An interdisciplinary treatment to reshape upper anterior displaced teeth by using dynamic occlusal recording with an intraoral scanner.

OBJECTIVE: This article describes an interdisciplinary treatment that helped a patient with displaced upper anterior teeth. A gingivectomy, root canal therapies, digital smile design, digital wax-up, and guided tooth preparations were applied. CLINICAL CONSIDERATIONS: A patient with pathologically migrated teeth asked for treatment without orthodontic involvement due to a primary failed orthodontic treatment history. A smile photo was taken and superimposed with the dentition in a CAD software to accomplish a digital smile design. The jaw movements were recorded with two different methods, a mechanical articulator and an intraoral scanner with Patient-Specific-Motion function. The occlusal contacts during protrusive and lateral movements were compared and the digital wax-up was designed according to the later occlusal data. An aesthetic crown lengthening and pre-op root canal treatment were carried out in advance accordingly. After guided tooth preparation with a silicone index, the final fixed restorations were manufactured and cemented. A 2-year follow-up showed that our prosthesis functions well. CONCLUSIONS: This clinical report revealed that an intraoral scanner with Patient-Specific-Motion function can effectively record individual dynamic occlusal patterns and these data can be integrated into the CAD/CAM process to enhance the fulfillment of clinical requirements. CLINICAL SIGNIFICANCE: This clinical procedure with a 2-year follow-up demonstrated that a prosthodontic-based interdisciplinary treatment of pathologically migrated teeth using dynamic occlusal recording with an intraoral scanner could achieve satisfactory esthetics in a relatively short treatment period. The Patient Specific Motion module may be used to record a personalized functional movement and the data can be integrated into the design process of the final restorations.

Conservative enucleation for physiologic space closure in adenomatoid odontogenic tumor.

Adenomatoid odontogenic tumor (AOT) is a rare, asymptomatic, slow-growing benign tumor that can be divided into three variants: follicular, extrafollicular, and peripheral. By treating AOT using an enucleation and curettage approach, recurrence can be avoided. We report a case of a 24-year-old female who presented with a lump in the right mandibular premolar area along with diastema between displaced teeth #43 and #44 and was diagnosed with extrafollicular AOT. The patient was managed with enucleation-curettage surgery without additional bone graft procedure along with routine follow-up. A successful outcome without recurrence was achieved, and diastema closure with repositioning of the displaced teeth did not require orthodontic treatment. AOT should be managed via enucleation and curettage to obtain successful outcomes without recurrence. Spontaneous bone regeneration following enucleation can be achieved without guided bone regeneration. Also, diastema closure and repositioning of displaced teeth can occur without orthodontic interventions through physiologic drift.

Clinical effectiveness of regenerative periodontal surgery and orthodontic tooth movement with clear aligners in stage IV periodontitis: a case series.

OBJECTIVES: To evaluate the clinical effectiveness of regenerative treatment of intrabony defects in combination with consecutive orthodontic therapy with clear aligners in stage IV (type 2) periodontitis. METHOD AND MATERIALS: Ten patients with a total of 103 intrabony defects were analyzed after regenerative surgery using collagen-deproteinized bovine bone mineral with or without collagen membrane or enamel matrix derivative followed by orthodontic therapy with clear aligners. Changes in radiographic bone level and probing pocket depths were evaluated after 1 year (T1) and at final splinting (T2) after orthodontic tooth movement. RESULTS: Mean radiographic bone level gain was significant, with 2.13 ± 1.64 mm at T1 and 3.02 ± 2.00 mm at T2. Mean probing pocket depth was significantly reduced from 5.40 ± 1.80 mm at baseline to 3.78 ± 1.73 mm at T1, and remained stable with 3.73 ± 1.70 mm at T2. Pocket closure (≤ 4 mm probing pocket depth) was accomplished in 76% of all defects. Tooth loss amounted to 2.9%. CONCLUSION: Within the limitations of the retrospective study design, the findings suggest that the interdisciplinary treatment of periodontitis stage IV by regenerative periodontal surgery and consecutive orthodontic therapy with clear aligners can lead to favorable results.

Biomechanical Considerations in the Orthodontic Treatment of a Patient with Stabilised Stage IV Grade C Generalised Periodontitis: A Case Report.

