Intrusion Injuries of Primary Incisors. Part III: Effects on the Permanent Successors

Resident: Adam J. Bottrill
Date: 10SEP
Region: Providence
Article title: Intrusion Injuries of Primary Incisors. Part III: Effects on the Permanent Successors
Author(s):Diab, Mai DDS et al.
Journal: Quintessence International
Page #s: 377-384
Year: 2000:30
Major topic: Intrusion Injuries
Minor topic(s): NA
Type of Article: Analysis of Intrusion Injury Characteristics
Main Purpose: Analyze the effects of intrusion injury of primary incisors on the permanent dentision.

Key points in the article discussion:

I. General:

A. The potential for disturbances of the developing permanent dentition is high following injuries to their predecessors. (12-74% ???)

B. 18-69% (????) of permanent developmental defects due to INTRUSION injuries of primary teeth.

II. Factors Influencing the Sequelae of Intrusion Injuries.

A. Age of child:
1. Before 3yo, crown formation can be effected. (enamel hypoplasia, coronal dilaceration, odontoma etc...)
2. After 3yo, typically, root formation effected.
3. Typically, younger=more potential for permanent injury.
4. Germ can still suffer mineralization disturbances even after crown is fully formed.

B. Direction of intrusion:
1. Most risk when intrusion forces crown labially and root palatally.

C. Severity of Intrusion:
1. Increased severity = increased chance of damage
2. Alveolar fracture also increases chance.

D. Type of Treatment:
1. Several studies report that there is no correlation between severity of damage and the decision to extract versus allow to re-erupt.
2. Injury to the tooth is sustained at time of intrusion and not dependent on subsequent extraction.
3. The only exception to this rule is when subsequent infection occurs to intruded primary tooth.

III. Sequelae affecting coronal portions of the permanent successor:

A. White or yellow brown discoloration
1. Intrusion of primary teeth during mineralization of permanent crowns between 2-7yo.
2. Result of hypocalcified areas of the labial surface. (during "maturation" stage)
3. Bleeding may also hemoglobin products to enter the mineralizing portion of the enamel.

B. White of yellow-brown discoloration associated with enamel hypoplasia
1. "imperfect formation" due to injury between 2-3yo
2. displacement of the normal alignment of the ameloblast activity
3. irreversible destruction of the active enamel epithelium
4. grooves may form around the discoloration

C. Dilaceration of the crown:
1. Typically due to intrusion injury at around 2yo. (when 1/2 the crown is formed.
2. Displaced enamel epithelium becomes activated in a new/displaced position.
3. May erupt normally but will likely necrose... prophylactic crown recommended to avoid abscess.

IV. Sequelae Affecting Rot Portions of the Permanent Successors:

A. Duplication:
1. Rare malformation usually occurs from severe intrusion at around 2yo.

B. Dilaceration of the root:
1. Intrusion between 2-5yo.
2. Displaced hard tissue relative to the developing root... likely to be impacted.
3. Lateral dilaceration occurs between 2-7yo and usually tooth erupts normally.

C. Partial or complete cessation of root formation:
1. Rare sequelae due to intrusion between 4-7yo.
2. Hertwig's epithelial root sheath damaged.

V. Sequelae affecting the whole successor tooth:

A. Odontomalike malformation:
1. Severe intrusion of primary incisor between 1-3yo. (early stages of odontogenesis)
2. Require surgical extraction.

B. Sequestration of the permanent tooth germ:
1. Underdeveloped tooth germ and inadequate rot formation.
2. RARE... caused by SEVERE intrusion.
3. Also related to severe periradicular infection
4. Surgical extraction.

C. Disturbances of permanent successor eruption:
1. Early primary tooth loss (3-4yo) can cause delay in permanent successor eruption
2. Primary tooth loss later than 5yo can accelerate permanent eruption.
2. Ankylosed or delayed root resorption can also cause delayed eruption.

VI. Conclusion:

A. High probability of permanent tooth damage when primary tooth is intruded.
B. If the "wait and see" method is chosen... periodic recall is necessary to avoid periradicular infection and probably permanent tooth damage.

Assessment of article: Informative... BUT, the bottom line is, the permanent tooth is likely to be damaged. Knowing all the percentages of the type of sequelae doesn't really help me because it doesn't change treatment options. Also... despite the information presentd, I'm extracting the primary tooth if it's intruded. Not taking chances WRT subsequent infection.

The diagnostic value of lateral extraoral radiography for intruded maxillary primary incisors.

