Pouzdanost kompjuterizovanih kefalometrijskih predviđanja rezultata hirurške korekcije mandibularnog prognatizma

Introduction. A successful treatment outcome in dentofacial deformity patients commonly requires combined orthodontic-surgical therapy. This enables us to overcome functional, aesthetic and psychological problems. Since most patients state aesthetics as the primary motive for seeking therapy, cephalometric predictions of treatment outcome have become the essential part of treatment planning, especially in combined orthodontic-surgical cases. Objective. The aim of this study was to evaluate the validity and reliability of computerized orthognathic surgery outcome predictions generated using the Nemotec Dental Studio NX 2005 software. Methods. The sample of the study consisted of 31 patients diagnosed with mandibular prognathism who were surgically treated at the Hospital for Maxillofacial Surgery in Belgrade. Investigation was done on lateral cephalograms made before and after surgical treatment. Cephalograms were digitized and analyzed using computer software. According to measurements made on superimposed pre- and postsurgical cephalograms, the patients were retreated within the software and the predictions were assessed by measuring seven angular and three linear parameters. Prediction measurements were then compared with the actual outcome. Results. Results showed statistically significant changes between posttreatment and predicted values for parameters referring to lower lip and mentolabial sulcus position. Conclusion. Computerized cephalometric predictions for hard-tissue structures in the sagittal and vertical planes, as well as the VTO parameters, generated using the Nemotec Dental Studio NX 2005 software are reliable, while lower lip and mentolabial sulcus position predictions are not reliable enough.Uvod. Radi postizanja što boljih krajnjih rezultata, osobe sa dentofacijalnim deformitetima najčešće se leče kombinovanom ortodontsko-hirurškom terapijom. Na taj način rešavaju se funkcionalni, estetski i psihološki problemi. Kako najveći broj pacijenata navodi estetsku promenu kao primarni motiv lečenja, kefalometrijsko predviđanje ishoda je važan deo planiranja terapije, posebno kod složenih slučajeva. Cilj rada. Cilj rada je bio da se proceni preciznost i pouzdanost predviđanja ishoda hirurške korekcije mandibularnog prognatizma razvijenih u okviru kompjuterskog softvera Nemotec Dental Studio NX 2005. Metode rada. Ispitan je 31 pacijent s mandibularnim prognatizmom koji je operisan na Klinici za maksilofacijalnu hirurgiju Stomatološkog fakulteta Univerziteta u Beogradu. Istraživanje je izvedeno na profilnim teleradiogramima snimljenim pre i posle hirurške intervencije. Nakon digitalizacije snimaka izvršena je kompjuterizovana kefalometrijska analiza. Na osnovu merenja određenih horizontalnih i vertikalnih rastojanja na preoperacionim i postoperacionim radiogramima, urađena je simulacija hirurških korekcija i na njima izmerena vrednost sedam angularnih parametara i tri linearna parametra, čija je vrednost upoređena s vrednostima na postoperacionim radiogramima. Rezultati. Ustanovljene su statistički značajne razlike između postoperacionih i predviđenih vrednosti za parametre koji govore o položaju donje usne i mentolabijalnog sulkusa. Zaključak. Kompjuterizovana kefalometrijska predviđanja položaja čvrstotkivnih struktura u sagitalnoj i vertikalnoj ravni, kao i VTO parametara, dobijena u okviru korišćenog programa su pouzdana, dok su predviđanja položaja donje usne i mentolabijalnog sulkusa nedovoljno pouzdana

Promene krivine vratne kičme i morfologije cervikalnih pršljenova u različitim uzrastima i mogućnost procene skeletne zrelosti

