Orthodontic therapy and gingival recession: a systematic review

To perform a systematic review on the effect of changes in incisor inclination owing to orthodontic treatment and the occurrence of gingival recession. PubMed, EMBASE Excerpta Medica and CENTRAL of the Cochrane Library were searched and a hand search was performed. From 1925 articles identified, 17 articles were finally included: six experimental animal studies and 11 retrospective clinical studies in humans. More proclined teeth compared with less proclined teeth or untreated teeth had in most studies a higher occurrence or severity of gingival recession. Contradictory results were found regarding a possible statistically significant correlation between the extent of gingival recession and the amount of incisor proclination during treatment, width of attached gingiva, hygiene, periodontal condition or thickness of the symphysis. There are no high quality animal or clinical studies on this topic. Movement of the incisors out of the osseous envelope of the alveolar process may be associated with a higher tendency for developing gingival recessions. The amount of recession found in studies with statistically significant differences between proclined and non-proclined incisors is small and the clinical consequence questionable. Because of the low level of evidence of the included studies, the results should be considered with caution. Further randomized clinical studies including clinical examination of hygiene and gingival condition before, during and after treatment are needed to clarify the effect of orthodontic changes in incisor inclination and the occurrence of gingival recession.

Minimally invasive strabismus surgery (MISS) for inferior obliquus recession

PURPOSE: To present a novel, minimally invasive strabismus surgery (MISS) technique for inferior obliquus recessions. METHODS: Graded MISS inferior obliquus recessions were performed in 20 eyes of 15 patients by applying two small conjunctival cuts, one at the insertion of inferior obliquus and another where the scleral anchoring of the muscle occurred. RESULTS: The amount of recession was 12.2 +/- 2.3 mm (range 6 to 14 mm). The vertical deviation, which was measured in 25 degrees of adduction, decreased from preoperatively 12.8 degrees +/- 5.6 degrees to 2.7 degrees +/- 2.2 degrees (p < 0.0001) at 6 months. LogMAR visual acuity was preoperatively -0.10 +/- 0.17 and at 6 months -0.14 +/- 0.22 (p > 0.1). In one eye (2.5%) the two cuts had to be joined because of excessive bleeding. Binocular vision improved in eight patients, remained unchanged in six patients, and decreased from 30 to 60 arcsec in one patient (p > 0.1). Conjunctival and lid swelling were hardly visible on the first postoperative day in primary gaze position in 10/20 (50%) of eyes. Five of the eyes (25%) had mild and five (25%) moderate visibility of surgery. One patient out of 15 (7%) needed repeat surgery because of insufficient reduction of the sursoadduction within the first 6 months. The dose-effect relationship 6 months postoperatively for an accommodative near target at 25 degrees adduction was 0.83 degrees +/- 0.43 degrees per mm of recession. CONCLUSIONS: This study demonstrates that small-incision, minimal dissection inferior obliquus graded recessions are feasible and effective to improve ocular alignment in patients with strabismus sursoadductorius.

Comparison of a new, minimally invasive strabismus surgery technique with the usual limbal approach for rectus muscle recession and plication

AIM: To present a novel, minimally invasive strabismus surgery (MISS) technique for rectus muscle operations. METHODS: In this prospective study with a non-concurrent, retrospective comparison group, the first 20 consecutive patients treated with MISS were matched by age, diagnosis and muscles operated on, with 20 patients with a limbal opening operated on by the same surgeon at Kantonsspital, St Gallen, Switzerland. A total of 39 muscles were operated on. MISS is performed by applying two small radial cuts along the superior and inferior muscle margin. After muscle separation from surrounding tissue, a recession or plication is performed through the resulting tunnel. Alignment, binocular single vision, variations in vision, refraction, and number and types of complications during the first 6 postoperative months were registered. RESULTS: Visual acuity decreased at postoperative day 1 in both groups. The decrease was less pronounced in the group operated on with MISS (difference of decrease 0.14 logMAR, p<0.001). An abnormal lid swelling at day 1 was more frequent in the control group (21%, 95% confidence interval (CI) 9% to 41%, 5/24 v 0%, 95% CI 0 to 13%, 0/25, p<0.05). No significant difference was found for final alignment, binocular single vision, other visual acuities, refractive changes or complications (allergic reactions, dellen formation, abnormal conjuctival findings). A conversion to a limbal opening was necessary in 5% (95% CI 2% to 17%, 2/39) of muscles. CONCLUSIONS: This study shows that this new, small-incision, minimal dissection technique is feasible. The MISS technique seems to be superior in the direct postoperative period as better visual acuities and less lid swelling were observed. Long-term results did not differ in the two groups.

