IZBOR TERAPIJSKE METODE U PACIJENATA SA HIPODONCIJOM THE CHOICE OF THERAPEUTIC METHODS IN PATIENTS WITH HYPODONTIA

Uvod: Hipodoncija predstavlja razvojno odsustvo jednog do šest zuba. Nepoznate je etiologije, ali se dovodi u vezu sa naslednim faktorom i poremećajima tokom faze inicijacije. Cilj ovog rada je bio da se na osnovu ortopantomografskih snimaka ortodonskih pacijenata proveri učestalost hipodoncije a na osnovu stomatoloških kartona izbor terapijske metode u pacijenata sa hipodoncijom. Metod rada: Istraživanjem je obuhvaćeno ukupno 525 pacijenata jedne privatne stomatološke ordinacije u Beogradu. Ova epidemiološka retrospektivna studija je izvedena analiziranjem ortopantomografskih snimaka a određeni podaci su prikupljeni iz zdravstvenih kartona pacijenata. Podaci su razvrstani prema starosti, polu, vilici, strani vilice, nedostajućem zubu, klasi po Angle-u i terapiskoj metodi. Rezultati:Dobijeni rezultati su pokazali da je učestalost hipodoncije 6.28%, i češće je zabeležena kod žena. Od terapijskih metoda najčešće je primenjivano zatvaranje prostora (61%), zatim otvaranje prostora (33%) a najmanje otvaranje i zatvaranje prostora (6%). Između terapijske metode (otvaranje i zatvaranje prostora) i zubne regije sa hipodoncijom (frontalna i premolarna) je uočena statistički značajna korelacija (p< 0.05).Hipodoncija je češće bila prisutna u donjoj vilici, najčešće su nedostajali donji drugi premolari. Zaključak: Zabeleženaučestalost hipodoncije je 6.28%. Između terapijske metode (otvaranje i zatvaranje prostora) i zubne regije sa hipodoncijom (frontalna i premolarna) postoji statistički značajna korelacija . U frontalnoj regiji je češće primenjivano otvaranje prostora, dok je u premolarnoj regiji češće primenjivano zatvaranje prostora kao terapijska metoda Abstract


Introduction
Hypodontia is a condition where one to six teeth are missing, absence of more than six teeth isoligodontia and total absence of teeth isanodontia [1][2][3][4] .Etiology of this anomaly is unclear but family predisposition is obvious.
This teeth anomaly is developed as a result of abnormalities during initiation phase, due to morphology teeth development phase, apposition of firm teeth tissue and during teeth eruption 5 .Hypodontia or oligodontia can often be seen among people with Down syndrome too 6 .
Absence of third molar in constant dentition is most present and it can be seen in (3% to 8.5% ) of population, but it can not be included in hypodontia 7 , and prevalence in molar dentition is around 1% 8 .Lateral incisor is often missing in upper jaw and second premolar, while second premolar is often absent in lower jaw 9,10 .Absence of teeth can be unilateral and bilateral 11 .The appearance of hypodontia, oligodontia and hyperdontia at the same time, in same person, is the consequence of the mix numeric variation and this is very rear 12 .The case of hypodontia of first and second molar, lower canine and upper central incisors is very rare 13 .
Despite having a low frequency, hypodontia are very complicated to treat because participate in occlusion, it is aesthetic problem and contribute to the development of other oral complication 14 .Kazanci and his associates researched prevalence of hypodontia and hyperdontia in permanent dentition of Turkish orthodontic patients and concluded that the prevalence rate of hypodontia was 4.74% 15 .Sismanand his associates researched prevalence and distribution of hypodontia among 2413 orthodontic patients and the result was 7.54% of hypodontia prevalence 16 .Altug-Atacand Erdemаhad researched prevalence and distribution of dental anomalies in orthodontic patients and came to the data that prevalence orthodontic patients hypodontia was 2.63% 17 .Khalafand his associates came to the data that prevalence was 6.4%, and that kontinentima.Tako je Afrika imala najvišu prevalencu (13.4%), zatim Evropa (7%), Australija (6.3%), dok je niža prevalenca zabeležena u Severnoj (5.0%) i Latinskoj Americi (4.4%) 18 .
There are two main hypodontia treatment modalities.These are closing of the space with remaining teeth and opening of the space for the tooth which is missing in order to get space to insert implant or prosthetic addition.
Implants are not inserted until the jaw is fully developed (when the person is 20 years old), so younger patients with hypodontia case prosthetic additions are made 19 .
The aims of this study were to analyse prevalence of hypodontia by othopatnomography radiology in ortodontically patients and the choice of therapy method in patients with hypodontia by analyzing existing medical documentation.

