Odborna praâce ORTODONCIE

Transcription

1 SpolecÏnyÂvy skyt ageneze hornõâho staâleâ ho postrannõâho rïezaâ ku a jinyâ ch dentaâ lnõâch anomaâ liõâ Agenesis of maxillary permanent lateral incisors and associated dental anomalies *MDDr. Mariana RaszkovaÂ, **Mgr. Jana VrbkovaÂ, Ph.D.,*Doc. MUDr. PavlõÂna CÏ ernochovaâ, Ph.D. *Ortodonticke oddeï lenõâ, Stomatologicka klinika FN u sv. Anny a LF MU v BrneÏ *Department of Orthodontics, Clinic of Stomatology, University Hospital of St.Anne, Masaryk University Brno **Katedra matematickeâ analyâzy a aplikacõâ matematiky, PrÏF UP v Olomouci **Department of mathematical analysis and applied mathematics, Faculty of Science, Palacky University Olomouc Souhrn CõÂl studie: CõÂlem retrospektivnõâ studie bylo zjistit, zda se u pacientuê s agenezõâ hornõâho staâleâ ho postrannõâho rïezaâ ku hodnoty vyâ skytu dalsï õâch dentaâ lnõâch anomaâ liõâ signifikantneï lisï õâ od hodnot vyâ skytu teï chto anomaâ liõâ v populaci. Materia l a metodika: Zkoumany soubor tvorïilo 120 pacientuê s agenezõâ hornõâho staâleâ ho postrannõâho rïezaâ ku. U teï chto pacientuê byla sledovaâ na prevalence dvanaâ cti dentaâ lnõâch anomaâ liõâ, ktereâ se vyskytujõâ v souvislosti s hypodonciõâ. ZjisÏteÏne prevalence byly srovnaâ ny s referencï nõâmi hodnotami z populacï nõâch studiõâ. Vy sledky: Ve zkoumaneâ m souboru byl ve srovnaâ nõâ s beï zï nou populacõâ zaznamenaâ n vysï sï õâ vyâ skyt mikrodoncie hornõâho staâ leâ ho postrannõâho rïezaâ ku, ageneze staâ lyâ ch zubuê, ageneze trïetõâch molaâ ruê, taurodontismu, palatinaâ lnõâ retence hornõâho staâleâhosï picïaâ ku, ektopickeâ erupce a impakce dolnõâho staâleâ ho druheâ ho molaâ ru a distoangulace zaâ rodku dolnõâho druheâ ho premolaâ ru. Naopak u hyperodoncie, syndromu kraâ tkyâ ch korïenuê, transpozice zubuê, ektopickeâ erupce hornõâho staâ leâ ho prvnõâho molaâ ru a infraokluze docï asnyâ ch molaâ ruê nebyl zjisï teï n signifikantnõâ rozdõâl ve vyâ skytu oproti beïzïneâ populaci. ZaÂveÏr:Vzhledem k vyâ sledkuê m studie lze doporucï it dlouhodobeâ sledovaâ nõâ pacientuê s agenezõâ hornõâho staâ leâ ho postrannõâho rïezaâ ku s ohledem na vcï asneâ zahaâ jenõâ leâ cï by prïidruzï enyâ ch dentaâ lnõâch anomaâ liõâ (Ortodoncie 2013, 22, cï. 2, s ). Abstract Aims: Our retrospective study aimed to find out whether the occurrence of other dental anomalies in patients with missing maxillary permanent lateral incisor is significantly different from the overall occurrence of those anomalies in the general population. Material and method: The sample included 120 patients with missing maxillary permanent lateral incisor. The prevalence of twelve other dental anomalies associated with hypodontia was monitored in these patients. The values obtained were compared with reference values recorded in population studies. Results: In the monitored sample of patients a higher prevalence of maxillary permanent lateral incisor microdontia was found as well as permanent teeth agenesis, third molars agenesis, taurodontism, palatal impaction of maxillary permanent canine, ectopic eruption, impaction of lower permanent second molar, and distoangulation of lower second premolar germ. On the other hand, the prevalence of hyperodontia, short root syndrome, teeth transposition, ectopic eruption of maxillary permanent first molar, and infraocclusion of deciduous molars, was almost the same as in the rest of the population. redakce@orthodont-cz.cz 91

2 ORTODONCIE Conclusion: With regard to the study results we recommend a long-term follow-up of the patients with missing maxillary permanent lateral incisor with respect to the potential early treatment of associated dental anomalies (Ortodoncie 2013, 22, No. 2, p ). KlõÂcÏ ovaâ slova: ageneze, hypodoncie, dentaâ lnõâ anomaâ lie Key words: agenesis, hypodontia, dental anomaly U vod TermõÂn hypodoncie obecneï oznacï uje dentaâ lnõâ anomaâ lii, jejõâzï podstatou je primaâ rneï snõâzïenyâ pocï et zubuê, jejichzï zaâ rodky nejsou vyvinuty. V prïõâpadeï,zï e se nevytvorïil jednotlivyâ zub, hovorïõâme o jeho agenezinebo aplaâ zii. Prevalence hypodoncie ve staâ leâ m chrupu se pohybuje mezi2,2 a 10,1 %. S vyâjimkou ageneze trïetõâch molaâruê, je nejcï asteï jipostizïenyâm staâlyâm zubem dolnõâ druhyâ premolaâ r,naâ sledovanyâ hornõâm postrannõâm rïezaâ kem a hornõâm druhyâm premolaâ rem [1]. V zaâ vislosti na pocï tu a typu nezalozï enyâ ch zubuê je pacient v ruê zneâ mõârïe posï kozen funkcï neï i esteticky. Estetika je narusï ena zejmeâ na pokud se jednaâ o agenezive frontaâ lnõâm uâ seku chrupu, jako je tomu v prïõâpadeï ageneze hornõâho staâ leâ ho postrannõâho rïezaâ ku. RÏ esï enõâ teâ to vady pak muê zï e byâ t pouze ortodontickeâ [2] nebo ve spolupraâ ci s implantologem [3] cï iprotetikem [4]. Etiologie hypodoncie je multifaktoriaâ lnõâ. UplatnÏ ujõâ se faktory genetickeâ a faktory prostrïedõâ. Faktory genetickeâ majõâ prïi vzniku hypodoncie zrïejmeï rozhodujõâcõâ roli. Geneticke pozadõâ agenezõâ je postupneï odhalovaâ no dõâky studiu postizïenyâch rodin, dvojcï at a kandidaâtnõâch genuê. Jako prïõâcï ina izolovaneâ (nesyndromoveâ) formy hypodoncie byly identifikovaâ ny mutace v genech PAX9, MSX1 a AXIN2. Dosud bylo nalezeno 5 mutacõâ genu MSX1, 11 mutacõâ genu PAX9 a 2 mutace genu AXIN2 spojenyâch s hypodonciõâ [5]. I prïes zaâ sadnõâ rozvoj teâ to oblastivyâ zkumu zuê staâ vajõâ geny zodpoveï dneâ za lehcï õâ formy hypodoncie neodhaleny. TyÂka se to iageneze hornõâho staâ leâ ho postrannõâho rïezaâ ku. JednõÂm z prvnõâch, kterïõâ rozpoznalispolecï nyâ genetickyâ puê vod strukturaâ lneï velmiodlisï nyâ ch vyâ vojovyâ ch poruch dentice vcï etneï hypodoncie byl Hoffmeister [6, 7, 8]. Zavedl pojem ¹mikrosymptomy geneticky determinovaneâ predispozice k porusï eneâ mu vyâ vojidenticeª a doporucï il sledovaânõâ teï chto mikrosymptomuê coby signaâ luê mozï neâ ho vyâ skytu hyperodoncie, dystopie zaâ rodkuê nebo hypodoncie u pacienta a jeho prïõâbuznyâ ch. DuÊ kazy o tom, zï e hypodoncie nenõâ izolovanyâ m jevem, ale maâ vztah k pocï tu, velikosti, morfologii, mineralizaci a erupci ostatnõâch zubuê v dentici, podaâ vajõâ praâ ce imnoha dalsï õâch autoruê [9, 10, 11, 12]. Markova avaâsï kovaâ uvaâdeïjõâ,zï e na hypodoncii je trïeba pohlõâzïet nikoli jako na pouhou anomaâ lii pocï tu zubuê, ale