Impacted Wisdom Tooth: How to Prevent Complications (1/5)

Introduction

Impaction refers to a tooth that has not erupted fully or correctly in the dental arch, leading to issues such as pain, swelling, and bad breath. Commonly impacted teeth include the third molars (wisdom teeth) and can be diagnosed through various radiographic assessments. Tools such as intraoral radiography, panoramic x-rays, and cone-beam computed tomography (CBCT) are used to visualize impacted teeth and plan for their removal. Factors such as root development, proximity to nerves, and bone density can affect the ease or difficulty of extracting impacted teeth. Anesthesia and patient age also play a role in the complexity of wisdom tooth extraction.

Impaction

When a tooth has failed to erupt completely or partially to its correct position in the dental arch and its eruption potential has been lost, it is called impaction, and the tooth is called an impacted tooth.
Impacted teeth are a common dental issue where a tooth fails to erupt from its non-functional position in the alveolar bone into the occlusal plane within a normal developmental period.
The third molars, also known as wisdom teeth, are the most commonly impacted teeth.

Unerupted Tooth

It is a tooth that is in the process of eruption and is likely to erupt based on clinical and radiographic findings.

Malposed Tooth

A tooth unerupted or erupted which is in an abnormal position in the maxilla or in the mandible.

Commonly Impacted Teeth

According to recent studies, impacted teeth occur in the following order of frequency:

Mandibular 3^rd molar
Maxillary 3^rd molar
Maxillary canine
Mandibular canine
Mandibular premolar
Maxillary premolar
Maxillary central incisors
Maxillary lateral incisor

History Taking in Tooth Impaction

When assessing a patient with tooth impaction, it is crucial to take a comprehensive dental history to understand the patient’s symptoms, concerns, and overall oral health.
Patients with symptoms of impacted teeth may report the following:
Pain and tenderness of the gingiva
Bad breath
Swelling of the gums around the impacted tooth
Unpleasant taste when biting
Headache or jaw ache

Investigations

To diagnose impacted teeth, several investigations can be conducted to determine the severity and location of the impaction. The following are some of the tools commonly used by dentists:

Evaluation of the Condition of Tooth and Gum: Dentists typically start with a physical examination to assess the symptoms and appearance of the affected tooth and surrounding gum tissue. While this method can provide initial insights, it may not always be accurate due to overlapping symptoms with other oral conditions.
Intra-oral Radiography: This diagnostic tool involves various types of x-rays such as Bite-wing x-rays, Periapical x-rays, and Occlusal x-rays. Although commonly used, intra-oral radiography has limitations in field-of-view, which could result in missing impacted teeth despite targeting the correct area.
Extraoral Radiography (Panoramic X-rays): Dentists often prefer panoramic x-rays for detecting impacted teeth within a broader region of the mouth. While effective in identifying impactions, this method may lack specificity in pinpointing the exact location of impacted teeth.
Cone-Beam Computed Tomography (CBCT): CBCT provides a 3D scan that is safer and more accurate than traditional radiography methods. It allows for precise visualization of impacted teeth without repetitive radiation exposure. However, mastering 3D software and interpreting CBCT images may require additional expertise.
AI Driven 3D Segmentation: This innovative approach utilizes artificial intelligence to segment teeth and bone from CBCT scans automatically. It offers a detailed 3D view that aids dentists in accurately identifying impacted teeth without manual segmentation efforts.

These investigations play a crucial role in diagnosing tooth impaction by providing detailed information about the position, orientation, and impact on surrounding structures.

Examinations in Tooth Impaction

When examining impacted teeth, there are several key assessments and diagnostic tools used to evaluate the condition. The following are the main examinations and procedures involved in diagnosing tooth impaction:

Clinical Examination

Dentists will visually inspect the mouth and may use instruments to assess the area where a tooth has not emerged or has only partially emerged.
Signs of infection such as redness, drainage, tenderness, and swollen tissue over the impacted tooth may be observed during the clinical examination.

Radiograhic Assessment

The best assessment of the impacted teeth can be done by radiographic evaluation.
The primary goal of radiographic assessment in impacted teeth is to gather additional clinical information essential for planning safe surgical removal.
By understanding the exact position, orientation, and relationship of the impacted tooth to surrounding structures through radiographs, dental professionals can plan precise treatment strategies.

Different types of radiographs used for evaluation are:

Intraoral radiographs

IOPA

Intraoral periapical radiography (IOPA) is a type of dental X-ray that provides a detailed image of a specific tooth and the surrounding tissues.
When it comes to impacted teeth, IOPA can be a valuable tool in assessing the impacted tooth’s position, orientation, and proximity to adjacent structures.
In cases of impacted teeth, an IOPA X-ray can help determine the exact location of the impacted tooth in relation to other teeth, nerves, and bone structures.
It can also reveal any potential complications such as root resorption or damage to neighboring teeth.
By examining an IOPA X-ray of an impacted tooth, a dentist or oral surgeon can better plan for the extraction or management of the impacted tooth.
The radiographic image allows for a more precise understanding of the situation, aiding in treatment decisions and ensuring optimal outcomes for the patient.

