Iatrogenic Damage to the Periodontium Caused by Orthodontic Treatment Procedures: An Overview

Novel biomaterial advanced platelet-rich fibrin plus block for multiple gingival recession

BACKGROUND

The study was aimed to assess and compare hard and soft tissue augmentation clinicoradiographically with and without advanced platelet-rich fibrin + (A-PRF+) block for the treatment of multiple gingival recession using vestibular incision subperiosteal tunnel access (VISTA).

METHODS

A total of 24 patients, exhibiting multiple Miller's Class I or II recessions in the maxillary esthetic zone were included. Participants were divided into two groups, Group 1 was treated with VISTA & A-PRF+ block whereas Group 2 was with VISTA technique alone. Clinical parameters probing depth, width of keratinized gingiva, gingival biotype, recession depth, and clinical attachment level were recorded at baseline and the end of 6 months. The radiographic cone beam computed tomography measurements of labial plate thickness were taken at baseline and 6 months postoperatively.

RESULTS

From baseline to 6 months both the groups showed a clinical and statistical improvement in the parameters. However, a statistically significant difference between the treatment modalities was not observed. In the inter-group comparison radiographically, labial plate thickness was statistically significant at the end of 6 months when compared to the baseline.

CONCLUSION

A-PRF+ block along with the VISTA technique can be an alternative effective root coverage procedure for the management of multiple gingival recessions in the maxillary esthetic zone.

KEY POINTS

Why is this study new information? To the best of our knowledge, this is the first study using advanced platelet-rich fibrin plus block for the treatment of multiple gingival recession with a thin labial plate. What are the keys to the successful management of these types of cases? Minimally invasive vestibular incision subperiosteal tunnel access technique, and avoidance of second surgical site morbidity are important factors for treatment and for patient compliance. What are the primary limitations of this study? Short study duration, small sample size, and no histological correlation can be considered as limitations of the study.

Three-dimensional assessment of periodontal support of lower incisors for skeletal Class II malocclusion undergoing presurgical orthodontic treatment with different vertical skeletal patterns

BACKGROUND

The aim of the present study was to compare periodontal support changes during retraction of mandibular anterior teeth for skeletal Class II malocclusion with different facial divergence and to analyze relevant factors influencing bone remodeling by applying three-dimensional (3D) cone-beam computed tomography (CBCT) reconstruction technology.

METHODS

Forty-eight patients with Class II malocclusion requiring surgical orthodontic treatment enrolled in the study were divided into the hyperdivergent group (n = 16), normodivergent group (n = 16) and hypodivergent group (n = 16) according to their vertical skeletal patterns. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T1) and after presurgical orthodontic treatment (T2). The two-dimensional (2D) alveolar bone morphology, movement of mandibular central incisors and volume of the alveolar bone around incisors were measured on the labial and lingual sides by 3D CBCT reconstruction technology. Statistical analyses were performed with one-way ANOVA, paired t tests and multiple linear regression.

RESULTS

During presurgical orthodontic treatment, the alveolar bone height on the labial side of the hyperdivergent group decreased significantly (P ≤ 0.05), but was maintained in the normodivergent and hypodivergent groups (P > 0.05). However, the alveolar bone volume, alveolar bone thickness at each level and alveolar bone height on the lingual side decreased significantly for all the groups. Apart from the initial morphometric measurements at T1, the morphology of lingual alveolar bone at T2 was significantly influenced by the direction and amount of tooth movement. Horizontal retraction and vertical protrusion of the root apex were negatively related to the alveolar bone on the lingual side after presurgical orthodontic treatment.

CONCLUSION

For Class II malocclusion patients undergoing presurgical orthodontic treatment, the changes in the periodontal support of the lower central incisors varied in different vertical skeletal patterns. There exists a great periodontal risk of alveolar bone resorption on the lingual side for various vertical types. To avoid alveolar bone deterioration, it is essential to investigate the bone remodeling of patients with different alveolar bone conditions and cautiously plan tooth movement prior to orthodontic treatment. Moreover, 3D measurements based on CBCT construction can provide complementary information to traditional 2D measurements.

Accurate gingival segmentation from 3D images with artificial intelligence: an animal pilot study

BACKGROUND

Gingival phenotype plays an important role in dental diagnosis and treatment planning. Traditionally, determining the gingival phenotype is done by manual probing of the gingival soft tissues, an invasive and time-consuming procedure. This study aims to evaluate the feasibility and accuracy of an alternatively novel, non-invasive technology based on the precise 3-dimension (3D) soft tissue reconstruction from intraoral scanning and cone beam computed tomography (CBCT) to predict the gingival biotype.

METHODS

As a proof-of-concept, Yorkshire pig mandibles were scanned, and the CBCT data were fed into a deep-learning model to reconstruct the teeth and surrounding bone structure in 3D. By overlaying the CBCT scan with the intraoral scans, an accurate superposition was created and used for virtual measurements of the soft tissue thickness. Meanwhile, gingival thicknesses were also measured by a periodontal probe and digital caliper on the buccal and lingual sides at 3 mm apical to the gingival margin of the posterior teeth and compared with the virtual assessment at the same location. The data obtained from virtual and clinical measurements were compared by Wilcoxon matched-pairs signed-rank analysis, while their correlation was determined by Pearson's r value. The Mann-Whitney U test was used for intergroup comparisons of the amount of difference.

