What is the difference between permanent and temporary dentine?

Temporary dentine refers to the deciduous or baby teeth, 20 teeth- 8 incisors, 4 canines and 8 molars, Permanent dentine, also known as secondary or adult

FORENSIC ODONTOLOGY FORENSIC SCIENCE

Shubham Kumar

1/29/20246 min read

Dentine refers to the set of teeth a human possess. The set of teeth is basic requirement for survival. Dentine is of two types of Primary Dentine and Secondary Dentine. The human set of teeth are organized in two opposite arches. The upper arch is called Maxillary and lower arch is called Mandibular. Permanent Dentine are also called adult set of teeth, whereas temporary dentine is called as deciduous or baby teeth.

In this article we are going to understand the difference between the permanent and temporary dentine.

Difference between Temporary Dentine and Permanent Dentine on the basis of their definition

Temporary dentine, also known as primary or baby dentine, is a crucial component of the human tooth that plays a vital role during the early stages of tooth development. This dentition has a total of 20 primary teeth, also known as baby teeth. These teeth start to erupt around the age of 6 months and continue until the child is about 2 to 3 years old. The eruption of these teeth is a natural part of tooth development. However, the process of tooth development begins long before we are born. Temporary dentine is the first type of dentine formed during this process.

Permanent dentine, also known as secondary or adult dentin, it is a crucial component of the adult tooth system and plays a significant role in one’s survival. Permanent dentine evolves from the temporary dentine. Therefore, it contains 32 teeth in total.

Difference between Temporary Dentine and Permanent Dentine on the basis of Premolars

Premolars are teeth with 2 cups on their heads, usually called as cuspids. However, they are not found in temporary dentine but present in permanent dentine and are present after the canines. Furthermore, are smaller and shorter in size than the canines.

Temporary Dentine has 0 premolars. On the other hand, Permanent Dentine has 8 premolars. Four on maxilla and four on mandible.

Difference between Temporary Dentine and Permanent Dentine on the basis of their developmental stage

Development of Temporary Dentine:

1. Tooth Development: Tooth development starts in the early stages of pregnancy. It is a fascinating process that involves the formation of different layers that make up a tooth.

2. Dentine Formation: Dentine is one of the primary materials that make up a tooth. It is a hard, mineralized tissue found beneath the outer layer called the enamel and surrounding the soft inner part known as the pulp. Dentine provides strength and support to the tooth structure.

3. Primary or Baby Teeth: Before permanent teeth come in, children have a set of temporary teeth. These teeth are often referred to as baby teeth or primary teeth. They are essential for several reasons:

  • Chewing and Speech: Baby teeth help children chew their food properly and speak clearly.

  • Spacing for Permanent Teeth: Baby teeth hold the space in the jaw for the permanent teeth to erupt correctly as the child grows.

4. Role of Temporary Dentine: Temporary dentine is specifically related to baby teeth. During tooth development, temporary dentine forms first, and then enamel and other layers cover it. It acts as a foundation for the tooth structure and provides a surface for enamel to attach.

5. Gradual Replacement: As a child grows, their jaw expands to make room for the larger permanent teeth. As a result, the baby teeth, along with their temporary dentine, will eventually fall out to allow the permanent teeth to take their place.

6. Caring for Baby Teeth: Even though baby teeth are not permanent, they require proper care. It is essential to practice good oral hygiene, such as regular brushing and dental check-ups. Healthy baby teeth contribute to the overall health and development of a child.

Stages of Development of Permanent Dentine:

1. Dental Bud Formation: The process begins during the early stages of prenatal development, usually around the sixth to eighth week of pregnancy. Dental buds, which are small bulges of specialized cells, start to form along the dental lamina, a thickened band of oral epithelium in the developing jawbone. These dental buds will eventually give rise to individual teeth.

2. Cap Stage: As the dental bud grows, it undergoes further differentiation, forming a cap-shaped structure called the enamel organ. The enamel organ consists of several distinct layers of cells, each playing a specific role in tooth development.

3. Dental Papilla Formation: Inside the enamel organ, a cluster of cells called the dental papilla begins to form. The dental papilla will eventually become the dentine and pulp of the tooth.

4. Dentine Formation: The dental papilla cells start to differentiate into odontoblasts, specialized cells responsible for producing dentine. Odontoblasts begin to lay down dentine matrix, a soft collagen-based material that will eventually mineralize and harden into dentine.

