Occlusal trauma and excessive occlusal forces: Narrative review, case definitions, and diagnostic considerations

Survival rate of teeth adjacent and nonadjacent to dental implants: A retrospective cohort study

BACKGROUND

The aim of this retrospective study was to investigate the risk of tooth loss for teeth adjacent and nonadjacent to dental implants.

METHODS

A total of 787 patients with an average follow-up of 57.1 months were examined to define the tooth loss, cumulative survival rate, and odds ratio (OR) for teeth adjacent versus nonadjacent to implants. A multivariate logistic regression was employed to assess the association between dental history and various recorded etiologies of tooth loss among teeth adjacent to implants.

RESULTS

The incidence of tooth loss for teeth adjacent to implants was 8.1% at the tooth level and 15.1% at the patient level, while 0.7% and 9.5% at the tooth and patientlevel for teeth nonadjacent to implants. The 10-year cumulative survival rate for teeth adjacent to implants was 89.2%, and the primary etiology of tooth loss was root fracture (45.2%). The risk of tooth loss among teeth adjacent versus nonadjacent to implants was significantly higher (OR 13.15). Among teeth adjacent to implants, root canal-treated teeth had a significantly higher risk of tooth loss due to root fracture (OR 7.72), a history of existing restoration significantly increased the risk of tooth loss due to caries (OR 3.05), and a history of periodontitis significantly increased the risk of tooth loss due to periodontitis (OR 38.24).

CONCLUSION

The present study demonstrated that after patients received dental implant treatment, teeth adjacent to implants showed a 13.2-fold higher risk of tooth loss compared to teeth nonadjacent to implants, with the primary etiology being root fracture.

The PocketPerio application significantly increases the accuracy of diagnosing periodontal conditions in didactic and chairside settings

The study aimed to determine the accuracy of diagnosing periodontal conditions using the developed web-based PocketPerio application and evaluate the user's perspective on the use of PocketPerio. First, 22 third-year dental students (DS3) diagnosed ten cases without PocketPerio (control) and with PocketPerio (test) during a mock examination. Then, 105 DS3, 13 fourth-year dental students (DS4), and 32 senior second-year International Standing Program students (ISP2) used PocketPerio chairside. Statistical analysis was performed using a non-parametric paired two-tailed test of significance with the Wilcoxon matched-pairs signed rank test. The null hypothesis that PocketPerio did not increase the accuracy of periodontal diagnoses was rejected at α < 0.01. Periodontal diagnoses made using PocketPerio correlated with those made by periodontics faculty ("gold standard") in all cases. During the mock examination, PocketPerio significantly increased the accuracy of periodontal diagnoses compared to the control (52.73 vs. 13.18%, respectively). Chairside, PocketPerio significantly increased the accuracy of primary (100 vs. 40.0%) and secondary (100 vs. 14.25%) periodontal diagnoses compared to the respective controls. Students regardless of their training year felt more confident in diagnosing periodontal conditions using PocketPerio than their current tools, provided positive feedback on its features, and suggested avenues for its further development.

Precautions and possibilities in orthodontic treatment of periodontally compromised patients: Current recommendations

OBJECTIVE

Orthodontic treatment plays a crucial role in achieving optimal dental esthetics and functional occlusion. However, when periodontally compromised patients are involved, additional precautions and considerations are critical. This article aims to provide up-to-date recommendations for the orthodontic treatment of periodontally compromised patients.

CLINICAL CONSIDERATIONS

Comprehensive diagnosis of the patient's periodontal status, inherent malocclusion, and secondary malocclusion resulting from periodontal disease are essential for achieving optimal esthetics and functional occlusion. This can be facilitated through the use of a simplified checklist. Prior to orthodontic treatment, pre-existing periodontal diseases should be managed. Light and controlled forces should be used to minimize the risk of adverse effects on the periodontium, and any potential traumatic occlusion during tooth movement should be minimized. Furthermore, careful anchorage management is required, and proper application of temporary anchorage devices can significantly expand the scope of orthodontic treatment. Finally, treatment results are maintained by ongoing supportive periodontal therapy even during the retention period.

CONCLUSIONS

This article presents clinical cases demonstrating the importance of accurate diagnosis in orthodontics and periodontics and the positive impact of orthodontic treatment on patients with pre-existing periodontal diseases.

CLINICAL SIGNIFICANCE

An up-to-date orthodontic treatment protocol for periodontally compromised patients is presented.

Malocclusion in cats associated with mandibular soft tissue trauma: a retrospective case-control study

OBJECTIVES

The aim of this study was to determine whether an association existed between cephalometric measurements, maxillomandibular dental arch distances and the occurrence of traumatic malocclusions in the mandibular soft tissues of cats.

METHODS

Cats that had presented for dental consultations and that underwent cone-beam CT during diagnostic assessment were included in the study and categorised as cases and controls in a 1:2 ratio. Cases were designated as cats with a clinical diagnosis of malocclusion causing trauma to the buccal mandibular soft tissues or pyogenic granuloma secondary to the trauma, and controls were designated as cats with the absence of such diagnoses and without a history of other musculoskeletal anomalies in the head. Cephalometric measurements, including skull and facial indexes, as well as distances and angulations between dental crowns and crown tips, were calculated and analysed statistically.

RESULTS

In total, 72 cats (24 cases and 48 controls) were included in the study. Cephalometric measurements revealed a significant association between the skull and facial indexes and the occurrence of traumatic malocclusions in the caudal teeth. Brachycephaly was a strong predictor of the occurrence of traumatic malocclusions. In addition, the space between crown tips and teeth angulations was a contributing factor to the trauma.

CONCLUSIONS AND RELEVANCE

Cats with traumatic malocclusions in the cheek teeth tend to present a narrower interdental space between the maxillary and mandibular carnassial teeth, mostly attributed to skeletal and dental malocclusion. These findings can be used to help raise awareness about this disease in cats and its association with brachycephaly. Cut-off values have been proposed and could be used in the selection of cats by breeders to reduce the occurrence of this disease.

A qualitative analysis of dentists' understanding and management of non-carious cervical lesions (NCCL)

INTRODUCTION

Non-carious cervical lesions (NCCLs) are considered to have a multi-factorial aetiology and their management is affected by a range of variables perhaps most importantly clinical judgement. The aim of this study was to elicit information from practicing dentists, using interviews, to explore their understanding of NCCL aetiology, the decision-making criteria of when to restore, and the restorative techniques used to restore NCCLs. This may help identify gaps or anomalies in our understanding to inform future research and clinical practice for the management of NCCLs.

METHODS

An interview guide was developed from a literature search which formed 2 domains framed around understanding and management of NCCLs based on: understanding of diagnosis and aetiology, and factors affecting decision making for management. Practicing dentists with more than 10 years of experience were purposively recruited to conduct in-depth, semi-structured interviews. Fifteen interviews were audio recorded and transcribed verbatim. A thematic content analysis was conducted and the results analysed.

RESULTS

From the thematic analysis, 2 domains were identified. In the domain of "diagnosis and aetiology", while participants have similar understanding and methods of diagnosing NCCL, most stated NCCLs in a patient were caused by a "main aetiology" such as "abrasion", "abfraction" while few described the inter-relationship of these aetiological factors. In the domain of "factors affecting decision making". "Patient reported symptoms" and "lesion dimension" were the main factors that affected participants' decision to provide restorative or non-restorative management. However, a "restorative threshold" was not able to be identified.

