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.

Orthodontic treatment in patients with aggressive periodontitis.

INTRODUCTION: Aggressive periodontitis (AP) is a condition that promotes breakdown of the periodontal tissues in a short time. In severe cases, pathologic migration of teeth and tooth loss can occur, producing esthetic and functional problems for the patient. Orthodontic treatment may be recommended to restore esthetics and masticatory function. We assessed the effects of orthodontic movement in the periodontal tissues of treated patients with AP. METHODS: Ten subjects (ages 25.0 ± 5.22 years) with AP received periodontal treatment followed by orthodontic treatment. Maintenance sessions were performed monthly under a strict dental biofilm control. They were compared with 10 periodontally healthy subjects (ages 22.9 ± 5.23 years) who received orthodontic treatment. Probing pocket depth, clinical attachment level, bleeding on probing, and dental plaque index were measured at baseline, after orthodontic treatment, and after 4 months. RESULTS: Statistical analysis showed improvement in all clinical parameters between baseline and 4 months after orthodontic treatment: probing pocket depth (0.29 mm), clinical attachment level (0.38 mm), bleeding on probing (4.0%), and dental plaque index (11%). CONCLUSIONS: The periodontal parameters of the AP patients remained stable during orthodontic treatment under strict biofilm control.

Development of the gingival sulcus at the time of tooth eruption and the influence of genetic factors.

Tooth eruption is characterized by a concert of mechanisms that result in the emergence of teeth in the oral cavity. Genetic variants seem to regulate this process and the formation of a gingival sulcus around the teeth. Interindividual variability in the response to microbial triggers in the sulcus plays an important role in the onset and progression of periodontal diseases. Host genetic variants can influence this variability, affecting the response of the host to the subgingival biofilm. Genetic factors affecting tooth eruption could potentially influence susceptibility to periodontal diseases and, specifically, susceptibility to localized aggressive periodontitis. This review aims to discuss the evidence available for the role of host genetic variants in tooth eruption and to and to give some directions for prospective research in this topic.

Mesiodistal dental movement toward remodeled edentulous alveolar ridge: Digital model assessment.

INTRODUCTION: The aims of this study were to compare the changes in posterior dental inclination and angulation, and the posterior tooth crown sizes and alveolar ridge thicknesses consequent to the orthodontic procedures of closing and opening of mandibular first molar edentulous spaces. METHODS: The sample comprised 16 patients (4 men, 12 women) with an initial mean age of 34.17 years and unilateral or bilateral absence of mandibular permanent first molars. The space closure group (SCG) comprised 12 hemiarches with a mandibular first molar edentulous space varying from 2 to 7 mm, orthodontically treated with space closure. The space opening group (SOG) comprised 14 quadrants with a mandibular first molar edentulous space varying from 7.1 to 12 mm, orthodontically treated with space reopening for prosthetic replacement. Digital dental models were obtained before treatment and after space closure or opening, and posterior tooth angulation and inclination, cervico-occlusal crown height, and alveolar ridge thickness were evaluated. Interphase and intergroup comparisons were performed with dependent t tests and t tests, respectively (P <0.05). RESULTS: Mandibular second molar uprighting and changes in buccolingual inclination of the posterior teeth were similar in the groups. The second molar cervico-occlusal crown height increased in the SCG and decreased in the SOG. The alveolar ridge thickness increased in the SCG and remained stable in the SOG. CONCLUSIONS: The only significant intergroup differences were that the second molar cervico-occlusal crown height and the alveolar ridge thickness increased in the SCG, and decreased and remained stable in the SOG.

Repositioning of a pathologically migrated tooth using autologous platelet-rich plasma: a case report with 3-year follow-up.