v sïirsïõâm slova smyslu jako na jeden z projevuê anomaâ lnõâho vyâvoje zubnõâ lisï ty a zubuê z nõâ vznikajõâcõâch [13]. Do vyâcï tu Introduction In general, hypodontia refers to a dental anomaly that is characterized by a lower number of teeth, the germs of which are not developed. In case of an individual tooth we speak about agenesis or aplasia. In permanent dentition hypodontia's prevalence oscillates between 2.2% and 10.1%. With the exception of third molars agenesis, the most frequently affected tooth is the lower second premolar, followed by upper lateral incisor and upper second premolar [1]. Depending on number and type of not established teeth patients suffer from functional and esthetic harm. Esthetic problems arise mainly when agenesis affects anterior segment of dentition (i.e. upper permanent lateral incisor agenesis). The anomaly may be solved solely by an orthodontist [2] or in cooperation with an implantologist [3] and an prosthodontist [4]. Hypodontia etiology is based on multiple factors. We can mention genetic factors and factors of the environment. It appears that genetic factors play the most important role. Genetic causes of agenesis have been revealed gradually thanks to the studies of affected families, twins, and candidate genes. As the causes of isolated (non-syndrome) form of hypodontia mutations in genes PAX9, MSX1 and AXIN2 were identified. So far 5 mutations of MSX1 gene, 11 mutations of PAX9 gene, and 2 mutations of AXIN2 gene connected with hypodontia were found [5]. In spite of substantial development in this area of research the genes responsible for mild forms of hypodontia have not been determined yet. This holds also true about missing upper permanent lateral incisor. Hoffmeister [6, 7, 8] was one of the first experts who recognized the common origin of structurally different developmental anomalies of dentition (including hypodontia). He introduced the concept of ªmicrosymptoms of genetically determined predisposition to defective development of dentitionª, and recommended to observe these microsymptoms as signals of potential occurrence of hyperodontia, germ dystopia, or hypodontia in a patient and their relatives. A number of works prove that hypodontia is not an isolated phenomenon but that it is related to number, size, morphology, mineralisation and eruption of other teeth in dentition [9, 10, 11, 12]. Markova and VaÂsÏ kovaâ state that hypodontia should be seen not as a mere anomaly in the number of teeth, but as a manifestation of abnor redakce@orthodont-cz.cz

3 dentaâ lnõâch vad, u kteryâch byl pozorovaâ n spolecïnyâvyâskyt s hypodonciõâ, patrïõâ: redukce mesiodistaâ lnõâ sï õârïky vsï ech zubuê, mikrodoncie hornõâho staâ leâ ho postrannõâho rïezaâ ku, syndrom kraâ tkyâ ch korïenuê, taurodontismus, palatinaâ lneï retinovanyâ hornõâ staâ lyâ sï pi cï aâ k, transpozice zubuê, ektopickaâ erupce zubuê a vyâ razneâ inklinace zubnõâch zaâ rodkuê, rotace zubuê, infraokluze docï asnyâch molaâruê, opozïdeïnyâ dentaâ lnõâ vyâvoj a opozïdeïneâ prorïezaâvaânõâ zubuê, poruchy tvrdyâch zubnõâch tkaânõâ. Tato retrospektivnõâ studie se zameï rïila na konkreâ tnõâ typ hypodoncie - agenezi hornõâho staâ leâ ho postrannõâho rïezaâ ku. Jedna se o anomaâ lii, kterou lze diagnostikovat jizï mezi8-9 rokem veï ku, kdy tento zub nejcï asteï jiprorïezaâvaâ. CõÂlem bylo zjistit, zda majõâ pacienti s agenezõâ hornõâho staâ leâ ho postrannõâho rïezaâ ku ve srovnaâ nõâ s beï zïnou populacõâ vysïsïõâvyâskyt dalsï õâch dentaâ lnõâch vad a zda muê zï e ageneze staâ leâ ho hornõâho postrannõâho rïezaâ ku slouzï it jako vcï asnyâ varovnyâ signaâ l (rizikovyâ faktor) mozïneâhovyâskytu jinyâch dentaâ lnõâch anomaâliõâ. Materia l a metodika Retrospektivnõ studie zkoumala dokumentaci 120 jedincuê bõâleâ rasy (pruêm.veï k 15,1 let, ± 7,3) s jednostrannou nebo oboustrannou agenezõâ staâ leâ ho hornõâho postrannõâho rïezaâ ku, kterïõâ bylievidovaâ nijako pacienti Ortodonticke ho oddeï lenõâ Stomatologicke kliniky u sv. Anny v BrneÏ a privaâ tnõâ ortodontickeâ praxe MUDr. JirÏõÂho Tvardka mezilety Vstupnõ kriteâ ria pro zarïazenõâ pacienta do studie byla naâ sledujõâcõâ: jednostrannaâ nebo oboustrannaâ ageneze staâ leâ ho hornõâho postrannõâho rïezaâ ku potvrzenaâ klinickyâ m a radiologickyâ m vysï e- trïenõâm s vyloucï enõâm mozï nostiextrakce, zï aâ dnaâ prïedchozõâ ortodontickaâ leâcï ba, dostupneâ uâ plneâ diagnostickeâ uâ daje zõâskaneâ anamneâ zou a klinickyâm vysï etrïenõâm, ortodontickeâ dokumentacï nõâ modely, kvalitnõâ standardizovanyâ ortopantomogram (OPG). Ze studie byli vyrïazenipacientise syndromy a rozsï teï py v orofaciaâ lnõâ oblasti, u kteryâch je vysïsïõâ vyâskyt dentaâ lnõâch anomaâ liõâ typickyâ. VeÏ koveâ rozpeï tõâ pacientuê bylo 6-43 let. V souboru bylo 45 muzïuê (pruêm. veï k 14,2 let, ± 6,1) a 75 zï en (pruêm.veï k 15,6 let, ± 7,9), pomeï r muzïi:- zï eny byl tedy 1 : 1,67. Na OPG snõâmcõâch (v neï kteryâch prïõâpadech doplneïnyâ ch iintraoraâ lnõâm snõâmkem nebo CT vysï etrïenõâm) a na ortodontickyâ ch dokumentacï nõâch modelech kazïdeâ ho pacienta ze souboru byly diagnostikovaâny na zaâkladeï prïesneï definovanyâ ch diagnostickyâ ch kriteâ riõâ naâsledujõâcõâ dentaâ lnõâ anomaâ lie: 1. mikrodoncie staâleâ ho hornõâho postrannõâho rïezaâ ku, 2. ageneze staâ lyâ ch zubuê (kromeï trïetõâch molaâ ruê), zvlaâsït' hodnocena ageneze hornõâho a dolnõâho druheâ ho premolaâ ru, 3. ageneze trïetõâch molaâruê, 4. prïespocï etneâ zuby (hyperodoncie), mal development of dental lamina and teeth originating there [13]. The dental anomalies associated with hypodontia include: reduction of mesiodistal width of all teeth, microdontia of upper permanent lateral incisor, short root syndrome, taurodontia, palatally impacted upper permanent canine, teeth transposition, ectopic eruption of teeth and expressive inclination of dental germs, teeth rotation, infraocclusion of deciduous molars, late dental development and late eruption of teeth, defects of hard dental tissues. Our retrospective study focuses on the specific type of hypodontia - agenesis of upper permanent lateral incisor. The anomaly can be diagnosed as early as between the age of 8 and 9, when this tooth usually erupts. The aim of our study was to determine whether patients with missing upper