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Purpose: The prevalence of gingival recession in orthodontically treated patients and the relative impact of retainer type on its occurrence remain poorly understood. The objective of this study was to investigate the association between previous orthodontic treatment and retainer type on the long-term prevalence of gingival recession and to evaluate the role of other patient-related factors, such as gender, age, smoking and gingival phenotype. Materials and Methods: We included subjects both with and without a history of previous orthodontics (at least 5 years post-treatment). The periodontal status assessment and the presence of gingival recession were recorded. A generalised estimating equation (GEE) logistic regression model was used to examine the effect of the mode of retention and tooth type on recession adjusted for age, smoking, gender and gingival phenotype. Results: A total of 251 individuals (mean age of 32 ± 9.43 years) were included. Ninety-nine (39.4%) had a history of orthodontics with an observation period of 15.7 years. Those undergoing orthodontics followed by fixed retention had the highest prevalence and magnitude of recession; a history of orthodontics was statistically associated with the occurrence of recession (odds ratio: 2.40; 95% CI: 1.52; 3.82; P 0.001). Both age and the presence of a thin gingival phenotype were significant predictors for recession (P 0.001). The adjusted probabilities of recession per tooth indicated that the mandibular central incisors had the highest probability for recession, with either a fixed or removable retainer. Conclusions: Based on this observational study, the provision of orthodontic treatment followed by removable or fixed retention had a bearing on the occurrence of recession. The aetiology of gingival recession is multifactorial with a thin periodontal phenotype, age and smoking history being risk factors, while mandibular central incisors are particularly susceptible. Keywords: gingival recession, periodontal disease, orthodontic retainers, orthodontics

Ziel: Unsere Studie hatte zum Ziel, die Therapieergebnisse von Klasse-II-Korrekturen unter Ver- wendung einer vollständig individuellen lingualen Apparatur in Verbindung mit der Herbst-­Apparatur mithilfe des Bewertungssystems des American Board of Orthodontics (ABO) qualitativ zu bewerten. Material und Methode: Die Kriterien der Patientenselektion für diese Studie lauteten: Klasse-II/1- oder -II/2-Fehlstellung, behandelt mit einer WIN-Lingualapparatur in Kombination mit einer L-Pin-Herbst-Apparatur. Insgesamt wurden 32 konsekutiv entbänderte Patienten in diese retro- spektive Fallserie inkludiert. Für die Datensammlung standen die Anfangs- und Abschlussmodelle, Set-ups, Panoramaschichtaufnahmen, Fernröntgenseitenanalysen, Fotografien und Patienten­karteien zur Verfügung. Primäre Ergebnisvariable war der ABO-Score, basierend auf dem Diskrepanzindex (Discrepancy Index, ABO-DI, mit horizontalem und vertikalem Überbiss, frontoffenem Biss, seitlich offenem Biss, Engstand, Bisslage [Angle-Klasse], lingualem und bukkalem lateralem Kreuzbiss sowie ANB-, IMPA und SN-GoGN-Winkeln) und auf der Modell- und Röntgenanalyse (Cast- Radiograph Evaluation, ABO CR-Eval, mit Einordnung/Drehständen, Randleisten, vestibulooraler Kippung, horizontalem Überbiss, Okklusionskontakten, Bisslage [Angle-Klasse], Approximalkontakten und Wurzelkippung). Zusätzlich wurden der horizontale und vertikale Überbiss sowie die Klasse-II-Korrektur anhand der Anfangs- und Abschlussmodelle bewertet. Sekundäre Ergebnisvariablen waren Bracketverlustraten und Komplikationen im Zusammenhang mit der Herbst-Apparatur. Ergebnisse: Die endgültige Studienkohorte umfasste 18 Patientinnen und 12 Patienten im Durchschnittsalter von 15,8 Jahren (von 12,6 bis 18,5 Jahren). Hiervon wiesen 20 Patienten eine ­Klasse-II/1- und 10 eine Klasse-II/2-Fehlstellung auf. Der mittlere Wert für den ABO-DI vor der Behandlung lag bei 20,8 (Spannweite: 10 bis 39). Bei mehr als zwei Dritteln der Patienten wurde die Schwierigkeit der Behandlung als moderat (ABO-DI 16 bis 24) oder hoch (ABO-DI über 25) bewertet. Der durchschnittliche ABO-CR-Eval-Wert nach der Behandlung betrug 15,0 (Standardabweichung [SD]: 4,4) und liegt deutlich unter dem Grenzwert des ABO. Bei 26 Patienten war der Wert ≤ 20 (dies gilt als vorbehaltlos bestanden). Die Klasse-II-Diskrepanz konnte wirksam korrigiert werden, von einem Wert von 16,83 Strafpunkten (SD: 3,65) vor auf einen Wert von 1,57 (SD: 1,70) nach der Behandlung. Ein Zusammenhang zwischen inititalem Schweregrad der Malokklusion und der Qualität des erzielten Ergebnisses fand sich nicht (p = 0,42), das heißt, schwierige und einfachere Anfangsbefunde wurden gleichermaßen erfolgreich korrigiert. Die mittlere Bracket-Verlustrate betrug 3,8 pro Patient. Komplikationen im Zusammenhang mit der Herbst-Apparatur waren mit 1,6 pro Patient selten, wobei die Mehrzahl sehr einfach zu behebende Komplikationen waren. Insgesamt hatten 43 % der Patienten gar keine Komplikationen mit der Herbst-Apparatur. Schlussfolgerung: Mit der in der vorliegenden Studie nachuntersuchten vollständig individuellen lingualen Apparatur in Kombination mit einer L-Pin-Herbst-Apparatur kann eine Klasse-II-­Korrektur wirksam durchgeführt werden, und dies unabhängig von der initialen sagittalen Diskrepanz. Der mittlere ABO-CR-Eval-Score der Patienten lag deutlich unterhalb der Akzeptanzgrenze (­vorbehaltlos bestanden) und verdeutlicht die hohe Qualität der Behandlungsergebnisse. Keywords: Linguale Apparatur, Herbst-Apparatur, American Board of Orthodontics (ABO), American Board of Orthodontics Objective Grading System, objektives Bewertungssystem, Klasse-II-­Korrektur, Behandlungsergebnisse