Gingival recession following apical surgery in the esthetic zone: a clinical study with 70 cases

The present study evaluated gingival recession 1 year following apical surgery of 70 maxillary anterior teeth (central and lateral incisors, canines, and first premolars). A visual assessment of the mid-facial aspect of the gingival level and of papillary heights of treated teeth was carried out using photographs taken at pre-treatment and 1-year follow-up appointments. In addition, changes in the gingival margin (GM) and clinical attachment levels (CAL) were calculated with the use of clinical measurements, that is, pre-treatment and 1-year follow-up pocket probing depth and level of gingival margin. Changes in GM and CAL were then correlated with patient-, tooth-, and surgery-related parameters. The following parameters were found to significantly influence changes in GM and CAL over time: gingival biotype (P < 0.05), with thin biotype exhibiting more gingival recession than thick biotype; pre-treatment pocket probing depth (PPD) (P < 0.03), with cases of pre-treatment PPD < 2.5 mm demonstrating more attachment loss than cases of PPD > or = 2.5 mm; and type of incision (P < 0.01), with the submarginal incision showing considerably less gingival recession compared with the intrasulcular incision, papilla-base incision or papilla-saving incision. The visual assessment using pre-treatment and 1-year follow-up photographs did not demonstrate significant changes in gingival level or papillary height after apical surgery. In conclusion, gingival biotype, pre-treatment PPD, and type of incision may significantly influence changes in GM and CAL following apical surgery in maxillary anterior teeth.

State of the science on controversial topics: orthodontic therapy and gingival recession (a report of the Angle Society of Europe 2013 meeting)

BACKGROUND Controversy exists in the literature between the role of orthodontic treatment and gingival recession. Whilst movement of teeth outside the alveolar bone has been reported as a risk factor for gingival recession, others have found no such association. FINDINGS The Angle Society of Europe devoted a study day to explore the evidence surrounding these controversies. The aim of the day was for a panel of experts to evaluate the current evidence base in relation to either the beneficial or detrimental effects of orthodontic treatment on the gingival tissue. CONCLUSIONS There remains a relatively weak evidence base for the role of orthodontic treatment and gingival recession and thus a need to undertake a risk assessment and appropriate consent prior to the commencement of treatment. In further prospective, well designed trials are needed.

Unconventional Monetary Policy and the Great Recession: Estimating the Macroeconomic Effects of a Spread Compression at the Zero Lower Bound

We explore the macroeconomic effects of a compression in the long-term bond yield spread within the context of the Great Recession of 2007–09 via a time-varying parameter structural VAR model. We identify a “pure” spread shock defined as a shock that leaves the policy rate unchanged, which allows us to characterize the macroeconomic consequences of a decline in the yield spread induced by central banks’ asset purchases within an environment in which the policy rate is constrained by the effective zero lower bound. Two key findings stand out. First, compressions in the long-term yield spread exert a powerful effect on both output growth and inflation. Second, conditional on available estimates of the impact of the Federal Reserve’s and the Bank of England’s asset purchase programs on long-term yield spreads, our counterfactual simulations suggest that U.S. and U.K. unconventional monetary policy actions have averted significant risks both of deflation and of output collapses comparable to those that took place during the Great Depression.

The loss of trust in the European Union during the great recession since 2007: The role of heuristics from the national political system

How can we explain the decline in support for the European Union (EU) and the idea of European integration after the onset of the great recession in the fall of 2007? Did the economic crisis and the austerity policies that the EU imposed—in tandem with the IMF—on several member countries help cause this drop? While there is some evidence for this direct effect of EU policies, we find that the most significant determinant of trust and support for the EU remains the level of trust in national governments. Based on cue theory and using concepts of diffuse and specific support, we find that support for the EU is derived from evaluations of national politics and policy, which Europeans know far better than the remote political system of the EU. This effect, however, is somewhat muted for those sophisticated Europeans that are more knowledgeable about the EU and are able to form opinions about it independently of the national contexts in which they live. We also find that the recent economic crisis has led to a discernible increase in the number of those who are disillusioned with politics both at the national and the supranational level. We analyze 133 national surveys from 27 EU countries by estimating a series of cross-classified multilevel logistic regression models.