permanent lateral incisor show higher prevalence of other dental anomalies (in comparison with the general population), and whether agenesis of upper permanent lateral incisor may serve as an early warning signal (risk factor) of potential occurrence of other dental anomalies. Material and methods The retrospective study examined orthodontic records of 120 Caucasians (mean age 15.1 years, ± 7.3) with unilateral or bilateral agenesis of upper permanent lateral incisor, patients of the Department of Orthodontics, Clinic of Stomatology of St.Anne's Hospital in Brno, and the private practice of MUDr. JirÏõ Tvardek, between The following criteria were adopted: unilateral or bilateral agenesis of upper permanent lateral incisor proved by clinical and radiological examination, without possible extractions, without prior orthodontic treatment, available complete diagnostic data obtained through anamnesis and clinical examination, orthodontic documentation models, good quality standard OPG. Patients with syndromes and/or clefts in the orofacial area were excluded from the sample, because higher prevalence of dental anomalies are typical for them. The age of patients was between 6 and 43 years. The sample included 45 males (mean age 14.2 years, ± 6.1), and 75 females (mean age 15.6 years, ± 7.9), the proportion of males to females was 1 : In OPGs (sometimes supplemented by an intraoral x-ray or CT examination) and in orthodontic documentary models of each patient in the sample, the following dental anomalies were diagnosed according to defined diagnostic criteria: 1. Microdontia of upper permanent lateral incisor 2. Agenesis of permanent teeth (except third molars), agenesis of upper and lower second premolar was assessed individually 3. Third molars agenesis redakce@orthodont-cz.cz 93

4 ORTODONCIE 5. syndrom kraâ tkyâ ch korïenuê, 6. taurodontismus, 7. palatinaâ lneï retinovanyâ hornõâ staâ lyâ sï pi cï aâk, 8. transpozice zubuê, 9. ektopickaâ erupce staâleâ ho hornõâho prvnõâho molaâ ru, 10. ektopickaâ erupce a impakce staâ leâ ho dolnõâho druheâ ho molaâ ru, 11. distoangulace zaâ rodku druheâ ho dolnõâho premolaâ ru, 12. infraokluze docï asnyâ ch molaâ ruê. Vy skyt jednotlivyâ ch dentaâ lnõâch vad v souboru pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê byl srovnaâ n s referencï nõâmihodnotamipro beï zï nou populaci. Jako referencï nõâ hodnoty byly zvoleny vyâ sledky rozsaâ hlyâ ch populacï nõâch studiõâ. Pokud bylo k dispozici võâce populacï nõâch studiõâ, byl vyâbeï rovyâm kriteâ riem pocï et pacientuê v souboru, bõâlaâ nebo evropskaâ populace a shodnaâ diagnostickaâ kriteâ ria. VsÏ ichni pacienti s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê byli pacienty z ortodontickyâ ch praxõâ. Ortodonticka populace nereprezentuje beïzïnou neselektovanou populacia lze prïedpoklaâ dat, zï e prevalence urcï i tyâ ch dentaâ l- nõâch vad je u ortodontickyâch pacientuê vysïsï õânezï vbeïzïneâ populace. U anomaâ liõâ, kde byla data pro ortodontickeâ pacienty k dispozici, byly zjisïteïneâ prevalence pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê srovnaâ ny i s teï mito hodnotami. Ve vsï ech prïõâpadech srovnaâ vaâ nõâ prevalence anomaâliõâ byl pouzïit oboustrannyâ typ testu - test binomickyâ, tj. testovala se shoda prevalencõâ oprotioboustranneâ alternativeï (prevalence mohla byâ t vysï sï õâ inizï sï õâ). Pozorovana cï etnost daneâ anomaâ lie v souboru pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâkuê (odhad prevalence) se porovnaâ vala s referencï nõâ prevalencõâ v procentech. Odhad prevalence se pocïõâtaâ jako odhad parametru binomickeâ ho rozdeï lenõâ. Ve vyâ sledcõâch je uveden bodovyâ odhad i95% konfidencï nõâ interval (CI). Vy sledky jsou prezentovaâ ny jako P-hodnota. Statisticky vyâ znamneï odlisï neâ jsou vyâ sledky na hladineï vyâ znamnosti5 % (P-hodnota < 0,05). Diagnosticka kriteâ ria dentaâ lnõâch anomaâ liõâ pouzïitaâ ve studii PrÏi diagnostice dentaâ lnõâch anomaâ liõâ byly vizuaâ lneï hodnoceny OPG snõâmky pacienta, prïõâp. iskusoveâ snõâmky, intraoraâ lnõâ snõâmky a vyâ sledky CT vysï etrïenõâ. K hodnocenõâ vyâ skytu dentaâ lnõâch vad bylo vyuzï ito takeâ vizuaâ lnõâ hodnocenõâ a meï rïenõâ ortodontickyâ ch dokumentacï nõâch modeluê posuvnyâm meï rïidlem. Diagnosticky m kriteâ riem mikrodoncie bylo srovnaâ nõâ mesiodistaâ lnõâ sï õârïky hornõâho postrannõâho rïezaâ ku s mesiodistaâ lnõâ sï õârïkou dolnõâho postrannõâho rïezaâ ku. Byl-li tento rozmeï r stejnyâ nebo mensï õâ, byl rïezaâ k diagnostikovaâ n jako mikrodontickyâ. Pokud meï l mikrodontickyâ rïezaâ k normaâ lnõâ morfologii korunky, byl oznacï en jako 4. Supernumerary teeth (hyperodontia) 5. Short root syndrome (short root anomaly) 6. Taurodontia 7. Palatally impacted upper permanent canine 8. Teeth transposition 9. Ectopic eruption of upper permanent first molar 10. Ectopic eruption and impaction of lower permanent second molar 11. Distoangulation of lower second premolar germ 12. Infraocclusion of deciduous molars Prevalence of individual dental anomalies in the sample of patients with missing upper lateral incisors was compared with reference values for the general population. Reference values were derived from comprehensive population studies. In the case of several studies the criteria for the selection were a number of patients in the sample, Caucasian or European population, and consistent diagnostic criteria. All patients with missing upper lateral incisors came from orthodontic departments. The orthodontic population does not represent the common - non-selected - population, and therefore the prevalence of specific dental anomalies is higher in orthodontic patients than in the rest of the population. In the case of anomalies where the data for orthodontic patients was accessible, the prevalence found in patients with missing upper lateral incisors was compared with these values. In all cases two-sided tests were used - i.e. binomial tests - the correspondence of prevalences was tested against a two-sided alternative (the prevalence may have been higher as well as lower). The frequency of a given anomaly in the sample of patients with missing upper lateral incisors (prevalence estimation) was compared with reference prevalence values given in per cents. The prevalence