Cov hniav yog ib qho tseem ceeb tshaj plaws ntawm tib neeg lub cev. Txhua tus ntawm lawv muaj cov qauv tshwj xeeb thiab ua haujlwm tshwj xeeb. Cov hniav dab tsi ntawm cov hniav sab sauv muaj? Lub puab tsaig ntawm lub puab tsaig yog dab tsi? Hauv cov no thiab lwm yam teeb meem ntsig txog tus qauv ntawm cov hniav, peb yuav tsum paub txog nws.
Cov lus qhia dav dav txog cov hniav
tus neeg laus muaj peev xwm muaj li ntawm 28 mus rau 32 cov hniav hauv qhov ncauj. Lawv yog cov tshwj xeeb formations nrog ib tug complex qauv. Qhov pom ntawm txhua tus hniav yog hu ua crown. Ib qho ntawm nws cov khaubncaws sab nraud povtseg yog dentin - ib qho nyuaj calcified uas tsis muaj cov hlab ntsha. Los ntawm saum toj no nws yog them nrog cov hniav enamel. Nws ua raws li lub plhaub tiv thaiv sab nraud.
Qhov zais ntawm cov hniav yog hauv paus. Nws muab tso rau hauv kev nyuaj siab nyob rau hauv lub puab tsaig hu ua alveolus. Hauv paus kuj muaj dentin. Nws yog them nrog ib txheej ntawm cement, vim hais tias cov hniav yog tuav nyob rau hauv lub recess ntawm lub puab tsaig. Hauv cov pob txha tsim yog cov kab noj hniav, muaj cov hlab ntsha, cov hlab ntsha thiab cov nqaij mos.cov ntaub so ntswg sib txuas.
Hom thiab kev ua haujlwm ntawm cov hniav
Kev tshuaj ntsuam xyuas ntawm lub puab tsaig qis thiab lub puab tsaig sab sauv faib cov pob txha tsim nyob rau hauv lub qhov ncauj kab noj hniav mus rau ntau hom:
- molars loj (molars);
- pem hauv ntej (incisors);
- conical (fangs);
- molars me (premolars).
Hniav ua ntau yam haujlwm tseem ceeb. Ua ntej, lawv muab cov khoom siv tshuab ua khoom noj. Ua tsaug rau cov hniav, tib neeg tuaj yeem noj zaub mov tag nrho. Qhov thib ob, cov pob txha pob txha no koom nrog kev tsim cov lus hais. Lawv tsim cov suab sib txawv. Thib peb, cov hniav yog ib feem ntawm kev luag nyav. Lawv ua lub luag haujlwm tseem ceeb hauv kev zoo nkauj.
Koj tuaj yeem hais txog cov haujlwm uas muaj nyob hauv txhua tus hniav tshwj xeeb. Cov incisors nyob rau hauv lub frontal ib feem ntawm lub qhov ncauj kab noj hniav muab txiav zaub mov. Qhov no yog yooj yim los ntawm lawv lub tiaj tus chisel-shaped crown. Cov fangs ua haujlwm ntawm crushing thiab ntes cov zaub mov, raws li lawv muaj ib tug taw tes cone puab. Molars thiab premolars koom nrog kev sib tsoo zaub mov, vim tias lawv qhov chaw dav heev.
txoj hauj lwm ntawm cov hniav ntawm lub puab tsaig
Kev kho lub puab tsaig ntawm lub puab tsaig sab hauv thiab sab sauv qhia tau hais tias cov pob txha tsim muaj nyob rau hauv daim ntawv ntawm arcs, txhua tus tuaj yeem muab faib ua 2 sab (quadrant). Ib quadrant hauv ib tug neeg laus muaj 8 tus hniav:
- 3 molars;
- 2 txiav;
- 1 fang;
- 2 premolars.
Qee tus neeg muaj molars nyobqhov kawg nyob rau hauv cov hniav thiab hu ua "cov hniav ntse", yog tsis tuaj. Hauv txhua lub quadrant, tsis yog 8, tab sis 7 pob txha tsim tau. Qhov tsis muaj "cov hniav ntse" yog qhov qub. Hauv qee tus neeg, lawv tawg thaum muaj hnub nyoog 24-26 xyoo thiab yuav tsum tau tshem tawm vim kev loj hlob ntawm lub kaum sab xis tsis ncaj ncees lawm, thaum lwm tus lawv tsis tshwm sim.
cov molars
Raws li lub cev nqaij daim tawv ntawm lub puab tsaig sab sauv thiab sab qis qhia tau hais tias, qhov nyuaj tshaj plaws morphological units ntawm tib neeg cov hniav yog cov molars. Lawv nyob rau hauv qhov chaw kho hniav tom qab cov molars me me. Muaj 6 molars ntawm lub puab tsaig sab sauv - 3 cov hniav ntawm ib sab thiab lwm yam. Cov kws tshaj lij paub qhov txawv ntawm cov molars thawj, thib ob thiab thib peb.