CONCLUSION

There was notable variety in participants' understanding of the aetiology, management, and treatment of NCCLs, particularly the restorative threshold of when to treat.

CLINICAL SIGNIFICANCE

The variability demonstrates the need to have a clearer understanding of the key elements that affect the management of NCCLs and better information to support the decision of when to treat.

Occlusion as a predisposing factor for peri-implant disease: A review article

BACKGROUND

The restoration of dental implants presents a unique challenge due to the intrinsic biomechanical differences between osseointegrated implants and natural teeth, and their subsequent responses to occlusal loading. However, controversy exists regarding the role that occlusion plays in the physiology of the peri-implant complex.

PURPOSE

To provide an overview of the scientific literature regarding occlusion as it relates to implant dentistry and peri-implant disease.

MATERIALS AND METHODS

This article presents a narrative review on occlusal loading and its potential effects on the peri-implant complex, as well as some generally accepted guidelines for occlusion in implant dentistry.

RESULTS AND CONCLUSIONS

Although there is strong evidence linking occlusal factors to mechanical complications of dental implants, the same cannot be said regarding biological complications. There is no clear scientific evidence on the relationship between occlusal overload and peri-implant disease. However, occlusal overload may be an accelerating factor for peri-implant disease in the presence of inflammation. As the biomechanical properties of dental implants differ from that of the natural dentition, modifications to classic concepts of occlusion may be necessary when dental implants are involved. Thus, clinical recommendations are proposed which function to minimize unfavorable occlusal forces on implant restorations and reduce the associated biological and mechanical complications.

Alteration of extracellular matrix proteins in atrophic periodontal ligament of hypofunctional rat molars

OBJECTIVES

The aim of this study was to investigate the effect of mechanical force on possible dynamic changes of the matrix proteins deposition in the PDL upon in vitro mechanical and in vivo occlusal forces in a rat model with hypofunctional conditions.

MATERIALS AND METHODS

Intermittent compressive force (ICF) and shear force (SF) were applied to human periodontal ligament stem cells (PDLSCs). Protein expression of collagen I and POSTN was analyzed by western blot technique. To establish an in vivo model, rat maxillary molars were extracted to facilitate hypofunction of the periodontal ligament (PDL) tissue of the opposing mandibular molar. The mandibles were collected after 4-, 8-, and 12-weeks post-extraction and used for micro-CT and immunohistochemical analysis.

RESULTS

ICF and SF increased the synthesis of POSTN by human PDLSCs. Histological changes in the hypofunctional teeth revealed a narrowing of the PDL space, along with a decreased amount of collagen I, POSTN, and laminin in perivascular structures compared to the functional contralateral molars.

CONCLUSION

Our results revealed that loss of occlusal force disrupts deposition of some major matrix proteins in the PDL, underscoring the relevance of mechanical forces in maintaining periodontal tissue homeostasis by modulating ECM composition.

Survival analysis of root-resected molars from 1 to 13.4 years: A retrospective cohort study

STATEMENT OF PROBLEM

While root resective therapy may extend the longevity of a molar, data on patient selection and outcomes of root resection are scarce.

PURPOSE

The purpose of this retrospective cohort study was to analyze the survival of root-resected molars and investigate factors affecting the decision and outcomes of the therapy.

MATERIAL AND METHODS

Patient- and tooth-related data from participants who had received root resection between 1999 and 2022 were collected. Cox regression was used to build predictive models for time-to-tooth loss based on predictors-initial diagnoses (carious, endodontic, periodontal, or endodontic-periodontal lesions), the presence of a complete-coverage crown, and the location of the tooth in the arch (P<.001).

RESULTS

Of 60 teeth, all from different participants, 31 molars were resected because of endodontic lesions. The failure rate was 35% with 21 teeth extracted. At 5 years, the survival probability was 0.58, considering all predictors. The survival of molars resected because of carious or endodontic lesions was significantly lower than those because of periodontal or endodontic-periodontal lesions (P<.05). The hazard ratio for tooth loss in the resected teeth was 15.6, 95% confidence interval (CI) (3.7 to 83.2) without complete-coverage crowns and 8.6, 95% CI (2.2 to 43.2) at the most posterior location.

CONCLUSIONS

Root resection provided to manage a localized periodontal lesion had the highest prognosis. The absence of a crown and the location as the most posterior tooth in the arch were associated with poor survival following resection.

Complications and treatment errors involving periodontal tissues related to orthodontic therapy

In this review, typical clinical complications involving periodontal tissues are illustrated that can be encountered in conjunction with orthodontic therapy (OT). Special considerations are given for various clinical scenarios, such as the patient presenting in periodontal health, with periodontitis, or with mucogingival conditions. While some of the complications are seen as common side effects of OT, other, more severe, problems that could have been avoided may be viewed as treatment errors. Recommendations are made on how to prevent these complications, based on the currently available evidence, on clinical practice guidelines, and on expert opinion. In conclusion, while there are several areas in which OT can have unwanted adverse effects on periodontal/mucogingival conditions, there is also great potential for synergies, offering opportunities for close cooperation between the two specialties (periodontics and orthodontics) for the benefit of patients affected by tooth malpositioning and/or periodontal or mucogingival problems.

Emerging Roles of YAP/TAZ in Tooth and Surrounding: from Development to Regeneration

Yes associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are ubiquitous transcriptional co-activators that control organ development, homeostasis, and tissue regeneration. Current in vivo evidence suggests that YAP/TAZ regulates enamel knot formation during murine tooth development, and is indispensable for dental progenitor cell renewal to support constant incisor growth. Being a critical sensor for cellular mechano-transduction, YAP/TAZ lays at the center of the complex molecular network that integrates mechanical cues from the dental pulp chamber and surrounding periodontal tissue into biochemical signals, dictating in vitro cell proliferation, differentiation, stemness maintenance, and migration of dental stem cells. Moreover, YAP/TAZ-mediated cell-microenvironment interactions also display essential regulatory roles during biomaterial-guided dental tissue repair and engineering in some animal models. Here, we review recent advances in YAP/TAZ functions in tooth development, dental pulp, and periodontal physiology, as well as dental tissue regeneration. We also highlight several promising strategies that harness YAP/TAZ activation for promoting dental tissue regeneration.

When (and when not) to use the Dahl Concept

The Dahl Concept describes the re-establishment of occlusal contacts after the provision of a planned localised appliance or restoration in supraocclusion. Initially developed to create space for prosthetic rehabilitation of anterior teeth suffering from localised wear, the principle has later been successfully applied to a variety of situations, including the Hall technique and resin-bonded bridges cemented in supraocclusion. Despite high levels of success seen in the relevant literature and widespread adoption in specialist care, the wider profession appears to be far more cautious in its use. This article aims to provide a brief summary of the Dahl Concept and discuss the local and general factors that influence its successful implementation in the hope of promoting its increased adoption by the broader dental profession.

