EKSTRAKCIONA I NEEKSTRAKCIONA TERAPIJA PACIJENATA SA MALOKLUZIJOM II-1 KLASE EXTRACTION AND NON-EXTRACTION THERAPY IN CLASS II / 1 PATIENTS

Uvod: Malokluzija II klase karakterise se distokluzijom i deli se na dva odeljenja u zavisnosti od inklinacije gornjih frontalnih zuba. Prvo odeljenje se karakteriše protruzijom gornjeg fronta. Mogućnosti terapije malokluzije II-1 klase zavise od prisutne skeletne forme, uzrasta pacijenta i funkcionalnog statusa. Terapija dentoalveolarnih oblika II-1 klase bez velike skeletne diskrepance isključivo je ortodontska. Izraženiji skeletni oblici malokluzije II-1 mogu zahtevati pored ortodontskog i hirurško rešenje. Prikaz slučaja: U radu je prikazana ortodontska terapija kod pacijenata M.P. (dečak) i I.T. (devojčica) uzrasta 13 godina. Dijagnoza je obavljena na osnovu kliničko-funkcionalnog i intraoralnog nalaza, analize studijskih modela, fotografija lica, ortopana i profilnog snimka glave. Predložena je neekstrakciona terapija kod dečaka i ekstrakciona terapija kod devojčice, uz upotrebu gornjeg i donjeg fiksnog aparata. U terapiji fiksnim aparatima tehnikom pravog luka korišćene su Dentaurum bravice Root preskripcija, slot 22. Kod dečaka M.P. postojao je blagi maksilarni prognatizam, mandibularni retrognatizam, anteriorni tip rasta, protruzija gornjeg, a retruzija donjeg fronta. Korpus maksile bio je 2 mm duži u odnosu na kranijalnu bazu. U slučaju devojčice I.T odlučili smo se za ekstrakciju gornjih prvih premolara zbog postojanja maksilarnog prognatizma, mandibularnog retrognatizma, povećane dužine korpusa maksile, smanjene dužine korpusa mandibule i izražene protruzije gornjeg fronta. Nakon završetka terapije, kod oba pacijenta postignita je funkcionalna okluzija i poboljšanje facijalne estetike. Promene na licu bile su vidljivije kod pacijenta kod kojeg je sprovedena ekstrakciona terapija. Po završetku terapije neophodno je sprovesti retenciju postignutih rezultata.


Introduction
Class II malocclusion is characterized by distoclusion and is divided into two divisions depending on the inclination of the upper front teeth.The first division is characterized by protrusion of the upper front.Protrusion can be combined with diastemata, correct approximal tooth contact or crowding.Maxillary dental arch is in most cases elongated and narrow, whereas mandibular dental arch is commonly short due to retrusion of the lower front.
Persons with this malocclusion often develop orofacial functional disorders, lips incomepetence and infantile swallowing.There is a convex face profile with prominent upper lip and distally positioned lower lip and chin.
Malocclusion II-1 is commonly seen in everyday orthodontic practice.1Its appearance may vary in different parts of the world, and it is present in 17,6% of adolescent in Iran 2 , 40% of adolescent in Turkey 3 , while there are 18,4% 4 in Brazil.There are different skeletal variations of class II-1 malocclusion: maxillary normognathism with mandibular retrogmathism, maxillary prognathism with mandibular retrognathism, maxillary prognathism with mandibular normognathism, bimaxillary prognathism with dominantion of maxilla, bimaxillary retrognathism with domination of mandible.
Mandibular retrognathism is considered as the most common feature of class II/1 malocclusion 5 , while maxillary prognathism is not commonly seen.Unlike this theory, Rothstein 6 states that mandible of these patients is often normally developed and in normoposition, while Rosenblum 7 found that even 56,6% of patients with class II/1 malocclusion have maxillary prognathism and only 26,7% have mandibular retrognathism.
Treatment possibilities of class II/1 maloclussion depend on the skeletal form, patient's age and functional status.
Understanding of skeletal morphology and jaws relationship in these patients is a key element in planning the therapy 1 .
In patients with maxillary prognathism, orthodontic therapy includes extraction of the first pre-molars and retruding of upper front teeth 9 .
Nonextraction therapy of class II-1 patients can be implemented even when molars distalization is possible by using headgear, distally positioned mini implants or palatal structures such as pendulum usually combined with wisdom teeth extraction 10 .
Class II-1 patients with vertical type of growth are more difficult to treat.For their treatment headgear is often required, with the parietal anchoring to achieve impaction of maxilla, intrusion of maxillary first permanent molars and consequent anterior rotation of mandible.Sometimes, treatment of these patients also demands surgery.
In many cases, class II-1 patients also have narrow maxilla that forcibly holds the mandible in retrograde position ("moccasinlike" effect by McNamara) 11 .
If distoclusion is caused by mandibular retrognathism, good results in therapy can be achieved by the use of functional therapy 12 , only during the period of most intense stages of growth.Fixed functional appliance (Herbst) and elastic intermaxillary traction can also be used in combination with the fixed appliances.
The aim of this study was to compare the results of extraction and nonextraction therapy in class II-1 patients with maxillary prognathism and mandibular retrognathism at puberty age.

