Oral Implantology, patient-reported outcome measures Stomatological Hospital of Chongqing Medical University, No 5, (PROMs) to reflect patients’ feelings Shangqingsi Road, Yuzhong District, Chongqing 400010, China. 8,9 Fax: (+86)-023-88830222. Email: [email protected] about their oral health condition. However, PROMs on the ARS tech- Submitted June 20, 2019; accepted August 25, 2019. ©2020 by Quintessence Publishing Co Inc. nique are still sparse. doi: 10.11607/prd.4512 © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. 2 Consequently, this retrospec- Surgical Procedure Postoperative Management tive study aimed to estimate the and Follow-up radiographic and patient-centered With local infiltration anesthesia, a outcomes of the ARS technique crestal horizontal incision and two Patients were instructed to take combined with guided bone re- vertical releasing incisions were amoxicillin and metronidazole and to generation (GBR) and compare its formed, followed by a mucoperios- rinse with 0.2% chlorhexidine mouth- efficacy with GBR alone in maxillary teal flap (Fig 1a). No bone cuts were wash thrice daily for 3 to 5 days. Su- anterior narrow ridges. performed in the GBR group. In the tures were removed after 10 days. ARS group, the alveolar crest was After 6 months of submerged cut horizontally using a piezoelectric healing without any interim pros- Materials and Methods device (Piezosurgery insert #OT7S-3, theses, implant sites were exposed Mectron), 1.5 mm away from the ad- again and healing abutments were Patient Selection jacent teeth or implants, reaching a inserted. Cement-retained provi- 7-mm depth. Two vertical cuts were sional crowns or partial dentures In accordance with the Declaration then performed lateral to the previ- were fabricated to optimize facial of Helsinki, this retrospective con- ous formed groove until reaching soft tissue level and contour for 1 trolled study was implemented in the sufficient depth for the desired im- to 2 months (Fig 1h). Whereafter, Department of Oral Implantology, plant length (Fig 1b). Subsequently, cement-retained definitive super- Stomatological Hospital of Chong- the corresponding bone expander structures were placed and patients qing Medical University. The files of (expanding osteotome, Osstem) was were informed of annual follow-up patients who had received the max- inserted into the prepared site, slowly visits (Fig 1i). illary anterior implantation by ARS increasing the intercortical space un- technique with GBR (ARS group) or til enough width was achieved for the by GBR alone (GBR group) from June desired implant diameter (Fig 1c). CBCT Measurements 2014 to June 2017 were screened. All The implant sites were prepared patients signed the informed consent under the manufacturer’s guidelines, The preoperative (T0), immediately about the details and risks of the pro- and the corresponding implants postoperative (T1), and 6 months cedure. The inclusion criteria were were installed nearly 0.5 mm sub- postoperative (T2) CBCT scans were as follows: Having (1) crown insertion crestally in both groups (Fig 1d). Af- made (Fig 2) using the same CBCT for at least 12 months; (2) preopera- terwards, in the ARS group, the gap machine (iCAT, KaVo; field of view: tive, immediately postoperative, and around implants and the surface of 100 × 100 mm; voxel size: 0.4 mm), 6-months–postoperative CBCT data; the expanded bone were filled with and the data were imported into (3) ridge width from 2.5 to 6.5 mm the polymerization of the injectable an image viewing software (Scan and ridge height more than 10 mm; platelet-rich fibrin (i-PRF)10 and depro- eXam Vision, KaVo). The examiner (4) no obvious undercut in the facial teinized bovine bone mineral (DBBM) (L.Z.) measured all variables twice bone; (5) natural teeth or prostheses (Bio-Oss, Geistlich) (Figs 1e and 1f), with an interval of 1 week between in the mandible; and (6) good gen- while the fenestrations and dehis- measurements. The implant served eral health before surgery. The exclu- cences in the GBR group were only as a reference by showing its cen- sion criteria were as follows: (1) ridge filled with DBBM. The graft materi- ter on sagittal views. The natural width ≤ 2.5 mm; (2) having vertical als were then covered by a trimmed teeth or prostheses in the mandible defects in need of vertical bone aug- absorbable barrier membrane (Bio- could also indicate the same loca- mentation; (3) heavy smokers (> 20 Gide, Geistlich), which was stabilized tion on CBCT images. The variables cigarettes/day); and (4) uncontrolled with horizontal mattress sutures. Fi- assessed were as follows (Fig 3): periodontal diseases or systematic nally, the flap was repositioned and (1) ridge width (RW): the distance diseases. sutured without tension (Fig 1g). between the buccal and palatal The International Journal of Periodontics & Restorative Dentistry © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. 3 a b c d e f g h i Fig 1 The surgical procedure and final restoration in the ARS group. (a) A crestal horizontal incision and two vertical releasing incisions were made to form a mucoperiosteal flap. (b) One horizontal and two vertical bone cuts were formed by the piezoelectric device. (c) The bone expander was inserted to separate the buccal bone plate. (d) The implant was placed subcrestally. (e) The i-PRF (left) and its poly- merization with bone grafts (right). (f) Gaps around the implant and the surface of the expanded bone were filled with the bone grafts, covered by a barrier membrane. (g) Sutured operative site. (h) A provisional crown was fabricated. (i) Buccal view of the final restoration. border of the bone at the crest; coefficient (ICC) was applied to test visual analog scales (VAS) to quan- (2) buccal bone thickness (BBT): the intraexaminer reliability. tify the esthetics and function of distance from the implant surface implant-supported restorations and to the outer margin of bone sub- overall patient satisfaction. Patients stitutes at 0 to 4 mm from the im- Patient-Reported Outcome were instructed to indicate their feel- plant shoulder; and (3) buccolingual Measures ings about each statement by mak- implant angulation7: the angle be- ing a mark on a 10-cm line, labeled tween the implant’s long axis and All included patients were contacted with the worst experience on the left the palatal plane (connection of the by telephone calls to complete a and the best experience on the right. anterior and posterior nasal spine) questionnaire, which was returned The clinician measured the distance in the immediately postoperative by a self-addressed stamped enve- from the beginning of the line to the CBCT view. Based on five samples lope. All eight statements11 in this marking, and this distance was used in each group, intraclass correlation subjective questionnaire utilized as the VAS score for each statement. doi: 10.11607/prd.4512 © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.