Orthodontic treatment of periodontally compromised patients presents unique challenges, including controlling periodontal inflammation, applying appropriate force, designing an effective dental anchorage, and maintaining treatment results. Deteriorated periodontal support leads to alterations in the biological responses of teeth to mechanical forces, and thus orthodontists must take greater care when treating patients with periodontal conditions than when treating those with a good periodontal status. In this article, we report the case of a 59-year-old woman with stabilised Stage IV grade C generalised periodontitis characterised by pathological tooth migration (PTM). The assessment, planning, and treatment of this patient with orthodontic fixed appliances is described. Moreover, the anchorage planning and biomechanical considerations are detailed. Specific orthodontic appliances were employed in this case to produce force systems for achieving precise tooth movement, which included a cantilever, mini-screws, and a box loop. Careful application of those appliances resulted in satisfactory aesthetic and functional orthodontic outcomes in the patient. This case highlights the importance of multidisciplinary collaboration in the treatment of patients with severe periodontitis and the potential for tailored biomechanical approaches in orthodontic treatment to furnish good outcomes.

The Apical Tooth Replantation with Surgical Intrusion Technique (ATR-SIT) for Regenerative Treatment of Hopeless Teeth: A Report of Two Cases.

The aim of the present clinical report is to introduce a novel surgical procedure, the 'Apical Tooth Replantation with Surgical Intrusion Technique' (ATR-SIT) for managing teeth with hopeless prognosis compromised with a severe endodontal-periodontal lesion, pathologic tooth migration, and gingival recession. Two cases are presented managing teeth diagnosed with a hopeless prognosis. ATR-SIT involves tooth extraction, extra-oral root debridement, root surface conditioning, apicectomy, retrograde filling and the application of enamel matrix derivatives prior to reimplantation. Following reimplantation, the teeth are covered with a combination of autogenous bone chips and bone substitute materials, covered with resorbable membranes. Following ATR-SIT, the patients received either orthodontic treatment or tooth-supported fixed dental prostheses. The described ATR-SIT effectively improved the initially hopeless prognosis of the teeth and maintained periodontal health over time, evidenced by favourable clinical and radiographic outcomes. ATR-SIT might be a potential alternative to tooth extraction of hopeless teeth in patients with stage IV periodontitis.

Variability in human tooth cementum thickness reflecting functional processes.

OBJECTIVE: The aim of this study was to investigate the thickness of acellular extrinsic fibre cementum (AEFC) at four root positions of anterior and posterior teeth with special focus on functional aspects. Furthermore, the correlations between cementum thickness and chronological age and sex are investigated. BACKGROUND: While numerous studies confirm continuous cementum apposition with age, masticatory forces as well as physiological and orthodontically induced tooth movements also have the potential to affect tooth cementum thickness. MATERIALS AND METHODS: Undecalcified teeth were embedded in resin and transverse-sectioned in the cervical third of the root. Two sections per root were selected, and digital images at four positions were obtained (mesial, distal, oral, and vestibular) using light microscopy. The AEFC thickness of 99 teeth (anterior = 66, posterior = 33, male = 54, female = 45) were measured in both sections. The differences in mean values between root positions and the association of root position variation with tooth type, age, sex, and subject as well as the overall effects of age and sex were analysed using a mixed model. RESULTS: First incisors and canines showed the greatest mean AFEC thickness, in contrast to premolars which had the lowest values. Differences were found across the four root positions, with a pattern varying considerably between anterior and posterior teeth and between maxilla and mandible in the anterior teeth. An interaction between root position and subject pointed to the existence of an individual component in the variation of AEFC thickness across the four root positions. There was an age trend with an almost linear increase in cementum thickness of 1 µm per year. Overall, females tended to exhibit a significantly lesser AEFC thickness compared to males. CONCLUSIONS: Distinct differences in the pattern of thickness values across the four root positions in anterior and posterior teeth support the assumption that the AEFC is strongly affected by functional processes. In addition to sex-specific differences and age-related trends, the root position variation of AEFC thickness varies from individual to individual.

Three-dimensional finite element analysis of retracting pathological migration of the right upper central incisor with a clear aligner.