Introduction During growth, proportions of craniofacial and cervical structures are changed. Craniofacial and cervicovertebral structures are morphologically and functionally connected, but their each other's influence is still unknown. Objective The aim of this study was to determine the changes in cervical lordosis and cervicovertebral morphology in different age periods and the possibility of estimating skeletal maturity, based on the percentage of anterior cervical vertebrae body height sum in the total anterior C2-C5 height. Methods The study included lateral radiographs of 120 patients of both sexes, divided into three different age groups: eight, 12-13 and 17-18 years of age. Five craniofacial and 15 cervical parameters were measured and analyzed. Results The results showed significant correlation between cervical lordosis angle and age, gender, anterior and posterior body height of C3, C4, C5, anterior C4-C5 and posterior C2-C3, C3-C4, C4-C5 intervertebral space, anterior body height of C2-C5. Overall values of all cervical body heights were more present in the total height of the spine in females, while all intervertebral spaces were more present in males. The percentage of anterior and posterior C2, C3, C4, C5 body height sum compared to total C2-C5 height increases with age. Conclusion The cervical lordosis becomes more curved and vertebral bodies occupy more space in females, while intervertebral spaces occupy more in males. Skeletal maturity could be estimated following vertebral percentage distribution in the total anterior C2-C5 part.Uvod Tokom rasta proporcije kraniofacijalnih i cervikovertebralnih struktura se menjaju. Ove strukture su morfološki i funkcionalno povezane, ali je njihov međusobni uticaj i dalje nepoznat. Cilj rada Cilj ove studije je bio da se uoče promene krivine vratne kičme i morfologije vratnih pršljenova u različitim uzrasnim grupama, kao i mogućnost procene skeletne zrelosti zasnovane na procentualnoj zastupljenosti zbira prednjih visina vratnih pršljenova C2, C3, C4 i C5 u ukupnoj dužini prednje visine kičme od C2 do C5. Metode rada Studija je obuhvatila 120 ispitanika oba pola koji su svrstani u tri starosne grupe: 8, 12-13 i 17-18 godina. Pet kranijalnih i 15 cervikalnih parametara je mereno i analizirano. Rezultati Rezultati su pokazali statistički značajnu korelaciju između zakrivljenosti vratne kičme i godina, pola, prednje i zadnje visine tela pršljena C2, C3, C4, prednjeg C4-C5 i zadnjeg C2-C3, C3-C4, C4-C5 međupršljenskog prostora. Prosečne vrednosti visine tela vratnih pršljenova procentualno su bile češće kod ispitanica, a svi međupršljenski prostori kod osoba muškog pola. Procenat zbira prednje i zadnje visine pršljena C2, C3, C4 i C5 povećavao se sa godinama. Zaključak Krivina vratne kičme postaje zakrivljenija i tela pršljenova zauzimaju više prostora kod žena, a međupršljenski prostor više kod muškaraca. Procena skeletne zrelosti bi mogla da se prati na osnovu procentualne zastupljenosti visine tela pršljena u ukupnoj dužini prednjeg dela kičme (C2-C5)

Orthodontic treatment of nongrowing patient with class II division 2 malocclusion by Herbst appliance

Background. Inheritance is most casual etiological factor of Class II division 2 malocclusion. This kind of malocclusion is very difficult for treatment specially in older patients. Case report. In the female patient, 20 years old, at the beginning of the treatment at the School of Dentistry in Belgrade, lateral cephalogram showed skeletal and dentoalveolar Class II division 2 malocclusion. She was in the Herbst treatment for 8 months and 12 months more with a fixed multibracket appliance. The measurements were performed on lateral cephalograms before and after the treatment: ii, is, mi, ms, Pg and ss. The distance from these points to occlusal perpendicular line (Olp) were measured and compared from cephalogram before to cephalogram after the treatment. Temporomandibular joint (TMJ) tomograms were compared from before and after the treatment by superimposition. Correction was found in molar and incisor relation, overjet and overbite. There were found sagital skeletal changes and soft tissue profile improvement. Conclusion. Herbst appliance is effective in the treatment of Class II malocclusions, even in adult patients. Dental and skeletal changes as a result of Herbst treatment could be good choice instead of camouflage orthodontics or surgical decision