Clinical and histologic evaluation of granular Beta-tricalcium phosphate for the treatment of human intrabony periodontal defects: a report on five cases

BACKGROUND: The aim of the study is to clinically and histologically evaluate the healing of advanced intrabony defects treated with open flap debridement and the adjunct implantation of granular beta tricalcium phosphate (beta-TCP). METHODS: Five patients, each displaying advanced combined 1- and 2-wall intrabony defects around teeth scheduled for extraction or root resection, were recruited. Approximately 6 months after surgery, the teeth or roots were removed together with a portion of their surrounding soft and hard tissues and processed for histologic evaluation. RESULTS: The mean probing depth (PD) was reduced from 10.8 +/- 2.3 mm presurgically to 4.6 +/- 2.1 mm, whereas a mean clinical attachment level (CAL) gain of 5.0 +/- 0.7 mm was observed. The increase in gingival recession was 1.2 +/- 3.2 mm. The histologic evaluation indicated the formation of new cellular cementum with inserting collagen fibers to a varying extent (mean: 1.9 +/- 0.7 mm; range: 1.2 to 3.03 mm) coronal to the most apical extent of the root instrumentation. The mean new bone formation was 1.0 +/- 0.7 mm (range: 0.0 to 1.9 mm). In most specimens, beta-TCP particles were embedded in the connective tissue, whereas the formation of a mineralized bone-like or cementum-like tissue around the particles was only occasionally observed. CONCLUSION: The present data indicates that treatment of intrabony periodontal defects with this beta-TCP may result in substantial clinical improvements such as PD reduction and CAL gain, but this beta-TCP does not seem to enhance the regeneration of cementum, periodontal ligament, and bone.

Oral health risks of tobacco use and effects of cessation

The purpose of this paper is to review the epidemiologic evidence for the effects of tobacco use and tobacco use cessation on a variety of oral diseases and conditions. Exposures considered include cigarette and bidi smoking, pipe and cigar smoking, and smokeless tobacco use. Oral diseases and disorders considered include oral cancer and precancer, periodontal disease, caries and tooth loss, gingival recession and other benign mucosal disorders as well as implant failure. Particular attention is given to the impact of tobacco use cessation on oral health outcomes. We conclude that robust epidemiologic evidence exists for adverse oral health effects of tobacco smoking and other types of tobacco use. In addition, there is compelling evidence to support significant benefits of tobacco use cessation with regard to various oral health outcomes. Substantial oral health benefits can be expected from abstention and successful smoking cessation in a variety of populations across all ages.

Clinical and radiographic evaluation of intrabony periodontal defect treatment by open flap debridement alone or in combination with nanocrystalline hydroxyapatite bone substitute

The aim of this study has been to compare the clinical and radiographic outcome of periodontal intrabony defect treatment by open flap debridement alone or in combination with nanocrystalline hydroxyapatite bone substitute application. Thirty patients diagnosed with advanced periodontits were divided into two groups: the control group (OFD), in which an open flap debridement procedure was performed and the test group (OFD+NHA), in which defects were additionally filled with nanocrystalline hydroxyapatite bone substitute material. Plaque index (PI), gingival index (GI), bleeding on probing (BOP), pocket depth (PD), gingival recession (GR) and clinical attachment level (CAL) were measured prior to, then 6 and 12months following treatment. Radiographic depth and width of defects were also evaluated. There were no differences in any clinical and radiographic parameters between the examined groups prior to treatment. After treatment, BOP, GI, PD, CAL, radiographic depth and width parameter values improved statistically significantly in both groups. The PI value did not change, but the GR value increased significantly after treatment. There were no statistical differences in evaluated parameters between OFD and OFD+NHA groups 6 and 12months after treatment. Within the limits of the study, it can be concluded that the additional use of nanocrystalline hydroxyapatite bone substitute material after open flap procedure does not improve clinical and radiographic treatment outcome.

