Oral histology and embryology Mgr. Jan Krivanek, Ph.D. jan.krivanek@med.muni.cz March 10, 2021 •Aims of the subject • •Microskopic anatomy of orofacial organs •Connections of structure and function •Detailed understanding of developmental processes •Understanding of congenital malformations • • •Lectures: even Wednesdays 10:00 (online) • •Practises: odd Wednesdays 10:00 Seminar room • • •Lecturers: •Mgr. Jan Křivánek, Ph.D. •(Mgr. Eva Švandová, Ph.D.) • http://www.med.muni.cz/histology/masters-degree-programmes Needs to pass the course successfully Practicals: 100% attendance Tests Exam: Successful Practicals Written test All ropots, individually fulfilled Literature Ten Cate's Oral Histology: Development, Structure, and Function. Antonio Nanci Essentials of Oral Histology and Embryology: A clinical Approach Illustrated Dental Embryology, Histology and Anatomy, Fehrenbach and Popowics Oral Anatomy, histology and Embryology, Berkovitz, Holland, Moxham Presentations (lectures + practicals) • •Ten Cate's Oral Histology: Development, Structure, and Function. •Antonio Nanci Essentials of Oral Histology and Embryology: A Clinical Approach Daniel J. Chiego •Orofacial system • •Structures of the head and neck which: oAre essential for intake, grinding and processing of food oMaintain taste and tactile sensations oForms an interface for social interactions (phonetic, aesthetic-physiognomic function, mimics, speak) • • • (Helms et al. 2005) Development from pharyngeal or branchial arches, projections of frontal (frontonasal) prominence, upper and maxillomandibular prominence •Orofaciální systém • •Orofacial system is composed of: • •Skeleton faciei - (facial skeleton) mandible, maxilla, ossa zygomatica, os ethmoides, ossa nasalia et lacrimalia, vomer, ossa palatina, os hyoides) + art. temporomandibularis) •Cavitas oris - lingua (tongue), dentes, periodontium, salivary glands (glandulae salivariae) •Art. temporomandibularis •Mimic muscles and muscles of mastication •Soft tissues of the face – lips, cheeks •Hard and soft palate – (palatum durum a palatum molle) •Isthmus of the fauces – (isthmus faucium) •Palatinal and tongue tonsils •Oral cavity (cavitas oris) • •Basic anatomy • •Oral mucosa and microscopic structure •Lining mucosa •Masticatory mucosa •Specialized mucosa • •Lips •Microscopic structure of tongue •Taste buds Oral cavity (cavitas oris) vestibulum oris / cavitas oris propria Borders Lips, cheeks, hard and soft palates, caudally floor of cavity, faucial isthmus (connection to oropharynx) Inside Tongue, teeth, gums, tonsilla palatina Major salivary glands: gl. submandibulatis gl. sublingualis gl. parotis dut Mucosa of oral cavity Except of teeth it covers all surfaces inside the oral cavity Oral mucosa has 2 layers (epithelium + lamina propria mucosae) At some places is between mucosa and the base (bone/muscles) located connective tissue - tela submucosa Functions of oral mucosa: •Protective - resistant to mechanical and chemical forces or effects of the bacterial flora •Secretory - saliva - a product of small and large salivary glands •Sensory - contains receptors for perception of temperature, pain, touch and taste •Thermoregulatory - in animals - (protruding tongue) Forms special transitory zone inserted between the skin and the mucosa of the alimentary canal (starts in the pharynx) The oral mucosa differs from mucosa of the alimentary canal or mucosa other tubular organs by the origin - it was developed from the ectoderm and head mesenchyme of ectodermal origin (while elsewhere from the entoderm or mesoderm and mesenchyme of mesodermal provenience) Thanks to these circumstances) the oral mucosa shows some characteristics of the skin: keratinization of the epithelium, presence of lamina propria protrusions against the epithelium (papillae) Image result for oral mucosa Cook, Sarah et al. A food perspective. Food Hydrocolloids. 2017. Oral mucosa Oral mucosa classification Lining (65 %) Inner part of lips, cheeks soft palate, inferior aspect of the tongue, floor of the mouth and alveolar process (except of the gingiva) tela submucosa located under mucosa soft and slightly movable (submucous coat) lamina propria from loose connective tissue Masticatory (25 %) Hard palate and gingiva epithelium keratinized tela submucosa is missing lamina propria composed from dense collagenous of irregular type and firmly connected with periosteum (mucoperiosteum) Specialized (10 %) dorsal surface of the tongue mucosa protrudes into papillae tela submucosa is missing lamina propria connected with aponeurosis linguae https://i.ytimg.com/vi/pl3jnDRr9f4/hqdefault.jpg