Kraniofacijalni rast u adolescenciji i utjecaj na zbijenost mandibularnih sjekutića

Background: To analyze craniofacial growth during adolescence from the ages of 12 to 21 years and its relation to late mandibular incisor crowding. Methods: The study included 61 orthodontically untreated subjects (49% males). Lateral cephalograms were used to assess the jaw growth and inclination of the incisors. Little’s Irregularity Index and the anterior mandibular dental arch depth of mandibular dentition were measured. Results: A reduction of the skeletal class angle (ANB) was observed in both genders, although it was significant only in males (η2=0.188; p=0.015). The growth of the mandible was more prominent compared to that of the maxilla, and it was more prominent in males than in females. The skeletal vertical dimension, however, demonstrated a significant reduction in both genders (η2=0.527-0.593, p<0.001). The mandibular incisors tended to retrocline in both genders, while the maxillary ones tended to procline in males, and slightly retrocline in females. A decrease in the mandibular dental arch depth occurred in both genders (η2=0.259; p<0.05). An increase in the irregularity of incisors for 1.8±1.7 mm on average (95% CI 1.3-2.2; η2=0.520; p<0.001) was observed in both genders. A logistic regression revealed that less sagittal growth of maxilla (increase of SNA angle ≤2°) and reduction of convexity in skeletal sagittal interjaw relationship (reduction of ANB ≥1°) were significant predictors of the occurrence of crowding (Δ Little Irregularity Index ≥1mm) yielding odds ratios of 4.9 and 4.8. Conclusions: The differential growth of the maxilla and mandible is related to the occurrence of late crowding, mostly in smaller amounts in maxillary sagittal growth compared to the mandible.Cilj: Analizirati kraniofacijalni rast tijekom adolescencije u dobi od 12. do 21. godine i njegovu povezanost s kasnom zbijenošću mandibularnih sjekutića.Metode: U studiji je sudjelovao 61 ortodontski netretirani ispitanik (49 % muškaraca). Za procjenu rasta čeljusti i nagiba sjekutića korišteni je laterolateralni kefalogram. Izmjereni su Littleov indeks nepravilnosti i prednja dužina donjega zubnog luka.Rezultati: Uočeno je smanjenje kuta skeletne klase (ANB) kod oba spola, iako značajno samo kod muškaraca (η2 = 0,188; p = 0,015). Mandibula je rasla više od maksile i to više kod muškaraca negoli kod žena. No, skeletna vertikalna dimenzija pokazala je značajno smanjenje u oba spola (η2 = 0,527 – 0,593, p < 0,001). Mandibularni sjekutići imali su tendenciju retroinklinacije u oba spola, a maksilarni su bili skloni proklinaciji kod muškaraca te blažoj retroinklinaciji kod žena. Primijećeno je smanjenje prednje dužine donjega zubnog luka u oba spola (η2 = 0,259; p < 0,05). Povećanje nepravilnosti sjekutića u prosjeku je iznosilo 1,8 ± 1,7 mm (95 % CI 1,3 – 2,2; η2 = 0,520; p < 0,001), a uočeno je u oba spola. Logistička regresija otkrila je da su manji sagitalni rast maksile (povećanje kuta SNA ≤ 2°) i smanjenje konveksiteta sagitalnoga međučeljusnog odnosa (smanjenje ANB ≥ 1°) bili značajni prediktori nastanka zbijenosti (Δ Littleov indeks nepravilnosti ≥ 1 mm) dajući omjere izgleda od 4,9 i 4,8. Zaključci: Diferencijalni rast maksile i mandibule povezan je s pojavom kasne zbijenosti mandibularnih sjekutića uglavnom zbog manje količine sagitalnoga rasta maksile u odnosu na mandibulu

Mandibular second molar extraction: A retrospective cohort study of spontaneous occlusal changes in adolescent patients.