Patients and methods
Patients M.P. (boy) and I. T. (girl), both aged thirteen, came with their parents to the Department of Orthodontics of the Clinic of Dentistry in Nis seeking opinion about the existing orthodontic problem.During general health check at school, they were informed that they needed orthodontic treatment.
The diagnosis was established based on clinical and functional intraoral findings, analysis of dental casts, face photos, orthopatomogram and profile x-ray.
After the diagnostic procedure was completed, non-extraction therapy was proposed for M.P, and extraction therapy for the I.T., with the use of upper and lower fixed appliances.. Nakon sprovedene dijagnostičke procedure, predložena je neekstrakciona terapija kod dečaka i ekstrakciona terapija kod devojčice, uz upotrebu gornjeg i donjeg fiksnog aparata.
Pacijent je imao prepubertetski glas Upon the consent of the patients and their parents, therapeutic procedures began.In the treatment with fixed appliances, the technique of straight arch, Dentaurum brackets, root prescriptions, slot 22 were used.

Patient M.P. Extra-oral examination
The profile was convex.The lower third of the face was short and mentolabial sulcus was deep.The chin was placed distally in biometric field, and there was no visible facial asymmetry, the lips were competent (Figure 1).
The patient had a prepuberty voice.

Intraoral examination
Intraoral examination showed the presence of chronic marginal gingivitis.The patient was in the early stage of the permanent dentition.
The middle of the lower incisors was shifted 2mm to the right, and the curve of Spee was pronounced.Mild crowding was present in the lower front, while molars and premolars were well aligned.
Analysis of the dental casts showed ½ class II molar relation, on the left side canines were in the semi class, and on the right in a full class II.Overjet was 4 mm, and overbite was 7mm.

Patient I. T. Extraoral examination
There was a convex profile, reduced height of the lower third of the face, and also deep mentolabial sulcus.The upper lip was cutting the N vertical, the lower lip was in place, chin was placed distally in the biometric field.The face was symmetrical viewed ,,en face" (Figure 4).There was an incompetence of the lips.The voice was prepubertal.
Intraoral examination Intraoral examination revealed the existence of chronic marginal gingivitis.The patient was in an early stage of permanent dentition.The upper dental arch was symmetrical, narrow and elongated.There was a protrusion of the upper front and diastema mediana (2mm).The upper right canine had vestibular position with the lack of space in the dental arch.There was an asymmetry of the lower dental arch, while the middle of incisors was moved into the left 2 mm.The curve of Spee was emphasized.There was mild crowding in the lower front, while molars and premolars were well aligned (Figure 5).Analysis of the dental casts showed ½ class II molar relations on the right side, and class I on the left side.The relations of canines were in ½ class II .Overjet and overbite were 6mm.Radiografska analiza Analiza ortopana je potvrdila prisustvo svih stalnih zuba, pri čemu su bili vidljivi i zameci umnjaka.Rezultati analize telerendgena pre početka terapije prikazani su u tabelama 3 i 4 (slika 6).Postojao je blagi maksilarni prognatizam, mandibularni retrognatizam, anteriorni tip rasta, protruzija gornjeg, a retrutija donjeg fronta.Korpus maksile bio je duži 2 mm u odnosu na kranijalnu bazu.

