Dental and Oral Biology

A diastema is an area of extra space between two or more teeth. The two front teeth of the upper jaw area is where diastema is most frequently seen. Many children experience diastema as primary teeth fall out, though in most cases these spaces close when the permanent teeth erupt. Diastemas may also be caused by a tooth size discrepancy, missing teeth or an oversized labial frenum, the tissue that extends from the inside of the lip to the gum tissue where the upper two front teeth are located. Secondary reasons involve oral alignment issues such as a protrusion of the teeth. Thus, option B is correct.

The four front teeth in each arch are called incisors, and their function is to cut food with their sharp thin edges. On each side of the incisors, at the corners of the mouth, are the canines. These teeth have one cusp, or pointed edge, and are used for holding or grasping food, and are very strong, stable teeth. Behind the canines are the premolars, which are designed for holding food like the canines because they have cusps, but they also function to crush food. Sometimes these teeth are referred to as bicuspids, meaning two cusps, but this is not always accurate because some premolars may have three cusps. Therefore the term premolar is preferred. The teeth farthest back in the mouth are the molars. These teeth have broad chewing surfaces with four or five cusps, and are designed for grinding food. The incisors and canines are called anterior teeth, because they are located in the front of the mouth, while the premolars and molars are called posterior teeth because they are located in the back of the mouth. Thus, option A is correct.

In anatomy, a heterodont is an animal which possesses more than a single tooth morphology. For example, members of the Synapsida generally possess incisors, canine, premolars, and molars. The presence of heterodont dentition is evidence of some degree of feeding/hunting specialization in a species. In contrast, homodont dentition refers to a set of teeth that possess the same tooth morphology. Acrodont is a formation of the teeth whereby the teeth are consolidated with the summit of the alveolar ridge of the jaw without sockets. Pleurodont is a formation of the teeth that are fused by their sides to the inner surface of the jaw bones. Thus, option D is correct.

The permanent molars occupy the most posterior portion of the dental arch. They have the largest occlusal surfaces of any of the teeth and have from three to five major cusps. Lower permanent molars always have two lingual cusps and upper permanent molars always have two buccal cusps. Lower molars have two roots and upper molars have three roots. Molar teeth by definition are cheek teeth that are not preceded by primary teeth. Permanent molars are accessional teeth without primary predecessors. In contrast to the molars, permanent incisors, canines and premolars are succedaneous (successional teeth). Premolar, canine and incisors does not have three roots. Thus, option A is correct.

The skeletal system is divided into an axial and appendicular skeleton and it provides both support protection to the brain as well as give shape to the face. The skull is part of the axial skeleton. Skull or cranium has 22 bones out which mandible  (lower jaw) is a single bone. It is lowest and strongest bone which hold the lower teeth in the socket and gives shape to the face. 

There are several types of teeth and each performs its own special function in the chewing process, depending on its size, shape, location within the jaws. Starting at the midline, the permanent dentition is comprised of incisors, canines, premolars and molars.
Therefore, the correct answer is option D.

Teeth are the hardest substance in the human body. The enamel on your teeth is the hardest and most highly mineralized substance in your body. It covers the outer layer of each tooth and it is the most visible part of the tooth. The enamel is made up mostly of minerals, primarily hydroxyapatite. So, enamel is the hardest substance in our body compared to dentine, collagen and melanin. 

Canines are pointed teeth located between the incisors and premolars, specifically adapted for tearing food, particularly flesh.

Dental pulp is an unmineralized oral tissue composed of soft connective tissue, vascular, lymphatic and nervous elements that occupies the central pulp cavity of each tooth. Pulp has a soft, gelatinous consistency. The pulp cavity extends down through the root of the tooth as the root canal which opens into the periodontium via the apical foramen. The blood vessels, nerves etc. of dental pulp enter and leave the tooth through this foramen. This sets up a form of communication between the pulp and surrounding tissue - clinically important in the spread of inflammation from the pulp out into the surrounding periodontium. 

Dentine is the calcified tissue of the body, is one of the components of the teeth along with enamel, cementum and pulp. It is generally surrounds the entire pulp is a covering beneath the enamel. 70% of the weight of dentine is made up of mineral hydroxylapatitie, while 20% is organic material and the rest 10% is water.

• The canines are the pointed and the sharp teeth which are found in the mouth of the humans. 
• These are the teeth that are used for tearing of the food. The sugarcane is made up of tough fibers. These fibers can be torn with the help of canine teeth. 
• Thus, the correct answer is option B. 

Human teeth have two sets of teeth during their life one temporary set of milk teeth and one permanent set. Once the milk teeth have replaced by permanents, then the permanent teeth are not going to replace again in life naturally after 12 years of age.

Canines are well developed in carnivore animals. They having pointed ends which help in tearing of fleshy food

An adult human has 32 permanent teeth which of four types, namely incisors, canines, premolar, and molars. Such type of dentition is called heterodont dentition.