Three-dimensional evaluation of secondary alveolar bone grafting in patients with unilateral cleft lip and palate: A 2-3 year post-operative follow-up.

OBJECTIVES: The present study aims to quantitatively assess secondary alveolar bone graft (SABG) resorption in unilateral cleft lip, alveolus and palate (UCLAP) patients in a 2-3 year longitudinal follow-up setting by using a validated 3D protocol. Furthermore, the potential relation of SABG resorption with maxillary canine position and a number of patient-related factors was investigated. METHODS: UCLAP patients who underwent SABG and had good quality CBCT images at the following timepoints were included in the study: pre-operative (T0), immediate (T1), 6 months (T2) and either 1-2 years (T3) or 2-3 years (T4) post-operative. The final bone grafted region was defined on the T1 scans and refined in the registered T0 scans. The bone graft after resorption was determined by applying threshold-based segmentation on the registered T2, T3 or T4 scans within the segmented bone graft volume. The position of the canines was determined at every timepoint at the cleft and non-cleft side. RESULTS: Forty-five UCLAP patients (mean age 9.0 ± 1.3 years) were included. In the first 6 months after SABG, 43.6% bone resorption was recorded. 2-3 years post-operative, 56% bone resorption was found if the maxillary canine was not yet erupted and 42.7% if it erupted through the graft. The vertical position of the canines was significantly higher on the cleft side at T3. CONCLUSIONS: The present study reports significant SABG resorption over time. However, no correlation was found between SABG resorption and canine position, nor between other patient-related factors.

Risk factors for gingival recessions after orthodontic treatment: a systematic review.

BACKGROUND/OBJECTIVES: To systematically review the available evidence concerning the risk factors for gingival recessions (GR) after orthodontic treatment (OT). DATA COLLECTION AND ANALYSIS: Data was obtained and collected by systematically searching 3 data bases: Pubmed, EMBASE, and Web of Science until 20 April 2023. Controlled trials, cohort, case-control or cross-sectional studies describing GR or clinical crown height (CCH) after OT were included. The risk of bias in the selected studies was evaluated with the methodological index for non-randomized studies. RESULTS: Forty-eight articles were included, investigating the following six risk factors for GR: 1. OT (n = 21), 2. Type of orthodontic intervention (n = 32), 3. Patient's baseline occlusal and skeletal characteristics (n = 14), 4. Mucogingival characteristics (n = 10), 5. Oral hygiene (n = 9), and 6. Others (n = 12). Significantly higher prevalence, severity and extent of GR were found in orthodontic patients by 10/15, 4/10, and 2/2 articles respectively. 10/16 articles reported significantly more GR and increased CCH in patients where orthodontic incisor proclination was performed. The evidence surrounding maxillary expansion and orthodontic retention was too heterogeneous to allow for? definitive conclusions. Pre-treatment angle classification, ANB, overjet, overbite, arch width and mandibular divergence were found not to be associated with GR (9/14), while pre-treatment crossbite, symphysis height and width were (5/7 studies). A thin gingival biotype, presence of previous GR, baseline width of keratinized gingiva and facial gingival margin thickness were correlated with increased risk of GR after OT by nine articles, while pocket depth was not. Oral hygiene, sex, treatment duration, and oral piercings were found not to be linked with GR in orthodontic patients, while GR was reported to increase with age in orthodontic patients by 50 per cent of the articles investigating this factor. The mean risk of bias for comparative and not comparative studies was 14.17/24 and 9.12/16. LIMITATIONS: The selected studies were quite heterogeneous regarding study settings, variables reported and included very limited sample sizes. CONCLUSION: Although studies regarding the risk factors for GR are relatively abundant, they are very heterogeneous concerning design, studied factors, methodology and reporting, which often leads to contradictory results. Uniform reporting guidelines are urgently needed for future research. PROSPERO REGISTRATION: CRD42020181661. FUNDING: This research received no funding.

Validation of a 3D methodology for the evaluation and follow-up of secondary alveolar bone grafting in unilateral cleft lip and palate patients.

OBJECTIVE: The aim of the study was to propose and validate a method for three-dimensional (3D) quantitative assessment of secondary alveolar bone grafting (SABG) and its stability in time for patients with unilateral cleft lip and palate (UCLP). SETTINGS AND SAMPLE POPULATION: Ten non-syndromic UCLP patients (9 males and 1 female with a mean age of 9.5 ± 0.9 years) undergoing SABG with good quality preoperative, immediate postoperative (6 weeks) and 6 months postoperative Cone Beam Computed Tomography (CBCT) scans were selected. MATERIALS AND METHODS: The preoperative and 6 months postoperative scans were registered onto the immediate postoperative scan. The bone-grafted region was defined on the immediate postoperative scan and refined on the registered preoperative scan resulting in a 3D volume. The residual bone graft was calculated by applying threshold based segmentation on the registered 6 months postoperative scan within the segmented bone graft volume of the previous step. Inter and intra observer tests using intra-class correlation coefficient (ICC) were applied comparing the volumes of the 3D models. RESULTS: An excellent reliability was found for inter and intra observers with ICC ≥ 0.95. CONCLUSIONS: The presented method proved to be reliable for volumetric assessment of the alveolar bone graft in UCLP patients, as well as to assess the percentage of bone resorption during follow-up.