Radiographic analysis
Orthopantomogram analysis confirmed the presence of all permanent teeth, with visible embryos of all wisdom teeth.Profile x-ray analysis results before the treatment are shown in Table 3 and 4 (Figure 6).There were a slight maxillary prognathism, mandibular retrognathism, anterior type of growth, protrusion of the upper and retrusion of the lower incisors.Body of maxilla was 2mm longer in comparison to the cranial base.
Patient (I.T.) was treated with extraction therapy in the upper jaw using fixed appliances.We decided to extract the upper first premolars because of maxillary prognathism, mandibular retrognathism, increased length of maxillary corpus, reduced length of mandibular corpus and severe protrusion of upper incisors.After extraction of the upper first premolars, fixed appliances were set .The first stage of the treatment resulted in leveling and placing the upper right canine in dental arch with NiTi archwires 0.12 and 0.14.In the second phase the upper front was retruded on the account of the (remaining) free space which was made by extraction therapy with square NiTi 16x16 and 16x22 and with use of laceback sliding mechanism and stoppers placed in front of the first molars tubes.Final area space closing and bite correction were performed by intermaxillary class II elastics on stanlessteel archwire 0,16 x0,22.
The treatment lasted 20 months and it included retention with the upper and lower Hawley retainer.After the treatment was done, in the the patient M.P., the relationship between canine and first molars within class I was obtained, while the patient I.T. had class I canine and class II molar relationship.Such occlusal results at the end of treatment of the patient I.T. were expected according to extraction therapy which was applied.
The results of treatment were observed using the analysis of facial photographs (Figure 1 and 4), intraoral photographs ( Figure 2 and 5) , analysis of the pre-and post therapy profile x-rays (Figure 3 and 6) and based on sketches which were carried out by superimposing the profile x rays before and after the orthodontic treatment (Figure 7 and 8).
Results of the analysis of profile x rays of patients before and after completion of therapy are shown in Tables 1,2,3 and 4 .

Discussion
During the treatment of the patient M.P., there was no major change in the inclination of the upper front but there was a protrusion of the lower anterior teeth.The protrusion of the lower front was not clinically expressed but was evident in the profile x-ray.During the treatment with intermaxillary traction of class II there is a distal movement of the upper front teeth and the mesial movement of the lower teeth.Moving of the lower teeth is always more pronounced.As a result of treatment of class II patients using intermaxillary elastics, protrusion of the lower front may occur.That can be a factor of instability of achieved results because of the lower lip pressure.
In the extraction treatment of patient I.T., a significant retrusion of the upper front was achieved, while there were no significant changes in the inclination of the lower anterior teeth.
Having in mind the age of treated patients, we can explain the change in the corpus length of the mandible as a result of adolescent growth.Both patients had anterior type of growth that was improved in the course of therapy.
During nonextraction treatment of patient M.P. there were no major changes in facial appearance.There was a slight mesial movement of the chin and a slight increase in the height of the lower third of the face.
In treatment of patient I. T. there were major changes in the facial appearance.There was a distal movement of the upper lip, medial movement of the lower lip in the biometric field and posterior rotation of chin, which led to an increase of the lower third of the face high.

Conclusion
When planning the treatment of class II-1 patients, detailed analysis of profile x rays, besides facial analysis and analysis of dental casts, is the most important thing.
After finishing the treatment, both patients had improvements in functional occlusion and facial aesthetics.Facial changes were more apparent in a patient who had extraction treatment.After the treatment it is necessary to maintain the achieved results.More attention should be paid to a patient in whom extraction therapy was not applied, due to changes in the inclination of the lower anterior teeth which can increase the possibility of relapse.

Figure 7 . 8 . 8 .
Superposition of profile X-rays of the patient M.P. before and after therapy Slika Superpozicija skica telerendgena pacijenta I.T. pre i nakon završene terapije Figure Superposition of profile X-rays of the patient I.T. before and after therapy

Table 1
Angular parameter values for cephalometric profile X-ray analysis before and after therapy (M.P.)

Table 2 .
Linear parameter values for cephalometric profile X-ray analysis before and after therapy (M.P.)

.
Angular parameter values for profile x-ray analysis before and after therapy (I.T.)