We aimed to explore the best orthodontic step distance of the right upper central incisor with mild, moderate, and severe pathological displacement achieved via a clear aligner. Three-dimensional models of maxilla-tooth-periodontal ligament clear aligner of the right upper central incisors with five different steps of 0.1, 0.125, 0.15, 0.165, 0.25 mm and three different alveolar bone heights were established via finite element analysis. We analysed the changing trends in initial displacement, the periodontal ligament, the alveolar bone, and apical stress of right upper central incisor. In the process of retraction, the right upper central incisor a movement trend of the crown deviating from the distal root to the mesial, and with the decrease of the height of the alveolar bone and the increase of the displacement, the crown would appear distal labial torsion with a deepening trend of vertical overlay.The maximum stress distribution of the periodontal ligament and alveolar bone showed a positive correlation. The overall stress distribution of the periodontal ligament and apical stress increased with decrease of alveolar bone height and the increase of alveolar bone displacement. In patients with mild, moderate, and severe pathological displacement of the right upper central incisor, the best step distance of anterior tooth retraction is 0.165, 0.15, and 0.125 mm, respectively.

Orthodontic treatment in patients with periodontitis - a narrative literature review.

Patients with periodontitis often require an inter-disciplinary approach, including orthodontic treatment, for effective rehabilitation of masticatory function, aesthetics and quality of life. The aim of this narrative review was to comprehensively discuss literature focusing on the biology, indications and inter-disciplinary connections related to the orthodontic approach in patients with periodontitis and to present clinical concepts in accordance with valid guidelines. The outcomes of the experimental studies indicate that orthodontic tooth movement (OTM) can be performed safely for teeth with reduced periodontium, provided infection and inflammation are controlled. Orthodontic treatment can correct pathological tooth migration, is not associated with deterioration of clinical periodontal parameters and improves aesthetics. Intrusion is safe when performed with light forces and under a strict oral hygiene regimen. Teeth can be moved either towards or away from the intrabony defect previously subjected to regenerative procedures, and research suggests that OTM has the potential to enhance bone formation after regenerative therapy. The data on orthodontic movement of teeth with furcation involvement are very scarce. The improvement in furcation involvement following either combined periodontal and orthodontic treatment was only documented in animal model studies. Due to bone and tooth loss, special consideration should be given to orthodontic treatment mechanics. © 2023 Australian Dental Association.

Adjacent tooth migration after maxillary first molar loss in patients with sinus augmentation: A retrospective research.

PURPOSE: The objectives of this study are to: (1) investigate the extent of antagonistic and distal neighboring tooth migration in the maxillary posterior single tooth-missing site during the healing period of bone augmentation and implant surgery; (2) identify factors associated with tooth migration. MATERIALS AND METHODS: One hundred and forty-three cases that lost the maxillary first molar were included, and their CBCT data during the edentulous period were obtained. Dentition models were reconstructed from CBCT, and superimpositions were performed, followed by measuring migration distances and calculating migration rates of antagonistic and distal neighboring teeth. Factors were analyzed using multivariate generalized estimating equations (GEE). RESULTS: The mean migration distances were 208 ± 137 µm and 403 ± 605 µm for antagonistic teeth and distal teeth, and the mean migration rates were 26.8 ± 21.2 µm/month and 48.5 ± 76.7 µm/month, respectively. One hundred and nineteen out of 143 distal neighboring teeth migrated toward the edentulous site, and all antagonistic teeth migrated occlusally. Occlusal contact loss and chronic apical periodontitis both significantly accelerated antagonistic tooth migration (p < 0.05), the latter also accelerated distal tooth migration (p < 0.05). Besides, the displacement of the distal teeth was somewhat accelerated by the impacted adjacent third molar and root protrusion into the sinus. CONCLUSIONS: The neighboring teeth tend to migrate toward the edentulous gap in the maxillary posterior region. Occlusal contact loss and chronic apical periodontitis are two significant risk factors for accelerating antagonistic tooth migration, and for distal teeth, chronic apical periodontitis is the risk factor. The impacted adjacent third molar and root protrusion into the sinus are also potential risk factors for accelerating the migration of the maxillary distal tooth. Thus, to prevent maxillary edentulous gap reduction, the factors mentioned above should be taken into consideration when planning treatment flow.