estimation is calculated as the estimation of a binomial differentiation parameter. In results there is given both point estimation and 95% confidence interval (CI). The results are presented as P-value. Statistically significant differences are on the level of significance of 5% (P-value < 0.05). Diagnostic criteria of dental anomalies used in the study OPGs, sometimes also occlusal radiographs, periapical radiographs and results of CT examinations were evaluated visually during diagnostics of dental anomalies. To evaluate the prevalence of dental anomalies visual assessment and measurements of orthodontic models with a caliper ruler were used. The diagnostic criterion of microdontia was the comparison of mesiodistal width of upper lateral incisor and mesiodistal width of lower lateral incisor. If the parameter was identical or smaller, the incisor was diagnosed as microdontic. In the case that the microdontic incisor had normal crown morphology, it redakce@orthodont-cz.cz

5 Obr. 1. Metoda meïrïenõâ pomeïrudeâ lky korunky a korïene [dle 16]: S - strïed uâ secï ky spojujõâcõâ body na konturïe zubu, kde korunka prïechaâzõâ v korïen; v - vyâsï ka korunky je deâ lka kolmice z bodu S k prïõâmce i, prochaâ zejõâcõâ incizaâ lnõâ hranou rïezaâ ku; l - deâ lka korïene je deâ lka kolmice z bodu S k prïõâmce a, kteraâ prochaâ zõâ apexem korïene a je rovnobeïzïnaâ sprïõâmkou i. Fig. 1. Measurement of crown/root ratio[acc.16]: S - middle of the line segment connecting points on the tooth contour at the place where the crown converts into the root; v - height of the crown is the length of the perpendicular from S point to i line running through the incisal edge of an incisor; l - the root length is the length of the perpendicular from S point to a line, running through the root apex parallel to iline. malyâ hornõâ postrannõâ rïezaâ k.meï l-lirïezaâ k kuzï elovityâ (koânickyâ) tvar, byl oznacï en jako cï õâpkovityâ [14]. PrÏihodnocenõ ageneze zubuê, byl urcïityâ typ zubu oznacï en jako nezalozïenyâ, pokud chybeï l v zubnõâm oblouku, z anamneâ zy vyplyâvalo, zïe nebyl extrahovaânana OPG snõâmku nebyl zub prïõâtomnyâ v prïõâslusï neâ m kalendaârïnõâm veï ku pacienta. Pro jednotliveâ typy zubuê byl zohledneï n odlisï nyâ pocï aâ tek mineralizace zubnõâho zaârodku. S veï tsï õâ variabilitou zahaâ jenõâ mineralizace se muêzï eme setkat u druheâ ho premolaâ ru a trïetõâho molaâ ru. PruÊ meï rneï zacï õânaâ mineralizace druheâ ho premolaâ ru ve 3-3,5 letech, ale muêzïe byât zahaâ jena io mnoho let pozdeï ji[1]. Ageneze druheâ ho premolaâ ru byla proto u pacientuê diagnostikovaâna ve veï ku 10 a võâce let. Ageneze trïetõâch molaâruêveveï ku 14 a võâce let. U syndromu kraâ tkyâ ch korïenuê byly sledovaâ ny pouze staâ leâ hornõâ prvnõâ rïezaâ ky s dokoncï enyâ m vyâ vojem korïene. Z hodnocenõâ byly vyrïazeny rentgenoveâ snõâmky, na kteryâ ch byla kontura zubuê neostraâ nebo zkreslenaâ vlivem velkeâ ho steï snaâ nõâ. Da le byly vyrïazeny zuby, u kteryâ ch byla kontura korunky porusï ena karieznõâm procesem, uâ razem nebo vyâ raznou abrazõâ. Jako syndrom kraâ tkyâ ch korïenuê (SRA) byly diagnostikovaâ ny prïõâpady, kdy pomeïrdeâ lky korïene/korunky (R/C ratio) byl 1,0 u obou hornõâch strïednõâch rïezaâ kuê [15]. Byla pouzï ita metoda meï rïenõâ navrzï enaâ HoÈ lttaè ovou a kolektivem (obr. 1) [16]. Vy skyt taurodontismu byl sledovaâ n u prvnõâch a druhyâch staâlyâch molaâruê v obou cï elistech s dokoncï enyâm vyâ vojem korïenuê. PouzÏ ita byla diagnostickaâ kriteâ ri a was considered as a small upper lateral incisor. In the case the incisor had a conical shape, it was referred to as a peg lateral [14]. The agenesis of a tooth was considered when it was missing in the dental arch, the case history made it clear that it had not been extracted, and OPG did not show the tooth in the relevant calendar age of a patient. In individual types of teeth the different beginning of mineralization of a germ was taken into account. In cases of second premolar and third molar we can see variable beginning of mineralization. On average, second premolar mineralization starts at the age of years, however, it may even start many years later [1]. Therefore, agenesis of second premolar was diagnosed at the age of 10 and later, agenesis of third molars at the age of 14 and later. In case of short root syndrome we monitored only upper permanent first incisors with the finished root development. Radiographs with blurred teeth contours or radiographs biased due to substantial crowding were eliminated from the evaluation. Teeth in which the crown contour was distorted due to caries, injury or expressive abrasion were also eliminated. Short root anomaly (SRA) was represented by cases in which the proportion root/crown (R/C ratio) was 1.0 in both upper central incisors [15]. The measurement method by HoÈ lttaè et al was adopted (Fig. 1) [16]. Taurodontia was monitored in first and second permanent molars in both jaws with the finished root development. Diagnostic criteria proposed by Shiftman and Chanannel were used [17]. According to these criteria, taurodonta is diagnosed when: Distance A-B ³ 0.2 mm, Distance A-Apex and at the same time the distance B-CEJ ³ 2.5 mm, where A is the most occlusal point of pulp cavity, B is the most apical point of pulp cavity, Apex is the most apical point on the longest root, and CEJ is cementoenamel junction. Palatally impacted upper permanent canine was diagnosed in children at the age of 10 or older. OPGs and occlusal radiographs were evaluated with parallax redakce@orthodont-cz.cz 95