Bond strength of orthodontic adhesives

The objective of this study was to evaluate and compare bond strength of four adhesives used in orthodontics for bonding brackets to tooth enamel. The adhesives used in this investigation were resin-reinforced glass-ionomer cement (Fuji Ortho LC-GC Corporation, Japan), light cured composite resin adhesives (ConTec LC-Dentaurum, Germany and Enlight Bonding system-Ormco, USA) and dual cured composite resin adhesive (ConTec Duo-Dent aurum, Germany). A sample of 80 extracted human premolars was divided into four groups of 20 teeth which were etched with 37% phosphoric acid and bonded in dry field to enamel of buccal and lingual surfaces of the teeth with the same adhesive in one group. The debonding force was produced using universal Instron testing machine with cross head speed of 1mm/min and shear bond strength was measured. Statistical analysis used in this study included: Kolmogorov-Smirnov test i Shapiro-Wilk test, Mann Whitney test, Kruskal Wallis chi-squared test. Even though, all four adhesives showed sufficient bond strength for orthodontic bonding, ConTec LC and ConTec Duo displayed the superior bonding properties comparing to Enlight and Fuji Ortho LC.

Referentni geometrijski entiteti u ortodonciji na trodimenzionalnim modelima

3D modeling is often used in orthodontics. Most commonly used software today is problem- oriented CAD system (OrthoCAD and others), as well as general CAD software for engineering modeling. Both methods require definition and use of various geometric entities to describe and monitor orthodontic status, but still there have been more than one approach to definition of geometric entities that characterize orthodontic parameters. The aim of this study was to define the referent geometric entities (RGE) on 3D models, perform their classification and provide examples of their application. For defining and monitoring orthodontic parameters the following RGE groups are used: (a) basic geometric entities (point, line, straight line, plane, curve, curved surface); (b) derived geometric entities (coordinate origin, coordinate system, coordinate plane, axis, edge, perspective); and (c) anatomical geometric entities (surfaces, points). In this study, using 11 examples is shown how orthodontic parameters can be modeled over three classification groups RGE. Presented analysis and RGE examples indicate that RGE give interdisciplinary and systematic approach to computer modeling in orthodontics, and create a basis for development and implementation of methods of anatomical features in orthodontics which can be used to set up an integrated orthodontic parameter.Trodimenzionalno (3D) modeliranje u ortodonciji nalazi sve veću primenu. Danas se za ove namene koriste problemski orijentisani sistemi CAD (OrthoCAD i drugi), kao i opšti softveri CAD za inženjerska modeliranja. Oba načina zahtevaju definisanje i korišćenje različitih geometrijskih entiteta pomoću kojih se opisuju i prate ortodontska stanja, ali još nema jednoznačnog prilaza definisanju geometrijskih entiteta, odnosno definisanju ortodontskih parametara. Cilj ovog rada je bio da se definišu i klasifikuju referentni geometrijski entiteti (RGE) na 3D modelima, te navedu konkretni primeri primene. U ortodonciji se, radi definisanja i praćenja ortodontskih parametara, koriste sledeće grupe RGE: a) osnovni geometrijski entiteti (tačka, prava, duž, ravan, kriva linija, kriva površina); b) izvedeni geometrijski entiteti (koordinatni početak, koordinatni sistem, koordinatne ravni, osa, ivica, perspektiva); i c) anatomski geometrijski entiteti (površine, tačke). U radu je kroz 11 primera prikazano kako se preko tri klasifikacione grupe RGE mogu modelirati ortodontski parametri. Prikazana analiza i primeri RGE pokazuju da je RGE sistematičan i interdisciplinarni pristup kompjuterskom modeliranju u ortodonciji, odnosno da stvara osnove za definisanje i primenu metoda anatomskih odlika u ortodonciji, pomoću kojih se može postaviti integrisani ortodontski parametar

