CHAPTER II - IMPACTED TEETH (Contraindications for removal of impacted teeth, EFFECTS (intervention & non-intervention), PRE-ASSESSMENT (clinical & radiographic)

CONTRAINDICATIONS FOR REMOVAL OF IMPACTED TEETH

1. Extremes of age

2. probable excessive damage to adjacent structures

3. Compromised medical status or condition

4. Prosthetic consideration

5. Presence of adequate arch space

6. Uncontrolled active Pericoronal infection

7. Fracture of the atrophic mandible may occur

8. Underlying pathologic disease may worsen upon removal of the impacted tooth

9. Deep seated impacted teeth with no history of pathology

10. Socio-economic status

11. When there is a question about the future status of the second molar

EFFECTS OF INTERVENTION

I. RISKS

II. BENEFITS

RISKS

1. Minor transient risks

2. Minor permanent risks

3. Major risks

MINOR TRANSIENT RISKS

• includes sensory nerve alteration, alveolitis, trismus, infection, hemorrhage, dentoalveolar fractures, and displacement of the tooth

MINOR PERMANENT RISKS

Pertains to periodontal injury, adjacent tooth injury, & temporomandibular joint (TMJ) injury

MAJOR RISKS

Involved altered sensation, vital organ infection, and fracture or injury of the mandible & maxillary tuberosity

BENEFITS

1. Relative to the patient’s age

2. In relation to different therapeutic measures

RELATIVE TO THE PATIENT’S AGE

Less morbidity in younger patients compared to older patients

IN RELATION TO DIFFERENT THERAPEUTIC MEASURES

Includes local measures against alveolitis, pain, swelling, trismus, etc.

EFFECTS OF NON-INTERVENTION (RISKS)

1. Crowding of the dentition based on growth predilection

2. Resorption of adjacent teeth and periodontal status

3. Development of pathological conditons or lesions that would include infection, cysts, & tumors

EFFECTS OF NON-INTERVENTION (BENEFITS)

1. Avoidance of risk

2. Preservation of functional teeth

3. Preservation of the residual ridge

PRE-OPERATIVE ASSESSMENT

I. CLINICAL ASSESSMENT

II. RADIOGRAPHIC ASSESSMENT

CLINICAL ASSESSMENT

• refers to proper treatment planning that is based on a thorough clinical evaluation of the patient with respect to general & local factors relevant to possible postoperative sequelae

CLINICAL ASSESSMENT

• aims to assess the status of the impacted tooth & excludes other causes of the symptoms

• retruded mandible,

• restricted mouth opening

• small mouth commissures

• these result to poor access to the surgical field:

• protruded mandible & large mouth opening

these provide better access to the operative field:

1. eruption status of the impacted tooth

2. presence of a local infection

3. occlusal relationship

4. mobility of the impacted tooth and adjacent teeth

5. orientation & relationship of the tooth to adjacent vital structures (such as the inferior alveolar canal, maxillary sinus etc.)

6. caries and/or resorption of the impacted tooth or adjacent tooth

7. temporomandibular joint (TMJ) function

8. any associated pathology

9. regional lymph nodes

clinical assessment involves any or all of the following:

RADIOGRAPHIC ASSESSMENT

• pertains to the logical, sequential, and consistent method for interpreting a radiograph which is an essential part of the diagnostic process

STEPS FOR RADIOGRAPHIC INTERPRETATION (LOGIC)

1. Localization

2. Observation

3. General Consideration

4. Interpretation

5. Correlation

LOCALIZATION

• gives data about position, size, if it is localized or generalized, and if it is single or multiple (depending on the condition or situation)

OBSERVATION

• all radiolucent & radiopaque areas should be taken into consideration

GENERAL CONSIDERATION

• a radiograph is a two-dimensional image of a three-dimensional object which means it involves the width & height, but depth is not included

INTERPRETATION

• entire tooth, bone, and other supporting structures must be efficiently evaluated

CORRELATION

• considered as the final step to draw a diagnosis after inclusion of other data from case history, clinical examination, other diagnostic aids, etc.