6 ORTODONCIE Shifmana a Chanannela [17]. Podle teï chto autoruê se jednaâ o taurodontismus pokud: vzdaâ lenost A-B ³ 0,2 mm vzdaâ lenost A-Apex a soucï asneï vzdaâ lenost B-CEJ ³ 2,5 mm, kde A je nejokluzaâ lneïjsï õâbod drïenï oveâ dutiny, B je nejapikaâ lneï jsï õâ bod drïenï oveâ dutiny, Apex je nejapikaâ lneï jsï õâ bod na nejdelsï õâm korïenizubu a CEJ je cemento-sklovinnaâ hranice. Palatina lneï retinovanyâ hornõâ staâ lyâ sï picï aâ k byl diagnostikovaân u deï tõâ ve veï ku 10 a võâce let. OPG a okluznõâ snõâmky byly vyhodnoceny paralaxnõâ metodou (teâzï Clarkovou metodou) k oveï rïenõâ palatinaâ lnõâ lokalizace korunky sïpicïaâ ku [18]. V neï kteryâchprïõâpadech bylo k dispozici CT vysï etrïenõâ pacienta. Diagno za byla cï asto potvrzena beï hem chirurgickeâ expozice sïpicïaâ ku. Jako transpozice staâ lyâ ch zubuê byly hodnoceny pouze prïõâpady potvrzeneâ CT vysï etrïenõâm nebo po uâ plneâm prorïezaâ nõâ zubuê. Ektopicka erupce staâleâ ho hornõâho prvnõâho molaâ ru byla hodnocena jen u pacientuê v obdobõâ jeho prorïezaâvaâ nõâ. Diagnosticka kriteâ ria byla naâ sledujõâcõâ: sklon erupcï nõâ draâ hy molaâ ru mesiaâ lnõâm smeï rem, korunka v abnormaâ lnõâm kontaktu s distaâ lnõâm korïenem druheâ ho docï asneâ ho molaâ ru. Ve veï tsï ineï prïõâpaduê je duê sledkem anomaâ lnõâ erupcï nõâ draâ hy resorpce distaâ lnõâ cï aâ stidruheâ ho docï asneâ ho molaâ ru. Nebyl rozlisï ovaâ n reverzibilnõâ a ireverzibilnõâ typ teâ to anomaâ lie. Pro ektopickou erupci a impakci staâ leâ ho dolnõâho druheâ ho molaâ ru byla diagnostickaâ kriteâ ria naâ sledujõâcõâ: sklon erupcï nõâ draâ hy molaâ ru mesiaâ lnõâm smeï rem, korunka v abnormaâ lnõâm kontaktu s distaâ lnõâ steï nou korunky nebo korïene prvnõâho staâleâ ho molaâ ru, vyâvoj korïene alesponï ze 3/4 dokoncï en. Distoangulace zaâ rodku druheâ ho dolnõâho premolaâ ru byla hodnocena dle modifikovaneâ metody navrzï eneâ Shalishovou a spolupracovnõâky [19]. Na OPG snõâmcõâch byl zmeïrïen distaâ lnõâ uâ hel (na obr. 2 oznacïena), kteryâ svõâraâ podeâ lnaâ osa zaâ rodku druheâ ho dolnõâho premolaâ ru s mandibulaâ rnõâ tangentou. Mandibula rnõâ tangenta je tecï na k dolnõâ hraneï teï la mandibuly na prïõâslusïneâ straneï cï elisti. Pokud je uâ hel mensï õâ nezï 75, jednaâ se o distoangulaci. Hodnoceny byly premolaâ ry ve vyâ vojoveâ m stadiu korïene E-G dle Demirjianovy klasifikace [20] (obr. 2). U infraokluze docï asnyâ ch molaâ ruê byly sledovaâ ny vsï echny docï asneâ molaâ ry v obou cï elistech. Pro diagnoâ zu infraokluze musela byât splneïnanaâ sledujõâcõâ kriteâ- method (also Clark method) to verify palatal location of canine crown [18]. In some patients there was CT examination made. The diagnosis was often proved during surgical exposure of a canine. Transposition of permanent teeth was diagnosed only in cases supported with CT examination, or after the complete eruption of dentition. Ectopic eruption of upper permanent first molar was evaluated in patients only during its eruption. The following diagnostic criteria were used: mesial inclination of eruption, crown in an abnormal contact with distal root of deciduous second molar. In most cases the abnormal eruption results in resorption of a distal part of deciduous second molar. There was not made a difference between reversible and irreversible type of the anomaly. The diagnostic criteria for ectopic eruption and impaction of lower second molar were the following: mesial inclination of eruption, a crown in an abnormal contact with a distal part of a crown or a root of permanent first molar, root development finished at least in 75%. Distoangulation of the lower second premolar germ was evaluated according to a modified method proposed by Shalish et al. [19]. In OPGs the distal angle (in Figure 2 as a) between the longitudinal axis of lower second premolar germ and the mandibular tangent. The mandibular tangent is a tangent to the lower border of the mandible on the relevant side of the jaw. Distoangulation means that the angle is less than 75. Premolars in the stage of development E-G according to Demirjian classification were evaluated [20] (Fig.2). In regard to infraocclusion of deciduous molars all temporary molars in both jaws were monitored. The diag- Obr. 2. Princip meï rïenõâ distoangulace dolnõâho druheâ ho premolaâ ru na OPG snõâmku (modifikovanaâ metoda dle [19]). Vy vojovaâ stadia korïene premolaâ ru E-G dle Demirjianovy klasifikace [20]. Fig. 2. Principle of measurement of distoangulation of lower second premolar in OPG (modified method according to [19]). Stages of premolar root development E-G according to Demirjian`s classification [20] redakce@orthodont-cz.cz

7 Tab. 1. Hodnoty prevalence dentaâ lnõâch anomaâ liõâ v souboru pacientuê s agenezõâ postrannõâho rïezaâ ku, v beï zïneâ populacia v populaciortodontickyâch pacientuê. Tab. 1. Prevalence of dental anomalies in the sample of patiens with agenesis of the upper lateral incisor, in the general population and in the population of orthodontic patients. Dental anomaly Dentální anomálie Prevalence in our sample of 120 patients (Raszková) (estimate; CI) Výskyt v našem souboru 120 pacientů (odhad; CI) Reference values in the general population Výskyt v běžné populaci Reference values in the orthodontic population Výskyt v souboru ortodontických pacientů Microdontia of the upper lateral incisor Mikrodoncie horního laterálního řezáku 26,7 % (32/120) (19,01 %; 35,51 %) 1,7 % Grahnén, 1956 [21] P < 0,001 4,7 % Baccetti, 1998 [11] P < 0,001 3,6 % Alvesalo et Portin, 1969 [22] P < 0,001 0,8 % Bäckman et Wahlin, 2001 [24] P < 0,001 4,5 % Černochová et Hollá, 2011 [23] P < 0,001 Tooth agenesis (excluding third molars) Ageneze zubů (mimo 3.molár) - upper second premolar agenesis - ageneze horního druhého premoláru - lower second premolar agenesis -ageneze dolního druhého premoláru Third molar agenesis Nezaložený třetí molár 26,7 % (32/120) (19,01 %; 35,51 %) 5,9 % (7/118) (2,42 %; 11,84 %) 12,8 % (15/117) (7,36 %; 20,26 %) 45,3 % (34/75) (33,79 %; 57,25 %) 5,5 % Polder et al., 2004 [1] P < 0,001 1,5 % Polder et al., 2004 [1] P = 0,0021 3,1 % Polder et al., 2004 [1] P < 0,001 22,5 % Rozkovcová et al., 2004 [25] P < 0,001 22,4 % Sonnabend 1966 [26] P < 0,001 28,5 % Tröndle, 1973 [27] P = 0,002 20,7 % Hübenthal, 1989 [28] P < 0,001 24,6 % Grahnén, 1956 [21] P < 0,001 20,7 % Bredy et al., 1991 [29] P < 0,001 Supernumerary teeth Přespočetné zuby 0 % (0/120) (0 %; 3,03 %) 2,1 % Brook, 1974 [30] P = 0,1877 3,9 % Baccetti, 1998 [11] P = 0,0159 1,05 % Berrocal et al., 2007 [31] P = 0,6412 1,9 % Bäckman et Wahlin, 2001 [24] P = 0,1796 Short root syndrome Syndrom krátkých kořenů 0,9 % (1/113) (0,02 %; 4,83 %) 1,3 % Apajalahti et al., 2002 [32] P = 1 2,4 % Jakobsson et Lind, 1973 [33] P = 0,5305 2,7 % Brook et Holt, 1978 [34] P = 0,3788 0,6 % Bergström, 1977 [35] P = 0,4934 Taurodontism Taurodontismus 20,5 % (23/112) (13,49 %; 29,2 %) 22 % Haavikko, 1971 [36] P = 0,8195 5,6 % Shifman et Chanannel, 1978 [17] P < 0,001 