A Multi-Disciplinary Approach in the Management of Endo-Perio Lesions: A 4-year Follow-Up Case Report

Summary. This case report discusses the multi-disciplinary approach and long-term follow-up of a 66-year-old male who suffered a combined endodontic-periodontal lesion (EPL). As EPL is uncommon in daily practice and dentists' knowledge and awareness of EPL is quite low, this case becomes of high interest and value to document and research. The objective of this study is to present the diagnosis, multi-disciplinary approach, and long-term follow-up of compromised teeth with EPL. It highlights the importance of the identification and elimination of all causative factors as well as the correct treatment sequence to achieve a predictable outcome. The patient was referred to the periodontist after multiple unsuccessful attempts by his previous dentist. He complained of recurrent dull pain and abscess on his upper left tooth (tooth #26) that had been present for the past three years. A diagnosis of combined EPL was obtained after thorough anamnesis, clinical evaluation, and radiographic examination. The clinician identified several predisposing factors, such as plaque, trauma from occlusion, and excessive force on tooth #26 due to incorrect denture design. Treatment involved multiple dental specialties. At the periodontist, the patient underwent scaling, root planning, and removal of overhanging part of the restoration. At the endodontist, root canal treatment (RCT) was completed. Two months after RCT, a periodontal regenerative procedure was done. The defect was filled with a combination of allograft/alloplastic bone graft and covered with a barrier membrane. Upon healing, the prosthodontist did the final restoration of fiber post with a metal crown on tooth #26 and constructed a new denture with a periodontal-friendly design. A follow-up at five months and four years showed excellent results. The patient was symptom-free, and tooth #26 showed no periodontal inflammation. Radiographic examination showed a good bone fill at the defect. Supportive periodontal therapy should be emphasized to achieve the long-term success of EPL.

Biomechanical properties of periodontal tissues in non-periodontitis and periodontitis patients assessed with an intraoral computerized electronic measurement device

OBJECTIVE

To identify tooth mobility (TM) by time-dependent tooth displacement using an electronic intra-oral loading device (ILD) in periodontally healthy and periodontally compromised patients.

MATERIALS AND METHODS

Twenty-eight untreated periodontitis and 20 periodontally healthy patients [25 female and 26 male; ages: 20-81 years], contributing with 68 teeth (periodontitis: n_teeth = 28; non-periodontitis: n_teeth = 40), participated in the study. TM was measured in vivo by displacing central or lateral incisors to a maximum of 0.2 mm orally over durations of 0.5 s, 1 s, and 10 s with the ILD. The maximum force (Fmax) was extracted from the measured force/deflection curves for every single measurement.

RESULTS

Differences in TM-ILD values were found for periodontitis as compared to non-periodontitis patients derived from the same loading durations (differences of 3.9 (0.5 s), 3.1 (1 s), 2.8 (10 s), (95% CI for 0.5 s (1.2-6.7), p = 0.024; 1 s (1.4-6.0), p = 0.067; 10 s (0.2-5.3), p = 0.001), rejecting the null hypothesis of no difference (T-test) for durations of 0.5 and 10 s. There was a significant correlation of TM-ILD (Fmax) with BOP at 0.5 s (- 0.52) and with attachment loss at all time durations (- 0.47 at 0.5 s; - 0.57 at 1 s; - 0.47 at 10 s).

CONCLUSIONS

This clinical investigation could demonstrate that time-dependent tooth displacements using a new computerized electronic device were associated with attachment loss and bleeding on probing.

CLINICAL RELEVANCE

ILD can improve the monitoring of tooth mobility, as TM-ILD values reflect qualitative (inflammatory status interpreted by BOP) and quantitative parameters (interpreted as the amount of CAL loss) of periodontal disease.

Unloading of occlusal force aggravates alveolar bone loss in periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis (PD), a chronic infectious inflammatory disease initiated by bacteria, is associated with several local contributing factors including occlusal trauma. Previous studies have found that the traumatic occlusal force could aggravate alveolar bone loss during PD. However, the effect of reduced occlusal force during PD remains unclear. This study aimed to explore the effect of occlusal force unloading on PD onset and progression and its underlying mechanism as an effort to provide restoration suggestions for PD patients with dentition defect in clinic. This study might also propose occlusal force unloading could be a new local contributing factor for PD.

MATERIALS AND METHODS

C57BL/6 mice were used to establish a PD model by the ligation of 5-0 silk around the mandibular left first molar (PD group) and an unloading experiment model by the extraction of their left maxillary first molar (EX group). The THP-1-derived macrophages were used to verify in vivo results.

RESULTS

Micro-CT scanning and H&E staining results consistently showed that PD + EX group experienced the most severe alveolar bone resorption as compared to PD group and control group. Further RNA-sequencing analysis suggested that occlusal force unloading significantly enhanced osteoclastic resorption, inhibited osteoblastic activity, and promotes M1 and M2 macrophages polarization. Immunofluorescence staining (IF) results showed that compared with the PD group, PD + EX group significantly increased the ratio of M1/M2 polarization. Similar results were observed by RT-qPCR and IF in vitro: removal of compressive force led to an increased ratio of M1/M2 polarization in LPS-stimulated THP-1-derived macrophages.

CONCLUSIONS

Our study demonstrated that occlusal force unloading aggravates bone resorption by increasing the ratio of M1/M2 macrophages polarization during PD, suggesting a previously unknown local contributing factor for PD, and providing a novel insight for dentists to restore missing teeth as an effort to maintain remaining dentition.

Polymeric Nanotechnologies for the Treatment of Periodontitis: A Chronological Review

Periodontitis is a chronic infectious and inflammatory disease of periodontal tissues estimated to affect 70 - 80 % of all adults. At the same time, periodontium, the site of periodontal pathologies, is an extraordinarily complex plexus of soft and hard tissues, the regeneration of which using even the most advanced forms of tissue engineering continues to be a challenge. Nanotechnologies, meanwhile, have provided exquisite tools for producing biomaterials and pharmaceutical formulations capable of elevating the efficacies of standard pharmacotherapies and surgical approaches to whole new levels. A bibliographic analysis provided here demonstrates a continuously increasing research output of studies on the use of nanotechnologies in the management of periodontal disease, even when they are normalized to the total output of studies on periodontitis. The great majority of biomaterials used to tackle periodontitis, including those that pioneered this interesting field, have been polymeric. In this article, a chronological review of polymeric nanotechnologies for the treatment of periodontitis is provided, focusing on the major conceptual innovations since the late 1990s, when the first nanostructures for the treatment of periodontal diseases were fabricated. In the opening sections, the etiology and pathogenesis of periodontitis and the anatomical and histological characteristics of the periodontium are being described, along with the general clinical manifestations of the disease and the standard means of its therapy. The most prospective chemistries in the design of polymers for these applications are also elaborated. It is concluded that the amount of innovation in this field is on the rise, despite the fact that most studies are focused on the refinement of already established paradigms in tissue engineering rather than on the development of revolutionary new concepts.