Cov hniav loj tshaj plaws ntawm cov molars loj yog thawj cov molar sab saud. Nws yog daim duab peb sab. Qhov saum npoo ntawm cov molar, tig mus rau cov hniav ntawm cov kab rov tav, tej zaum yuav yog square lossis pob zeb diamond-puab hauv cov duab. Nws muaj 4 tubercles (tag nrho cov qhov siab hauv qab no yog sib cais los ntawm grooves):
- distal-palatal;
- disto-buccal;
- media-buccal;
- medial-palatal.
Cov molar thib ob txawv ntawm thawj tus hauv nws qhov chaw zom zaub mov. Ntawm nws, 30-40% ntawm cov neeg muaj 3 tubercles. Hauv 5% ntawm cov neeg mob, ob-cusp qaum molar tshwm sim. Ib tug hniav feem ntau muaj 3 cag. Qee zaum 2 ntawm lawv loj hlob ua ke.
Qhov thib peb lub puab tsaig sab sauv muaj lub kaus mom luv tshaj plaws. Qhov chaw zom zaub mov tuaj yeem yog tri-tubercular. Hauv qee tus neeg, tus hniav no muaj 4 cusps. Daim ntawv bicuspid yog qhov tsawg heev. Ib tug molar tej zaum yuav muaj2, thiab 3 roots. Qee zaum lawv coalesce.
cov molars
Qhov txawv ntawm qhov qis qis ntawm cov molars los ntawm sab sauv yog feem ntau nyob rau hauv cov duab ntawm cov yas. Nws tuaj yeem yog duab plaub lossis pentagonal. Lwm qhov txawv ntawm cov molars qis los ntawm sab saud yog tus naj npawb ntawm cov hauv paus hniav. Cov pob txha tsim nyob hauv qab no muaj 2 cag.
Lub cev ntawm lub mandibular molars yog raws li hauv qab no:
- thawj cov molar muaj qhov distal, distal-lingual, disto-buccal, mesial-lingual, thiab mesial-buccal cusps.
- Cov molar loj tom ntej no tsis muaj qhov cusp. Lub crown muaj plaub-cusp tsos.
- Qhov thib peb molar, uas yog qhov tsawg tshaj plaws ntawm cov molars loj ntawm lub puab tsaig qis, muaj 4 cusps hauv 50% ntawm cov neeg, 5 ntawm 40%.
Upper incisors
pob txha tsim nyob rau hauv pem hauv ntej ntawm lub puab tsaig sab sauv thiab muaj ib lub hauv paus yog hu ua Upper incisors. Feem ntau, yuav tsum muaj 4 hniav - 2 lub hauv paus thiab 2 sab. Txawm li cas los xij, ntau thiab ntau tus kws kho mob tau ntsib nrog thawj adentia (tsis tuaj) ntawm sab sauv incisors. Nyob rau hauv ancient sij hawm, tib neeg noj khoom noj khoom haus. Ob qho tib si hauv nruab nrab thiab sab nraud incisors tau koom nrog hauv kev zom zaub mov. Niaj hnub no, tib neeg noj cov zaub mov softer. Tam sim no lub zog ntawm lub hauv paus incisors yog txaus los tom cov zaub mov. Lateral hniav nqa tsawg kawg nkaus load. Hauv qhov no, lawv qhov txo qis tau pom.
Lub hauv paus ntawm lub hauv paus incisors yog dav. Nyob rau hauv nruab nrab-distal kev taw qhia, nws dav yog kwv yees li 8-9 mm. Hais txog lub vestibular nto, nws yog tsim nyog sau cia hais tias nyob rau hauv lub Upper incisors nws txawv. Anatomy ntawm lub puab tsaig sab hauv thiab sab sauv qhia tias:
- Central qaum cov hniav tuaj yeem yog duab plaub, daim duab peb sab;
- qee tus neeg muaj lub thoob-zoo li lub taub hau;
- Cov hniav sab sauv zoo li daim duab peb sab lossis lub thoob zoo li.