11,3 % Ruprecht et al., 1987 [37] P = 0,0041 Palatally displaced upper permanent canine Palatinálně uložený horní stálý špičák 8,8 % (9/102) (4,11 %; 16,09 %) 1,7 % Dachi et Howell, 1961 [38] P < 0,001 5,2 % Baccetti, 1998 [11] P = 0,1126 1,53 % Brin et al., 1986 [14] P < 0,001 8 % Pirinen et al., 1996 [39] P = 0,7143 Tooth transposition Transpozice zubů 1,7 % (2/120) (0,2 %; 5,89 %) 0,33 % Papadopoulos et al., 2010 [40] P = 0,0602 Ectopic eruption of the upper first permanent molar Ektopická erupce horního prvního stálého moláru 2,4 % (1/42) (0,06 %; 12,57 %) 4,3 % Bjerklin, 1994 [41] P = 1 2 % Cheyne et Wessels, 1947 [42] P = 0, % Young, 1957 [43] P = 1 4,6 % Baccetti, 1998 [11] P = 1 4,3 % Barberia-Leache et al., 2005 [44] P = 1 Ectopic eruption and impaction of the lower second permanent molar Ektopie a impakce dolního druhého stálého moláru 1,8 % (2/111) (0,22 %; 6,36 %) 0,15 % Varpio et Wellfelt, 1988 [45] P = 0,0123 0,06 % Grover et Lorton, 1985 [46] P = 0,0021 0,4 % Mead, 1930 [47] P = 0,0734 1,4 % Bondemark et Tsiopa, 2007 [48] P = 0,6705 Lower second permament premolar germ distoangulation Distoangulace zárodku dolního druhého premoláru 28,6 % (16/56) (17,3 %; 42,21 %) 0,2 % Matteson et al., 1982 [49] P < 0,001 Infraocclusion of primary molars Infraokluze dočasných molárů 15,4 % (8/52) (6,88 %; 28,08 %) 10,3 % Bjerklin et al., 1992 [10] P = 0,248 8,9 % Kurol, 1981 [50] P = 0,1354 5,6 % Baccetti, 1998 [11] P = 0, redakce@orthodont-cz.cz 97

8 ORTODONCIE ria: docï asnyâ molaâ r nenõâv kontaktu s antagonistou, uâ rovenï okluze docï asneâ ho molaâru je 1 cï ivõâce mm pod uâ rovnõâ okluznõâ roviny. Vada byla hodnocena u pacientuê se smõâsï enyâ m chrupem s plneï prorïezanyâ miprvnõâmistaâlyâ mimolaâ ry. Za rovenï bylivyrïazeniz hodnocenõâ pacienti, u nichzï nemohla byâ t vyloucï ena manifestace vady v pozdeïjsïõâmveï ku. Vy sledky Prevalence jednotlivyâ ch dentaâ lnõâch vad v souboru 120 pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâkuê byla statistickyâ m testovaâ nõâm srovnaâ na s referencï nõâmihodnotamipro beï zï nou populaci. U sï estidentaâ lnõâch anomaâ liõâ bylo srovnaâ nõâ provedeno takeâ s hodnotamize studiõâ na ortodontickyâ ch pacientech. Vy sledky jsou uvedeny v tabulce (tab. 1). Statisticky vyâ znamneï odlisï neâ vyâ sledky na hladineï vyâ znamnosti5 % (P-hodnota < 0,05) jsou pro prïehlednost znaâ zorneï ny cï ervenou barvou. Byl zjisïteï n statisticky vyâznamnyâ rozdõâl ve vyâskytu mikrodoncie hornõâho staâ leâ ho postrannõâho rïezaâ ku, ageneze staâ lyâ ch zubuê (kromeï trïetõâch molaâ ruê ), ageneze hornõâho druheâ ho premolaâ ru, ageneze dolnõâho druheâ ho premolaâ ru, ageneze trïetõâch molaâ ruê, taurodontismu, palatinaâ lneï retinovaneâ ho hornõâho staâleâho sï pi cï aâ ku, ektopickeâ erupce a impakce staâleâ ho dolnõâho druheâ ho molaâ ru a distoangulace zaâ rodku druheâ ho dolnõâho premolaâ ru mezi analyzovanyâ m souborem pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê a beï zï nou populacõâ. Hodnoty prevalence byly ve vsï ech prïõâpadech ve skupineï pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâkuê vysïsïõâ. U mikrodoncie hornõâho staâ leâ ho postrannõâho rïezaâ ku, ageneze trïetõâch molaâ ruê, prïespocï etnyâ ch zubuê (hyperodoncie), palatinaâ lneï retinovaneâ ho hornõâho staâ leâ ho sï picï aâ ku, ektopickeâ erupce staâ leâ ho hornõâho prvnõâho molaâ ru a infraokluze docï asnyâ ch molaâ ruê byla hodnota prevalence v analyzovaneâ m souboru srovnaâ na s prevalencõâ u ortodontickyâ ch pacientuê. Statisticky signifikantnõâ rozdõâl byl mezi hodnotami prevalencõâ mikrodoncie hornõâho staâleâho postrannõâho rïezaâ ku, ageneze trïetõâch molaâ ruê, infraokluze docï asnyâ ch molaâ ruê a prïespocï etnyâ ch zubuê (hyperodoncie). V prïõâpadeï mikrodoncie hornõâho staâleâ ho postrannõâho rïezaâ ku, ageneze trïetõâch molaâruê a infraokluze docï asnyâch molaâruê byla hodnota prevalence u pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê vysï sï õâ nezï prevalence uvaâ deï naâ ve studiõâch na ortodontickyâch pacientech. V prïõâpadeï hyperodoncie byla hodnota prevalence v analyzovaneâm souboru nizï sï õâ nezï u ortodontickyâ ch pacientuê. Diskuse Od 60. let 20. stoletõâ azï do soucï asnostise mnoho autoruê snazï ilo objasnit souvislost mezi vyâ skytem ruêznyâ ch dentaâ lnõâch anomaâ li õâ. CÏ aâ st autoruê se zameï rïila na pacienty s hypodonciõâ a dokaâ zala signifikantneï vysï- nostic criteria were the following: temporary molar is not in contact with its antagonist, occlusal level of temporary molar is at least 1 mm below the occlusal plane level. The anomaly was evaluated in patients with mixed dentition with fully erupted permanent first molars. Patients in which the later anomaly manifestation could not be ruled out were excluded from the evaluation. Results Prevalence of individual dental anomalies in the sample of patients with missing upper lateral incisors was compared (by means of statistical tests) with the reference values for the general population. Six dental anomalies were also compared with values obtained through studies of orthodontic patients. The results are given in Table 1. Statistically significant differences, the level of significance 5% (P-value < 0.05) are given in red. Statistically significant differences between patients with missing upper lateral incisors and the general population were found in the prevalence of microdontia of upper permanent lateral incisor, permanent teeth agenesis (except third molars), agenesis of upper second premolar, agenesis of lower second premolar, agenesis of third molars, taurodontia, palatally impacted upper permanent canine, ectopic eruption and impaction of lower permanent second molar, and distoangulation of lower second premolar germ. The prevalence in all the anomalies given above was higher in the sample of patients with upper lateral incisors agenesis. In the case of upper permanent lateral incisor microdontia, third molars agenesis, supernumerary teeth (hyperodontia), palatally impacted upper permanent canine, ectopic eruption of upper permanent first molar, and infraocclusion of temporary molars, the prevalence in the sample of our patients was compared with the prevalence in orthodontic patients. Statistically significant differences were found in the values for upper permanent lateral incisor microdontia, third molars agenesis, temporary molars infraocclusion, and supernumerary teeth (hyperodontia). In the case of upper permanent lateral incisor microdontia, third molars agenesis, and temporary molars infraocclusion, the prevalence was higher in the analyzed sample of patients than in orthodontic patients. Hyperodontia prevalence was lower than in orthodontic patients. Discussion Since the 60s of the 20th century a lot of authors have been trying to explain the relationship between the occurrences of different dental anomalies. Some authors focused on patients with hypodontia, and proved significantly higher prevalence of associated dental anomalies in these individuals and their relatives redakce@orthodont-cz.cz