Multidisciplinary approach involving strategic implant placement before orthodontic (SIMBO) treatment for generalized stage IV grade C periodontitis: A case report with 10-year follow-up.

OBJECTIVE: The aim of this case report was to demonstrate the long-term effects of a multidisciplinary approach involving periodontal reconstructive surgery and strategic implant placement before orthodontic (SIMBO) treatment in a patient with severe periodontitis (e.g., stage IV/grade C). CLINICAL CONSIDERATIONS: The patient presented with severe periodontitis and pathologic tooth migration (PTM) without stable occlusion or occlusal support. After performing cause-related therapy, periodontal regenerative surgery, pre-orthodontic posterior implant placement, and orthodontic treatment involving anterior implant placement with papilla reconstruction, the patient achieved full-mouth rehabilitation and improvement of dental and smile esthetics. The clinical and radiographic results obtained were maintained over a 10-year period. CONCLUSION: Within the limits of this as a single case, multidisciplinary treatment involving the SIMBO approach appeared to allow long-term improvement of periodontal condition, stability of the dental arches and occlusion, and esthetics in a patient with severe periodontitis, PTM and posterior bite collapse. Future studies with more subjects are needed to evaluate and validate this approach. CLINICAL SIGNIFICANCE: When addressing periodontal disease, SIMBO approach-based multidisciplinary treatment appears safe and effective as a clinical protocol for establishing esthetic and functional rehabilitation in generalized stage IV/grade C periodontitis.

Synergy of Regenerative Periodontal Surgery and Orthodontics Improves Quality of Life of Patients with Stage IV Periodontitis: 24-Month Outcomes of a Multicenter RCT.

In stage IV periodontitis patients with pathologic tooth migration (PTM), interdisciplinary treatment includes regenerative periodontal surgery (RPS) with an application of biomaterials and orthodontic therapy (OT) to restore function, esthetics and thereby quality of life (QoL). In a 24-month randomized trial we explored the synergy between regenerative medicine and biomechanical force application. The following methods were used: Forty-three patients had been randomized to a combined treatment comprising RPS and subsequent OT starting either 4 weeks (early OT) or 6 months (late OT) post-operatively. Clinical periodontal parameters and oral health-related QoL (GOHAI) were recorded up to 24 months. We obtained the following results: Mean clinical attachment gain (∆CAL ± SD) was significantly higher with early OT (5.96 ± 2.1 mm) versus late OT (4.65 ± 1.76 mm) (p = 0.034). Pocket closure (PPD ≤ 4 mm) was obtained in 91% of defects with early OT compared to 90% with late OT. GOHAI-scores decreased significantly from 26.1 ± 7.5 to 9.6 ± 4.7 (early OT) and 25.1 ± 7.1 to 12.7 ± 5.6 (late OT). Inconclusion, teeth severely compromised by intrabony defects and PTM can be treated successfully by RPS followed by early OT with the advantage of an overall reduced treatment time. As a result of the combined periodontal-orthodontic therapy, the oral health-related QoL of patients was significantly improved. Early stimulation of wound healing with orthodontic forces had a favorable impact on the outcomes of regenerative periodontal surgery.

Saving teeth: Revisited. Esthetic improvement and long-term periodontal stability of a pathologic tooth migration case: An 84-month follow-up.