B, In histologic sections, the gingival epithelium is seen to be tightly bound to bone by a dense fibrous connective tissue (CT), whereas the epithelium of the lip (C) is supported by a much looser connective tissue. Gingiva Lip •Lamina propria from dense collagenous connective tissue of irregular type •Firmly connected to periosteum (mucoperiosteum) •Lamina propria from loose collagenous tissue •Tela submucosa under mucosa •Mucosa is slightly movable Figure_135 epithelium stratified squamous •Masticatory mucusa •(Specialized mucosa) Oral mucosa nonkeratinized keratinized •Lining mucosa Lamina propria mucosae Contains numerous of melanocytes or melanophages Multiple papilae projected against the epithelium. Their shape and density are spatially different (depends on different mechanical needs of oral mucosa) Figure_12-08b Figure_12-08a • •nonkeratinized type • • stratum basale - melanin • stratum spinosum • stratum intermedium - glycogen • stratum superficiale keratinized type stratum basale - melanin stratum spinosum stratum granulosum - keratohyalin stratum corneum - keratin The lamina propria mucose: loose connective tissue – it contains numerous melanophages (= cells with ingested melanin, which was extruded from melanocytes in the epithelium). It protrudes into papillae whose shape, size and density correspond with mechanical forces Classification of cell layers in the epithelium - similar as in the epidermis oral-zakl kopie The lining mucosa lamina propria tela submucosa retP0008 Lining mucosa of the lip Masticatory mucosa clinnically: mucoperiost Bez názvu 1 kopie Figure_12-05 Figure_130 gingiva stropdut soft 1 palatum durum palatum mole Hard palate (palatum durum) Masticatory mucosa: •Epithelium stratified squamous keratinizing •Tela submucosa missing patro1 Adipous zone Glandular zone raphe palati Image result for ductus incisivi Huge regional variability: Local differences in hard palate structure Palatal raphe •Midline from the incisive papilla to soft palate, mucosa without glandulae and adipocytes • Foramen incisivum •Location on the papilla incisiva •Maintains connection with nasal cavity before birth is closed Adipose zone •Paired structure •Medially divided by papilla incisiva and raphe palati, Laterally bordered by gingiva and premolars •Mucosa is thickened into 3-5 transversal plicae - plicae palatinae transversae, core of plicae is formed by stripes of dense colagenous connective tissue interlaced with adipocytes Glandular zone •Paired structure •Mucosa is smooth and contains true mucous glands – gll. palatinae PMC2798069_stem0027-1899-f6 https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Gray160.png/300px-Gray160.png Image result for n. nasopalatinus 040_cut_hard palate Hard palate – glandular zone glandulae palatinae Image result for vermilion border Lip Sagitally: •ventral aspect of the lip •dorsal aspect of the lip a) lamina epithelialis mucosae - stratified squamous epithelium b) lamina propria mucosae - loose areolar connective tissue •m. orbicularis oris •vermilion zone 002 Why do the lips have a red color? This coloration represents the combined effect of a number of factors: the concentration and state of dilation of small blood vessels in the underlying connective tissue, the thickness of the epithelium, the degree of keratinization, and the amount of melanin pigment in the epithelium. Color gives an indication as to the clinical condition of the mucosa; inflamed tissues are red, because of dilation of the blood vessels, whereas normal healthy tissues are a paler pink. Vermilion zone Lidské rty jsou pravděpodobně jedním z tělesných znaků ovlivněných pohlavním výběrem. Splňují totiž všech sedm kritérií, které Barber (1995) pro znaky ovlivněné pohlavním výběrem vytyčil. Jsou to následující kritéria: znak je sexuálně dimorfní, není přímo zapojen při rozmnožování, je nejvýraznější v době rozmnožování, je buď atraktivní pro opačné pohlaví nebo slouží k zastrašování soupeřů, míra jeho fenotypového projevu ovlivňuje reprodukční úspěšnost jedince, znak se mění v průběhu života a je variabilní mezi jedinci stejného pohlaví, jeho projev je závislý na pohlavních hormonech. Plnost ženských rtů zvyšuje atraktivitu obličeje, signalizuje totiž mládí a plodivost. Ke zvýšení své atraktivity žena používá rtěnku, případně trvalejší kosmetické zásahy (augmentací). Zdobení rtů (tetování, mutilace, piercing) je rozšířené u mnoha kultur světa současnosti i minulosti. Jeho základním významem je signalizovat společenskou a pohlavní dospělost jedince, zpravidla žen. Rty jsou pravděpodobně