Procena saglasnosti i korelacija tri okluzalna indeksa u određivanju potrebe za ortodontskim lečenjem

Background/Aim. Occlusal indices are quantitative diagnostic indicators of malocclusion severity, orthodontic treatment need, complexity and outcome. The aim of this study was to determine correlations and agreement among three occlusal indices: the Index of Orthodontic Treatment Need (IOTN), the Peer Assessment Rating Index (PAR) and the Index of Complexity, Outcome and Need (ICON) in evaluating orthodontic treatment need. Methods. A total eighty study models of patients referred to the Department of Orthodontics, School of Dentistry, Belgrade, were assessed in this retrospective study. Malocclusions of various types and severity in the permanent dentition were included. Results. The Aesthetic and the Dental Health Component of IOTN determined orthodontic treatment need in 25% and 51% of the patients, respectively. PAR determined orthodontic treatment need in 59% and ICON in 53% of patients. The Aesthetic Component of IOTN and ICON had the highest correlation (Spearman's correlation coefficient 0.95, p lt 0.01). Correlations between indices were 0.44 to 0.61 with statistical significance (p lt 0.01). The agreement between indices, calculated using Kappa statistics, was 0.22 to 0.63. Conclusion. The most critical in malocclusion assessment was PAR. The Aesthetic Component of IOTN and ICON correlated highly (p lt 0.01). Correlations between other pairs of indices were moderate (p lt 0.01). The Aesthetic Component of IOTN and ICON had substantial agreement, whereas agreement between other indices was fair or moderate. ICON could replace PAR and IOTN. Application of occlusal indices enables objective evaluation of orthodontic treatment need and easier determination of the treatment priorities.Uvod/Cilj. Okluzalni indeksi su kvantitativni dijagnostički pokazatelji težine malokluzije, potrebe za ortodontskim lečenjem, složenosti i rezultata lečenja. Cilj rada bio je da se utvrde korelacije i saglasnost između tri okluzalna indeksa: Index of Orthodontic Treatment Need (IOTN), Peer Assessment Rating Index (PAR) i Index of Complexity, Outcome and Need (ICON) u pogledu određivanja potrebe za ortodontskim lečenjem. Metode. U retrospektivnom istraživanju ocenjeno je 80 studijskih modela bolesnika Klinike za ortopediju vilica Stomatološkog fakulteta u Beogradu. Obuhvaćene su malokluzije različitog tipa i težine u stalnoj denticiji. Rezultati. Potreba za ortodontskim lečenjem utvrđena je estetskim i zdravstvenim delom IOTN indeksa kod 25% i 51% bolesnika, redom. Na osnovu PAR indeksa potreba za ortodontskim lečenjem utvrđena je kod 59%, a na osnovu ICON indeksa kod 53% bolesnika. Estetski deo IOTN indeksa i ICON indeks imali su najveću korelaciju (Spearman-ov koeficijent korelacije 0,95; p lt 0,01). Korelacija među ostalim indeksima kretala se od 0,44 do 0,61 i bila je statistički značajna (p lt 0,01). Saglasnost među indeksima, izražena Kappa koeficijentom, kretala se od 0,22 do 0,63. Zaključak. Indeks PAR najkritičnije ocenjuje malokluzije. Korelacija između estetskog dela IOTN indeksa i ICON indeksa veoma je izražena i statistički značajna (p lt 0,01). Korelacije između ostalih parova okluzalnih indeksa srednje su izražene i statistički su značajne (p lt 0,01). Estetski deo IOTN indeksa i ICON indeks imaju odličnu saglasnost, dok je kod ostalih indeksa saglasnost dobra ili vrlo dobra. Indeks ICON mogao bi da zameni indekse PAR i IOTN. Primena okluzalnih indeksa omogućava objektivnu procenu potrebe za ortodontskim lečenjem i olakšava određivanje prioriteta u lečenju