Materials and methods
This retrospective epidemiologic study is conducted by survey of 525 ofone Dental Office patientsin Belgradein last 5 years, by analysing orthopantomography radiology.Datas of gender, age and used therapy metod were collected from patients' medical files with hypodontia.
All current teeth (excepting of third molars is not hypodontia) were analysed by using same orthopantomograph (PlanmecaPromaxrendgen, Dimax 3), in same conditions of analyse on the same negatoscopioin a room with subdued light, by the two investigators.The data collected by going through orthopantomography radiology, as well as from patients' medical files were classified according to age, gender, jaw (upper and lower), jaw side (right and left), tooth region (frontal and premolar), teeth, class according to Angle (I, II and III class) and therapy method (opening, closing and opening and closing of the space at the same time).Thereafter the prevalence of hypodontia was found and distribution of the selected therapy method (opening or closing of Analiza zavisnosti zubne regije i terapijske metode proveravana je pomoću Hi kvadrat testa nezavisnih uzoraka.
Analyse of dependence of tooth region and therapy method was tested by using Hi square test of independent samples.

Results
The occurrence of hypodontia was registered in 33 of 525 patients altogether (12 men and 21 women).Hypodontia prevalence was 6.28%.
Out of 12 men with hypodontia, in 1 man it was at left side (8.3%), in 6 men at right side (50.0%) and at both sides in 5 patients (41.7%).Out of 21 women in 8 women it was at left side (38.1%), in 3 women at right side (14.3%) and at both sidesin 10 patients (47.6%).
Within 58% of total number of patients with hypodontia class according to Angle was registered, 36% ofpatients had class II, and only 6% of patients had class III.
Hypodontia in frontal region was present in 39% (15% in men and 24% in women), while in premolar region there was 61% (21% in men and 39% in women).
We had 61% premolars hypodontia all together, in12% (4 patients) the therapy method which was used was opening of the space, in 45% (15 patients) closing of the space and in 3% (1 patient) opening and closing of the space.In frontal region there was 39% of hypodontia altogether (13 patients), out of this number in 21% (7 patients) opening of the space was applied, in 15% (5 patients) closing of the space was used and in 3% (1 patient) opening and closing of the space was used.
In 61% cases, closing of the space as therapy method was applied (7 men and 13 women) and opening of the space in 33% cases (5 men and 6 women) (Table 1).
The teeth in lower jaw are often missing, that is, left and right second premolar, and this was noticed in 10 patients (Table 2).
Of the total number of patients with hypodontia in frontal region at 60% was used opening space therapy method, and of total number of patients with hypodontia in premolar region at 68.8% was used closing space therapy method (Table 3).
By using Hi square test was tested dependence of tooth region and therapy method and came to the conclusion that tooth region where is the missing tooth and therapy method are not independent variables and that there is statistically significant correlation between them (p= 0.02) ( Table 4) .Slika 1. Hipodoncija u donjoj vilici Slika 2. Hipodoncija u gornjoj vilici Figure 1.Hypodontia in lower jaw Figure 2. Hypodontia in upper jaw