Objectives: To describe the step-by-step procedure of a novel surgical technique consisting of a combination of the laterally closed tunnel (LCT) and the modified coronally advanced tunnel (MCAT) (ie, LCT/MCAT), designed to treat multiple mandibular adjacent gingival recessions (MAGR) and to present the clinical outcomes obtained in 11 consecutively treated patients. Method and materials: Eleven systemically and periodontally healthy patients (7 females, mean ± SD 33.62 ± 14.6 years, min. 19 years max. 67 years) with a total of 40 adjacent mandibular RT1 (ie, Miller Class 1 and 2) gingival recessions with a minimum depth ≥ 3 mm, were consecutively treated with LCT/MCAT, in conjunction with an enamel matrix derivative (EMD) and subepithelial palatal connective tissue graft (SCTG). Treatment outcomes were assessed at baseline and at 12 months postoperatively. Prior to surgery and at 12 months postoperatively, recession depth (RD) and recession width (RW) were evaluated. The primary outcome variable was complete root coverage (CRC, ie 100% root coverage), the secondary outcome was mean root coverage (MRC). Results: Postoperative pain and discomfort were low and the healing was uneventful in all cases without any complications. At 12 months, statistically significant (P < .05) root coverage (RC) was obtained in all patients. CRC was obtained in five patients with a total of 21 recessions, while MRC measured 92.9% (ie, 3.75 mm). In seven patients (ie, 63.6%), RC amounted to > 93% while the minimum RC per patient measured 83.76%. Conclusion: The results of the present case series suggest that the LCT/MCAT is a valuable technique for the treatment of mandibular RT1 MAGR. Keywords: laterally closed tunnel, modified coronally advanced tunnel, multiple adjacent mandibular gingival recessions, recession coverage, subepithelial palatal connective tissue graft, surgical technique