INTRODUCTION: Advances in implant dentistry, often influence our clinical treatment planning and steer us as periodontists from our fundamental values of preserving teeth. Pathologic tooth migration (PTM) of maxillary anterior teeth is a common sequela of periodontitis in patients and results in significant esthetic and functional problems. Patients' growing concern about the esthetics of their teeth and their fears of losing teeth are often reasons for them to seek treatment. We commonly assign a hopeless prognosis to these pathologically migrated teeth because of the significant loss of periodontal support and go with the "safer" choice of replacing them with implants. The purpose of this case report is to present the long-term (7-year) periodontal stability of compromised teeth and to emphasize the successful outcomes achieved when orthodontics, non-surgical periodontal, and restorative treatments are combined. METHODS AND RESULTS: A 38-year-old, otherwise healthy male with compromised function and esthetics, PTM, periodontal disease, and missing teeth presented to our clinic. Primary treatment objectives were to 1) eliminate the periodontal inflammation and 2) restore and stabilize the occlusion by employing non-surgical periodontal treatment, adult orthodontics, and prosthodontics. Following interdisciplinary treatment, clinical and radiographic re-evaluation revealed significant clinical attachment gain, reduction in tooth mobility, favorable esthetics, and better overall prognosis. At an 84-month follow-up, the patient was periodontally healthy and retained his natural dentition. CONCLUSIONS: Interdisciplinary collaboration along with patient compliance may increase the longevity of periodontally compromised teeth and improve esthetics for periodontitis patients who suffer from PTM. Such long-term favorable outcomes reaffirm the value of classic periodontal treatment and the success of multidisciplinary treatment to save teeth as a viable alternative to the extraction of teeth and the placement of implant retained restorations.

Long-term stability of regenerative periodontal surgery and orthodontic tooth movement in stage IV periodontitis: 10-year data of a retrospective study.

BACKGROUND: This study aimed to evaluate the long-term effectiveness of regenerative treatment of intra-bony defects in combination with consecutive orthodontic therapy (OT) in stage IV periodontitis. METHODS: Twenty-two patients with a total of 256 intra-bony defects were analyzed after regenerative surgery followed by OT initiated 3 months later. Changes in radiographic bone level (rBL) and probing pocket depths (PPD) were evaluated after 1 year (T1), final splinting (T2), and 10 years (T10). RESULTS: Mean rBL gain was significant with 4.63 mm (±2.43 mm) after 1 year (T1), 4.19 mm (±2.61 mm) at final splinting (T2), and 4.48 mm (±2.62 mm) after 10 years (T10). Mean PPD was significantly reduced from 5.84 mm (±2.05 mm) at baseline to 3.19 mm (±1.23 mm) at T1, to 3.07 mm (±1.23 mm) at T2, and to 2.93 mm (±1.24 mm) at T10. Pocket closure (PPD ≤ 4 mm) was achieved in 90% of all defects. Tooth loss amounted to 4.5%. CONCLUSIONS: Within the limitations of this retrospective study design, these 10-year findings suggest that in motivated and compliant patients with stage IV periodontitis and in need of OT an inter-disciplinary treatment can lead to favorable and stable long-term results.

Periodontal and Orthodontic Synergy in the Management of Stage IV Periodontitis: Challenges, Indications and Limits.

This retrospective study described the clinical and radiographic long-term outcomes of combined periodontal and orthodontic treatment (OT) with fixed appliances in patients with Stage IV periodontitis and pathologic tooth migration (PTM) in the anterior sextants. OT was performed in either one or both arches, using tooth-supported or skeletal anchorage, following completion of active periodontal treatment and accurate planning of tooth movement biomechanics. Twenty-nine patients were identified and retrospectively examined when presenting for a supportive periodontal care (SPC) appointment. The mean SPC duration was 8.9 years (range 5 to 12 years). All anterior-migrated teeth showed statistically significant periodontal improvement compared to baseline values and stable radiographic bone levels at the final follow-up. Residual probing depths were 2.9 ± 0.5 mm at the end of active periodontal treatment, and they remained stable at the completion of OT (2.9 ± 0.6 mm) and at the last follow-up visit (2.8 ± 0.5 mm). These findings suggest that OT is a safe and effective treatment in improving the long-term prognosis of teeth with PTM in Stage IV periodontitis provided that periodontal health has been re-established and maintained with individualized SPC sessions.

Does treating proximal cavities in primary molars non-restoratively affect intra-arch space and alignment of successor teeth negatively? A 4-year longitudinal study.

