Shedding and Maxillary Sinus

Vocabulary flashcards covering shedding of deciduous teeth and maxillary sinus anatomy, histology, physiology, and clinical implications.

Shedding

Natural physiological elimination of deciduous teeth due to resorption of their roots before eruption of permanent successors.

Odontoclasts

Cells that resorb dentine and cementum during shedding; resemble osteoclasts and are responsible for resorption of hard tissues.

Cementum

Mineralized tissue covering the tooth root; resorbed by odontoclasts during shedding.

Dentin

Mineralized tissue of the tooth beneath enamel; resorbed by odontoclasts during shedding.

Resorption lacunae

Pits on exposed root surfaces where resorption by clasts occurs.

Howship’s lacunae

Bay-like depressions in bone/root surfaces where osteoclasts/odontoclasts reside during resorption.

PDL fibroblasts apoptosis

Programmed cell death of periodontal ligament fibroblasts observed during shedding, indicating genetic control.

Osteoclasts

Multinucleated cells that resorb bone; morphologically related to odontoclasts.

Odontoclasts

Multinucleated cells that resorb dentine and cementum during shedding; similar to osteoclasts.

Ruffled border

Resorptive surface of clasts with high surface area that pumps protons to demineralize.

Clear zone

Sealing/attachment zone around the clast where it adheres to the root surface.

Multinucleated cells

Cells containing multiple nuclei, characteristic of clasts involved in resorption.

Acid phosphatase activity

Enzymatic activity in clasts that helps degrade organic matrix during resorption.

Demineralization

Removal of inorganic mineral content from hard tissue during resorption.

Successional dental lamina

Epithelium that forms on the lingual side of a deciduous tooth and gives rise to the permanent successor.

Lingual apical resorption (anterior teeth)

Resorption of the root beginning at the lingual apical area of deciduous anterior teeth.

Inter-radicular resorption (molars)

Resorption occurring between roots of deciduous molars.

Eruption-related resorption pattern

Resorption pattern related to the location of erupting permanent successors.

Retained deciduous tooth

Deciduous tooth that remains in the arch beyond the age at which it should shed.

Ankylosis

Root fused to alveolar bone, leading to a submerged or non-erupting tooth.

Submerged tooth

Retained tooth surrounded by bone due to ankylosis, appearing below adjacent teeth level.

Remnants of deciduous teeth

Root fragments not in the path of eruption of permanent teeth; may be ankylosed or resorbed.

Hypodontia

Congenital absence of one or more teeth; frequency about 2–9%.

Physiologic resorption

Normal resorption of deciduous teeth even without a permanent successor; may be delayed if teeth are congenitally missing.

Undermining resorption

Root resorption caused by pressure from erupting permanent teeth, often affecting specific tooth pairs.

Pink tooth syndrome

Appearance of a pink shadow in the tooth due to pulp visibility through a thin shell or resorption of the root; may lead to early loss.

Maxillary sinus

Largest bilateral air sinus (antrum of Highmore); pyramidal in shape within the maxilla.

Antrum of Highmore

Another name for the maxillary sinus.

Ostium maxillare

Drainage opening of the maxillary sinus into the middle nasal meatus.

Hiatus semilunaris

Recess in the middle nasal meatus containing the ostium maxillare.

Capacity of the maxillary sinus

Approximately 15 ml.

Pneumatization

Growth of the maxillary sinus by inner resorption and facial bone deposition; enlarges sinus and thins its walls.

Respiratory (pseudostratified ciliated) epithelium

Lining of the maxillary sinus: pseudostratified columnar ciliated epithelium with goblet cells.

Goblet cells

Mucus-secreting cells in the sinus epithelium; apical mucus release followed by regeneration of the apex.

Cilia (9+1 arrangement)

Hair-like projections beating to move mucus toward the nasal cavity; organized in a microtubule pattern described here as 9+1.

Lamina propria

Connective tissue layer under the epithelium; contains mucous glands pertinent to the sinus.

Oro-antral communication

Pathway between the oral cavity and maxillary sinus, commonly after tooth extraction.

Oro-antral fistula

Persistent opening between the oral cavity and maxillary sinus.

Tooth-sinus relationship during extraction

Extraction of maxillary teeth can risk pushing a tooth into the sinus or creating an oro-antral communication.