Discussion
Many studies have been dealing with hypodontia within orthodontic patients.This study was tested patients undergoing orthodontic treatment already implemented various modalities of treatment.
In this study prevalence of hypodontia was 6.28%.Kazanci and his associates researched prevalence of hypodontia and hyperdontia in Turkish orthodontically treated patients between 9-25 years and concluded that hypodontia prevalence was 5.84% of 3165 patients 15 .Karadas and his associates came to the data that prevalence of less or increased number of teeth was 4.84% of 2722 patients 20 .
Razlike u učestalosti hipodoncije, polu kod kog je hipodoncija zastupljenija, najčešće nedostajućem zubu, vilici i strani vilice sa hipodoncijom kao i zubnoj regiji sa hipodoncijom objašnjene su populacijskom genetikom kao i veličinom uzorka.Ova studija i Fekonjina studija 19 daju isti rezultat da je kod pacijenata sa hipodoncijom najčešće bila prisutna I klasa po Angle-u i da je najčešće korišćeno zatvaranje prostora kao terapijska metoda.U ovoj studiji ispitivan je i izbor terapijske metode u osoba sa hipodoncijom.Установљено је да је у фронталној регији чешће примењивано отварање простора, док је у премоларној Gupta and his associates came to the data that hypodontia prevalence in Indian population was 4.19% of total number of 1123 patients 21 .Trakiniene with his associates got the data that hypodontia prevalence in orthodontically treathed patients at the Lithuanian population was 17.11% and there was not statistically significant difference between gender 9 , Gabrisand his associates found that prevalence of hypodontia at the University of Budapest was 14.69% 3 .Sismanand his associates were compared the prevalence of hypodontia at Turkish population with other populations and they found that prevalence of hypodontia were 7.54% 16 in orthodontically treated patients.The most often were missing upper second incisors,than lower second premolars, upper second premolars and lower first incisors.Karadas and his associates came to the data that the upper lateral incisor is the most missing tooth, than lower second premolаr and after it upper second premolar and lower central incisor and that hypodontia appears more often at left side than at right side, that is, unilateral is more common 20 .As well as our study Khalaf and his associates 18 show different result meaning represent that lower second premolar is the most missing tooth.Our study also shows that hypodontia often appears at both sides meaning bilateral.As well as our study Karadas and his associates 20 and Khalafand his associates 18 show that hypodontia is more common among women population than men population.Silva M and his associates 22 , Altuc-Atac 17 and his associates and Pekerand his associates 23 came to the result that hypodontia is more common in upper than lower jaw.As well as our study, Kirzioglu and his associates 24 present opposite result that hypodontia is more common in lower jaw than upper jaw.
The differences between prevalence of hypodontia, gender, most often missing tooth, jaw and side of jaw and tooth region with hypodontia was explained by population genetic and sample size.Our study and Fekonja's study 19 give the same result that patients with hypodontia most often have class I as perr Angle and that closing of the space is most used as therapy method.regiji češće primenjivano zatvaranje prostora kao terapijska metoda, što znači da između terapijske metode i zubne regije sa hipodoncijom postoji statistički značajna korelacija.Hipodoncija u frontalnoj regiji je viš estetski nego funkcionalni problem 19 .
In this study was investigated the dependence of thearapy method and tooth regia with hypodontia.It was found that in the frontal region were more used opening space but in the premolar region were more used closing space, which means that between therapy method and tooth region with hypodontia there is a statistically significant correlation.
Hypodontia in the frontal region is more aesthetic than the functional problem 19 .Aesthetic dentistry is coming to progress in the last few years, so the results of this study fit into these tendencies.
Space opening as the method of choice, for missing teeth in the frontal region in these patients provide the conditions for completing of the dental arch 19 .
In the premolar region, according to the results of this study, space closure was used more commonly as the method of choice, as patients, besides hypodontia, have other orthodontic anomalies.
Besides, the production of dental restorations is avoided.

Conclusion
The prevalence of hypodontia was 6.28%.Of therapy metods the most common was closing of the space between the teeth (61%), then opening space (33%), then opening and closing space (6%).There was statistically significant correlation between treatment modality (opening and closing of the space) and tooth regionwith hypodontia (frontal and premolar).In the frontal region were more used opening space but in the premolar region were more used closing space. .
Package for Social Science Program (SPSS Inc, version 20.0, Chicago, IL,USA).

Table 1 .
Tabela 1.Struktura pacijenata sa hipodoncijom prema modalitetu lečenja, polu i zubnoj regiji gde nedostaje zub Structure of Patients with Hypodontia according to treatment modalities, gender and tooth region where the tooth is missing

Table 2 .
Distribution and structure of the patients according to treatment modality and missing tooth

Table 3 .
Treatment modalities in specific Tooth region