Background: Removing plaque with toothbrush and toothpaste from proximal cavities in primary molars without restoring them follows sound cariological principles. But does this treatment affect space for and alignment of their permanent successors negatively? Hypothesis: There is no difference in impaction and displacement of the premolars, as well as in the D+E space in quadrants with three different statuses of the proximal surface of primary molars over a 4-year period. Methods: A total of 936 quadrants (466 maxillary and 470 mandibular quadrants) in 233 children were assessed. Treatment of cavities in the proximal surfaces of the primary molars consisted of amalgam and ART restorations using high-viscosity glass-ionomer cement, and cleaning of open large- and medium-sized cavities with toothbrush and toothpaste (UCT) under supervision for 220 days per year over 3 years. Dental casts were made at baseline, and after two, three, and 4 years. The D+E spaces were measured digitally. Status of the proximal surface of the primary molars was assessed by two calibrated examiners, and quadrants were grouped into normal anatomy, defective restoration, and proximal cavity. ANCOVA, ANOVA and LSD tests were applied. Results: There was a statistically significant difference between groups (p <= 0.001) and between evaluation times (p < 0.001), for the D+E space in both the maxilla and mandible. A sex difference related to the D+E space in the maxilla was found (p = 0.007). For boys, quadrants in the maxilla of the group 'proximal cavity' showed a significant shorter D+E space when compared to quadrants of the group 'normal anatomy' at the 3- and 4-year evaluation time. For girls the difference between the two groups was only present at the 3-year evaluation time. There was no significant difference between the D+E space in quadrants with defective restorations and those with normal anatomy in the mandible and in the maxilla. Displacement and impaction of the premolars showed no significant difference between groups. Conclusion: Primary molars with open proximal cavities that are cleaned with toothbrush and toothpaste do not result in displacement and impaction of the successor teeth, neither do primary molars with defective restorations in proximal tooth surfaces.

Pathological tooth migration-spontaneous correction of diastema after surgical periodontal therapy: a case report.

A common consequence of moderate to extreme periodontitis is pathologic migration. This denotes tooth movement when the periodontal disease interjects the equilibrium among the elements that preserve physiological tooth position. The balancing factors can migrate the teeth in any direction. The etiology of pathological migration tends to be multifactorial, thus achieving early diagnosis is imperative, which will ultimately lead to the prompt removal of the etiological factors while avoiding severe bone destruction. In this case maxillary central incisors had diastema due to pathological migration with mobility grade I in maxillary left central incisor. Many cases of moderate to severe pathological migration need a suitable, interdisciplinary approach. Nevertheless, since it is possible to detect mild cases of Pathological tooth migration (PTM) at an early stage, spontaneous correction of migrated teeth can be accomplished by periodontal therapy alone. Regardless of the treatment selected, maintenance of stable results should be considered as an aim of treatment.

Effects of different periodontal splints combined with orthodontic treatment on facial aesthetics in patients with sector displacement of periodontitis teeth / 中国医师杂志

Objective:To study the facial aesthetic effect of different periodontal splints combined with orthodontic treatment for patients with sector displacement of periodontitis teeth.Methods:A total of 186 patients with sector displacement of periodontitis teeth admitted to Hunan Second People′s Hospital from April 2018 to April 2020 were prospectively selected as the research objects. 186 patients were divided into observation group and control group by random number table method, with 93 cases in each group. Both groups were treated with orthodontic correction. The observation group was treated with orthodontic combined with super fiberglass periodontal splint, while the control group was treated with orthodontic combined with conventional periodontal splint. The treatment effect, serum inflammatory factors [tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), interleukin-6 (IL-6) ], periodontal pocket depth, bleeding index and plaque index before and after treatment were compared between the two groups, and the satisfaction of the two groups was compared.Results:At half year and 1 year after treatment, the effective rate of the observation group was 91.40%(85/93) and 100%(93/93), which were significantly better than those of the control group [84.95%(79/93), 95.70%(89/93), all P<0.05]. The levels of serum TNF-α, CRP and IL-6 in the two groups at half year and 1 year after treatment were significantly lower than those before treatment (all P<0.05); the levels of serum TNF-α, CRP and IL-6 in the observation group was significantly lower than the control group, with statistically significant difference (all P<0.05). The periodontal pocket depth, bleeding index and plaque index of the two groups after treatment were also significantly lower than those before treatment (all P<0.05); the periodontal pocket depth, bleeding index and plaque index of the observation group was significantly lower than the control group, with statistically significant difference (all P<0.05). At half year and 1 year after treatment, the patients′ satisfaction in the observation group reached 91.40%(85/93) and 94.62%(88/93), respectively, which was also significantly better than that in the control group [81.72%(76/93), 89.25%(83/93), all P<0.05]. Conclusions:Compared with the conventional periodontal splint, the combination of super fiberglass periodontal splint can significantly improve the treatment effect and patient′s satisfaction.