Objective: Transgingival probing is often used in the clinic to assess gingival thickness. However, what is not completely known is how well this method represents the true value of soft tissue thickness. The aim of this study was to assess differences and variation in gingival thickness when measured with transgingival probing or scanned with an intraoral device. Method and materials: This ex vivo study evaluated gingival thickness on 20 porcine cadavers. Gingival thickness was assessed at both central and lateral mandibular incisors through transgingival probing with a standard metal periodontal probe and also using intraoral scanning, which was considered as the method providing the ‘true value’ of soft tissue thickness. Intra-examiner repeatability and method error were evaluated. Results: No evidence of systematic difference for any of the mandibular central or lateral incisors (mandibular right incisors: mean difference −0.17 to −0.01 mm, and mandibular left incisors: mean difference −0.11 to 0.04 mm) was observed between the periodontal probe and intraoral scanning methods. The absolute differences between the repeated measurements with intraoral scanning for each tooth type (n = 30) were calculated: the overall median was 0.089 mm and the interquartile range was 0.080 mm. Conclusions: Transgingival probing with a standard metal periodontal probe for assessing gingival thickness is a reliable method, with values very close to the true gingival thickness, and it can thus be considered as the clinical gold standard. Keywords: periodontal, scan, tooth anatomy

Purpose: To use and evaluate two methods for measuring gingival thickness (GT) at mandibular incisors of orthodontic patients and compare their performance in assessing periodontal anatomy through soft tissue thickness. Materials and Methods: The sample consisted of 40 consecutive adult orthodontic patients. GT was measured just before bracket placement at both central mandibular incisors, mid-facially on the buccal aspect, 2 mm apically to the free gingival margin with two methods: clinically with an ultrasound device (USD) and radiographically with cone-beam computed tomography (CBCT). Results: CBCT measurements were consistently higher than USD measurements, with the difference ranging from 0.13 mm to 0.21 mm. No statistically significant difference was noted between the repeated CBCT measurements at the right central incisor (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.104). Although the respective results for the left incisor statistically indicated that the measurements were not exactly replicated, the magnitude of the point estimate was small and not clinically significant (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014). Small differences between CBCT measurements made by the 2 examiners at the left central incisor (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014) were detected. However, this difference was minor and also not clinically significant. The respective analysis on the right incisor showed no statistically significant difference (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.246). Conclusions: Based on reproducibility, CBCT imaging for gingival thickness assessment proved to be as reliable as ultrasound determination. However, CBCT consistently yielded higher values, albeit at a marginal level, than did the ultrasound device. Keywords: cone-beam CT, gingival phenotype, periodontal tissue, ultrasound

Objectives: To evaluate the healing of multiple adjacent type 1 and 2 gingival recessions (RT1 and RT2) treated with the modified coronally advanced tunnel (MCAT) or the laterally closed tunnel (LCT) in conjunction with a cross-linked hyaluronic acid and subepithelial palatal connective tissue grafts. Method and materials: Fifteen healthy patients exhibiting multiple adjacent mandibular or maxillary RT1 and RT2 of a depth of ≥ 2 mm, were treated with the MCAT or LCT in conjunction with cross-linked hyaluronic acid and subepithelial palatal connective tissue grafts. Results were assessed at baseline and after a minimum of 6 months. The primary outcome variable was root coverage. Esthetic outcomes were evaluated on photographs using the root coverage esthetic score. Results: Postoperative pain and discomfort were low and no complications occurred. Data analyses were performed at patient level. After a mean follow-up of 17 ± 5.4 months, statistically significant root coverage was obtained in all 15 cases (P .0001). Complete root coverage was obtained in 3 out of 15 cases (20%). Root coverage amounted to > 95% in three patients, was between 90% and 95% in four patients, and reached 87.5% in another patient. In three further patients root coverage measured 75%, 77%, and 64.6%, respectively. Mean root coverage measured 85.1 ± 23.2%. Mean keratinized tissue width increased from 2.5 ± 1.0 mm to 3.7 ± 0.7 mm (P .0001) from baseline to follow-up, while mean probing depth showed no statistically significant changes (1.3 ± 0.5 mm vs 1.5 ± 0.5 mm). The mean root coverage esthetic score was 7.9 ± 1.9, while in the three cases exhibiting complete root coverage, a maximum root coverage esthetic score (10) was given for all treated teeth. Conclusion: Within their limits, the present results indicate that the described treatment approach may lead to predictable root coverage of multiple mandibular and maxillary RT1 and RT2. Keywords: connective tissue graft, hyaluronic acid, laterally closed tunnel, modified coronally advanced tunnel, multiple gingival recession

