Dental and Oral Biology

Because the apical pulpal circulation is not disrupted, pulp necrosis in the apical segment is extremely rate. Pulp necrosis develops in the coronal segment owing to the displacement but occurs in only 25% of the cases.

Dental pulp is in many ways similar to the connective tissues of the body. It houses a number of tissue elements, including nerves, vascular tissues, CT fibres, ground substance, interstitial fluid, odontoblasts, fibroblasts, immune competent cells and other cellular components.

Stratified squamous epithelium is a multi-layered tissue that protects underlying structures from abrasion, mechanical stress, and pathogens. In the mouth cavity, it faces constant friction from chewing, food movement, and microbial exposure. The stratified arrangement allows surface cells to be worn away while deeper cells replace them, maintaining protection. This is why areas subjected to mechanical stress like the mouth, esophagus, and skin are lined with stratified epithelium rather than simple epithelium.

The permanent teeth of a man includes 8 incisors, 4 canines, 8 premolars and 12 molars. Thus, there are 4, 2, 4, 6 incisors, canines, premolars and molars respectively in each jaw of man.

Zone III-body of lesion A. It represents area of greatest demineralization B. Pore volume 5-25% C. Increased prominence of striae of Retzius is seen

Accretion-It is a process where most of the fluoride is buried within mineral crystallites during crystal growth.

Bones and teeth are primarily composed of calcium phosphate in the form of hydroxyapatite crystals. This mineral compound provides hardness and structural strength to skeletal tissues. Calcium sulphate is found in plaster of Paris, while calcium hydrogen sulphate is not a major component of bones or teeth.

Human canines are the longest and most stable of teeth in the dental arch. Only one tooth of this class is present in each quadrant. Humans have two upper (maxillary) canines and two lower canines. Canines play a vital role in the biting mechanism of the teeth. They touch first when the jaw closes and guide the other teeth into position.

The soft palate also known as velum or muscular palate is the soft tissue constituting the back of the roof of the mouth in mammals. It is movable and consists of muscle fibers sheathed in mucous membrane. It is responsible for closing off the nasal passages during the act of swallowing and also for closing off the airway. During sneezing, it protects the nasal passage by diverting a portion of the excreted substance to the mouth.

It is the material from which the teeth and tusks of animals are made. It is also called as enamel. It covers the surface of the tooth or tusk, which receives the most wear such as the tip or the crown. Ameloblasts are responsible for the formation of enamel and are lost after the enamel process is complete. 

The dental pulp is the central part of a tooth, which is made up of living connective tissue and cells called odontoblasts.

An abscess is a localized collection of pus that forms in tissues, organs, or spaces within the body due to infection. It typically develops as the immune system responds to bacterial infection, sending white blood cells to the site which then accumulate as pus. Lesion refers to any abnormal tissue change, inflammation is the body's response to injury/infection, and oedema is fluid swelling - none specifically mean pus collection.

It is in anaemia that the haemoglobin in the blood reduces. It is caused by the deficiency of iron. Hence, the oxygen carrying capacity of the blood reduces. It is in night blindness that the patient cannot see in dim light. In anaemia, the haemoglobin in the blood reduces.

This is the correct option. Molars are 12 in number in an adult human mouth.

Carnassials are paired upper and lower teeth (either molars or premolars and molars) modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. The modification arose separately in several groups of carnivorous mammals. Different pairs of teeth were involved in the separate modifications. In modern Carnivora, the carnassials are the modified fourth upper premolar and the first lower molar. These teeth are also referred to as sectorial teeth.