Primena okluzivnih indeksa u ortodontskoj praksi

Introduction. Occlusal indices were designed to improve diagnostic criteria and to enable an objective assessment of malocclusion severity. The aim of this study was to present the most frequently used occlusal indices in orthodontic practice and to determine their reliability when applied to dental models. Material and Methods. Three occlusal indices were selected for analysis: the Index of Orthodontic Treatment Need (IOTN), the Peer Assessment Rating Index (PAR) and the Index of Complexity, Outcome and Need (ICON). Twenty dental models of patients referred to Department of Orthodontics, School of Dentistry, Belgrade, with malocclusions of different type and severity were used in this study. All dental models were measured by three afore mentioned indices twice, two months apart, in order to determine intraexaminer reliability. Results. The results showed that three indices had good reliability. Weighted Kappa was calculated for IOTN (0.72 and 0.79 for the aesthetic and the dental health component, respectively) and root mean square error was calculated for PAR and ICON (2.1 and 4.5, respectively). There was no statistically significant difference in scores between two measurements of these two indices (p lt 0.01). Conclusion. Application of occlusal indices enables orthodontists to determine priorities in patient care, planning of orthodontic service, monitoring and promotion of standards. Occlusal indices are reliable diagnostic criteria.Uvod. Okluzivni indeksi su uvedeni u praksu sa ciljem da se poboljšaju dijagnostički kriterijumi i omogući objektivna procena težine malokluzije. Cilj ovog rada je bio da se predstave najčešće korišćeni okluzivni indeksi u ortodontskoj praksi i utvrdi pouzdanost njihove primene na studijskim modelima. Materijal i metode rada. Za analizu su odabrana tri okluzivna indeksa: Index of Orthodontic Treatment Need (IOTN), Peer Assessment Rating (PAR) i Index of Complexity, Outcome and Need (ICON). U istraživanju je korišćeno 20 studijskih modela pacijenata Klinike za ortopediju vilica Stomatološkog fakulteta u Beogradu s malokluzijama različitog tipa i težine u stalnoj denticiji. Svi modeli su ocenjeni sa tri pomenuta indeksa dva puta u razmaku od dva meseca radi utvrđivanja pouzdanosti. Rezultati. Rezultati analize su pokazali da je pouzdanost sva tri indeksa bila dobra. Za IOTN pouzdanost je izražena koeficijentom kapa (0,72 za estetski i 0,79 zdravstveni deo indeksa), dok je za PAR i ICON izračunat koren srednje kvadratne greške (2,1 i 4,5). Nije bilo statistički značajne razlike u broju bodova između dva merenja ova dva indeksa (p lt 0,01). Zaključak. Primena okluzivnih indeksa omogućava ortodontima određivanje prioriteta u zbrinjavanju pacijenata, planiranje ortodontske službe, pridržavanje i promociju standarda. Okluzivni indeksi su pouzdani dijagnostički kriterijumi koji mogu značajno uticati na plan lečenja malokluzija

Dentoalveolarni terapijski efekti Herbst aparata i aktivatora kod osoba u postpubertetskom uzrastu sa malokluzijom klase II/1