An intricate balance between the periodontal tissues and the forces of occlusion, tongue, and lips helps to maintain a tooth in its physiologic position within the dental arch. Disturbances in the equilibrium can cause a tooth to migrate pathologically, often requiring multidisciplinary treatment approaches. The present case demonstrates, for the first time, the use of autologous platelet-rich plasma to aid in tooth repositioning after pathologic tooth migration. A 25-year-old woman presented with extrusion and labial migration of the maxillary left central incisor, a diastema of 3 mm, and grade II mobility. Radiographic evaluation showed a deep, angular bone defect, extending to the apical third of the root, on both the mesial and distal aspects of the maxillary left central incisor. Comprehensive treatment consisted of nonsurgical and surgical periodontal therapy with autologous platelet-rich plasma. Without orthodontic intervention, the unesthetic diastema had completely closed by the end of 3 months postoperatively, and the results were stable at a 3-year follow-up examination. This successful, novel approach can be adopted as a conservative and time-efficient modality for management of unesthetic spaces caused by pathologic tooth migration.

Quantified diagnostic work-up casts: applications for interdisciplinary treatment planning.

Diagnostic casts that accurately replicate a patient's occlusion are essential for planning comprehensive care and interdisciplinary treatment. These casts can reveal the actual problem in the spatial relationship between the maxilla and the mandible, which may not be apparent on intraoral examination. Duplicate casts can be altered and measured to quantify the extent of the correction necessary for a predictable result. Treatment planning for interdisciplinary cases requires thorough evaluation of the entire problem and solution set as well as coordination of all procedures. Severe problems and invasive treatments require precise treatment planning. This case report illustrates these principles through multiple applications of quantified diagnostic work-up casts for a patient requiring orthognathic surgery, orthodontics, and occlusal adjustment after a mandibular subcondylar fracture.

Lower first permanent molars: developing better predictors of spontaneous space closure.

BACKGROUND: First, first permanent molars (FPMs) of poor prognosis are often planned for extraction at an 'ideal time' so that second permanent molars (SPMs) erupt favourably to replace them. However for lower FPM extractions, timing is not an accurate predictor of success. OBJECTIVE: The aim of this study was to identify additional radiographic factors that could better predict the degree of spontaneous space closure of the lower SPM following FPM extraction. METHODS: Data from a previous study of 127 lower SPMs from 66 patients was re-analysed by incorporating additional radiographic factors. These included calcification stage of the bifurcation of the SPM, position of the second premolar, mesial angulation of SPM in relation to the FPM, and presence of the third permanent molar. Results were analysed using ordered logistic regression. RESULTS: Only 58 per cent of FPMs extracted at the 'ideal time' (SPM development at Demirjian stage E) had complete space closure. The best outcomes resulted from a combination of SPMs not at Demirjian development stage G, together with the presence of mesial angulation of the SPM and presence of the third permanent molar, where 85 per cent of those cases had complete space closure. CONCLUSIONS: Apart from extraction timing of the FPM, consideration must also be given to the presence of the third permanent molar and angulation of the SPM in order to ensure a reliable degree of spontaneous space closure of the lower SPM.

Analysis of spontaneous repositioning of pathologically migrated teeth: a clinical and radiographic study.

OBJECTIVE: Pathologic migration is defined as a change in tooth position, resulting from a disruption of forces that maintain the teeth in the normal position with reference to the skull. Clinical evidence is limited that pathologically migrated teeth may reposition themselves after periodontal therapy. The current study was carried out to determine the frequency of spontaneous repositioning of pathologically migrated teeth after periodontal therapy, and to study the relation between the severity of migration and the degree of repositioning following treatment. METHOD AND MATERIALS: Twenty-five patients aged 20 to 45 years with moderate to severe form of periodontitis presenting 52 diastema sites secondary to pathologic migration involving maxillary anterior teeth participated in the study. After conventional periodontal treatment had been performed, reactive repositioning was assessed by measuring the space between pathologically migrated teeth and adjacent teeth on study models and radiographs obtained at baseline, reevaluation at 4 weeks after scaling and root planing (SRP), 3 months after periodontal surgery, and 6 months from baseline. RESULTS: No changes were noted after SRP. On study models, 88.46% of all sites (46 of 52 sites) demonstrated various degrees of repositioning (both partial closure and complete closure) after periodontal therapy 6 months after baseline. Of these 46 sites, all exhibited improvement after surgical therapy. Labiopalatal repositioning was seen in 32 out of 51 teeth (62.74%). On radiographs, 77.27% of all sites (34 of 44 sites) demonstrated various degrees of repositioning (both partial closure and complete closure) after periodontal therapy 6 months after baseline. Of these 34 sites, all exhibited improvement after surgical therapy. Complete repositioning occurred in 34.61% and partial closure was seen in 53.80%. CONCLUSION: The findings suggest that spontaneous repositioning after periodontal therapy is likely, particularly when light to moderate degrees of pathologic migration are considered.