Occlusal view

Occlusal view radiographs play a crucial role in the diagnosis of impacted teeth.
These radiographs provide valuable information about the position, orientation, and relationship of impacted teeth to surrounding structures.
In the context of tooth impaction, occlusal radiographs are used to visualize impacted teeth in cross-section and provide bucco-lingual positional information that complements other radiographic views such as periapical radiographs.
Occlusal view radiographs are essential for assessing impacted teeth in both mandibular and maxillary arches.
They offer unique perspectives on tooth orientation, bucco-lingual position, and relationships with adjacent structures that aid in treatment planning for impacted teeth.

Extraoral radiographs

OPG

One of the ways to diagnose impacted wisdom teeth is through an Orthopantomography (OPG), also known as a panoramic radiograph.
An OPG provides a detailed view of all the teeth in one image, allowing dental professionals to evaluate the position of impacted teeth, their relationship to neighboring structures, and any associated complications like resorption or erosion.
OPG plays a vital role in diagnosing and assessing impacted wisdom teeth by providing detailed images that aid in treatment planning and management of associated complications.

PA Water’s view:

The Waters view or occipitomental projection is an angled PA radiograph used to assess for facial fractures and acute sinusitis.
It is taken with the patient gazing slightly upwards, ensuring their head is straight and the mento-mandibular line is perpendicular to the receptor.
The image should show the petrous ridge inferior to the maxillary sinuses and assess for rotation via coronoid process symmetry.

Lateral oblique view:

The lateral oblique view is particularly useful for assessing impacted teeth that are not clearly visible on standard periapical or occlusal radiographs.
By angling the X-ray beam laterally and obliquely, this technique allows for a more comprehensive visualization of the tooth’s position in relation to surrounding structures.
In cases of tooth impaction, the lateral oblique view can reveal important details such as:
- The exact bucco-lingual location of the impacted tooth within the jaw.
- The relationship of the impacted tooth to adjacent teeth and bone structures.
- Any potential obstacles or abnormalities that may be affecting the eruption path of the tooth.
This view provides a three-dimensional perspective that enhances the clinician’s ability to plan for appropriate treatment strategies, including surgical interventions to expose and align impacted teeth properly.

CBCT:

Cone Beam Computed Tomography (CBCT) is a modern radiographic technique that has significantly enhanced the field of dentistry, particularly in the assessment and management of impacted teeth.
CBCT imaging provides detailed 3-D images of the impacted tooth and its surrounding structures, offering crucial information for accurate diagnosis, treatment planning, and risk assessment.

Benefits of CBCT in Tooth Impaction:
- Accurate Visualization: CBCT allows for precise visualization of impacted teeth and their exact positioning within the jaw, providing comprehensive information that conventional 2-D imaging techniques cannot offer.
- Identification of Critical Anatomy: CBCT helps in identifying critical anatomical structures such as nerves, blood vessels, and adjacent teeth, which is essential for minimizing risks during surgical interventions.
- Enhanced Treatment Planning: The detailed images from CBCT scans enable clinicians to develop tailored treatment plans based on the specific location and orientation of impacted teeth, leading to improved outcomes and reduced complications.
Role of CBCT in Risk Assessment:
- Preoperative Evaluation: CBCT plays a crucial role in preoperative risk assessment by identifying potential complications associated with impacted teeth, such as cysts, tumors, infections, and nerve damage.
- Preservation of Critical Structures: By visualizing important structures like nerves and blood vessels in proximity to impacted teeth, CBCT helps in preserving these critical anatomical features during surgical procedures.
- Pathology Detection: CBCT imaging aids in detecting underlying pathologies associated with impacted teeth early on, allowing for timely intervention and appropriate management strategies.
Clinical Applications of CBCT in Tooth Impaction:
- Assessment of Nerve Proximity: CBCT assists in evaluating the proximity of nerves like the inferior alveolar nerve to impacted teeth, reducing the risk of nerve injuries during extraction procedures.
- Evaluation of Adjacent Teeth: CBCT can assess external root resorption and bone loss in adjacent teeth caused by impacted teeth, guiding treatment decisions to prevent further complications.
- Risk Assessment for Fractures: CBCT enables clinicians to assess the risk of lingual plate fractures associated with impacted teeth, aiding in surgical planning to minimize potential fractures.

Radiographic assessment helps in determining the :

Classification of impacted tooth
Depth and orientation of the tooth (WAR lines)
Root pattern or shape of the root
Relation to the inferior alveolar canal
Localization of the impacted tooth

Root pattern:

- A tooth with limited root development is known as a rolling tooth. It is difficult to extract such tooth.
- It is easy to extract a tooth with 2/3^rd to completely developed root.
- A tooth with multiple roots which are fused and are conical is easy to extract.
- It is moderately difficult to extract a tooth with multiple and separated roots.
- A tooth with multiple and diverged roots is difficult to extract.