OBJECTIVES Evaluate long-term spontaneous occlusal changes following L7 extraction in adolescent patients. MATERIALS AND METHODS Study models of 144 participants (63 males, 81 females) retrospectively assessed prior to L7 extraction (9-16 years old; T1) and following L8 eruption (14-25 years old; T2). All received upper fixed appliances. A sub-group (n = 86) received no lower fixed appliances and acted as controls. Occlusal changes were compared between treatment (lower fixed appliance) and control (no lower fixed appliance) groups using PAR index. At T2, L8 occlusal outcome was assessed using ABO grading system. RESULTS Mean follow-up period 6 (SD 2) years. At T1, lower scores observed in control group for Lower Anterior (P < .001), Midline (P = .033) and Lateral Segments (P = .040) components. At T2, lower scores continued being observed in control group for Midline (P < .001) and Lateral segment (P = .019) components. Higher decrease in Lower Anterior PAR scores observed in treatment group (<.001) with comparable scores between groups at T2 (P = .057). Similar PAR score changes between groups for Lateral Segments, Overjet and Overbite components. At T2, no significant difference observed in Total PAR score reduction between control (83%) and treatment (82%) groups. Good-to-acceptable occlusal outcome of the L8 observed in 81.55% of cases at T2 with no difference between groups. CONCLUSION In growing patients with mild mandibular crowding, extraction of L7 followed by upper fixed appliance therapy, leads to favourable occlusal changes over a 6-year follow-up period, with or without lower fixed appliance therapy, being an alternative extraction protocol where lower fixed appliance therapy is not recommended

Long-term influence of fixed lingual retainers on the development of gingival recession: A retrospective, longitudinal cohort study

Objective: To investigate the long-term influence of fixed lingual retainers on the development of mandibular gingival recession and to compare the prevalence with untreated individuals. Materials and Methods: The material consisted of 144 subjects: 96 orthodontically treated patients followed for 5 years after therapy and 48 untreated age-matched subjects. The treated patients were divided in two groups: one receiving a fixed mandibular retainer (n = 48) and one receiving no form of retention in the mandible (n = 48). The presence or absence of gingival recession and calculus accumulation were scored before treatment (T0), after debonding (T1), and 5 years after debonding (T5) for each tooth in the mandibular intercanine region using plaster models and intraoral photographs. The chi-square test, one-way ANOVA, and Cochran's Q test were used to evaluate inter- and intragroup differences. Results: The prevalence of patients with recession increased gradually and significantly throughout the observation periods in all groups, but the intergroup differences at T5 were not significant. Significantly more calculus accumulation was observed at T5 in the retainer group compared with the group without retainers. Conclusions: Long-term presence of fixed lingual retainers does not seem to increase the development of mandibular gingival recession, but does increase calculus accumulation. © 2017 by The EH Angle Education and Research Foundation, Inc

Torque differences due to the material variation of the orthodontic appliance: a finite element study

BACKGROUND: Torque of the maxillary incisors is crucial to occlusal relationship and esthetics and can be influenced by many factors. The aim of this study was to assess the relative influence of the material of the orthodontic appliance (adhesive, bracket, ligature, and wire) on tooth displacements and developed stresses/strains after torque application. METHODS: A three-dimensional upper right central incisor with its periodontal ligament (PDL) and alveolus was modeled. A 0.018-in. slot discovery® (Dentaurum, Ispringen, Germany) bracket with a rectangular 0.018 x 0.025-in. wire was generated. The orthodontic appliance varied in the material of its components: adhesive (composite resin or resin-modified glass ionomer cement), bracket (titanium, steel, or ceramic), wire (beta-titanium or steel), and ligature (elastomeric or steel). A total of 24 models were generated, and a palatal root torque of 5° was applied. Afterwards, crown and apex displacement, strains in the PDL, and stresses in the bracket were calculated and analyzed. RESULTS: The labial crown displacement and the palatal root displacement of the tooth were mainly influenced by the material of the wire (up to 150% variation), followed by the material of the bracket (up to 19% variation). The magnitude of strains developed in the PDL was primarily influenced by the material of the wire (up to 127% variation), followed by the material of the bracket (up to 30% variation) and the ligature (up to 13% variation). Finally, stresses developed at the bracket were mainly influenced by the material of the wire (up to 118% variation) and the bracket (up to 59% variation). CONCLUSIONS: The material properties of the orthodontic appliance and all its components should be considered during torque application. However, these in silico results need to be validated in vivo before they can be clinically extrapolated

Survey on retention procedures and use of thermoplastic retainers among orthodontists in Norway, Sweden, and Denmark