Lub palatal nto ntawm sab sauv incisors tuaj yeem tiaj tus, sib npaug concave, spatulate (scoop-shaped). Nws cov tsos yog nyob ntawm qhov degree ntawm kev loj hlob ntawm qhov nruab nrab thiab distal marginal ridges, stretching ntawm lub hauv paus ntawm lub crown mus rau lub ces kaum ntawm txiav ntug ntawm cov hniav. Qhov txiav ntug ntawm hnav incisors muaj khoov - cov hniav thiab tubercles. Qhov no waviness ploj mus raws li cov hniav ua haujlwm hauv lub qhov ncauj.
qis qis
Cov hniav me tshaj plaws nyob rau hauv lub qhov ncauj kab noj hniav, raws li qhia los ntawm topographic anatomy ntawm lub puab tsaig sab, yog cov qis incisors. Lawv yog cov loj me me rau cov incisors nyob rau hauv lub Upper dentition. Qhov no yog vim qhov tseeb tias nyob rau hauv cov txheej txheem ntawm kev noj zaub mov, cov hniav qis ua haujlwm pabcuam.
Muaj 4 incisors ntawm lub puab tsaig qis - 2 nruab nrab thiab 2 sab. Cov hniav hauv nruab nrab tej zaum yuav muaj lub ntsej muag ovoid los yog duab plaub vestibular. Nyob rau sab nraud incisors, nws muaj daim ntawv ntawm daim duab peb sab isosceles, muajlub hauv paus ntawm ntug incisal thiab lub apex uas lub caj dab ntawm cov hniav nyob.
Lub lingual nto ntawm lub hauv qab incisors yog du, concave. Cov duab yog triangular. Raws li cov npoo ntawm lingual nto ntawm cov hniav hauv qab yog cov distal thiab medial marginal ridges. Lawv tsim tsawg dua nyob rau sab sauv incisors. Nyob rau hauv cov hniav tshiab erupted, lub incisal ntug yog tortuous. Cov pob no pom meej meej. Maj mam lawv ploj. ntug incisal yuav txawm.
Topographic anatomy ntawm cov hniav ntawm lub puab tsaig sab sauv thiab sab qis suav nrog kev kawm txog cov qauv ntawm cov canines. Cov no yog cov pob txha loj tsim ntawm cov kab mob dentoalveolar, muaj ib lub hauv paus muaj zog thiab ntev thiab ib leeg-tubercular crown. Cov qauv ntawm cov hniav saum toj no yog vim cov haujlwm uas lawv ua.
Cov canines sab saud yog nyob rau hauv qhov chaw uas qhov chaw kho hniav sab sauv nkhaus ntawm pem hauv ntej mus rau sab nraub qaum. Lub vestibular nto ntawm lub crown muaj ib tug rhomboid duab. Ib tug nruab nrab roller, kuj hu ua lub hauv paus mamelon, hla nws. Hauv qee tus neeg, nws pom meej meej, thaum nyob rau lwm tus nws nyuam qhuav qhia. Cov menyuam nruab nrab xaus nrog lub kua muag tubercle, uas yog qhov tshwj xeeb ntawm cov fangs. Raws li cov npoo ntawm lub crown, kuj tseem muaj lateral mamelons - medial thiab distal. Lawv tsim lub ntsej muag ntawm lub tubercle.
Lub palatal nto ntawm canines yog me ntsis convex thiab embossed. Ib tug me me tubercle pom nyob rau hauv lub ncauj tsev menyuam cheeb tsam. Qhov nruab nrab ridge khiav los ntawm nws mus rau lub ntsiab tubercle. Ntawm ob sab, qhov distal thiab medial marginal ridges tuaj yeem paub qhov txawv. Lawv txuas ntawm cov ces kaum ntawm lub crown mus rau lub palatine tubercle.
Ntaunqaim thiab elongated crown, tsawg loj - cov yam ntxwv uas paub qhov txawv qhov qis canines los ntawm sab sauv sawv daws yuav. Txawm li cas los xij, cov qauv ntawm cov hniav zoo ib yam. Yog tias peb sib piv cov canines ntawm lub puab tsaig qis thiab sab sauv, peb tuaj yeem pom tias lub kaus mom muaj lub pob zeb diamond. Tsuas yog ntawm no, ntawm cov hniav qis, sab saum toj ntawm lub rhombus nyob rau hauv cheeb tsam ntawm lub tearing tubercle yog smoothed, truncated.