Relation to inferior alveolar canal:

- The relation of an impacted tooth and its root with the inferior alveolar canal can be seen on the radiograph as:

(a) Darkening of root:

- Darkening of the third molar roots in panoramic radiographs is a significant indicator of a close anatomical relationship between the roots and the inferior alveolar canal (IAC).
- This darkening is often associated with specific conditions such as lingual cortical thinning, groove formation on the root, or other high-risk signs indicating proximity to important structures like the inferior alveolar nerve (IAN).

(b) Dark and bifid apex:

A bifid apex is a condition where the root tip of a tooth appears to have two points or forks, instead of one.
When this condition is associated with darkness on the radiograph, it can indicate the presence of an impacted wisdom tooth.
The darkness may be due to the overlying bone obstructing the x-ray beam, making it difficult to visualize the tooth’s crown.
This finding is important for dental professionals as it can help in diagnosing and planning for the extraction of impacted third molars.

(c) Deflection of root:

The deflection of the root refers to any deviation or angulation of the root from its normal position within the alveolar bone.
This deviation can occur due to various reasons such as limited space for eruption, presence of adjacent structures like other teeth or bone, or genetic factors affecting tooth development

(d) Diversion of canal:

In the radiograph of an impacted mandibular third molar, the diversion of the canal can be seen as a deviation or deflection of the inferior alveolar nerve (IAN) canal due to the proximity or pressure from the impacted tooth.
This diversion is crucial to note as it indicates a close relationship between the mandibular third molar and the IAN, increasing the risk of nerve injury during extraction procedures.

(e) Narrowing of canal:

Narrowing of the inferior dental canal in relation to the lower third molars is a common finding when impacted lower third molars are assessed using computed tomography (CT).
The inferior positioning of the inferior dental canal was the most common location identified on CT scans.
Radiographic markers such as superimposition, narrowing, deviation, or reduction in density on rotational panoramic radiographs were correlated with the narrowing observed on CT scans.
Deviation of the inferior dental canal on rotational panoramic radiographs was highlighted as the most significant predictor of narrowing of the inferior dental canal and its close relationship to the roots.

factors that make removal of impacted tooth easier

It is easier to remove or extract the impacted tooth in the following cases:

Mesio-angular impaction
Class 1 ramus
Class A depth
Roots 1/3 – 2/3 formed (present in the younger patient)
Fused conical roots
Wide periodontal ligament (present in the younger patient)
Large follicle (present in the younger patient)
Elastic bone (present in the younger patient)
Separated from 2nd molar

factors complicating the removal of impacted tooth

Several factors contribute to the difficulty of removing impacted wisdom teeth:

Location: Wisdom teeth are typically located at the back of the mouth, making them hard to access for dental instruments. Their position makes it difficult for dentists to apply sufficient force and leverage to remove them without causing damage to surrounding structures.
Anatomy: Third molars have multiple roots, making their extraction more complex than that of other teeth. The roots can be curved or twisted, which further complicates the procedure. Additionally, wisdom teeth may not fully erupt from the gum line, making it difficult to access them directly.
Bone density: The bone density around wisdom teeth is usually high, which can make their extraction more challenging. Dentists must carefully remove bone tissue to access the tooth’s root and extract it safely.
Proximity to nerves and sinuses: Wisdom teeth are close to nerves such as the lingual nerve and the nerve responsible for sensation in the lower lip and chin. Damage to these nerves during extraction can result in tingling, numbness, or even loss of sensation in the affected area. Additionally, upper wisdom teeth are located near sinus cavities, increasing the risk of complications if the sinus membrane is punctured during extraction.
Presence of infection or abscess: If a wisdom tooth is infected or has an abscess, its removal becomes more complicated due to the presence of pus and inflamed tissue around the tooth. In such cases, dentists may need to prescribe antibiotics before and after the procedure to prevent infection spread and ensure proper healing.
Patient’s medical history or current health conditions: Certain medical conditions or medications can increase the risk of complications during wisdom tooth extraction. For example, patients with bleeding disorders or those taking blood thinners may experience excessive bleeding during or after the procedure. Dentists must consider these factors when planning and executing a wisdom tooth extraction to minimize risks and ensure optimal patient care.
Age: Wisdom teeth are typically larger in size and have longer roots than other teeth, making their removal more complex as people age due to changes in bone density and tissue elasticity over time. Additionally, older patients may have more complex root structures that make extraction more challenging than in younger individuals with less developed roots and follicles surrounding their wisdom teeth.
Anesthesia: Extracting wisdom teeth while a patient is awake using local anesthesia can be difficult for dentists because they must ensure patient comfort throughout the procedure while also successfully extracting the tooth without causing unnecessary discomfort or injury to surrounding tissues or nerves. In some cases, sedation or general anesthesia may be necessary for more complex extractions or patients with anxiety related to dental procedures.

Impacted Wisdom Tooth: How to Prevent Complications (2/5)

Explore the Orthodontic theory of impaction, where jaw development and movement play a crucial role. how dental arches can lead to impaction.