Background Orthodontic retention is the most important factor after successful orthodontic treatment. The use of thermoplastic retainers has increased in recent years, but information is lacking about the product materials and orthodontists’ awareness of the products they use. The aim of this survey was to map the retention protocols among Scandinavian orthodontists, particularly their use of thermoplastic retainers. Furthermore, the aim was to investigate their knowledge of thermoplastic materials and record any possible adverse effects. Methods An online questionnaire was prepared, and 667 orthodontists in Norway, Sweden, and Denmark were invited to take the survey. The survey was sent to all members of the national orthodontic associations using Nettskjema in Norway and Microsoft Forms in Sweden and Denmark. Data were collected anonymously and analyzed using chi-square and correlation coefficients. Results Of the 667 orthodontists, 432 (64%) responded (59% female). The most common retention protocol (51%) was fixed retainer in both maxilla and mandible and thermoplastic retainer in the maxilla. Two-thirds of the orthodontists were unaware of the thermoplastic material used, and 58% did not acquire knowledge of the materials. Only 1% of the respondents had registered adverse reactions to thermoplastic retainers, and none were aware of the type of material that was used. Conclusions Scandinavian orthodontists use similar retention protocols, with the most common being fixed retainer in the mandible and dual retention, fixed, and thermoplastic retainer in the maxilla. Orthodontists’ knowledge about thermoplastic materials was insufficient, but adverse effects related to thermoplastic retainer use were rare

Occlusal outcome after orthodontic treatment with preadjusted straight-wire and standard edgewise appliances A retrospective cohort study

Abstract Purpose Orthodontic fixed appliances have been proven to be effective in treating a wide variety of malocclusions, and different types of appliances have emerged during recent decades. However, the comparative effects of different appliances have not been adequately assessed. Thus, the aim was to assess the occlusal outcome of orthodontic treatment with preadjusted straight-wire (SWIRE) and standard edgewise (SEDGE) appliances. Methods In all, 56 patients (mean age: 13.5 years; 45% male) receiving extraction-based treatment with either SWIRE or SEDGE appliances were included. Between-group differences in the occlusal outcome assessed with the American Board of Orthodontists Objective Grading System (ABO-OGS) and treatment duration were analyzed statistically at the 5% level. Results The average ABO-OGS score was 31.3 ± 7.2 points and 34.0 ± 10.4 points in the SWIRE and SEDGE groups with no statistically significant difference between groups ( P  = 0.26). Treatment duration was significantly shorter in the SWIRE group compared to the SEDGE group, with an average difference of −6.8 months (95% confidence interval [95% CI] = −9.6 to −4.0 months; P  &lt; 0.001). Likewise, fewer visits were needed with SWIRE compared to SEDGE appliances with an average difference of −7.2 visits (95% CI = −10.3 to −4.2 visits; P  &lt; 0.001). Adjusting for the influence of any potential confounders did not considerably impact the results. Conclusion Similar treatment outcomes were observed after premolar extraction treatment with SWIRE and SEDGE appliances. On the other hand, SEDGE appliances were associated with prolonged treatment duration and more visits needed to complete treatment compared to SWIRE appliances

Patient-Reported Outcome Measures on Oral Hygiene, Periodontal Health, and Treatment Satisfaction of Orthodontic Retention Patients up to Ten Years after Treatment&mdash;A Cross-Sectional Study

Background: This cross-sectional study evaluated patient-reported outcome measures (PROMs) on (1) oral hygiene, (2) periodontal health, (3) retainer failure, (4) orthodontic treatment satisfaction, and (5) outcome satisfaction in orthodontic retention patients. The purpose of the study was to evaluate whether orthodontic retention treatment is associated with patient-reported outcome measures on oral hygiene, periodontal health, and treatment satisfaction. Methods: A ten-item questionnaire on the five PROMs was conducted among 211 consecutive retention patients up to ten years following orthodontic treatment. Linear regression models were computed to detect possible associations between the PROMs and retention treatment or patient characteristics. Results: The presence of a fixed lingual retainer was not associated with the reduced ability to perform oral hygiene, self-perceived periodontal health, or orthodontic outcome satisfaction. Older patients were more content with the orthodontic treatment result (p &lt; 0.05). Patients with fixed lingual retainers in the mandible were less satisfied with the course of orthodontic treatment (p &lt; 0.05). Smokers more often reported gingival bleeding (p &lt; 0.05). Females reported increased gingival recessions (p &lt; 0.05) and perceived their teeth as longer than before treatment (p &lt; 0.05). Longer orthodontic treatment duration corresponded to retainer failure (p &lt; 0.05). Conclusions: In general, long-term orthodontic retention patients were satisfied with orthodontic treatment. These patients reported the satisfactory ability to perform adequate oral hygiene and periodontal health, and they communicated a high degree of treatment and outcome contentment. However, patients with a retainer in the mandible were less satisfied with orthodontic treatment