Dental cross-bite and gingival marginal recession. A cross-sectional study

Background

Materials and methods

Results

Conclusion

Periodontal-orthodontic interdisciplinary management of a “periodontally hopeless” maxillary central incisor with severe mobility: A case report and review of literature

BACKGROUND

Treating periodontally hopeless teeth with advanced bone resorption and severe tooth mobility is a great challenge for both orthodontists and periodontists. Biofilm-induced periodontal inflammation and occlusal trauma-related inflammation may synergistically aggravate tooth mobility. This case report illustrates that even periodontally hopeless teeth can be saved and have long-term stability with comprehensive periodontal treatment to control periodontal inflammation and promote periodontal bone regeneration and intricate orthodontic mechanical control to correct cross bite and occlusal trauma.

CASE SUMMARY

A 27-year-old female patient whose chief complaint was severe tooth mobility and discomfort of the maxillary incisor was diagnosed with severe aggressive periodontitis by clinical and radiographic examinations. To reduce tooth mobility and establish stable occlusion, we combined orthodontic treatment with periodontal therapy to preserve the tooth. Orthodontic treatment was performed after basic periodontal therapy and periodontal surgery. The loosened upper right central incisor was successfully retained, and the periodontal tissue remained stable during follow-up.

CONCLUSION

Teeth with severe mobility and bone loss can be saved through interdisciplinary treatment when periodontal inflammation is strictly controlled.

Traumatogenic Occlusion in a Pediatric Dental Patient: A Case Report

Aim and objective

This case report aims to describe the management of mandibular anterior teeth subjected to occlusal trauma.

Background

Occlusal trauma occurs as a result of reduced ability of the tissues to resist the occlusal forces most likely as a result of masticatory system dysfunction abnormal contact of the teeth, and prosthetic or orthodontic treatments that create occlusal interferences.

Case description

This paper describes a case of traumatogenic occlusion seen in the dentition of a 13-year-old female patient and its management by stabilization, endodontic, and orthodontic therapy.

Conclusion

The removal of the anomalous occlusal forces and stabilization of the affected teeth is the most relevant therapy for teeth affected by trauma from occlusion (TFO).

Clinical Significance

Periodic monitoring of developing occlusion contributes to preventive care and encourages the maintenance of a healthy periodontium.

How to cite this article

Kartha S, Vellore KP, Challa SK, et al. Traumatogenic Occlusion in a Pediatric Dental Patient: A Case Report. Int J Clin Pediatr Dent 2022;15(2):222-226.

Perceptions of NZ orthodontists and periodontists on the management of gingival recession in orthodontic patients

BACKGROUND

This study aimed to investigate the perceptions and opinions of orthodontists and periodontists on the management of gingival recession in orthodontic patients.

METHODS

An online survey was sent to 29 periodontists and 80 orthodontists registered and currently practising in New Zealand. All participants answered questions about the timing and clinical indications of mucogingival surgeries in orthodontic patients diagnosed with mucogingival deformities.

RESULTS

Most periodontists and orthodontists believed that gingival grafts should ideally be performed after orthodontic treatment. In clinical practice, 40% of periodontists indicated that they would receive referrals after completion of orthodontic treatment. However, 29.6% of orthodontists indicated that they would refer to a periodontist before orthodontic treatment in clinical practice. The most crucial factor that affected periodontists' decision-making was 'evidence-based guidelines' (35.0%), followed by 'clinical experience' (30.0%) and 'patient concerns' (15.0%). All four factors of 'gingival phenotype', 'presence of gingival recession', 'amount of keratinised tissue' and 'planning specific tooth movements' were equally considered by orthodontists regarding their decision-making.

CONCLUSIONS

The majority of the surveyed New Zealand periodontists and orthodontists expressed a belief that the ideal timing for the management of gingival recessions would be after the completion of orthodontic treatment.

Occlusal Trauma and Bisphosphonate-Related Osteonecrosis of the Jaw in Mice

Osteonecrosis of the jaw (ONJ) is a serious adverse event that is associated with antiresorptive agents, and it manifests as bone exposure in the maxillofacial region. Previous clinical reports suggest that mechanical trauma would trigger ONJ in a manner that is similar to tooth extractions. To the best of our knowledge, there have been few detailed pathophysiological investigations of the mechanisms by which occlusal/mechanical trauma influences ONJ. Here, we developed a novel mouse model that exhibits ONJ following experimental hyperocclusion and nitrogen-containing bisphosphonate (N-BP) treatment. This in vivo model exhibited ONJ in alveolar bone, particularly in the mandible. Moreover, the experimental hyperocclusion induced remarkable alveolar bone resorption in both mouse mandible and maxilla, whereas N-BP treatment completely prevented alveolar bone resorption. In this study, we also modeled trauma by exposing clumps of mesenchymal stem cells (MSCs)/extracellular matrix complex to hydrostatic pressure in combination with N-BP. Hydrostatic pressure loading induced lactate dehydrogenase (LDH) release by calcified cell clumps that were differentiated from MSCs; this LDH release was enhanced by N-BP priming. These in vivo and in vitro models may contribute further insights into the effect of excessive mechanical loading on ONJ onset in patients with occlusal trauma.

Treatment of a single gingival recession with a subepithelial connective tissue graft with a double papilla flap: A case report

Gingival recessions are widely prevalent deformities that affect the normal position of the gingiva and cause exposure of the tooth root, and are often associated with unsatisfactory aesthetics and dentin hypersensitivity. The double papilla technique for root covering is a periodontal plastic surgery technique recommended for the treatment of gingival recessions. In this case report, we show the clinical results after a 12-month follow-up of a root-covering procedure in an upper canine affected by a gingival recession. A 56-year-old patient presenting a Cairo type I gingival recession on the vestibular surface of tooth 23 was treated with a one-stage surgical procedure, carried out using the double papilla technique in combination with a partially epithelialized connective tissue graft, reaching 100% root coverage. After a 12-month follow-up, this technique showed highly successful results both in 100% coverage of the defect and in long-term stability and aesthetics.

Study on the role of pyroptosis in bone resorption induced by occlusal trauma with or without periodontitis

BACKGROUND AND OBJECTIVE

Occlusal trauma is considered to be a contributing factor to bone loss associated with inflammatory periodontal disease. We hypothesized that pyroptosis, a recently discovered inflammation-induced programmed cell death pathway, plays a role in occlusal trauma.

MATERIALS AND METHODS

The occlusal trauma model was established using a cemented 1-mm elevated computer-aided design and manufacturing (CAD/CAM) metal crown. The periodontitis model was established by periodontal wire ligation with lipopolysaccharide (LPS) injection. The rats were sacrificed at 1, 2, 3, and 4 weeks. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression of pyroptosis-, inflammation-, and osteoclast-related markers. Micro-computed tomography (micro-CT) was used to determine bone morphology parameters. Tissue morphology was evaluated using hematoxylin and eosin staining (H&E). Osteoclasts were identified using tartrate-resistant acid phosphatase (TRAP) staining. The expression and distribution of factors related to pyroptosis and inflammation were evaluated by immunohistochemistry (IHC). The colocalization of dead cells and cysteinyl aspartate-specific proteinase-1 (caspase-1)-positive cells was analyzed by immunofluorescence.