Numerical and biomechanical analysis of orthodontic treatment of recovered periodontally compromised patients.

OBJECTIVE: Generate a finite element (FE) model to simulate space closure and retraction mechanics for anterior maxillary teeth in periodontally compromised dentition, and compare the biomechanical effect of initial force systems with varying magnitude. MATERIALS AND METHODS: The geometry of an idealized finite element model (FEM) of a maxilla was adapted such that the teeth showed reduced periodontal support together with extruded and flared incisors. In a first step, leveling and alignment of the front teeth were simulated. In a second step, force systems for orthodontic space closure of residual spaces on both sides distal to the lateral incisors were simulated. A combined intrusion and retraction cantilever was modeled, to simulate en masse retraction mechanics with segmented arches and elastic chains. A commercial FE system was used for all model generations and simulations. RESULTS: Results of the simulations indicated that a force of 1.0 N is too high for space closure of flared front teeth in periodontally damaged dentition, as extreme strains may occur. En masse retraction using cantilever mechanics with lower forces showed a uniform intrusion and retraction movement and thus proved to be a better option for treating patients with a periodontally compromised dentition. CONCLUSION: The outcome of this study indicates that increased periodontal stresses resulting from severe attachment loss should be seriously considered by careful planning of the orthodontic mechanics and reduction of the applied forces is suggested. The presented cantilever mechanics seems to be an appropriate means for en masse retraction of periodontally compromised extruded front teeth.

Interrelación Entre Ortodoncia y Periodoncia en Periodonto Reducido. Estabilidad Periodontal Tras 6 Años de Seguimiento / Interrelation Between Orthodontics and Periodontics in Reduced Periodontium. Periodontal Stability After 6 Years of Follow-up

RESUMEN: En pacientes con periodontitis, la migración dentaria patológica es una consecuencia de la pérdida de soporte periodontal. El siguiente reporte de caso aborda el tratamiento periodontal y ortodóncico de una paciente con periodontitis y migración dentaria patológica. El protocolo utilizado fue el protocolo de la Unidad de Ortodoncia y Periodoncia de la Facultad de Odontología de la Universidad de Chile. La estabilidad periodontal se ha mantenido por al menos 6 años luego de finalizado el tratamiento de ortodoncia logran-do funcionalidad y estética de la dentición natural.

ABSTRACT: In patients with periodontitis, pathologic tooth migration is a consequence of loss of periodontal support. The following case report addresses the periodontal and orthodontic treatment of a patient with periodontitis and pathologic tooth migration. The protocol used was the protocol of the Orthodontics and Periodontics Unit of the Faculty of Dentistry of the University of Chile. The periodontal stability has been maintained for at least 6 years after the end of orthodontic treatment, achieving functionality and aesthetics of the natural dentition.

Self-correction of pathologic tooth migration after nonsurgical periodontal treatment in a metabolic syndrome patient with severe periodontitis and drug-influenced gingival enlargement.

Drug-influenced gingival enlargement (DIGE) and reduced bone support caused by periodontitis are two of the etiologic factors for pathologic tooth migration (PTM). Comprehensive management, including surgical, orthodontic, and prosthodontic treatment, is usually required for recovery from severe DIGE and PTM. An 85-year-old Taiwanese male with a history of hypertension and uncontrolled diabetes mellitus (DM) visited our dental department for severe gingival enlargement and spontaneous bleeding. He was diagnosed as having advanced periodontitis and DIGE. Remarkable PTM occurred on the front sextants of his dentition. The patient's DM was gradually controlled, and his calcium channel blocker treatment was substituted with a new regimen for 7 months. One year after nonsurgical periodontal treatment and reinforcing the patient's oral care, both DIGE and PTM were spontaneously resolved without any surgical or orthodontic intervention. We advocate the value of early diagnosis, improving patient's oral hygiene, and meticulous nonsurgical treatment for both DIGE and PTM.