Lower dental arch changes after bilateral third molar removal.

OBJECTIVE: To evaluate the changes in lower dental arch after bilateral lower third molars removal. MATERIAL AND METHODS: The study group consisted of 30 non-orthodontic patients (mean age 25,5 years, refered for bilateral lower third molars removal. Orthopantomograms and dental casts were made before and 6-8 months after surgical removal of lower third molars. Transversal lower arch widths between lower canines and second premolars and lower arch total tooth size-arch lenght discrepancy were evaluated on dental casts. The angulation of lower second premolars, first and second molars was measured in horizontal and mandibular planes on orthopantomograms. RESULTS: No significant difference of inter-canine and inter-premolar transversal width was noticed. No significant changes were observed in total tooth-size lenght discrepancy, except in S1 segment consisted of first and second premolar and the canine on the right quadrant of the lower dental arch. The angulation of second premolars and first molars did not show any significant changes, however there were statistically significant changes between angulation of lower second molars on both sides. CONCLUSIONS: After bilateral removal of lower third molars, lower second molars awhile showed a tendency to move backwards, but no obvious relationship between the third molar and anterior crowding was observed. Whereas the observation time is short and the patient's age is young and it can not be concluded that lower third molars cause the changes in the dental arch.

Effect of cytokines on osteoclast formation and bone resorption during mechanical force loading of the periodontal membrane.

Mechanical force loading exerts important effects on the skeleton by controlling bone mass and strength. Several in vivo experimental models evaluating the effects of mechanical loading on bone metabolism have been reported. Orthodontic tooth movement is a useful model for understanding the mechanism of bone remodeling induced by mechanical loading. In a mouse model of orthodontic tooth movement, TNF-α was expressed and osteoclasts appeared on the compressed side of the periodontal ligament. In TNF-receptor-deficient mice, there was less tooth movement and osteoclast numbers were lower than in wild-type mice. These results suggest that osteoclast formation and bone resorption caused by loading forces on the periodontal ligament depend on TNF-α. Several cytokines are expressed in the periodontal ligament during orthodontic tooth movement. Studies have found that inflammatory cytokines such as IL-12 and IFN-γ strongly inhibit osteoclast formation and tooth movement. Blocking macrophage colony-stimulating factor by using anti-c-Fms antibody also inhibited osteoclast formation and tooth movement. In this review we describe and discuss the effect of cytokines in the periodontal ligament on osteoclast formation and bone resorption during mechanical force loading.

Characterization of periodontal structures of enamelin-null mice.

BACKGROUND: Enamelin-null (ENAM(-/-)) mice have no enamel. When characterizing ENAM(-/-) mice, alveolar bone height reduction was observed, and it was hypothesized that enamel defects combined with diet are associated with the periodontal changes of ENAM(-/-)mice. The aim of the present study is to compare the dimension of interradicular bone of ENAM(-/-) (knock-out [KO]) with wild-type (WT) mice, maintained on hard (HC) or soft (SC) chow. METHODS: A total of 100 animals divided into four groups were studied at 3, 8, and 24 weeks of age: 1) KO/HC; 2) KO/SC; 3) WT/HC; and 4) WT/SC. Microcomputed tomography was performed, and the following measurements were made between mandibular first (M1) and second (M2) molars: relative alveolar bone height (RBH), crestal bone width (CBW), bone volume (BV), bone mineral content (BMC), and bone mineral density (BMD). The position of M1 and M2 in relation to the inferior border of the mandible was also determined at 24 weeks. All variables were analyzed by one-way analysis of variance and Dunnett test for pairwise comparisons. Morphologic analyses were conducted on hematoxylin and eosin-stained sections. RESULTS: Radiographically, the enamel layer was absent in ENAM(-/-) mice. Interproximal open contacts were observed exclusively in ENAM(-/-) mice, and the prevalence decreased over time, suggesting that a shifting of tooth position had occurred. Additionally, in the two ENAM(-/-) groups, RBH was significantly lower at 8 and 24 weeks (P <0.02); CBW, BV, and BMC were significantly less (P <0.05) at 24 weeks. No differences in BMD were found among the four groups. The molars migrated to a more coronal position in ENAM(-/-) mice and mice on HC. Histologic findings were consistent with radiographic observations. After eruption, the junctional epithelium was less organized in ENAM(-/-) mice. CONCLUSION: The interdental bone density was not affected in the absence of enamelin, but its volume was, which is likely a consequence of alternations in tooth position.