RESULTS

Quantitative real-time polymerase chain reaction and IHC results showed that occlusal trauma induced the expression of pyroptotic factors during the early stages, while occlusal trauma with periodontitis upregulated the expression of pyroptotic factors at the later stages. The results of qRT-PCR, TRAP staining, and micro-CT showed that occlusal trauma with periodontitis increased the production of proinflammatory cytokines, leading to severe bone loss. Glyburide, an NOD-like receptor pyrin domain containing protein 3 (NLRP3)inhibitor, reduced the expression of pyroptosis markers induced by occlusal trauma with periodontitis and reversed bone resorption.

CONCLUSIONS

Pyroptosis was involved in bone loss induced by occlusal trauma with or without periodontitis, while glyburide reversed inflammation and bone resorption.

Efficacy of tooth splinting and occlusal adjustment in patients with periodontitis exhibiting masticatory dysfunction: A systematic review

OBJECTIVE

To evaluate the efficacy of tooth splinting (TS) and occlusal adjustment (OA) compared to no TS or OA in patients with periodontitis exhibiting masticatory dysfunction.

MATERIAL

The primary outcome criterion was tooth loss (TL), and the secondary outcome parameters were change in probing pocket depth (PPD), change in clinical attachment level (CAL), tooth mobility (TM), and patient-reported outcome measures (PROMs). Literature search was performed on three electronic databases (from 01/1965 to 04/2021) and focused on clinical studies with at least 12 months follow-up.

RESULTS

From a total of 1515 publications, 51 articles were identified for full-text reading, of which 2 retrospective case series on TS with low risk of bias and 1 randomized and 2 prospective studies on OA with unclear risk of bias were included. For TS, synthesis of data showed that in 72 patients, 26 out of 311 teeth (weighted mean incidence of TL 8.4%) and 156 out of 1541 teeth with no TS (weighted mean incidence of TL 10.1%) were lost over 2 years following non-surgical periodontal therapy. The randomized controlled clinical trial (RCT) indicated CAL gain for teeth with OA compared to no OA. For the effect of OA on TL, PPD, and TM, heterogeneous data were retrieved from the included studies.

CONCLUSIONS

Within the limitations of this review and based on a low level of evidence, it is concluded that TS does not improve survival of mobile teeth in patients with advanced periodontitis. OA on teeth with mobility and/or premature contacts may lead to improved CAL, while the effect of OA on the remaining periodontal parameters remains unclear.

Incidence of Malocclusion among Young Patients with Gingival Recessions—A Cross-Sectional Observational Pilot Study

Background and Objectives: Dental occlusion and gingival recession have been studied over the past years especially because of the increasing incidence of occlusal interferences in young patients. The purpose of this pilot study is to investigate any association between occlusal dysfunctions and gingival recessions. Data on gingival phenotype and previous orthodontic treatment were also collected to assess any correlation with the presence of gingival recession. Materials and Methods: Forty systemically healthy subjects, without signs of periodontitis and with gingival recessions, were included in the study. The following parameters were determined: location and extent of the gingival recession, gingival phenotype and functional occlusion by means of observing and registering the occlusal contacts in maximum intercuspation position, protrusive and lateral guidance. Results: Premolars were mostly affected in cases of working-side interferences during lateral guidance (71.19% of the affected teeth during left and 75% during right mandibular movements). The chi-squared exact test applied for the analysis of contingency tables revealed statistically significant associations between excursive interferences during lateral guidance and anterior guidance and the presence of gingival recession on the involved group of teeth. Conclusions: The results suggest that most gingival recessions might be associated with working-side interferences, the highest number of gingival recessions being associated with active interferences during lateral guidance.

Comparison of Periodontal Bacteria of Edo and Modern Periods Using Novel Diagnostic Approach for Periodontitis With Micro-CT

Ancient dental calculus, formed from dental plaque, is a rich source of ancient DNA and can provide information regarding the food and oral microbiology at that time. Genomic analysis of dental calculus from Neanderthals has revealed the difference in bacterial composition of oral microbiome between Neanderthals and modern humans. There are few reports investigating whether the pathogenic bacteria of periodontitis, a polymicrobial disease induced in response to the accumulation of dental plaque, were different between ancient and modern humans. This study aimed to compare the bacterial composition of the oral microbiome in ancient and modern human samples and to investigate whether lifestyle differences depending on the era have altered the bacterial composition of the oral microbiome and the causative bacteria of periodontitis. Additionally, we introduce a novel diagnostic approach for periodontitis in ancient skeletons using micro-computed tomography. Ancient 16S rDNA sequences were obtained from 12 samples at the Unko-in site (18th-19th century) of the Edo era (1603–1867), a characteristic period in Japan when immigrants were not accepted. Furthermore, modern 16S rDNA data from 53 samples were obtained from a database to compare the modern and ancient microbiome. The microbial co-occurrence network was analyzed based on 16S rDNA read abundance. Eubacterium species, Mollicutes species, and Treponema socranskii were the core species in the Edo co-occurrence network. The co-occurrence relationship between Actinomyces oricola and Eggerthella lenta appeared to have played a key role in causing periodontitis in the Edo era. However, Porphyromonas gingivalis, Fusobacterium nucleatum subsp. vincentii, and Prevotella pleuritidis were the core and highly abundant species in the co-occurrence network of modern samples. These results suggest the possibility of differences in the pathogens causing periodontitis during different eras in history.

Comparison of Two Generations of Systems for Digital Occlusion Examination

BACKGROUND: The modern concept of occlusion includes the relationship between teeth, masticatory muscles, and temporomandibular joints in function and dysfunction. Occlusion can be defined very simply: it means the contacts between teeth. Qualitative and quantitative methods are used to register and evaluate occlusal contacts. The T-Scan handpiece model was updated in 2015 as T-Scan Novus (software version 9.1) and the latest updated one being the T-Scan version 10 software introduced in 2018. AIM: The purpose of this study is to demonstrate the capabilities and results of two generations of systems - T-Scan III and T-Scan Novus. MATERIALS AND METHODS: For the realization of the set goal, the occlusion of a patient with the initials S.K. is examined with two systems. The patient is 43 years old with intact teeth, Angle’s class I jaw relation. The study with T-Scan III was conducted in 2015 and with T-Scan Novus in 2019. RESULTS: The software of both systems uses a graphical interface, which transforms the data obtained during the recording of the occlusion as the model of the upper dentition of the patient in T-Scan III and the upper and lower dentition in T-Scan Novus. Registered occlusal contacts are illustrated as 2D and 3D images of different colors. The graph force/time shows the power versus time from the first contact to the end of the movie. The timing table displays the patient’s total occlusal bite timing, and the force applied. T-Scan Novus software allows you to import digital fingerprint files of the upper and lower dentition in.stl format. CONCLUSION: The software program of the system version 9.1 provides better visualization of dental arches making it much more informative than other versions. The T-Scan system allows fast and accurate registration and analysis of occlusion.