Background/Aim. Functional appliances can be used effectively in the treatment of skeletal Class II/1 malocclusions. The best treatment results are obtained during active period of facial growth when skeletal, as well as dentoalveolar, changes occur. In comparison with removable functional appliances, such as activator, that are effective only during adolescent period of growth, the Herbst fixed appliance is also successful at the end of the growth period. It also offers a shorter treatment time and a patient compliance is not necessary. The aim of this study was to analyze and compare dentoalveolar changes in the group of young adult patients with Class II/1 malocclusion treated with the Herbst appliance and an activator. Methods. The sample for this study consisted of 50 patients of both sexes, 14-21 years of age with Class II/1 malocclusion. For estimating the effect of functional appliances used, the following cephalometrics parameters were determined: inclination of the upper and lower incisors, interincisal angle, antero-posterior molars relationships, overjet and overbite. The results obtained were statistically tested. Results. The cephalometric findings after the treatment indicated retroinclination of upper incisors (average value of 9°) and proclination of lower incisors (average value of 7°), mostly expressed in the patients treated by Herbst appliance (p lt 0.001). Increased overjet and distocclusion were completely corrected in the group of patients treated with the Herbst appliance, while the correction of malocclusion in the activator group was only partially accomplished. No changes in the overbite were noticed at the end of the treatment in both groups. Conclusion. The results of this study revealed that the Herbst appliance is more effective in the treatment of Class II/1 malocclusion in young adults in comparison with the activator.Uvod/Cilj. Funkcionalni aparati uspešno se koriste u terapiji malokluzija klase II/1. Najbolji rezultati postižu se terapijom u periodu pubertetskog skoka rasta, kada su moguća najveća skeletna i dentoalveolarna pomeranja. U poređenju sa terapijom pokretnim funkcionalnim aparatima, kao što je aktivator prema Andresen-u, terapija Herbst-ovim fiksnim aparatom (Herbst aparat), uspešna je i nakon pubertetskog skoka rasta, vreme terapije je kraće, a bolesnike ne treba motivisati za saradnju jer je aparat fiksiran na zubima. Cilj istraživnja bio je da se kod bolesnika mlađeg odraslog uzrasta sa malokluzijom klase II odeljenja 1 uporede efekti fiksnog funkcionalnog Herbst aparata i pokretnog aktivatora na dentoalveolarne strukture. Metode. Ispitivanje je obuhvatilo 50 bolesnika sa malokluzijom klase II/1, oba pola, uzrasta 14-21 godine. Efekti primenjenih funkcionalnih aparata, aktivatora prema Andresen-u i Herbst aparata, procenjivani su na osnovu parametara merenih na profilnim telerendgenskim snimcima, nagiba gornjih i donjih sekutića, interincizalnog ugla, okluzije po Angle-u, incizalnog stepenika i incizalnog preklopa. Dobijeni rezultati obrađeni su statistički. Rezultati. Tokom terapije nastupile su statistički visokoznačajne promene u obe grupe: oralno naginjanje gornjih i vestibularno naginjanje donjih sekutića. Promene su bile izraženije u grupi bolesnika lečenih Herbst aparatom (p lt 0,001). Nagib gornjih sekutića promenjen je prosečno oko 9°, a donjih oko 7°. Odnos molara i incizalni razmak su u potpunosti korigovani na kraju lečenja u grupi lečenoj Herbst aparatom, dok su isti parametri u grupi sa aktivatorom bili nepotpuno korigovani. Nijedan od primenjenih aparata, na završetku lečenja, nije izazvao promene u vertikalnom preklopu sekutića. Zaključak. Poređenje terapijskih efekata Herbst aparata i aktivatora kod bolesnika uzrasta 14-21 godinu pokazalo je da je Herbst aparat efikasniji u korekciji dentoalveolarne malokluzije klase II odeljenja 1 nego aktivator

Cross-cultural adaptation and validation of the disease specific questionnaire oqlq in Serbian patients with malocclusions