9 Some studies monitored patients with agenesis of a given tooth, e.g. lower second premolar [12] or upper permanent lateral incisor [51]. Our retrospective study focused on the prevalence of dental anomalies in people with missing upper permanent lateral incisor, and compared the values with the prevalence of the same dental anomalies in the general population. A statistically significant difference was proved in seven dental anomalies. The prevalence of six dental anomalies in the sample with missing upper permanent lateral incisor was also compared with the values obtained through studies carried on orthodontic patients. The prevalence of upper permanent lateral incisor microdontia (26.7%) was significantly different and higher than in the general population ( %, P-value < 0.001). The prevalence of this anomaly in our sample of patients was also significantly different and higher than in orthodontic patients (4.7% and 4.5%, P-value < 0.001). This corresponds with the published results; these studies established that peg shape upper lateral incisor is often associated with agenesis of contralateral lateral incisor [22, 52, 53, 54]. The result appears to support the idea that the upper lateral incisor agenesis and upper lateral incisor microdontia are phenotype expressions of one and the same genetic defect. The prevalence of permanent teeth agenesis (26.7%), with the exception of third molars, was significantly different and higher than in the general population (5.5%, P-value <0.001). The prevalence of upper second premolar agenesis (5.9%) and lower second premolar (12.8%) was also significantly higher than in the rest of population (1.5%, P-value = , and 3.1%, P-value < Reference values were the results of Polder's meta-analysis based on 33 extensive population studies [1]. The prevalence of third molars agenesis (45.3%) was significantly different and higher than in the general population ( %, P-value 0.002). The prevalence was also significantly higher than in orthodontic population (20.7 and 22.4%, P-value < 0.001). This corresponds with the results of Grahne n [21] who identified missing third molars in approximately 50% of patients affected with agenesis of other teeth. The prevalence of taurodontia (20.5%) was compared with the values given in three comprehensive population studies. In two cases, the prevalence was significantly higher than in the general population (5.6% and 11.3%, P-value < ). However, the comparison with Finnish study [36] did not show statistically significant difference (22%, P-value = ). This may be due to different diagnostic criteria used. We can also observe great ethnic differences in regard to taurodontia prevalence. In our study we used diagnosïõâvyâskyt dalsï õâch dentaâ lnõâch vad u teï chto jedincuê a jejich prïõâbuznyâ ch. NeÏ ktereâ studie sledovaly pacienty s agenezõâ pouze urcïiteâ ho typu zubu, naprï. dolnõâho druheâho premolaâ ru [12] nebo hornõâho staâleâ ho postrannõâho rïezaâ ku [51]. Take tato retrospektivnõâ studie se zameï rïila na vyâ skyt dentaâ lnõâch anomaâ liõâ u jedincuê postizï enyâch agenezõâ hornõâho staâ leâ ho postrannõâho rïezaâ ku a srovnaâvala ho s vyâ skytem stejnyâ ch dentaâ lnõâch anomaâ liõâ vbeï zï neâ populaci. Statisticky vyâ znamnyâ rozdõâl v hodnotaâ ch prevalence byl prokaâ zaâ n u sedmidentaâ lnõâch vad. Ve vsï ech sedmiprïõâpadech byla hodnota prevalence vysï sï õâ. U sï estidentaâ lnõâch anomaâ liõâ byly hodnoty jejich prevalence v souboru pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê srovnaâ vaâ ny takeâ s hodnotamize studiõâ na ortodontickyâch pacientech. Prevalence mikrodoncie hornõâho staâ leâ ho postrannõâho rïezaâ ku (26,7 %) se signifikantneï lisï ila a byla vysïsïõâ nezï prevalence v beïzïneâ populaci(0,8-3,6 %, P-hodnota < 0,001). VyÂskyt teâ to anomaâ lie ve zkoumaneâm souboru se takeâ signifikantneï lisï il a byl vysïsï õâ nezï u ortodontickeâ populace (4,7 % a 4,5 %, P-hodnota < 0,001). To je v souladu s prïedchozõâmipublikovanyâ mivyâ sledky pracõâ, ktereâ zjistily, zïe cï õâpkovityâ hornõâ postrannõâ rïezaâk se vyskytuje cï asto s agenezõâ kontralateraâ lnõâho postrannõâho rïezaâ ku [22, 52, 53, 54]. VyÂsledek zaâ rovenï potvrzuje naâ zor, zïe ageneze hornõâho postrannõâho rïezaâku a mikrodoncie hornõâho postrannõâho rïezaâ ku jsou zrïejmeï fenotypovyâ m vyjaâ drïenõâm teâ hozï genetickeâ ho defektu. Prevalence ageneze staâlyâch zubuê (26,7 %), s vyâjimkou trïetõâch molaâruê, se signifikantneï lisï ila a byla vysïsïõâ nezï prevalence v beïzïneâ populaci(5,5 %, P-hodnota < 0,001). StejneÏ tak se signifikantneï li sï ila prevalence ageneze hornõâho druheâ ho premolaâ ru (5,9 %) a dolnõâho druheâ ho premolaâ ru (12,8 %) od hodnot v beïzïneâ populaci(1,5 %, P-hodnota = 0,0021 a 3,1 %, P-hodnota < 0,001) a byla vysïsï õâ. Jako referencï nõâ hodnoty byly v tomto prïõâpadeï pouzï ity vyâ sledky Polderovy metaanalyâzy, kteraâ vychaâ zela z 33 velkyâch populacï nõâch studiõâ [1]. Prevalence ageneze trïetõâch molaâruê (45,3 %) se v souboru pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâkuê signifikantneï li sï ila a byla vysï sï õâ nezï prevalence vbeïzïneâ populaci(22,5-28,5 %, P-hodnota 0,002). VyÂskyt teâ to vady se ve zkoumaneâ m souboru takeâ signifikantneï li sï il a byl vysï sï õâ nezï u ortodontickeâ populace (20,7 a 22,4 %, P-hodnota < 0,001). To je v souladu svyâ sledky praâ ce Grahne na [21], kteryâ nezalozï eneâ trïetõâ molaâ ry diagnostikoval prïiblizïneï u poloviny pacientuê postizï enyâ ch agenezõâ jinyâ ch zubuê. Hodnota vyâ skytu taurodontismu (20,5 %) byla srovnaâ vaâ na s hodnotamivyâ skytu trïõâ rozsaâ hlyâ ch populacïnõâch studiõâ. Ve dvou prïõâpadech se prevalence signifikantneï lisï ila a byla vysïsï õâ nezï prevalence v beïzïneâ populaci(5,6 % a 11,3 %, P-hodnota < 0,0041). PrÏisrovnaÂnõ redakce@orthodont-cz.cz 99