Bovine pericardium based non-cross linked collagen matrix for successful root coverage, a clinical study in human

Introduction The aim of this study was to clinically assess the capacity of a novel bovine pericardium based, non-cross linked collagen matrix in root coverage. Methods 62 gingival recessions of Miller class I or II were treated. The matrix was adapted underneath a coronal repositioned split thickness flap. Clinical values were assessed at baseline and after six months. Results The mean recession in each patient was 2.2 mm at baseline. 6 Months after surgery 86.7% of the exposed root surfaces were covered. On average 0,3 mm of recession remained. The clinical attachment level changed from 3.5 ± 1.3 mm to 1,8 ( ± 0,7) mm during the observational time period. No statistically significant difference was found in the difference of probing depth. An increase in the width of gingiva was significant. With a baseline value of 1.5 ± 0.9 mm an improvement of 2.4 ± 0.8 mm after six month could be observed. 40 out of 62 recessions were considered a thin biotype at baseline. After 6 months all 62 sites were assessed thick. Conclusions The results demonstrate the capacity of the bovine pericardium based non-cross linked collagen matrix for successful root coverage. This material was able to enhance gingival thickness and the width of keratinized gingiva. The percentage of root coverage achieved thereby is comparable to existing techniques. This method might contribute to an increase of patient's comfort and an enhanced aesthetical outcome.

Four-year results following treatment of intrabony periodontal defects with an enamel matrix derivative alone or combined with a biphasic calcium phosphate

The aim of this study was to evaluate the 4-year clinical outcomes following regenerative surgery in intrabony defects with either EMD + BCP or EMD. Twenty-four patients with advanced chronic periodontitis, displaying one-, two-, or three-walled intrabony defect with a probing depth of at least 6 mm, were randomly treated with either EMD + BCP (test) or EMD alone (control). The following clinical parameters were evaluated at baseline, at 1 year and at 4 years after regenerative surgery: plaque index, gingival index, bleeding on probing, probing depth, gingival recession, and clinical attachment level (CAL). The primary outcome variable was CAL. No differences in any of the investigated parameters were observed at baseline between the two groups. The test group demonstrated a mean CAL change from from 10.8 ± 1.6 mm to 7.4 ± 1.6 mm (p < 0.001) and to 7.6 ± 1.7 mm (p < 0.001) at 1 and 4 years, respectively. In the control group, mean CAL changed from 10.4 ± 1.3 at baseline to 6.9 ± 1.0 mm (p < 0.001) at 1 year and 7.2 ± 1.2 mm (p < 0.001) at 4 years. At 4 years, two defects in the test group and three defects in the control group have lost 1 mm of the CAL gained at 1 year. Compared to baseline, at 4 years, a CAL gain of ≥3 mm was measured in 67% of the defects (i.e., in 8 out of 12) in the test group and in 75% of the defects (i.e., in 9 out of 12) in the control group. There were no statistically significant differences in any of the investigated parameters at 1 and at 4 years between the two groups. Within their limits, the present results indicate that: (a) the clinical improvements obtained with both treatments can be maintained over a period of 4 years, and (b) in two- and three-walled intrabony defects, the addition of BCP did not additionally improve the outcomes obtained with EMD alone. In two- and three-walled intrabony defects, the combination of EMD + BCP did not show any advantage over the use of EMD alone.

Severe complication of a bonded mandibular lingual retainer

Bonding a flexible spiral wire retainer to the lingual surfaces of all 6 anterior mandibular teeth is a commonly used type of retention. Complications are rare but can be serious enough to produce biologic damage. This article presents a serious complication of a lingual flexible spiral wire retainer. Four years after the orthodontic treatment, a 20-year-old man sought treatment for a broken flexible spiral wire retainer. The clinical examination showed about 35° of buccal root torque of that tooth. A cone-beam computed tomography image showed that the root and the apex of the tooth were almost completely out of the bone on its buccal side. Surprisingly, the tooth's vitality was preserved. The tooth was moved back, nearly to its original position; clinically, only a gingival recession remained. Orthodontists and dentists should be aware of possible complications of bonded retainers. Patients should be clearly informed how to detect problems at an early stage.