The Biological Background of Relapse of Orthodontic Tooth Movement

Recent years have shown increased interest and research activity in retention procedures, and a number of clinical trials have tested retainer wear and effectiveness. In contrast, published data on the biological basis of relapse after a successful course of orthodontic treatment are still scarce. The majority of the studies on this issue are descriptive and led to the hypothesis that relapse is caused by the fibrous structures within the supporting tissues of the teeth. That would suggest that retention is needed until these structures are completely reorganized. However, there is considerable evidence that the rate of collagen turnover in the periodontal ligament is extremely fast, and that the gingival fibers, and especially the transseptal fibers, are remodeled rapidly. Therefore, it is concluded that collagen turnover is probably not the important factor in the etiology of relapse, and other extracellular matrix components may contribute significantly to this process. There is a definite need for more experimental and well‐designed clinical studies to elucidate the biological basis of relapse. This process will be time consuming, but only if the etiology has been unraveled, we will be able to design evidence‐based retention strategies

Occlusal outcome after orthodontic treatment with preadjusted straight-wire and standard edgewise appliances : A retrospective cohort study

PURPOSE Orthodontic fixed appliances have been proven to be effective in treating a wide variety of malocclusions, and different types of appliances have emerged during recent decades. However, the comparative effects of different appliances have not been adequately assessed. Thus, the aim was to assess the occlusal outcome of orthodontic treatment with preadjusted straight-wire (SWIRE) and standard edgewise (SEDGE) appliances. METHODS In all, 56 patients (mean age: 13.5 years; 45% male) receiving extraction-based treatment with either SWIRE or SEDGE appliances were included. Between-group differences in the occlusal outcome assessed with the American Board of Orthodontists Objective Grading System (ABO-OGS) and treatment duration were analyzed statistically at the 5% level. RESULTS The average ABO-OGS score was 31.3 ± 7.2 points and 34.0 ± 10.4 points in the SWIRE and SEDGE groups with no statistically significant difference between groups (P = 0.26). Treatment duration was significantly shorter in the SWIRE group compared to the SEDGE group, with an average difference of -6.8 months (95% confidence interval [95% CI] = -9.6 to -4.0 months; P < 0.001). Likewise, fewer visits were needed with SWIRE compared to SEDGE appliances with an average difference of -7.2 visits (95% CI = -10.3 to -4.2 visits; P < 0.001). Adjusting for the influence of any potential confounders did not considerably impact the results. CONCLUSION Similar treatment outcomes were observed after premolar extraction treatment with SWIRE and SEDGE appliances. On the other hand, SEDGE appliances were associated with prolonged treatment duration and more visits needed to complete treatment compared to SWIRE appliances

Incisor and profile alterations in extraction cases treated with standard Edgewise and pre-adjusted appliances: A controlled before-and-after study

BACKGROUND Even though treatment of Class II malocclusion with premolar extractions and incisor retraction might affect incisor inclination and soft tissue profile, the effects of bracket prescription on this have not been thoroughly assessed. METHODS Fifty patients (mean age: 13.6 years; 34% male) receiving extraction-based treatment with either standard Edgewise or pre-adjusted appliances were included. Between-group differences in the incisor inclination assessed with lateral cephalograms were analyzed statistically with linear/logistic regression at 5%. RESULTS Treatment-induced changes included retroclination of the upper/lower incisors (-3.0° and -2.0°, respectively), retraction of the upper/lower incisors (-3.4 mm and -1.5 mm, respectively), retraction of the upper/lower lip (-2.1 mm and -2.0 mm, respectively), and enlargement of the nasolabial angle (+1.6°). Analysis of the data adjusting for confounders indicated that the pre-adjusted group, after treatment, had larger inclination of the upper or lower incisors (+3.2° and +4.5°, respectively), more prominent upper incisors relative to the facial plane (+1.3 mm), and smaller interincisal angle (-7.3 or -7.7°). Post-treatment upper incisor inclination fell within the cephalometric norm significantly more in the pre-adjusted than in the standard Edgewise group (odds ratio 4.3; 95% confidence interval 1.1-16.6). No differences were found in lower incisor prominence, upper/lower lip prominence, or nasolabial angle. CONCLUSIONS Pre-adjusted appliances were associated with increased inclination of the upper and lower incisors, with more prominent upper incisors, and with more acute interincisal angle after retraction compared with standard Edgewise appliances. However, such differences did not translate in greater retraction of the upper/lower lips and greater nasolabial angle