Resident: Adam J. Bottrill
Date: 21AUG09
Region: Providence

Article title: The diagnostic value of lateral extraoral radiography for intruded maxillary primary incisors.

Author(s): Holan, Gideon DMD et al.
Journal: Pediatric Dentistry
Volume #; Number; Page #s: Volume 24:1 pp: 38-42
Year: 2002
Major topic: Diagnostic radiographs for intruded maxillary primary incisors.
Minor topic(s): None
Type of Article: Comparative diagnostic study.

Main Purpose: Assess the contribution of a lateral extraoral radiograph for diagnosing the relation between the root of intruded maxillary primary incisors and their permanent successors.
Overview of method of research: Quantitative, clinically diagnostic study.
Findings: N/A

Key points in the article discussion: Intrusive luxation has been found by some authors to be the most common type of injury to the primary incisor region. The proximity of the primary incisor to the labial surface of the permanent successor increases the risk of damage to the developing bud from trauma. It is therefore very important to determine the relation between the root of the intruded primary root and the permanent successor.

A. Methods
1. Study group: all children with intruded primary incisors who presented to XC clinic of the Dept of Ped Dent at the Hadassah School of Dental Medicine in Jerusalem, Israel.
a. 18 mo period.
b. 37 children with 55 intruded primary incisors.
c. age: 8 to 63 mo.
d. 56% were partially intruded and 44% completely disappeared in to tissue.
e. 29 pts (w/ 44 teeth) checked within 2 days
f. 60% w/ only 1 intruded tooth. Rest had 2 or more.
g. 93 total 3-step evaluations were available.
2. Teeth intruded more than 7 days are not included in the study.
3. Three steps for root relationship assessment.
a. Clinical exam: Inspection of tooth, and soft/hard tissue surrounding the intruded tooth.
b. PA evaluation: (and sometimes repeating step 1)
c. Lateral extraoral radiograph evaluation:
4. Clinical signs include:
a. hematoma presence
b. projection of labial bone plate
c. relative elongating or shortening of teeth.
d. “unable to assess”
5. Assessments are made independently
6. LATERAL RADIOGRAPH WAS CONSIDERED “CONTRIBUTORY” IF A FINAL DECISION COULD NOT BE MADE WITHOUT STEP 3, OR IF IT DIFFERED FROM THAT MADE FOLLOWING THE 1ST AND 2ND STEPS.
7. Ability to assess the tooth alignment following steps 2 and 3 was statistically analyzed using the McNemar test.

B. Results
1. Assessment was possible in 86% of step 1; 62% of step 2; 42% of step 3. All others were “unable to assess.”
2. In only 5 (5%) of evaluations was step #3 found “contributory.”
3. DIFFERENCE IN EVAUATORS ABILITY TO ASSESS POSITION AFTER STEP 3 VS AFTER STEP 2 WAS NOT STATISTICALLY SIGNIFICANT.
4. Separate evaluations made for:
a. Intrusion of single vs multiple teeth, central vs lateral, partially vs completely intruded, less than vs more than 20mo.,
b. no statistically significant differences in any of these parameters existed.
5. When useful, lateral radiographs were MORE useful when assessing single-tooth intrusions and central intrusions.
6. Also, lateral radiographs were more useful in pt’s under 20 mo.
a. this may be due to the overall difficulty in assessing the position as well as the low radiodensity of permanent succesors.
7. In the case of any evaluator disagreement, 5 of the 6 disagreements occurred in step 3.

Summary of conclusions: In the case of intrusion of maxillary primary incisors, the contribution of the lateral extraoral radiograph in determining the alignment of the root of intruded teeth is LOW.

A. Possible explanations:
1. Overlap, errors in aligning the cone correctly.
2. When evaluating the lateral radiograph alone, one can only clearly Dx when the root of the intruded tooth has been significantly displaced labially. OTHERWISE NO CONCLUSION CAN BE MADE.
3. Should still attempt to Dx based on PA radiograph and not clinical exam alone.
a. gap between intruded tooth and permanent successor.
b. shortened, more opaque image of intruded incisor
c. lack of rotation of the permanent successor

B. Finally:
1. Lateral extraoral radiographs should not be used routinely in cases of intrusion of primary incisors. Lateral radiographs should only be taken when it’s expected contribution can be confirmed by other methods.

Assessment of article: Applicable and well organized. This topic has the potential to be controversial as it seems we have all been instructed at some point in our education to use these lateral radiographs as a diagnostic tool.