Lifelong craniofacial growth and the implications for osseointegrated implants.

PURPOSE: The sequence of observations presented is intended to alert the dental profession to complications that may occur when teeth and implants co-exist and subtle adult craniofacial growth occurs. MATERIALS AND METHODS: The authors' observations of partially edentulous implant restorations with more than 20 years of follow-up included some observed changes relative to patients' remaining teeth and jaw structures. These changes, which were not easily explained and appeared to be random deviations from expected implant-restorative stability, conformed with research findings of craniofacial growth continuing into adulthood. The authors identified several distinct areas in which such adult craniofacial growth could potentially influence the relationship of implant restorations to the remaining teeth and jaw structure. RESULTS: Potential esthetic, occlusal, and periodontal ramifications of continued adult craniofacial growth were found to include changes in occlusion, opened contact as a result of teeth migration, and changes in anterior esthetic results. The latter may include labialization of the anterior implant restoration and a progressive discrepancy of the cervical gingival margin of the implant restoration relative to the adjacent teeth. Cases are presented showing poor sequellae of treatment due to growth occurring after the assumption was made that a stable jaw dimension had been reached. While continued adult craniofacial growth sufficient to cause clinical problems is not common, it is also presently not predictable. CONCLUSION: When changes in tooth position relative to implant restorations secondary to long-term adult growth occur, they can cause problems that are difficult or even impossible to correct. Future research will ideally enable identification of patients at risk for developing such problems.

Changes in molar position associated with missing opposed and/or adjacent tooth: a 12-year study in women.

The aim of this study was to radiographically analyse long-term changes in (i) overeruption of unopposed molars and (ii) tipping of molars with a mesial edentulous space, and whether there is an interaction between the two events. A further aim was to analyse if loss of alveolar bone height might influence overeruption and tipping. The sample consisted of panoramic radiographs taken at an interval of 12 years of 292 subjects from a prospective population study of women. The panoramic radiographs were scanned and analysed. Changes in tipping, overeruption and alveolar bone height of molars and control teeth were measured. The results showed that unopposed molars were more commonly found in the upper jaw and that unopposed molars showed 4·9 times higher risk of overeruption of ≥2 mm (95% CI 1·5-15·3) than opposed molars during the 12-year observation period. The average overeruption for the unopposed molars was 4·5% (s.d. 7·6), which corresponds to approximately 0·9 mm. The degree of overeruption increased with decreased bone support. Molars with a mesial edentulous space were most prevalent in the lower jaw, but neither an edentulous space nor alveolar bone level/bone level change were found to have a significant effect on tipping of the molars. The average mesial tipping was 0·8° (s.d. 5·6). In conclusion, unopposed molars showed a significantly increased risk for overeruption. Molars facing a mesial edentulous space showed a low risk for mesial tipping, but a significant interaction between overeruption and tipping was identified.

Gaining adequate interdental space with elastic separating rings against implants: a case series.