INTRAORAL RADIOGRAPHS and EXTRAORAL RADIOGRAPHS

Two main types of dental x-rays

1. INTRAORAL RADIOGRAPHIC TECHNIQUES

   1. Periapical radiograph

   2. Occlusal radiograph

   3. Clark’s rule

2. EXTRAORAL RADIOGRAPHIC TECHNIQUES

   1. TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MANDIBLE

      1. Panoramic radiograph

      2. Lateral Oblique View of the Mandible

   2. TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MAXILLA

      1. Panoramic radiograph

      2. Posterior-Anterior / P-A view & Water’s View)

   3. TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE

      1. Lateral Radiographs

      2. Cephalometric radiographs

      3. Three-Dimensional Radiographs

3. ASSESSMENT OF THE ACCESS TO THE TOOTH

4. CONDITION OF THE CROWN & ROOT OF THE TOOTH INVOLVED

5. CONDITION OF THE ADJACENT STRUCTURES

6. RELATIONSHIP TO THE VITAL STRUCTURES

7. FOLLICULAR WIDTH

8. PERIODONTAL STATUS OF THE IMPACTED TOOTH & ADJACENT TEETH

9. WHARFE’S ASSESSMENT

10. WINTER LINES

Radiographic assessment involves any or all of the following:

INTRAORAL RADIOGRAPHIC TECHNIQUES

• refers to the most common techniques for radiographic assessment of impacted teeth that provide clear & intricate images of minute structures

PERIAPICAL RADIOGRAPH

gives a detailed view of the entire tooth (or even 1 or 2 of its adjacent teeth), as well as the surrounding structures

PERIAPICAL RADIOGRAPH

• designed to view a tooth in itself from the angle of best advantage, unrelated to its position in space

  
  

PERIAPICAL RADIOGRAPH

provides information regarding the following:

• state of tooth development

• tooth resorption,

• & the presence of the dental follicle

PERIAPICAL RADIOGRAPH

for the film to show the most advantageous view of the tooth in the maxillary or mandibular segment:

• Central ray of the periapical view is oblique (or horizontal for mandibular posterior teeth), & will vary from 20-55° to the occlusal plane depending on the area to be viewed

OCCLUSAL RADIOGRAPH

• tracks the development & placement of a tooth in either the maxilla or the mandible by placing the film in the occlusal plane

OCCLUSAL RADIOGRAPH

may be carried out according to various projections and the most frequently used projection is SIMPSON wherein the beam is positioned perpendicular to the film through the glabella

OCCLUSAL RADIOGRAPHS

• maxillary occlusal projections:

• upper standard or anterior occlusal (standard occlusal)

• upper oblique occlusal (oblique occlusal),

• vertex occlusal

OCCLUSAL RADIOGRAPHS

• mandibular occlusal projections:

• lower 90° occlusal (true occlusal)

• lower 45° or anterior (standard occlusal),

• lower oblique occlusal (oblique occlusal)

CLARK’S RULE

used in the localization of an impacted tooth

CLARK’S RULE

it is the apparent displacement of an image relative to the image of a reference object, and is caused by an actual change in the angulation of the x-ray beam or the x-ray tube position

CLARK’S RULE

two exposures are taken:

• 1st exposure is in the usual position

• 2nd exposure is done with the tube shifted 2cm in one direction (left or right)

CLARK’S RULE

interpretation:

1. if in the 2nd film the impacted tooth has shifted in the same direction (as the tube) → impacted tooth is in the lingual or palatal position

2. if in the 2nd film the impacted tooth has shifted in the opposite direction (of the tube) → impacted tooth is in the labial or buccal position

CLARK’S RULE

also referred to as TUBE SHIFT TECHNIQUE, PARALLAX METHOD, or the SLOB RULE (acronym that stands for: Same Lingual Opposite Buccal)

EXTRAORAL RADIOGRAPHIC TECHNIQUES

useful for evaluating large areas of the skull & jaws, but are inadequate for detection of subtle changes such as early stages of dental caries or periodontal disease

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MANDIBLE:

PANORAMIC RADIOGRAPH

• provides a two-dimensional view and curvilinear variant of conventional tomography that shows the mandible & the temporomandibular joints

• trade names: PANOREX and ORTHOPANTOMOGRAPH (OPG)

note: panoramic radiograph is a form of tomography that takes images of multiple planes to make up a panoramic image, where the maxilla & mandible are the focal trough (curved zone or image layer) and the structures that are superficial & deep to the trough are blurred

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MANDIBLE:

LATERAL OBLIQUE VIEW OF THE MANDIBLE

pertains to lateral radiograph that gives an excellent view of the body and ramus of the mandible

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MAXILLA:

PANORAMIC RADIOGRAPH

displays a two-dimensional image and curvilinear variant of conventional tomography that shows the maxilla & the maxillary sinus

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN THE MAXILLA:

POSTERIOR-ANTERIOR P-A VIEW & WATER'S VIEW

• P-A view: demonstrates the mediolateral dimensions of the skull

• Water's view: exhibits the occipitomental dimensions of the skull

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

LATERAL RADIOGRAPHS

• its popularity has waned since the introduction of panoramic radiographs

  
  

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

LATERAL RADIOGRAPHS

• lateral radiographs of the head & jaw are divided into:

  • true laterals

  • oblique laterals,

  • bimolars (two oblique laterals on one film)

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

LATERAL RADIOGRAPHS

• due to limitations of a panoramic radiograph, these radiographs still have an important role especially for the following:

  • position of unerupted teeth,

  • detection of jaw fractures,

  • evaluation of jaw lesions,

  • specific views for the salivary glands & temporomandibular joint (TMJ)

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

CEPHALOMETRIC RADIOGRAPHS

• skull radiography that detects the relationship of the teeth to the jaws, and the jaws to the rest of the facial skeleton

  
  

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

CEPHALOMETRIC RADIOGRAPHS

• used as an adjunct for the diagnosis of impacted teeth in the maxilla and/or mandible

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA & THE MANDIBLE:

CEPHALOMETRIC RADIOGRAPHS

more commonly utilized for orthodontic and/or orthognathic considerations

TYPES of CEPHALOMETRIC RADIOGRAPHS

• lateral cephalometric radiograph,

• postero-anterior cephalometric radiograph

• antero-posterior cephalometric radiograph

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA AND THE MANDIBLE

THREE-DIMENSIONAL RADIOGRAPHS

• includes Computed Tomography (CT) scan and Cone Beam Computed Tomography (CBCT)

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA AND THE MANDIBLE

THREE-DIMENSIONAL RADIOGRAPHS

• utilized for the maxilla and/or mandible especially for high risk cases

  
  

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA AND THE MANDIBLE:

THREE-DIMENSIONAL RADIOGRAPHS

• both CT & CBCT provide a precise and accurate way to evaluate the following:

  • depth

  • exact crown-root morphology,

  • presence of pathology,

  • long axis orientation of the involved teeth,

  • presence of adverse conditions,

  • and proximity of the root of an impacted tooth to vital structures (such as the maxillary sinus & inferior alveolar nerve)

TECHNIQUES FOR DETECTION OF IMPACTED TEETH IN BOTH THE MAXILLA AND THE MANDIBLE:

THREE-DIMENSIONAL RADIOGRAPHS

• CT scans use a fan beam which radiates in a spiral or helix & the data is interpolated by a scanner into a set of slices making up a volume

• CBCT uses a cone beam which radiates in a cone shape & the image is reconstructed into algorithms to produce a high-resolution image

ASSESSMENT OF THE ACCESS TO THE TOOTH

• access to the impacted tooth depends on the position of the external oblique ridge which appears as a radiopaque line in the radiograph

• involves the type & orientation of impaction

CONDITION OF THE CROWN & ROOT OF THE TOOTH INVOLVED

pertains to the crown in reference to size, root number, and morphology of the impacted tooth

CONDITION OF THE ADJACENT STRUCTURES

indicates the condition of the bone with regards to depth, density, and the absence of bone (i.e., pathosis)

RELATIONSHIP TO THE VITAL STRUCTURES

refers to the proximity or relationship of the impacted tooth to vital structures (e.g., maxillary sinus, inferior alveolar nerve, etc.)

Relationship of the root and/or root apex which predicts potential tooth proximity to the inferior alveolar canal are as follows:

• 6.1) root apex is related but not involving the canal

• 6.2) root canal in relation to the changes in the roots or root apices

• 6.3) root apex is related with the changes in the root canal

root canal in relation to the changes in the roots or root apices

• darkening of the root or root apex

• dark bifid root apex

• narrowing of the root or root apex

• deflection of the root

root apex is related but not involving the canal

• root & canal are separated

• both are adjacent

• superimposition

root apex is related with the changes in the root canal

• converging canal

• interruption of the superior border (white line) of the canal

• diversion of the canal

ROOD & SHEBAB’S 7 RADIOGRAPHIC SIGNS

• darkening of the root or root apex

• Dark bifid root apex

• Narrowing of the root or root apex

• Deflection of the root

• Converging or narrowing of the canal

• Interruption of the superior border (white line) of the canal

• Diversion of the canal

FOLLICULAR WIDTH

• dental follicle is normally seen as a pericoronal radiolucency with a width of 2 - 2.5mm

• radiolucency that is 2.3mm could be considered as an indication of pathologic changes in the dental follicle 

• follicular width that is ≥ 3mm may be a precursor for cystic formation

PERIODONTAL STATUS OF THE IMPACTED TOOTH & ADJACENT TEETH

determined by the presence of pocket formation and/or bone loss

WHARFE'S ASSESSMENT

refers to a very detailed assessment that would indicate the difficulty of impaction

WINTER LINES

• also called WAR LINES (White, Amber, Red) which is an acronym for the three distinct imaginary lines that are drawn on a radiograph

WINTER LINES

• limited by the presence of an adjacent tooth