Introduction. Dentofacial disorders may potentially significantly affect the quality of life. Objectives of this study were to validate translated and culturally adapted Orthognatic Quality of Life Questionnaire (OQLQ) on a cohort of Serbian patients with malocclusions. Methods. The questionnaire was validated in 111 consecutive patients with malocclusions, seen between December 2014 and February 2015 at the Clinic of Orthodontics, Faculty of Dental Medicine, University of Belgrade. Clinical validity was assessed comparing the mean scores for the four subscales of the OQLQ and mean PAR pre-treatment score. In order to assess whether the allocation of items in the subscales corresponds to their distribution in the original questionnaire, an exploratory factor analysis (principal component analysis with varimax rotation) was conducted. Results. The results of the internal consistency analysis demonstrated good relationships between the items; Cronbach's alpha coefficients for the four subscales were highly significant (p lt 0.001) (0.88-0.91). All items were significantly correlated between baseline and the retest (6 weeks after). The correlations between the PAR and all four domains of the OQLQ were all significant (p lt 0.01). The loading weights obtained in the exploratory factor analysis showed that this model revealed four factors with eigenvalue greater than 1, explaining the 64.0% of the cumulative variance. The majority of the items (86.4%) in the Serbian version of the OQLQ presented the highest loading weight in the subscales assigned by the OQLQ developer. Conclusions. The psychometric properties of the OQLQ (Serbian version) have exceptional internal consistency and reproducibility as an instrument for evaluation of dental malocclusions. Additionally, this questionnaire may be useful as a supplementary outcome measure in persons with malocclusions

Terapijski efekti tri vrste funkcionalnih aparata u lečenju malokluzija II skeletne klase - sagitalne i vertikalne promene

Introduction/Objective Class II malocclusions are sagittal malocclusions characterized by a distal relationship of posterior teeth. Depending on the underlying problem, Class II malocclusions can be skeletal or dentoalveolar. Class II malocclusion treatment modality will depend on the cause, severity, and age. Growth modification is the best treatment option in growing patients with skeletal Class II malocclusions. The aim of this study was to establish and compare sagittal and vertical skeletal and dental changes in patients treated with the 'M block' appliance, the Frankel functional regulator, and the Balters' bionator. Methods The sample consisted of 70 patients diagnosed with skeletal Class II malocclusions (ANB > 4°) and mandibular retrognathism (SNB lt 80°). The patients were divided into three groups according to the type of appliance. All the patients went through the standard diagnostic procedure (anamnesis, clinical and functional analysis, study model, panoramic radiograph, and cephalometric analysis), and dental and skeletal age was determined. Treatment effects were analyzed on study models and cephalograms at the end of treatment. Results All the appliances led to significant mandibular anterior movement and sagittal growth, which reduced the ANB values. All three groups of patients presented with neutral growth pattern, upper incisor retrusion, and lower incisor protrusion at the end of treatment. Conclusion The results of this study indicate efficacy of all three appliances in skeletal Class II malocclusion treatment.Uvod/Cilj rada Malokluzije II klase su sagitalne nepravilnosti zagrižaja koje karakteriše distalni odnos bočnih zuba. U zavisnosti od toga koje strukture su u nepravilnom odnosu, dele se na skeletne i dentoalveolarne. Terapija II klase zavisi od uzroka, izraženosti i uzrasta. Najbolji vid terapije ukoliko pacijenti i dalje rastu je modifikacija rasta. Cilj ove studije bio je da se utvrde i uporede sagitalne i vertikalne promene na skeletnim i dentalnim strukturama u toku lečenja M blok-aparatom, Frenklovim regulatorom funkcije tip I i bionatorom po Baltersu tip I. Metode Sedamdeset ispitanika sa dijagnozom skeletnog distalnog zagrižaja (ANB > 4°) i mandibularnog retrognatizma (SNB lt 80°), prema vrsti aparata, podeljeni su u tri grupe. Svi su prošli kroz standardnu dijagnostiku (anamneza, klinička i funkcionalna analiza, analiza studijskih modela, ortopantomografskog i profilnog telerendgenskog snimka). Terapijski efekti i promene analizirani su na studijskim modelima i profilnom snimcima po završetku terapije. Rezultati Sva tri aparata dovela su do značajnog mezijalnog usmeravanja i sagitalnog rasta mandibule, što je smanjilo ANB ugao. U sve tri grupe je utvrđen neutralni rast, kao i retruzija gornjih i protruzija donjih sekutića. Zaključak Rezultati studije ukazuju na efikasnost sva tri ispitivana aparata u lečenju skeletnih malokluzija II klase