BACKGROUND: It is clinically challenging to place and restore an implant when the mesio-distal space is limited or reduced at the occlusal plane and/or the bone level. Placing implants in these cases while ignoring the clinical difficulties and compromising treatment could limit the successful outcome. Treatment options include strategic extractions, sectional orthodontics, and minor orthodontic movements. PURPOSE: To discuss the clinical problems and difficulties arising from limited edentulous mesio-distal space interdentally and to present a treatment modality and technique. MATERIALS AND METHODS: Orthodontic elastic separating rings are used to open interdental space between teeth and implants, exerting forces against implants for regaining the needed space and restoring implants with ease. RESULTS: The advantages of this technique are illustrated by clinical cases. CONCLUSIONS: Implants placed in limited interdental edentulous ridges may well assist in regaining lost spaces after loading. Neither an orthodontic background nor special instruments are required for this technique.

Effects of relaxin on relapse and periodontal tissue remodeling after experimental tooth movement in rats.

The relapse of teeth that have moved during orthodontic treatment is a major clinical issue with respect to the goals of successful treatment. Relaxin has an influence on many physiologic processes, such as collagen turnover. In this study, we determined the effects of relaxin on the relapse and remodeling of periodontal tissue after experimental tooth movement in rats, and we explored the molecular mechanism underlying these processes. To induce experimental tooth movement in rats, 10 g of orthodontic force was applied to the molars. After 14 days, the spring was removed, and then animals began receiving relaxin at a dose of 500 ng/ml for 1 week. The results were evaluated by micro-computed tomography and immunofluorescence staining. In addition, the effects of matrix metalloproteinase (MMP)-1 and MMP-8 production were investigated in human periodontal ligament (hPDL) cells in vitro. The expression of MMP-1 and MMP-8 was analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Furthermore, we demonstrated the signaling pathways involved in relaxin-regulated MMPs expression. The relapse distances and percentages were significantly decreased in the experimental group compared with the controls in vivo. A double-immunofluorescence analysis for Col-I/MMP-1 and Col-I/MMP-8 detected the expression of relaxin in the PDL. Relaxin significantly increased the MMP-1 and MMP-8 expression in a time-dependent manner in hPDL cells in vitro. Furthermore, a p38 inhibitor (SB203580) significantly inhibited the MMP-1 and MMP-8 expression. Our results indicated that relaxin modulates the collagen metabolism, and this hormone may therefore be useful to prevent orthodontic relapse following orthodontic treatment.

A study on clinical attachment loss and gingival inflammation as etiologic factors in pathologic tooth migration.

BACKGROUND: Several etiologic factors have been listed for pathologic migration of periodontally involved teeth based mainly on clinical observations with scarce scientific evidence. Present study was carried out to find out relationship of clinical attachment loss and gingival inflammation with pathologic tooth migration. MATERIALS AND METHODS: A total of 37 patients having 50 pairs of migrated and non-migrated contralateral teeth were taken into consideration. RESULTS: Mean total attachment loss per tooth in migrated and non migrated tooth is 13.32 ± 0.74 S.E. and 8.34 ± 0.58 S.E., respectively (P < 0.001), which reveals a positive correlation. There seems to be an association between frequency of migration and severity of attachment loss since highest percentage of migrations were seen in maximum total attachment loss group. Relationship could not be established between severity of attachment loss and severity of migration for which more data may be required. Also, it was seen that gingival index was significantly higher in migrated group. CONCLUSION: Findings suggest that there exists a direct relationship between pathologic migration and clinical attachment loss as well as gingival inflammation. CLINICAL RELEVANCE: Results emphasize the importance of early treatment of periodontitis to curb inflammation, which seems to be more important since it is completely reversible, and attachment loss also in order to prevent unaesthetic complications. Moreover bleeding along with recent change in position of teeth should be considered as important sign of active, moderate to severe periodontal disease by general dentists and hygienists so that they can refer for specialist consultation.

Osteopontin is required for unloading-induced osteoclast recruitment and modulation of RANKL expression during tooth drift-associated bone remodeling, but not for super-eruption.