ovlivněny pohlavním výběrem. Anemie je všeobecným ukazatelem zdravotního stavu člověka. Anemická bledost (tj. nedostatek červeného krevního barviva hemoglobinu) je tudíž často znakem infekce a je možné očekávat, že bude figurovat při pohlavním výběru. Kromě toho, jestliže je anemie adaptivní odpovědí na parazitickou infekci, pak zdravotní výdaje udržování vysoké hladiny hemoglobinu možná zajišťují, že organismus nesoucí těžkou zátěž parazitů nebude riskovat předstírání zdravé červenosti (Jones 1997). also called margin or zone, is the normally sharp demarcation between the lip and the adjacent normal skin. It is where lipstick is sometimes applied. It represents the change in the epidermis from highly keratinized external skin to less keratinized internal skin. It has no sebaceous glands, sweat glands, or facial hair.^[1]^[2] It has a prominence on the face, creating a focus for cosmetics and is also a location for several skin diseases. Its functional properties, however, remain unknown. RetNovor Trávící systém I - 1 Ret - schéma glandulae labiales (mixed) Tongue Lingua (lat.) Glossa (gr.) radix Base: intra- and extraglossal striated muscles Evulutionary: developed in terrestrial vertebrates and amphibians (tetrapods) from muscles of oral floor Image result for snake tongue http://bharatmarg.com/wp-content/uploads/2017/12/snake-with-toung-split.jpg Surface Dorsum linguae Specialized oral mucosa Inferior aspect Lining mucosa Fibrous parts aponeurosis linguae very stiff fibrous membrane septum linguae Composed from dense collagenous tissue Image result for septum linguae Figure_139 Glands of tongue Glandula apicis linguae (gl. Blandini) mixed Ebner‘s glands (gll. gustatoriae) serous Weber‘s glands (gll. linguales post) mucinous Glands of tongue Glandula apicis linguae (gl. Blandini) mixed jazP0008Exp Ebner‘s serous glands jazP0024Exp Ebner‘s glands - gll. gustatoriae serous jazP0023Exp Duct of Ebner´s gland (V); H.E., obj. 10x Weberova mucinózní žláza MT-mucinózní tubuly, V-vývod. H.E., obj. 20x jazP0019Exp Weber‘s glands - gll. linguales post mucinous 005 Ebner‘s glands gll. gustatoriae serous Weber‘s glands gll. linguales post mucinous Dorsum lingue Specialized oral mucosa •Firmly connected with aponeurosis linguae • •Rough surface • •Mucosal outgrowths - lingual papillae • •Covered by nonkeratinized squamous stratified epithelium (except of papillae filiformes) Papillae fungiformes Mushroom-shape (0.5-1.5 in height, 0.5–1.0 mm in width) Taste buds in epithelium 006 Papillae filiformes The most abundant and distributed over the entire dorsal surface of the tongue; Brush-like appearance (0.5-1 mm in height, 0.2-0.3 mm in width); The stratified squamous epithelium is often cornified Papillae filiformes vs. Papillae fungiformes FILIFORM%20COMPOSITE FUNGIFORM%20COMPOSITE HoubPapila Keratinisation differences Taste bud Trávící systém I - 7 Jazyk - papilae foliatae Papillae foliatae Count: 3 - 8 Vertically-oriented Rudimental Laterally on the edge of the main body and root of tongue Taste buds Papillae vallatae (Papila circumvallata) Largest (1-4 mm in height, 1-3 mm in width), 7–12 just in front of sulcus terminalis, submerged into mucosa. Deep circumpapillary furrow. Taste buds https://render.fineartamerica.com/images/rendered/default/canvas-print/8.000/7.875/mirror/break/ima ges-medium/false-colour-sem-of-a-papilla-vallata-professors-pm-motta-kr-porter-pm-andrews-canvas-pr int.jpg Trávící systém I - 10 Chuťové pohárky Papilla vallata HP_img6-14-8 papilla pure serous Ebner‘s glands circumpapillary furrow Taste buds (caliculi gustatorii) •Intraepithelial structures • •Localization: •epithelium of vallate papillae + circumpapillar furrows •epithelium of fungiform papillae and foliate papillae •Number: around 2000 – 2500 in young individual, reduction with age up to 1/3 •Every taste bud is composed of 80-100 cells • Trávící systém I - 10 Chuťové pohárky jazyk_papily porus gustatorius Supporting cells Taste cells sweet, umami, sour, salty, and bitter—the so-called “basic” tastes (Fig. 1). There are likely additional qualities such as fatty, metallic, and others that might also be considered basic tastes. ? Basic tastes: Sweet Salty Sour Bitter Umami Suggested: Fatty Metalic TASTE ? • • • • • • • • • • • • •Inervation of taste buds •taste buds on fungigorm papillae - facial nerve - chorda tympani (through lingual nerve) •taste buds on foliate papillae and vallate papillae - n. glossopharyngeus •taste buds in other locations (radix of the tongue, the isthmus faucium - n. vagus CalyxGust Signal transmission Thank you for your attention!