Main eruption anomalies
In oral surgery, several key disorders related to tooth eruption are distinguished:
- Retention — the formed tooth remains in the jaw and does not reach the surface.
- Semi-retention — the tooth crown emerges above the gum only partially.
- Dystopia — the tooth erupts in an abnormal position (e.g., tilted).
- Difficult eruption — a process accompanied by pronounced clinical symptoms and inflammation.
Why is it difficult for wisdom teeth to erupt?
Difficult eruption (most commonly of the lower third molars) arises due to a complex of anatomical and physiological factors:
- Lack of a predecessor. There was no deciduous tooth in place of the wisdom tooth. Because of this, the bone tissue (cortical plate) in this area is very dense.
- Soft tissue barrier. The alveolar process here is covered by a thick mucous membrane into which the fibers of the buccinator muscle are woven.
- Space deficiency. There is often insufficient space in the mandible, causing the wisdom tooth to begin growing at an angle toward the adjacent second molar.
Mechanism of inflammation development (pericoronitis)
When a tooth does not erupt completely, part of its crown remains covered by a fold of the mucous membrane. This formation is called the gingival "hood".
Ideal conditions for bacteria are created under the "hood": warm, humid, and dark. Microflora (mainly anaerobes) begins to multiply actively. The situation is aggravated by constant trauma: during chewing, the antagonist tooth from the upper jaw bites into the edematous "hood", forming erosions and ulcers. Local immunity drops, and inflammation of the tissues surrounding the crown develops — pericoronitis.
Clinical forms of pericoronitis
Depending on the severity of inflammation, several forms are distinguished:
- Acute catarrhal pericoronitis. The patient complains of pain during chewing and slight restriction in mouth opening. Lymph nodes are enlarged. There is no pus from beneath the hyperemic "hood", but it is painful to touch. Body temperature is usually normal.
- Acute purulent pericoronitis. The pain becomes severe, constant, radiating to the ear or temple. Swallowing is painful, and the mouth opens with difficulty. Temperature rises to 37.5–38.0 °C. Pus accumulates under the "hood" and is released upon pressure.
- Chronic pericoronitis. Occurs with frequent exacerbations and constant gum trauma. Pain is intermittent, halitosis appears. Destructive processes begin in the bone tissue (resembling chronic granulomatous periodontitis).
Briefly: answers to topical questions
What diseases should acute purulent pericoronitis be differentiated from?
The provided sources do not contain complete data for the differential diagnosis of acute purulent pericoronitis; however, for chronic pericoronitis, differential diagnosis with chronic pulpitis and chronic periodontitis is indicated.
What complications can arise from difficult wisdom tooth eruption?
- Acute catarrhal and purulent pericoronitis — forms of difficult wisdom tooth eruption.
- Chronic pericoronitis.
- Retromolar periostitis.
- Perimaxillary abscesses and phlegmons — complications of the spread of purulent infection.
- Eruption cysts — diagnosed in 30% of cases during difficult wisdom tooth eruption.
What does the surgical treatment of pericoronitis involve?
- Mucosal incision — performed from the base of the pterygomandibular raphe downward to the lower vestibular fornix; in case of infiltration, the incision is extended along the alveolar part.
- Wound drainage — the wound must be drained with a rubber strip.
- Tooth extraction — performed after the complete subsidence of inflammatory phenomena, taking into account the position of the tooth and the availability of space for its eruption.
What radiographic signs are characteristic of chronic pericoronitis?
- Bone tissue destruction — destructive changes in the bone tissue mesial or distal to the tooth are determined.
- Horizontal tooth position — in horizontal tooth position, destruction is determined inferiorly.
What are the indications for the extraction of an impacted and dystopic tooth?
- Impossibility of tooth eruption due to its retention or dystopia; extraction is performed after the subsidence of inflammatory symptoms.
- Inflammatory complications — pericoronitis, acute periostitis, abscess, phlegmon, or jaw osteomyelitis; extraction is performed after the subsidence of inflammatory symptoms.
- Abnormal tooth position traumatizing the mucous membrane.
Remember the difference: Retention — the tooth Relinquished hope of coming out (hidden). Dystopia — the tooth Drifted off track (out of place).
Class and exam questions
This is a fold (duplication) of the mucous membrane that covers part of the crown of a partially erupted tooth.
This is a fold (duplication) of the mucous membrane that covers part of the crown of a partially erupted tooth.
Where can pus spread in pericoronitis?
The infection can spread along loose connective tissue spaces: into the retromolar region, under the buccal and mylohyoid muscles, as well as along the superior constrictor of the pharynx.
What diseases should chronic pericoronitis be differentiated from?
Differential diagnosis is carried out with chronic pulpitis and chronic periodontitis.
What else to study on this topic
- Radiographic picture in various forms of pericoronitis
- Classification of lower third molar positions
- Pathomorphology of bone tissue in chronic pericoronitis
- Surgical treatment methods (hood excision, tooth extraction)
Master the entire topic in the course "Surgical Dentistry"
This is a summary. The course covers everything tested in classes and exams.
- Full study guide on "Tooth retention and dystopia" and 866 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 28 video lessons on the subject
Other topics in the section "Chapter 6. Retention, dystopia, tooth eruption disorders (A.M. Panin)"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.