Objectives: To clinically evaluate the healing of mandibular Miller Class I and II isolated gingival recessions treated with the modified coronally advanced tunnel (MCAT) or laterally closed tunnel (LCT) combined with hyaluronic acid (HA) and subepithelial connective tissue graft (SCTG). Method and materials: Twelve healthy patients exhibiting one isolated mandibular Miller Class I or II (Cairo Class 1) gingival recession of a depth of ≥ 3 mm, were consecutively treated with the MCAT or LCT in conjunction with HA and SCTG. Treatment outcomes were assessed at baseline and at least 6 months postoperatively. The primary outcome variable was complete root coverage (CRC). Results: Postoperative pain and discomfort were low and no complications such as postoperative bleeding, allergic reactions, abscesses, or loss of SCTG occurred. After a mean follow-up of 18.9 ± 10 months, statistically significant (P .0001) root coverage was obtained in all 12 defects. CRC was measured in six out of the 12 cases (50%), four cases showed a root coverage of over 95%, while the remaining two cases reached 80% and 85%. Mean root coverage was 96.09%. Mean keratinized tissue width increased from 1.6 ± 0.8 mm to 4.9 ± 1.3 mm (P .0001) from baseline to follow-up, while mean probing depth showed no statistically significant changes (1.8 ± 0.9 mm vs 1.3 ± 0.5 mm). Conclusion: Within their limits, the present results indicate that the described treatment approach may lead to predictable root coverage of isolated mandibular Miller Class I and II (Cairo Class 1) gingival recessions. (Quintessence Int 2020;51:456–463; doi: 10.3290/j.qi.a44492) Keywords: connective tissue graft, gingival recession, hyaluronic acid, laterally closed tunnel, modified coronally advanced tunnel

Purpose: Gingival phenotype influences the outcomes of various dental procedures. The objective of the current study was to assess the agreement between various clinical and radiographic methods for evaluating gingival thickness. Materials and Methods: This ex-vivo study evaluated gingival thickness on 20 porcine cadavers. Gingival thickness was assessed at both central mandibular incisors with: a) trans-gingival probing with a standard periodontal probe (PB); b) trans-gingival probing with a stainless steel acupuncture needle (AN); c) ultrasound device (USD); and d) Cone Beam Computed Tomography (CBCT). Intra-examiner reproducibility and method error were also evaluated. Results: Trans-gingival measurements with the standard PB and the AN were found to be almost identical in gingival thickness assessment (mean GT 1.11 mm vs 1.14 mm for the left incisor and mean GT 1.12 mm vs 1.11 mm for the right incisor, respectively). USD and CBCT yielded values that were statistically significantly higher than AN. Both USD and CBCT values were higher than PB, but this difference was statistically significant only for the left central incisor. Finally, USD values exceeded CBCT measurements, but this difference was not statistically significant. There was no evidence of systematic differences between the repeated CBCT measurements (p = 0.06 for the left incisor and p = 0.55 for the right incisor). Conclusions: CBCT measurements proved to be highly repeatable and comparable to the USD measurements, while there were some indications that both CBCT and USD measurements were systematically higher than either PB or AN. Keywords: cone-beam computed tomography, gingival biotype, periodontal tissue, ultrasound