5. Enamel Formation: At the same time, ameloblasts, another type of specialized cells in the enamel organ, start producing enamel matrix, the hard outer layer of the tooth. Enamel matrix mineralizes to become enamel, the hardest substance in the human body.

6. Cementum Formation (For Rooted Teeth): In the case of teeth with roots, a layer of specialized cells called the dental follicle or dental sac forms around the developing tooth. These cells will differentiate into cemento blasts, which are responsible for forming cementum, the hard connective tissue that covers the tooth roots.

7. Eruption: After the tooth's crown and root are fully formed, the tooth undergoes a process called eruption, where it emerges from the jawbone and pushes through the gum tissue to take its place in the mouth.

8. Root Development (For Molars): In the case of permanent molars, the roots continue to develop and elongate even after eruption, which allows the tooth to properly anchor into the jawbone.

Difference between Temporary Dentine and Permanent Dentine on the Basis of Tooth Composition:

Temporary Dentine- In primary or baby teeth (temporary dentine), the dentine layer tends to be thinner compared to permanent dentine. Temporary dentine serves as a foundation for the tooth structure, providing a surface for enamel to attach. Since baby teeth are smaller and eventually fall out, the dentine in these teeth doesn't need to be as extensive as in permanent teeth.

Permanent Dentine- In permanent teeth, the dentine layer is thicker and more substantial compared to temporary dentine. This thicker dentine provides strength and support to the adult tooth structure, which must withstand the forces of chewing and grinding food throughout a person's lifetime. Permanent dentine is designed to endure for the long term, and it is a key component in the overall structure and durability of adult teeth.

Difference between Temporary Dentine and Permanent Dentine on the basis of their Identification (FDI)

The Federation Dentine Internationale 1966, introduced a simple and accurate method to specifically point out the particular tooth from temporary and permanent dentine.

Temporary Dentine

FDI has introduced four numbers which represents the address of tooth in temporary dentine. These numbers are. 5,6,7,8.

  • 5: Maxillary (upper jaw) right quadrant of temporary dentine.

  • 6: Maxillary (upper jaw) left quadrant of temporary dentine.

  • 7: Mandible (lower jaw) left quadrant of temporary dentine.

  • 8: Mandible (lower jaw) right quadrant of temporary dentine.

Permanent Dentine

FDI has introduced four numbers which represents the address of tooth in permanent dentine. These numbers are. 1,2,3,4.

  • 1: Maxillary (upper jaw) right quadrant of permanent dentine.

  • 2: Maxillary (upper jaw) left quadrant of permanent dentine.

  • 3: Mandible (lower jaw) left quadrant of permanent dentine.

  • 4: Mandible (lower jaw) right quadrant of permanent dentine.

5 Point Difference (Temporary Dentine Vs. Permanent Dentine)

Temporary dentine, also known as deciduous or baby teeth, constitutes the initial set of teeth a human develops after birth, serving as the foundation for the tooth structure. This set comprises 20 teeth, including 8 incisors, 4 canines, and 8 molars, and begins to form between 6 months and 2-4 years of age.

In contrast, permanent dentine, referred to as secondary or adult dentine, is a critical component of the adult tooth system, evolving from temporary dentine and containing a total of 32 teeth: 8 incisors, 4 canines, 8 premolars, and 12 molars.

The development stages of both types of dentine involve processes such as tooth development, dentine formation, enamel formation, and eruption, but they differ in composition and longevity.

Temporary dentine teeth are thinner, less stable, and less durable since they are meant to be shed, whereas permanent dentine teeth have thicker dentine, providing greater endurance against tearing forces and long-term stability.

Additionally, temporary dentine lacks premolars, only featuring incisors, canines, and molars, while permanent dentine includes all types of teeth.

The identification codes assigned by the Federation Dentaire Internationale (FDI) distinguish between the two, with temporary dentine labeled 5, 6, 7, and 8, and permanent dentine labeled 1, 2, 3, and 4.

Reference

  • "Forensic DNA Typing" by John M. Butler

  • "The Forensic Casebook: The Science of Crime Scene Investigation" by Ngaire E. Genge

  • "Forensic Science: A Very Short Introduction" by Jim Fraser

  • "Practical Crime Scene Processing and Investigation" by Ross M. Gardner