RESULTS

Among 108 investigated locations, the clinical and virtual measurements are strongly positively correlated (r = 0.9656, P < 0.0001), and only clinically insignificant differences (0.066 ± 0.223 mm) were observed between the two assessments. There is no difference in the agreement between the virtual and clinical measurements on sexually matured samples (0.087 ± 0.240 mm) and pre-pubertal samples (0.033 ± 0.195 mm). Noticeably, there is a greater agreement between the virtual and clinical measurements at the buccal sites (0.019 ± 0.233 mm) than at the lingual sites (0.116 ± 0.215 mm).

CONCLUSION

In summary, the artificial intelligence-based virtual measurement proposed in this work provides an innovative technique potentially for accurately measuring soft tissue thickness using clinical routine 3D imaging systems, which will aid clinicians in generating a more comprehensive diagnosis with less invasive procedures and, in turn, optimize the treatment plans with more predictable outcomes.

Assessment of gingival biotype in different facial patterns: A cross-sectional study

Objective

The aim of the present study is to evaluate the relationship of gingival biotype in different malocclusions.

Methods

A total of 157 periodontally healthy subjects (88 males and 69 females) were enrolled in this cross-sectional study. The study participants were divided into three groups of skeletal class I, class II, and class III. The probe transparency method was used to determine the quality and gingival tissue into thick and thin biotype.

Results

There was significant difference in gingival biotype among different skeletal malocclusion with high prevalence of thin gingival biotype in class I subjects and more prevalence of thick biotype in class II and class III individuals (P-value: 0.022). Pairwise comparison of gingival biotype in class I versus class II showed significant difference (P-value: 0.032); however in class I versus class III and class II versus class III, the test result was nonsignificant. The overall frequency of thin gingival biotype was significantly less in female subjects with respect to males (P-value: 0.025).

Conclusion

A significant relationship is present between skeletal malocclusion and quality of gingival biotype. The prevalence of thick gingival biotype is found more in females as compared to male individuals. The thin gingival biotype is more commonly seen in skeletal class I than class II and class III.

Periodontal effect of augmented corticotomy-assisted orthodontics versus conventional orthodontics in treatment of adult patients with bialveolar protrusion

Background

The patients of bialveolar protrusion always demonstrate thin anterior alveoli which may aggravate subsequent gingival recession and bone loss during retraction. This study aimed to investigate the periodontal changes, including alveolar height, thickness, and area, and the width of keratinized gingiva, in mandibular anterior teeth after augmented corticotomy-assisted orthodontics (ACAO) compared with traditional orthodontics.

Methods

Twenty adult patients with skeletal class I bialveolar protrusion were selected from two groups: ACAO group (augmented corticotomy on the labial side of the anterior mandibular teeth, n = 10) and control group (conventional orthodontics, n = 10). In all patients, four first premolars were extracted and the incisors were retracted under the maximum anchorage. The measurements included the labial alveolar bone area, vertical alveolar bone height, alveolar bone thickness surrounding the mandibular anterior teeth, root length, gingival recession and width of keratinized gingiva after alignment (T0) and 3 months after space closure (T1).

Results

The labial alveolar height, area, and thicknesses all decreased after space closure in the control group but significantly increased in the ACAO group. The decrease in the lingual alveolar height was statistically less in the ACAO group than that in the control group. Besides, the width of keratinized gingiva increased in the ACAO group but decreased in the control group. There was no significant difference in the changes of root length between groups. The dentoalveolar changes between anterior teeth were consistent but with different scales. The lateral incisors gained the most labial bone height and area.

Conclusion

Compared to conventional orthodontics, ACAO provided a more favorable effect of improving periodontal status surrounding the mandibular anterior teeth for Class I maxillary protrusion patients.

Nrf2 Activation Is Involved in Cyclic Mechanical Stress-Stimulated Osteogenic Differentiation in Periodontal Ligament Stem Cells via PI3K/Akt Signaling and HO1-SOD2 Interaction

Nuclear factor erythroid-2-related factor-2 (Nrf2), the major transcriptional regulator in antioxidant response and cellular defense, had the vital effect on regulating osteogenic differentiation. Our previous study revealed that Nrf2 activation was involved in cyclic mechanical stress-stimulated osteogenic differentiation in the human periodontal ligament stem cells (PDLSCs). However, the mechanisms of Nrf2 underlying this process remained unclear. The goal of the study was to explore the mechanisms of Nrf2 in PDLSCs during cyclic mechanical stress-stimulated osteogenic differentiation via the tandem mass tag (TMT)-based liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis. And we applied tert-Butylhydroquinone (t-BHQ), the Nrf2 activator, to the orthodontic rats and detected the expression levels of the osteogenesis markers by immunohistochemistry (IHC) staining. Our results showed that Nrf2 activation in PDLSCs was involved in cyclic mechanical stress-stimulated osteogenic differentiation via phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) pathway. The protein-protein interaction between Akt and Nrf2 was detected. And the protein-protein interaction between heme oxygenase 1 (HO1) and superoxide dismutase 2 (SOD2), the downstream antioxidants of Nrf2, was associated with cyclic mechanical stress-stimulated osteogenic differentiation. T-BHQ enhanced the expression levels of the osteogenesis markers in orthodontic rats. Nrf2 might possess the potential to be a feasible molecular target in orthodontics.

