Dental Impaction: A Comprehensive Guide for Medical and Dental Professionals

Medi Study Go

Related Resources

What is Dental Impaction?

Dental impaction refers to a condition where a tooth is prevented from erupting into its normal functional position within the dental arch. According to the World Health Organization (WHO), an impacted tooth is one that cannot erupt into its proper position due to obstruction by soft tissues, bone, or another tooth.

Impacted teeth are a common clinical challenge in dental practice, with third molar impaction being the most prevalent. If you're studying for your NEET exam, understanding the fundamentals of dental impactions is crucial for both theoretical knowledge and clinical application.

Why Do Teeth Become Impacted?

Several factors contribute to dental impactions:

Lack of adequate space in the dental arch
Abnormal eruption path or angulation
Physical barriers like dense bone or adjacent teeth
Genetic factors influencing tooth development
Premature loss of primary teeth affecting eruption sequence

Understanding these underlying causes is essential for proper diagnosis and treatment planning, which is frequently tested in NEET previous year question papers.

Classification of Dental Impactions

Dental impactions are typically classified based on location and angulation. Let's explore the most common classifications you'll need to know for your NEET preparation.

Mandibular Third Molar Impactions

Mandibular third molars (wisdom teeth) are the most commonly impacted teeth. These impactions are classified using several systems:

Pell & Gregory Classification

This classification system considers two key factors:

Relationship to the Ramus of the Mandible:
- Class I: Sufficient space between the ramus and the second molar
- Class II: Reduced space where the crown is partially covered by the ramus
- Class III: No space available, with the crown fully enclosed in the ramus
Depth Relative to Occlusal Plane:
- Position A: Occlusal surface of the impacted tooth at the same level as the adjacent second molar
- Position B: Occlusal surface between the occlusal plane and cervical line of the second molar
- Position C: Occlusal surface below the cervical line of the second molar

Winter's Classification

This system classifies impactions based on the angulation of the third molar's long axis relative to the second molar:

Mesioangular: Tilted toward the second molar (most common)
Horizontal: Perpendicular to the second molar
Vertical: Parallel to the second molar
Distoangular: Tilted away from the second molar
Inverted: Upside down with crown pointing toward the mandibular border
Buccoversion: Tilted toward the cheek
Linguoversion: Tilted toward the tongue

Maxillary Third Molar Impactions

Maxillary third molars also frequently become impacted. They are classified as:

Vertical Impaction: Most common (63%)
Distoangular Impaction: Second most common (25%)
Mesioangular Impaction: Less common (12%)
Horizontal Impaction: Rare
Inverted Impaction: Very rare (1%)

Additionally, maxillary third molars may be categorized based on their proximity to the maxillary sinus:

Sinus Approximation
Non-Sinus Approximation

Maxillary Canine Impactions

Maxillary canines are the second most commonly impacted teeth. Their classification is based on position:

Buccal Impaction: Canine positioned on the buccal surface
Palatal Impaction: Canine positioned in the palate (more common)
Alveolar Impaction: Canine positioned within the alveolar process
Combined Impaction: Canine positioned in both palatal and labial aspects
Impaction in Edentulous Maxilla

Radiographic Assessment of Impaction

Proper radiographic evaluation is crucial for accurate diagnosis and treatment planning of impacted teeth. Various imaging techniques assist in determining:

Exact position and angulation of the impacted tooth
Relationship to adjacent structures
Presence of pathological conditions
Anatomical variations

Radiographic Techniques

Intraoral Periapical Radiographs (IOPA): Provides detailed view of the impacted tooth and surrounding structures
Panoramic Radiographs: Offers a comprehensive view of the entire dentition
Occlusal Radiographs: Helps in determining buccolingual position
Cone Beam Computed Tomography (CBCT): Provides 3D visualization for complex cases

WHARFE Assessment

The WHARFE assessment by MacGregor evaluates the difficulty of extraction based on:

W: Winter's classification (angulation)
H: Height of the mandible
A: Angulation of the third molar
R: Root shape and development
F: Follicle development
E: Exit path availability

Predicting Inferior Alveolar Nerve Injury

The Rood and Shehab classification identifies radiographic signs that predict potential injury to the inferior alveolar nerve during extraction:

Root-Related Signs:

Darkening of the root
Deflected root
Narrowing of the root
Dark and bifid root apex

Canal-Related Signs:

Interruption of white line
Diversion of canal
Narrowing of canal

Management Approaches

The management of impacted teeth depends on several factors including the type of impaction, patient's age, medical history, and presence of pathological conditions.

Indications for Removal of Impacted Mandibular Third Molars

Recurrent pericoronitis
Caries in the third or adjacent second molar
Periodontal disease
Pathological conditions (cysts, tumors)
Unexplained pain
Orthodontic considerations
Pre-prosthetic considerations

Contraindications for Removal

Advanced age (>35 years)
Compromised medical status
Proximity to vital structures with high risk of damage
Asymptomatic deeply impacted teeth in older patients
Potential for spontaneous eruption (in younger patients)

Surgical Procedure for Mandibular Third Molar Extraction

The typical procedure involves eight key steps:

Aseptic Environment Preparation
Regional Anesthetic Administration
Flap Raising: Various designs including Ward's, modified Ward's, envelope, or triangular flaps
Bone Removal: Using chisel and mallet, burs, or the "postage stamp" method
Tooth Division: Based on the type of impaction
Tooth Removal
Wound Management
Primary Closure

Lingual Split Bone Technique

This specialized technique is particularly useful for deeply impacted third molars and involves:

Vertical Stop Cuts: Created at the mesial and distal aspects
Buccal Cortical Plate Removal
Distolingual Bone Fracturing
Remaining Bone Removal
Tooth Elevation
Saucerization and Delivery

Complications of Impaction

Despite careful planning and execution, complications may occur during or after the extraction of impacted teeth. These include:

Intraoperative Complications

Damage to adjacent teeth
Fracture of the mandible
Displacement of tooth fragments
Injury to nerves (inferior alveolar, lingual)
Excessive bleeding
Soft tissue injury

Postoperative Complications

Alveolar osteitis (dry socket)
Infection
Trismus (limited mouth opening)
Paresthesia or anesthesia
Postoperative pain and swelling
Oro-antral communication (in maxillary impactions)

Understanding these complications and their management is essential for clinicians and students preparing for their NEET mock tests.

Preventive Measures

Several preventive approaches can reduce the incidence and complications of dental impactions:

Early Orthodontic Intervention: Space maintenance and guidance of eruption
Regular Dental Check-ups: Early detection of potential impactions
Timely Extraction of Primary Teeth: When indicated
Prophylactic Removal: In specific cases before complete root formation
Patient Education: Importance of oral hygiene and regular follow-ups

These preventive strategies form an important part of comprehensive dental care and are crucial topics for NEET exam preparation.

Conclusion

Understanding dental impactions is essential for dental practitioners and students preparing for their NEET MDS. From classification systems to management techniques, this knowledge enables effective treatment planning and execution.

For more detailed information on specific aspects of dental impactions, explore our related articles below. If you're preparing for your NEET examination, our comprehensive guides provide valuable NEET tips and last-minute revision material to help you succeed.

Back to blog

Country/region