Tib neeg cov hniav

Tib neeg cov hniav - khoom kawm ntawv, uas muaj nyob rau hauv lub alveoli ntawm lub puab tsaig. Lawv muaj ib qhov chaw ntawm lub tshuab, uas nws muaj nuj nqi yog zom nws. tib neeg cov hniav muaj ib tug muaj peev xwm rau ntau yam. Lawv yog cov me npaum li cas piv rau lub genus ntawm liab.

Muaj plaub pab pawg ntawm cov hniav: hniav puas, premolars, incisors, canines. Nyob rau hauv kev kho hniav ib yam li tsim faib los ntawm cov sab thiab pem hauv ntej. Tus txiv neej mus rau xya xyoo kev khiav hauj lwm rau ntawm lub ntus hniav, uas yog ces hloov mus rau tas mus li. Cov nuj nqis no yuav variations, uas yog tshwm sim los ntawm lub peculiarities ntawm kev noj haus thiab cov ib puag ncig. Rau 32 xyoo muaj lub xeem hniav ntawm no hom. Yog li, yuav tsum paub ntau npaum li cas cov hniav ib tug neeg muaj peev xwm tsuas yog nyob rau hauv lub hnub nyoog no. Qhov no yog tus nqi sib npaug zos rau 32. Qhov kawg hniav feem ntau txo, tej zaum lawv tsis tuaj. Muaj yog ib tug tshwj xeeb mis los mus txiav txim rau qhov nyiaj ntawm cov pob txha tsim cov ntaub ntawv. Nws yog hu ua tus hniav. Nyob rau hauv neeg laus, nws yog raws li nram no: peb hniav puas, ob premolars, ib canine, ob incisors nyob rau hauv txhua ib nrab ntawm ob leeg lub puab tsaig.

Anatomy ntawm tib neeg cov hniav

Muaj peb qhov chaw ntawm no tsim: lub crown, lub caj dab hauv paus. Hauv txhua hniav yog ib tug kab noj hniav, uas yog muab faib mus rau hauv ib tug hauv paus kwj dej thiab cov kab noj hniav ntawm lub crown. Los ntawm qhov apex nyob qab haus huv, cov hlab ntsha kom lub cev tau hauj lwm ntawm qhov hloov. Lawv muaj nyob rau hauv lub sis plawv hniav, uas yog sawv cev los ntawm xoob connective cov ntaub so ntswg. Phab ntsa uas ncaj qha mus rau lub zom nto ntawm ib tug hniav yog hu ua tsev ceev nyiaj.

Nyob rau hauv kev kho hniav kev cai uas kom paub qhov txawv plaub nto formations cov ntaub ntawv: vestibular, lingual, masticatory (y premolars thiab hniav puas - clamping dav hlau) hu rau. Cov kev tswj tsim los ntawm ncaj qha kev xeem. Lub crown thiab paus yog muab faib ua peb qhov chaw: hauv lub occlusal, nruab nrab, ncauj tsev menyuam thib peb.

tib neeg cov hniav muaj ib tug complex muaj pes tsawg leeg. Lawv tsim dentine, uas yog sawv cev kostepodobnoy daim ntaub muaj odontoblasts. Muaj pes tsawg leeg ntawm lub yav tas muaj xws li mineral ntsev (calcium fluoride, magnesium phosphate, calcium phosphate) thiab organic fibers (collagen).

hniav yas npog tshwj xeeb khoom substance - lub enamel, uas yog lub tsev ntawm prisms uas muaj ib tug tuab ntawm 3-5 microns. Nws muaj mineral ntsev zoo li cov uas nyob rau hauv lub dentin.

Lub caj dab thiab hauv paus them nrog xis mas - ib yam khoom uas tsa pob txha. Nws muaj 30% ntawm cov organic tshuaj (collagen), nyob rau hauv lub tshuav luj ntawm mineral ntsev (calcium carbonate, calcium phosphate).

Tag nrho cov kev kawm qhov ncauj ua ke nyob rau hauv lub sij hawm: dentition. Nws muaj ib tug complex hierarchy thiab nrog rau tus periodontium, cov leeg, cov pob qij txha, muaj qaub ncaug, cov hniav. Qhov no system muab lub zog ntawm zom thiab yog muab kev koom tes nyob rau hauv lub tsim ntawm kev hais lus.

Hniav antagonists hu ua osculating tsim sab sauv mandible. Pob Txha kabmob nyob rau sab laug thiab sab xis yog raug xa mus rau raws li antimeres.

Lub spatial kev sib raug zoo ntawm lub puab tsaig thiab dentition rau tag nrho cov taw yog hu ua kev. Kev daim ntawv ntawm lub sij hawm no occlusion, uas yog txiav txim los ntawm kev kaw cov formations thaum lub sij hawm zom. Nws yog ib tug txiav txim tau nyob rau hauv lub tsim ntawm ib tug occlusion.

Qhov no lub sij hawm yog hais txog tus piv ntawm lub sab sauv, qis dentition thaum lub sij hawm kaw ntawm lub puab tsaig. Cov nram qab no hom ntawm malocclusion: alveolar koov nyob rau tib theem, ib tug ntawm lawv yog nyob rau hauv pem hauv ntej ntawm lub lwm yam. Physiological xam tau tias yog ib qhov teeb meem nyob rau hauv uas lub sab sauv kab ntawm cov hniav yog dog dig txav tom ntej nrog kev sib hwm mus rau hauv qab. Txawm li cas los, nyob rau hauv ntau yam pathological tej yam kev mob nyob rau hauv lub qhov ncauj kab noj hniav, kev poob plig, occlusion tej zaum yuav txawv. Tib neeg cov hniav nyob rau hauv cov ntaub ntawv no, muaj peev xwm hloov tau lawv lub zoo thiab muaj pes tsawg leeg.