Cemental tear: Literature review, proposed classification and recommendations for treatment

Cemental tears are an important condition of relevance to Endodontics but are often overlooked. A cemental tear is the partial or complete detachment of the cementum from the cemento-dentinal junction or along the incremental line within the body of cementum. The limited attention received is most likely due to the limited awareness amongst dental professionals and challenges in accurately diagnosing them, resulting in misdiagnosis and erroneous treatment. The aim of this review is to describe the: (i) epidemiology and predisposing factors; (ii) clinical, radiographic and histological features and (iii) the clinical management and treatment outcomes of cemental tear. The review included 37 articles published in English that comprised eight observational studies and 29 case reports. The prevalence of cemental tears was reported to be lower than 2%; whilst the incidence remains unknown. Internal factors due to the inherent structural weakness of cementum and its interface with the dentine, and external factors that are associated with stress have been proposed as the two mechanisms responsible for the development and propagation of cemental tears. Predisposing factors that have been implicated were tooth type, gender, age, previous root canal treatment, history of dental trauma, occlusal trauma and excessive occlusal force; however, evidence is limited. Common clinical and radiographic manifestations of cemental tears resemble the presentations of primary endodontic diseases, primary periodontal diseases and combined endodontic-periodontal lesions. Clinical management tended to focus on complete removal of the torn fragments and periodontal treatment, often combined with regenerative treatment. In this article, a new classification for cemental tears is developed that consists of classes 0 to 6 and stages A, B, C and D based on the: (i) location and accessibility of the torn cemental fragment; (ii) the pattern and extension of the associated bony defect in relation to the root length and (iii) the number of root surface/s affected by the cemental tear/s and the associated bony defect. Recommendations for treatment strategies are also provided and linked to the classification to aid in streamlining the process of treatment decision making.

Comprehensive treatment for severe periodontitis with pathologic tooth migration-related bimaxillary protrusion: A case report with 3-year follow-up

BACKGROUND AND OVERVIEW

Patients with severe periodontitis often experience pathologic tooth migration (PTM), which impairs esthetics and leads to occlusal disharmony (for example, premature contacts and traumatic occlusion) that can further exacerbate periodontitis. The authors describe a patient who exhibited severe periodontitis with PTM-related bimaxillary protrusion. This report includes 3-year clinical outcomes after periodontal regenerative therapy, implant-anchored orthodontic therapy, and implant prosthodontics intended to achieve both functional and esthetic improvements.

CASE DESCRIPTION

A 63-year-old woman sought treatment with the chief complaint of maxillary anterior tooth mobility. Clinical examination revealed excessive tooth mobility, deep periodontal pockets, and infrabony defects in all teeth. All teeth exhibited PTM; the mandibular anterior teeth exhibited marked protrusion caused by the progression of periodontitis. After initial periodontal therapy, periodontal regenerative therapy was performed in all molar regions. At 6 and 9 months postoperatively, comprehensive orthodontic treatment was initiated for the mandible and maxilla, respectively, using orthodontic anchorage devices to achieve acceptable functional occlusion. After orthodontic treatment, staged guided bone regeneration was performed and dental implants were placed in the severely resorbed maxillary anterior ridge. This comprehensive treatment yielded favorable periodontal conditions, stable occlusion, and good esthetic outcomes.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Favorable esthetics, stable occlusion, and highly cleansable periodontal tissues were achieved with well-planned interdisciplinary and comprehensive treatment, although the patient had severe periodontitis and PTM-related bimaxillary protrusion.

The Loop-Mediated Isothermal Amplification Technique in Periodontal Diagnostics: A Systematic Review

The course of periodontal disease is affected by many factors; however, the most significant are the dysbiotic microflora, showing different pathogenicity levels. Rapid colonization in the subgingival environment can radically change the clinical state of the periodontium. This systematic review aims to present an innovative technique of loop-mediated isothermal amplification for rapid panel identification of bacteria in periodontal diseases. The decisive advantage of the loop-mediated isothermal amplification (LAMP) technique in relation to molecular methods based on the identification of nucleic acids (such as polymerase chain reaction (PCR or qPCR) is the ability to determine more pathogens simultaneously, as well as with higher sensitivity. In comparison with classical microbiological seeding techniques, the use of the LAMP method shortens a few days waiting time to a few minutes, reducing the time necessary to identify the species and determine the number of microorganisms. The LAMP technology requires only a small hardware base; hence it is possible to use it in outpatient settings. The developed technique provides the possibility of almost immediate assessment of periodontal status and, above all, risk assessment of complications during the treatment (uncontrolled spread of inflammation), which can certainly be of key importance in clinical work.

Occlusal trauma is associated with periodontitis: A retrospective case-control study

BACKGROUND

Excessive occlusal forces and occlusal trauma have been implicated as co-destructive factors for periodontitis in animal models. The objective of this study was to assess the association between occlusal trauma and periodontitis.

METHODS

A total of 167 cases and 205 controls were included for analysis. Occlusal trauma was the exposures of interest and was registered for cases and controls. Additional clinical co-variables were registered as well for further analysis. The association of the exposure and periodontitis was determined by the odds ratio and logistic regression analysis adjusted for confounders.

RESULTS

Amalgam restorations, pathogenic occlusion and occlusal trauma were more frequent in cases as compared to controls (P ≤ 0.05). The distribution of pathogenic occlusion and occlusal trauma was similar according to the stage and class of periodontitis. Logistic regression analysis showed a significant association for cigarette smoking, systemic conditions, amalgam restorations, pathogenic occlusion, and occlusal trauma with periodontitis (P ≤ 0.05). After adjusting for confounding variables in the model, amalgam restorations and occlusal trauma remained strongly associated with periodontitis (P ≤ 0.05).

CONCLUSIONS

Occlusal trauma is strongly associated with periodontitis. Additional long-term prospective studies are necessary to further understand the impact of the occlusal condition and periodontitis.

Tissue Engineering for Periodontal Ligament Regeneration: Biomechanical Specifications

The periodontal biomechanical environment is very difficult to investigate. By the complex geometry and composition of the periodontal ligament (PDL), its mechanical behavior is very dependent on the type of loading (compressive versus tensile loading; static versus cyclic loading; uniaxial versus multiaxial) and the location around the root (cervical, middle, or apical). These different aspects of the PDL make it difficult to develop a functional biomaterial to treat periodontal attachment due to periodontal diseases. This review aims to describe the structural and biomechanical properties of the PDL. Particular importance is placed in the close interrelationship that exists between structure and biomechanics: the PDL structural organization is specific to its biomechanical environment, and its biomechanical properties are specific to its structural arrangement. This balance between structure and biomechanics can be explained by a mechanosensitive periodontal cellular activity. These specifications have to be considered in the further tissue engineering strategies for the development of an efficient biomaterial for periodontal tissues regeneration.

Parafunctional masseter muscle activity during waking is related to periodontitis progression: A pilot prospective cohort study

AIM

The purpose of this pilot prospective cohort study was to investigate the effects of parafunctional masseter muscle activity on periodontitis progression among patients receiving supporting periodontal therapy (SPT).

MATERIALS AND METHODS

We collected data of patients treated at Okayama University Hospital from August 2014 to September 2018. The progression group was defined as patients with ≥2 teeth demonstrating a longitudinal loss of proximal attachment of ≥3 mm during the 3-year study period and/or at least one tooth extraction due to periodontitis progression. Surface electromyography of masseter muscles at baseline was continuously recorded while patients were awake and asleep.

RESULTS

We analysed 48 patients (36 females) aged 66.8 ± 9.1 years (mean ± SD). The rate of parafunctional masseter muscle activity during waking hours and sleeping hours at baseline was 60.4% and 52.1%, respectively. Cox's proportional hazards regression model showed that the incidence of periodontitis progression was significantly associated with number of teeth present (p = 0.001) and parafunctional masseter muscle activity during waking hours (p = 0.041).