10 ORTODONCIE svyâsledky finskeâ studie [36] vsï ak nebyl rozdõâl ve vyâskytu statisticky vyâ znamnyâ (22 %, P-hodnota = 0,8195). MuÊzÏ e to byât zpuê sobeno pouzï itõâm jinyâch diagnostickyâch kriteâ riõâ pro taurodontismus. StejneÏ tak existujõâ velkeâ etnickeâ rozdõâly ve vyâ skytu taurodontismu. Vte to praâ cibyla pouzï ita diagnostickaâ kriteâ ria dle Shifmana a Chanannela [17] a ve srovnaâ nõâ s jejich populacï nõâ studiõâ na 1200 IzraelcõÂch se vyâ skyt taurodontismu u pacientuê s agenezõâ hornõâho postrannõâho rïezaâ ku statisticky vyâznamneï li sï il a byl vysïsï õâ (5,6 %, P-hodnota < 0,001). Prevalence palatinaâ lneï retinovaneâ ho hornõâho staâleâhosïpicïaâ ku (8,8 %) se signifikantneï lisï ila a byla vysïsïõâ nezï prevalence v beïzïneâ populaci(1,53 % a 1,7 %, P- hodnota < 0,001). VyÂskyt teâ to vady ve zkoumaneâm souboru se vsï ak signifikantneï nelisï ilodvyâ skytu u ortodontickeâ populace (5,2 % a 8 %, P-hodnota = 0,1126 a P-hodnota = 0,7143). ZatõÂmco ve studiõâch na ortodontickyâ ch pacientech autorïirozlisï ujõâ lokalizaci retinovaneâ ho hornõâho staâleâho sïpicïaâ ku a uvaâdeï jõâ prevalenci pro palatinaâ lneï retinovanyâ sï picï aâ k, velkeâ populacï nõâ studie impaktovanyâ ch zubuê veï tsï inou nerozlisï ujõâ polohu retinovaneâ ho hornõâho staâ leâ ho sï picï aâ ku. Vzhledem k tomu, zïe palatinaâ lnõâ poloha je 2-3x cï asteïjsï õâ nezï vestibulaâ rnõâ, lze prïedpoklaâ dat, zï e referencï nõâ hodnoty pro beï zï nou populaciby byly v prïõâpadeï rozlisï ovaâ nõâ polohy sï picï aâku nizïsï õâ. RozdõÂl meziprevalencõâ ve zkoumaneâm souboru a v beïzïneâ populaciby byl jesïteï signifikantneï jsï õâ.acï kolinevysï el signifikantnõâ rozdõâl mezi vyâ skytem palatinaâ lneï retinovaneâ ho sï picï aâ ku u pacientuê s agenezõâ hornõâch lateraâ lnõâch rïezaâ kuê a u beï zï nyâ ch ortodontickyâ ch pacientuê, nelze spojitost a spolecïneâ genetickeâ pozadõâ mezipalatinaâ lneï retinovanyâmsï picï aâ kem a agenezõâ hornõâho postrannõâho rïezaâ ku vyloucï it. Sacerdoti a Baccetti [55] zjistili vysï sï õâ prevalencipalatinaâ lneï retinovaneâ ho sï picï aâ ku u pacientuê s agenezõâ hornõâho postrannõâho rïezaâ ku ve srovnaâ nõâ s kontrolnõâ skupinou, nepotvrdili vsï ak reciprocï nõâ vztah, tedy vysï sï õâ vyâ skyt ageneze hornõâho postrannõâho rïezaâ ku u pacientuê s palatinaâ lneï retinovanyâm sïpicïaâ kem. Hodnota prevalence ektopickeâ erupce a impakce staâleâ ho dolnõâho druheâ ho molaâ ru (1,8 %) byla srovnaâvaâ na s hodnotamiprevalence cï tyrï rozsaâ hlyâ ch populacï nõâch studiõâ. Ve dvou prïõâpadech se prevalence signifikantneï lisï ila a byla vysïsï õâ nezï prevalence v beïzïneâ populaci(0,06 % a 0,15 %, P-hodnota = 0,0021 a P- hodnota = 0,0123). PrÏisrovna nõâ s populacï nõâmistudiemi Meada [47], Bondemarka a Tsiopove [48] vsïak nebyl rozdõâl ve vyâ skytu statisticky vyâ znamnyâ (0,4 % a 1,4 %, P-hodnota = 0,0734 a P-hodnota = 0,6705). PrÏõÂcÏ inou mohou byâ t zejmeâ na odlisï naâ diagnostickaâ kriteâ ria pouzï i taâ v jednotlivyâ ch studiõâch. Nale zt alesponï dveï studie vyuzï õâvajõâcõâ stejnaâ diagnostickaâ kriteâ ria je obtõâzï neâ, jelikozï pracõâ zameï rïenyâ ch na vyâ skyt ektopickeâ stic criteria according to Shifman and Chanannel [17]. In comparison with their study carried out on 1200 Israelis, the prevalence of taurodontia in patients with missing upper lateral incisor was statistically different and higher (5.6%, P-value < 0.001). The prevalence of palatally impacted upper permanent canine (8.8%) was significantly different and higher than that in the general population (1.53% and 1.7%, P-value < 0.001). Nevertheless, this anomaly prevalence in the sample monitored was not significantly different from that in the orthodontic population (5.2% and 8%, P-value = and P-value = ). While in studies with orthodontic patients authors make difference in impacted upper permanent canine location, and give prevalence for palatally impacted canine, comprehensive population studies of impacted teeth usually make no difference in the location of impacted upper permanent canine. With regard to the fact that palatal position is 2-3 times more frequent than the vestibular one, we can assume that reference values for the general population would be lower in the case the position would be differentiated. The difference in prevalence between the sample of patients and the general population would be even more significant. Though we did not find a significant difference between patients with missing upper lateral incisors and orthodontic patients, we cannot exclude the possible connection and common genetic background in palatally impacted canine and missing upper lateral incisor. In comparison with a control group, Sacerdotiand Baccetti[55] found higher prevalence of palatally impacted canine in patients with missing upper lateral incisor. However, they did not prove reciprocal relationship, i.e. higher prevalence of upper lateral incisor agenesis in patients with palatally impacted canine. The prevalence of ectopic eruption and impaction of lower permanent second molar (1.8%) was compared with values given in four comprehensive population studies. In two cases the prevalence was significantly different and higher than prevalence in the general population (0.06% and 0.15%, P-value = and P- value = ). When compared with population studies by Mead [47], Bondemark and Tsiop [48] the difference was not statistically significant (0.4% and 1.4%, P-value = and P-value = ). The fact may be due to different diagnostic criteria applied. It is rather difficult to find at least two studies using the same diagnostic criteria because there are not many works dealing with the prevalence of ectopic eruption or impaction of lower permanent second molar. Garibe et al [12] observed increased prevalence of mesially inclined lower second molar in patients with missing second premolar. Another work by Garibe et al [51] found redakce@orthodont-cz.cz