Unloading of teeth results in extensive alveolar bone remodeling, causing teeth to move in both vertical ("super-eruption") and horizontal direction ("drift"). In order to decipher the molecular mechanisms of unloading-induced bone remodeling during tooth movement, we focused on the role of osteopontin (OPN) in the un-opposed molar model, comparing wild-type (WT) and OPN-null mice. Our data indicated that OPN was not required for the continuous eruption of un-opposed teeth while OPN was necessary for the drift of teeth. OPN expression and osteoclast counts were greatly increased on alveolar bone surfaces facing the direction of the drift in WT mice, while osteoclast counts were diminished in OPN-/- mice. RANKL expression in the distal periodontal ligament of WT molars increased significantly by day 6 following unloading, while overall levels of RANKL expression were decreased in both WT and OPN-null mice. In vitro treatment of MC3T3 cells, WT BMCs and OPN-/- BMCs with recombinant OPN resulted in significantly increased RANKL expression in all three cell types. The PI3K and MEK/ERK pathway inhibitors Ly294002 and U0126 reduced RANKL expression levels in vitro. Treatment of BMCs and MC3T3 with OPN also resulted in increased ERK phosphorylation and reduced OPG levels. Together, our studies suggest that increased OPN expression during unloading-induced drifting of teeth enhances localized RANKL expression and osteoclast activity on drift-direction alveolar bone surfaces via extracellular matrix signaling pathways.

Dentoalveolar changes after unilateral extractions of mandibular first molars and their influence on third molar development and position.

AIM: To investigate the spontaneous tooth position changes after unilateral extraction of mandibular first molars and the influence on third molar position. METHODS: Panoramic radiographs of 111 individuals (mean age 19 years 8 months) in whom one mandibular first molar was extracted at least 5 years prior. Comparison of all measurements of the control and the affected side was performed by paired Student t test. RESULTS: The mandibular second molars tipped mesially, whereas the premolars, canines, and incisors moved distally toward the extraction space. Vertical alveolar resorption was significant, particularly in older patients. Mesial inclination of the third molar occurred in only subjects in whom this tooth was completely developed. No significant vertical change of the third molars was observed. CONCLUSION: Unilateral extraction of mandibular first molars causes a significant displacement of all teeth of the affected side toward the extraction site and a progressive vertical bone resorption of this area. The closer the teeth are to the extraction site, the more they are affected. No significant changes were observed on third molar vertical position.

Periodontal ligament remodeling and alveolar bone resorption during orthodontic tooth movement in rats with diabetes.

BACKGROUND: Pathological displacement of teeth caused by periodontitis-related bone loss in patients with diabetes is often corrected with orthodontic treatments. However, recovery from orthodontic therapy is often delayed for unclear reasons. This study explored effects of streptozotocin-induced diabetes in rats on protein expression involved in remodeling of the periodontal ligament (PDL) and alveolar bone during orthodontic tooth movement. METHODS: Forty-eight Sprague-Dawley rats were randomly divided into two experimental groups: "normal" and "diabetes" (n = 24 each). Diabetes was induced by a single dose of streptozotocin (65 mg/kg). Animals were euthanized at 3, 7, and 14 days after orthodontic induction. Changes in expression of collagen type I (Col-I), matrix metalloproteinase type 1 (MMP-1), and tissue inhibitor of MMP-1 (TIMP-1) were measured immunohistochemically in the pressure side. Col-I and collagen type III (Col-III) fibers were assessed by picrosirius red staining in the tension side. Osteoclasts were observed on the surface of the alveolar bone. RESULTS: Diabetes increased expression of MMP-1 and Col-III and decreased expression of Col-I in PDL. After the orthodontic induction, osteoclast action was delayed, and higher Col-III/Col-I and MMP-1/TIMP-1 ratios persisted in the diabetes group compared with the normal group. The ratio of MMP-1/TIMP-1 in the diabetes group reached a peak on Day 7, whereas the ratio remained at near control levels in the normal group. The diabetes group appeared to have worse recovery from damage caused by orthodontic movement. CONCLUSIONS: Under mechanical forces, diabetes prolonged duration of degradation of PDL and remodeling of PDL and resorption of alveolar bone.