CONCLUSION

Our results suggest that parafunctional masseter muscle activity during waking hours is a risk factor for periodontitis progression among patients receiving SPT.

Association of probable bruxism with periodontal status: A cross-sectional study in patients seeking periodontal care

OBJECTIVE

The goals of this study were to investigate the prevalence of probable bruxism in a group of patients seeking a periodontal care and the association between probable bruxism and periodontal status.

BACKGROUND

The results of previous studies evaluating the relationship between bruxism and periodontitis are contradictory. In addition, the relationship between probable bruxism and periodontitis in adults has not been evaluated, yet. Therefore, new studies are required in this field to clarify the relationship between bruxism and periodontitis.

METHODS

Patients seeking periodontal care at a university periodontology unit were considered in this study. Their periodontal diagnosis, number of missing teeth, presence of probable bruxism, and sociodemographic characteristics were recorded. The periodontal status of each study participant was defined according to the latest consensus of the American Association of Periodontology/European Federation of Periodontology, and the 2018 consensus report on the assessment of bruxism was used to evaluate probable bruxism. A multiple logistic regression analysis was performed to determine the effects of bruxism on periodontitis.

RESULTS

A total of 541 patients (289 females and 252 males, mean age 42.1 ± 15.9 years) were enrolled in the present study. The prevalence of probable bruxism was 36.6%. Additionally, 40.9% of the study population was diagnosed with periodontitis. The probable bruxers were older (P < 0.001), had a higher number of missing teeth (P < 0.001), and had poor periodontal status (P < 0.001). The multivariate logistic regression analysis suggested that probable bruxism was associated with periodontitis, after adjusting relevant factors (odds ratio: 2.243, 95% CI: 1.465-3.434, P < 0.001).

CONCLUSIONS

It was observed that the prevalence of probable bruxism was 36.6% and probable bruxers showed higher odds of periodontitis. Future studies with prospective randomized design should be conducted to confirm these results among a larger study population.

Influence of restorative design on the progression of peri-implant bone loss: A retrospective study

BACKGROUND

Clinical data on the restorative designs affecting the early progression of peri-implantitis are scarce. The aim of this retrospective study was to evaluate the influence of several restorative factors (e.g., restoration emergence angle, and internal screw length/diameter) on the marginal bone loss around implants with peri-implantitis.

METHODS

Implants diagnosed with peri-implantitis having 1- (T1) and 2-year (T2) follow-ups were included. In addition, within 6 months pre-diagnosis (Tb), all cases required to have full documentation in which no evidence of peri-implantitis was not indicated. Changes in marginal bone levels (MBLs) from Tb to T1 and from T1 to T2 were evaluated. The effect of several variables on MBLs changes was assessed via univariate and multivariate generalized estimating equations.

RESULTS

Eighty-three bone-level implants from 65 patients were selected. The mean follow-up before peri-implantitis diagnosis was 99.47 ± 47.93 months. The radiographic mean marginal bone loss was 1.52 ± 1.33 mm (Tb to T1) and 0.58 ± 0.52 mm (T1 to T2). Restoration emergence angle and frequency of maintenance visits significantly affected MBLs from Tb to T1. Besides, 66.3% of the included implants' bone levels were in a zone within 1 mm of the apical end of the internal screw at T1 and remained in this zone during the second follow-up year.

CONCLUSIONS

Significant marginal bone loss occurred in the early post-diagnosis period of peri-implantitis, which could be affected by the restoration emergence angle. Peri-implant MBLs were frequently located in a zone within 1 mm of the apical end of the internal screw.

Ineffectiveness of ozone therapy in nonsurgical periodontal treatment: a systematic review and metaanalysis of randomized clinical trials

OBJECTIVE

This systematic review (SR) aimed at assessing the adjunctive clinical effect of ozone therapy (OT) on nonsurgical periodontal treatment.

MATERIALS AND METHODS

Articles published prior to September 2019 were electronically searched in four databases without any other date or language restrictions and manually searched in regular journals and in gray literature. This review was performed according to the PICO format. The eligibility criteria comprised randomized controlled trials (RCTs) that analyzed the adjunctive effect of OT on nonsurgical periodontal treatment.

RESULTS

Twelve studies published between 2010 and 2019 were included in this SR. A metaanalysis of ten reports showed that there was no statistically significant difference in the periodontal parameters analyzed when scaling and root planing (SRP) plus sulcus irrigation with ozonated water or sulcus insertion of ozonated gas were used when compared to SRP alone. Additionally, there was no significant difference when the effect of SRP plus ozonated water was compared with SRP plus 2% chlorhexidine gluconate (CLX). No studies reported significant microbiological differences when the use of ozone was compared with SRP alone.

CONCLUSIONS

The results of this SR do not support the use of OT for nonsurgical periodontal treatment. However, due to the potential heterogeneity across the studies, the presence of confounding factors, and the short follow-up of some included RCTs, these results should not be considered definitive.

CLINICAL RELEVANCE

The current evidence indicates that ozone has antimicrobial activity and good biocompatibility with periodontal cells and gingival fibroblasts. However, no evidence was found for a positive effect of OT as an adjunct to scaling and root planing.

Relationship between Malocclusion and Periodontal Disease in Patients Seeking Orthodontic Treatment in Southwestern Saudi Arabia

Background:

Malocclusion is known to cause plaque accumulation and periodontal breakdown. However, no previous study from Saudi Arabia has assessed this relationship in patients seeking orthodontic treatment for esthetics.

Objective:

The objective of this study was to investigate the relationship between malocclusion and periodontal disease in terms of gingival inflammation, probing pocket depth (PPD) and recession in patients seeking orthodontic treatment for esthetic improvement.

Materials and Methods:

This prospective cross-sectional study was conducted at the Outpatient Division of Periodontics, College of Dentistry, King Khalid University, Saudi Arabia, among consecutive new patients seeking orthodontic treatment for esthetic improvement between June and August 2018. Angle’s class of malocclusion, various malalignments, plaque index (PI), gingival index (GI), adequacy of width of attached gingiva (WAG), response to fremitus test, PPD and gingival recession (GR) were recorded. P < 0.05 was considered statistically significant.

Results:

A total of 410 consecutive patients were included. Of these, 314 patients had Class I, 57 had Class II (division I), 25 had Class II (division II) and 14 had Class III malocclusions. In patients with all types of malocclusion, the majority had a PI and GI of score 2 (74.1% and 83.7%, respectively). Most of the patients (85.9%) had adequate WAG; similarly, 94.9% had a negative fremitus test, which shows the absence of trauma from occlusion. Mean PPD and GR in the maxillary and mandibular arches showed varying results.

Conclusion:

This study demonstrates a relationship between malocclusion and presence of periodontal disease in patients seeking orthodontic treatment for esthetic improvement in the southwestern region of Saudi Arabia. Therefore, in patients seeking orthodontic treatment, careful evaluation of gingival and oral hygiene along with adequacy of attached gingiva should be considered.