Ntau tus neeg muaj lub plab mog ntawm lub puab tsaig qis. Anatomy piav qhia qhov no los ntawm qhov tseeb tias cov menyuam nruab nrab, dhau ntawm lub vestibular nto, tau qhia zoo heev. Lateral ridges feem ntau tsis tshua pom. Txawm li cas los xij, hauv qee tus neeg, vestibular nto ntawm cov hniav muaj cov duab flattened. Qhov nruab nrab ridge nyob rau hauv xws li yog tsawg pronounced.
Txoj kev nyem ntawm lub lingual nto ntawm cov canines qis yog qhov tsis zoo. Nyob rau hauv lub ncauj tsev menyuam cheeb tsam muaj ib tug lingual tubercle. Nws merges smoothly nrog lub ntsiab ridge, xaus nyob rau hauv nruab nrab peb ntawm lub lingual nto. Marginal ridges yog pom raws ntug ntawm lub crown.
Upper premolars
Muaj 4 premolars ntawm lub puab tsaig sab sauv - 2 cov molars me me ntawm txhua sab. Lawv nyob rau hauv nruab nrab ib feem ntawm kev kho hniav koov, tuav lub 4th thiab 5th txoj hauj lwm. Premolars, raws li muaj pov thawj los ntawm lub cev nqaij daim tawv ntawm cov hniav ntawm lub puab tsaig sab sauv thiab sab qis, ua haujlwm pabcuam hauv cov txheej txheem ntawm cov khoom noj khoom haus. Lawv tsoo thiab zom cov zaub mov uas lawv noj.
Qhov txawv ntawm thawj thiab thib ob sab sauv premolars. Thawj cov molar me me, muaj lub ntsej muag prismatic, tuaj yeem yog ob lossis ib qho hauv paus. Nyob ntawmzom zawg nto muaj 2 tubercles - buccal thiab palatine. Thawj tus yog feem ntau loj dua thiab siab dua. Nruab nrab ntawm lawv muaj ib tug intertubercular furrow. Muaj marginal ridges raws ntug ntawm lub crown.
Qhov thib ob sab sauv premolar muaj yuav luag tib lub qauv. Tsuas muaj ob peb tus yam ntxwv txawv:
- hniav feem ntau muaj ib lub hauv paus kwj dej thiab ib lub hauv paus;
- crown nyem yog smoother;
- chewing tubercles yuav luag tib qhov siab;
- lateral ridges are underdeveloped.
qis premolars
Cov molars qis dua, tsis zoo li cov sab sauv, me dua, muaj ib lub hauv paus ntev dua thiab ib puag ncig puag ncig hauv kab rov tav. Cov neeg uas paub lub cev nqaij daim tawv ntawm cov hniav ntawm lub puab tsaig sab hauv lub puab tsaig txawv ntawm thawj thiab thib ob qis premolars, uas txawv me ntsis hauv cov qauv.
thawj tus dais no zoo ib yam li tus fang. Cov hniav no muaj cov yas zoo sib xws. Txawm li cas los xij, ib qho molar me me, tsis zoo li ib tug canine, muaj 2 tubercles ntawm qhov zom zaws. Thawj ntawm lawv yog hu ua buccal, thiab lub thib ob - lingual. Cov tubercles yog sib cais los ntawm ib tug intertubercular furrow. Hauv ntau tus neeg nws cuam tshuam los ntawm qhov nruab nrab transverse crest.
Qhov thib ob me me molar, raws li pov thawj los ntawm lub cev nqaij daim tawv ntawm tib neeg lub puab tsaig qis, yog me ntsis loj dua thawj. Qhov chaw zom zaws yog bicuspid. Qee zaum 3 thiab 4 tubercles tau tshwm sim. Nyob rau saum npoo ntawm ib tug me me molar muaj ib tug tob transverse zawj nrogceg ceg. Lub hauv paus ntawm tus thib ob premolar yog ntev tshaj qhov thawj.
Yog li, cov hniav uas ua rau lub puab tsaig sab sauv thiab sab qis, cov qauv, lub cev nqaij daim tawv ntawm cov ntsiab lus no yog lub ntsiab lus nyuaj tab sis nthuav. Txhua pob txha tsim los ntawm cov ntaub so ntswg tshwj xeeb, muaj nws cov hlab ntsha thiab lub paj hlwb. Cov qauv ntawm cov hniav yog qhov nyuaj heev, vim nws nyob ntawm cov haujlwm uas lawv ua.