A study to evaluate the prevalence of teeth without clinically detectable mucogingival junction

Context:

The mucogingival junction (MGJ) is one of the important anatomical entities which mark the apical termination of attached gingiva, except that at palatal side. Its position is genetically determined like other organs and tissues in our body. There are certain anatomic aberrations such as abnormal teeth eruption or high frenal attachments and pathologies, such as periodontitis, leading to its absence. There are no studies on the prevalence of teeth having no clinically detectable MGJ. There is a resurgence of importance of attached gingiva, reflected by the definite presence of MGJ, through the field of dental implantology.

Aims:

We aim to evaluate the prevalence of teeth without clinically detectable MGJ on the buccal aspect of dentate alveolar processes.

Settings and Design:

This cross-sectional observational clinical study was conducted in the department of periodontology which was approved by the institutional ethical committee.

Materials and Methods:

Periodontally healthy as well as diseased patients of age 18–50 years were included in the study. The detection of MGJ was carried out by visual method, tension test, rolling probe method, and Lugol's iodine solution, and confirmation from any two methods was considered for the absence of MGJ. The etiology of MGJ absence (gingival recession, pocket till MGJ, trauma, abnormal frenal attachment, malposition of tooth, abnormal habits, severe abrasion, etc.,) was also evaluated.

Statistical Analysis Used:

Simple statistics in the form of averages and percentages were used for calculations.

Results:

A total of 130 subjects (3637 teeth) were examined out of which 32 (24.6%) subjects showed no clinically detectable MGJ. In all subjects, on an average, every subject has 28 teeth and out of the total 3637 teeth analyzed, only 91 (2.5%) teeth were without detectable MGJ.

Conclusion:

Almost 25% of the population may show a tooth or few teeth without a clinically detectable MGJ. The prevalence of teeth without clinically detectable MGJ per mouth is very low at 0.7 (approximately 1 tooth/subject).

Nrf2 activation is involved in osteogenic differentiation of periodontal ligament stem cells under cyclic mechanical stretch

During orthodontic treatment, mechanical stretch serves a crucial function in osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Up-regulated reactive oxygen species (ROS) level is a result of cyclic mechanical stretch in many cell types. Nuclear factor erythroid-2-related factor-2 (Nrf2) is a master regulator in various antioxidants expression. However, it is not known whether cyclic mechanical stretch could induce the ROS generation in PDLSCs and whether Nrf2 participated in this process. The present study was aimed to investigate the role of Nrf2 in PDLSCs under cyclic mechanical stretch. Our results showed that cyclic mechanical stretch increased ROS level and the nuclear accumulation of Nrf2 during osteoblast differentiation. Knocking down Nrf2 by siRNA transfection increased ROS formation and suppressed osteogenic differentiation in PDLSCs. T-BHQ, a Nrf2 activator, promoted the osteogenic differentiation in PDLSCs under cyclic mechanical stretch, and improved the microstructure of alveolar bone during orthodontic tooth movement in rats by employing micro-CT system. Taken together, Nrf2 activation was involved in osteogenic differentiation under cyclic mechanical stretch in PDLSCs. T-BHQ could promote the osteogenic differentiation in vitro and in vivo, suggesting a promising option for the remodeling of the alveolar bone during orthodontic tooth movement.

Torturous path of an elastic gap band: Interdisciplinary approach to orthodontic treatment for a young patient who lost both maxillary central incisors after do-it-yourself treatment

Spacing between the maxillary anterior teeth is a common concern for young patients and their parents. Patients often consider a diastema to be an annoying but minor problem; they might consult their general dentists for help, or try to address the issue themselves by applying elastic "gap bands." Moreover, parents, without any informed consent, sometimes accept this erroneous method as an easy and inexpensive treatment approach. A 9-year-old boy had severe acute periodontitis involving the maxillary central incisors caused by the placement of an elastic band and its apical migration. Despite periodontal and surgical interventions, the maxillary central incisors were finally extracted, and the patient started orthodontic treatment. The orthodontic treatment plan included maxillary lateral incisor substitution to replace the lost central incisors and mesialization of the maxillary posterior dentition. An interdisciplinary approach with excellent cooperation among the orthodontist, general dentist, and other dental specialists obtained an esthetically pleasing and optimized functional result. Treating the diastema between the anterior teeth with elastic gap bands and without fixed orthodontic appliances should be avoided. Patients should seek proper orthodontic advice for even small-scale orthodontic problems to prevent catastrophic outcomes, as exhibited in this case report.