Periodontal manifestations of systemic diseases and developmental and acquired conditions: Consensus report of workgroup 3 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions

BACKGROUND

A variety of systemic diseases and conditions can affect the course of periodontitis or have a negative impact on the periodontal attachment apparatus. Gingival recessions are highly prevalent and often associated with hypersensitivity, the development of caries and non-carious cervical lesions on the exposed root surface and impaired esthetics. Occlusal forces can result in injury of teeth and periodontal attachment apparatus. Several developmental or acquired conditions associated with teeth or prostheses may predispose to diseases of the periodontium. The aim of this working group was to review and update the 1999 classification with regard to these diseases and conditions, and to develop case definitions and diagnostic considerations.

METHODS

Discussions were informed by four reviews on 1) periodontal manifestions of systemic diseases and conditions; 2) mucogingival conditions around natural teeth; 3) traumatic occlusal forces and occlusal trauma; and 4) dental prostheses and tooth related factors. This consensus report is based on the results of these reviews and on expert opinion of the participants.

RESULTS

Key findings included the following: 1) there are mainly rare systemic conditions (such as Papillon-Lefevre Syndrome, leucocyte adhesion deficiency, and others) with a major effect on the course of periodontitis and more common conditions (such as diabetes mellitus) with variable effects, as well as conditions affecting the periodontal apparatus independently of dental plaque biofilm-induced inflammation (such as neoplastic diseases); 2) diabetes-associated periodontitis should not be regarded as a distinct diagnosis, but diabetes should be recognized as an important modifying factor and included in a clinical diagnosis of periodontitis as a descriptor; 3) likewise, tobacco smoking - now considered a dependence to nicotine and a chronic relapsing medical disorder with major adverse effects on the periodontal supporting tissues - is an important modifier to be included in a clinical diagnosis of periodontitis as a descriptor; 4) the importance of the gingival phenotype, encompassing gingival thickness and width in the context of mucogingival conditions, is recognized and a novel classification for gingival recessions is introduced; 5) there is no evidence that traumatic occlusal forces lead to periodontal attachment loss, non-carious cervical lesions, or gingival recessions; 6) traumatic occlusal forces lead to adaptive mobility in teeth with normal support, whereas they lead to progressive mobility in teeth with reduced support, usually requiring splinting; 7) the term biologic width is replaced by supracrestal tissue attachment consisting of junctional epithelium and supracrestal connective tissue; 8) infringement of restorative margins within the supracrestal connective tissue attachment is associated with inflammation and/or loss of periodontal supporting tissue. However, it is not evident whether the negative effects on the periodontium are caused by dental plaque biofilm, trauma, toxicity of dental materials or a combination of these factors; 9) tooth anatomical factors are related to dental plaque biofilm-induced gingival inflammation and loss of periodontal supporting tissues.

CONCLUSION

An updated classification of the periodontal manifestations and conditions affecting the course of periodontitis and the periodontal attachment apparatus, as well as of developmental and acquired conditions, is introduced. Case definitions and diagnostic considerations are also presented.

Orthodontic Management of a Migrated Maxillary Central Incisor With a Secondary Occlusal Trauma

INTRODUCTION

Normal or excessive occlusal forces exerted on teeth with a reduced periodontal support might result in a secondary occlusal trauma. This type of injury is diagnosed based on histological changes in the periodontium. Multiple clinical and radiographic indicators are, therefore, required as surrogates to assist the presumptive diagnosis of a (secondary) occlusal trauma.

CASE PRESENTATION

In this case report, the diagnosis, management, and the 1-year follow-up of a secondary occlusal trauma of a maxillary central incisor are described. The occlusal relationship was rehabilitated with fixed orthodontic appliances and was further stabilized with both fixed and removable retainers.

CONCLUSIONS

A combined periodontal-orthodontic approach for a secondary occlusal trauma allows the rehabilitation of periodontal, occlusal, and esthetic parameters. Twelve months after the end of the active orthodontic treatment, a combination of fixed and removable retainers showed to be effective in retaining the treatment outcome.

Quantitative tooth mobility evaluation based on intraoral scanner measurements

BACKGROUND

Tooth mobility assessment is subjective and current techniques require the translation of a continuous variable to a categorical variable based on the perception of the examiner. The aim of this study was to evaluate the reliability of a novel technique to assess tooth mobility.

METHODS

Three experienced periodontists were asked to push tooth #16 into a buccal position to in a typodont model with different mobility (M1-M2). Tooth position was obtained using an intraoral scanner and files were compared in metrology software. Mobility was calculated at three reference points at the cervical (C), middle (M), and occlusal (O) regions of the buccal surface of the tooth to determine the linear deviation in the three axes (x, y, and z). Reliability was determined by intraclass-correlation coefficient, differences between M1 and M2 determined by t test, and the analysis of variance (ANOVA) was used to compare the data at the C-M-O regions.

RESULTS

Excellent reliability was assessed by Cronbach alpha >0.9 on the x-y-z axes for both mobility tested, except for M1-C X (0.85), M1-M Y (0.89), and M2-M Z (0.89). The correlation between the examiners demonstrated excellent (˃0.90) or good (0.75˃ x ˂0.90) consistency, except for M1-C Y (0.73; examiner 1 to 2) and M1-M X (0.69; examiners 1 to 3). Significant changes were detected in all axes at the three reference points comparing M1 and M2, and a similar proportional change was observed between O-M-C reference points for M1 and M2.

CONCLUSION

A novel technique to assess tooth mobility based on intraoral scanner measurements provided reliable data in an in vitro experiment.

Effect of gingival augmentation procedure (free gingival graft) on reducing the risk of non-carious cervical lesions: A 25- to 30-year follow-up study

BACKGROUND

The aim of this long-term case series was to assess the development/prevalence of non-carious cervical lesions (NCCLs) at sites that have and have not been treated with gingival augmentation following free gingival graft (FGG).

METHODS

Fifty-two patients had at least one test and one control site: 1) test site showing absence of attached gingiva (AG) associated with gingival recession (GR) treated with FGG; and 2) contralateral site with or without AG. Patient/tooth/site-associated variables were recorded for each tooth/site at baseline (T0), 12 months after surgery (T1), during the follow-up period (T2) (15 to 20 years), and at the end of the follow-up period (T3) over 25 to 30 years. Mixed-effects logistic regression was used throughout the study.

RESULTS

Forty-nine patients/130 sites were available for analysis at T2 whereas 44 patients/120 sites at T3. Twenty-two NCCLs >0.5 mm were restored in the test sites and in 35 in the untreated sites. The development of NCCL over time appeared associated with sites with attached KT <2 mm (i.e., odds ratio [OR]: 3.80 [P = 0.045] and 3.47 [P = 0.046], 15- to 20- and 20- to 30-year follow-ups, respectively), as well as to teeth presenting a thin/non-modified periodontal phenotype (i.e., OR: 3.53 [P = 0.037] and 5.51 [P = 0.008], 15- to 20- and 20- to 30-year follow-ups, respectively).

CONCLUSIONS

Periodontal phenotype modification achieved by FGG may prevent the development/progression of NCCL. Evidence suggests that the thickness and width of the AG had a direct influence on the need of restoring these lesions during the 25- to 30-year observation period.