Purpose: This retrospective cohort study investigated the long-term effectiveness of one type of maxillary and 2 types of mandibular fixed lingual retainers. Materials and Methods: Eighty orthodontic patients in retention for 10-15 years were included. Irregularity index, intercanine width, overjet (OJ) and overbite (OB) were measured on plaster models at 3 occasions: (T1) pre-treatment, (T2) post-treatment and (T3) 10-15 years post-treatment. Analyses assessed the effect of the retainer type and time on mandibular irregularity, intercanine width and retainer failure. Results: In the mandible, the irregularity index increased (0.43 mm) between T2 and T3 for the 0.027" β-titanium (TMA) retainers bonded to canines only while it was stable (-0.02 mm) for the 0.016" x 0.022" braided stainless steel retainers (SS6) bonded to all six anterior teeth. The intercanine width was relatively stable in both groups during the entire observation period. In the maxilla, the irregularity index was stable between T2 and T3 (+0.07 mm). The intercanine width increased (+2.02 mm) during treatment T1-T2 and was stable (-0.02 mm) in the retention phase T2 to T3. Conclusions: In the mandible, SS6 retainers were slightly more effective in maintaining alignment compared to the TMA retainers. In the maxilla, the SS4 retainers without canine extensions were effective in maintaining alignment. All retainers were effective in maintaining the intercanine width. Keywords: adverse effects, effectiveness, efficiency, failures, fixed retainers, irregularity index, long-term retention, retention

Die Ergebnisse der Behandlung singulärer und multipler Gingivarezessionen der Miller-Klassen I und III an überkronten Oberkieferzähnen im ästhetischen Bereich mit der modifizierten Tunneltechnik wurden klinisch untersucht. Acht allgemeinmedizinisch gesunde Patienten (davon fünf Frauen) mit insgesamt 23 singulären oder multiplen Gingivarezessionen der Miller-Klassen I und III wurden konsekutiv mit der modifizierten Tunneltechnik in Kombination mit einem subepithelialen Bindegewebstransplantat behandelt. Von den 23 Rezessionen entfielen 16 auf die Miller-Klasse I und sieben auf die Miller-Klasse III. Jeder Patient wies mindestens eine faziale Rezession an einem überkronten Zahn im ästhetischen Bereich des Oberkiefers auf. Die faziale Rezession war in allen Fällen mit einer ästhetischen Beeinträchtigung assoziiert. Klinische Parameter wurden zu Behandlungsbeginn (vor der chirurgischen Therapie) und 12 Monate post operationem erhoben. Hauptzielvariable war eine komplette, d. h. 100%ige Wurzeldeckung. Die Wundheilung verlief in allen Fällen komplikationslos. Sämtliche Patienten und Defekte zeigten 12 Monate post operationem eine statistisch hochsignifikante (p 0,0001) Wurzeldeckung. Eine komplette Wurzeldeckung wurde bei 22 der 23 Rezessionen erreicht (bei 16 Miller-Klasse-I- und bei sechs der sieben Miller-Klasse-III-Rezessionen). Eine einzige Miller-Klasse-III-Rezession wies eine Wurzeldeckung von 89,1 % auf. Durch die Behandlung konnten eine mittlere Wurzeldeckung von 92,62 % bzw. 3,75 mm und ein mittlerer Gewinn an keratinisiertem Gewebe von 0,62 ± 1,15 mm (p 0,05) erzielt werden. Die Ergebnisse dieser Fallserie zeigen, dass die modifizierte Tunneltechnik in Kombination mit einem subepithelialen Bindegewebstransplantat eine gute Option für die Behandlung singulärer und multipler Gingivarezessionen an überkronten Oberkieferzähnen im ästhetischen Bereich darstellt. Keywords: Überkronte Zähne, Gingivarezession, Miller-Klasse-I-Rezession, Miller-Klasse-III-Rezession, modifizierte Tunneltechnik, subepitheliales Bindegewebstransplantat