Biomechanics of maxillary tooth extraction
The choice of technique and instruments in the maxilla is dictated by crown shape and root anatomy.
- Incisors: Have a shovel-shaped crown. The root of the central incisor forms a circle on a cross-section, while the lateral incisor forms an ellipse (in the mesiodistal direction) with a slight palatal bend. Straight forceps are used for extraction. The main force vector is rotational movements. For remaining roots, bayonet forceps or straight forceps with converging beaks are used. Difficulties arise with fractures in the middle or apical third, which requires the use of a dental bur.
- Canines: Characterized by a long, powerful, and pointed root, which in cross-section at the neck appears as a triangle with smoothed corners. Extracting a tooth with an intact crown is physically difficult. Primarily inclined movements toward the lip are used in combination with slight rotation.
- Premolars: Have a bicuspid crown. The first premolar usually has buccal and palatal roots; in cross-section, this is a flattened oval. The second premolar is more often single-rooted, straight, with a longitudinal groove. They are extracted using the luxation method in the buccal direction.
- Molars: Massive teeth with a rhomboid crown and three roots. Two buccal roots form a bifurcation into which the beak of S-shaped forceps is inserted. Second and third molars are gently rocked in the buccal direction. The first molar is luxated in the palatal direction because the dense zygomaticoalveolar crest (crista zygomaticoalveolaris) is located vestibularly.
Specifics of working on the mandible
The mandible is covered by a dense cortical plate and is movable. These factors require the use of additional instruments, such as elevators, and a modified working technique.
- Mandibular incisors: The smallest teeth with a high chisel-shaped crown (convex vestibularly and concave lingually). A single root, thin, flattened, oval in cross-section. Falcon-beaked forceps with narrow beaks are used. Vestibular luxation and very careful rotation are applied.
- Third molars (wisdom teeth): The difficulty of their extraction is associated with an atypical position and unpredictable root anatomy. Falcon-beaked forceps bent on the edge (or bent on the flat for limited mouth opening) are used. The primary luxating vector is directed in the lingual direction, and extraction from the socket proceeds in the buccal direction.
Reparative osteogenesis: how the socket heals
After root extraction, the socket fills with a blood clot, which is soon replaced by granulation tissue with a dense vascular network. Leukocytes, fibroblasts, and mesenchymal progenitor cells actively function within it.
The osteogenesis process is triggered by bone morphogenetic proteins (BMPs). Under their influence, mesenchymal cells differentiate, and osteoblasts begin to form primary woven bone from the defect walls.
Remodeling follows: osteoclasts resorb the temporary tissue, and osteoblasts create mature lamellar bone. A key condition for successful healing is full angiogenesis and high-quality blood supply to the surgical area.
Complications of tooth extraction
All complications are classified by time of occurrence (intraoperative and postoperative) and by prevalence (general and local).
- General complications: Syncope, collapse, hypertensive crisis. They arise due to severe patient stress, acute pain with poor anesthesia, or excessively traumatic actions by the surgeon. They require immediate assistance according to emergency care algorithms.
- Local intraoperative complications: The most frequent is crown or root fracture. Causes can be objective (deep caries, complex root structure, dense bone tissue) or iatrogenic. Physician errors include: mismatch of the forceps axis with the tooth axis, superficial placement of beaks (without immersion below the alveolar margin), as well as sharp, rough, forced movements during luxation.
Briefly: answers to topical questions
What types of elevators are used to extract tooth roots in the mandible?
Angular and side elevators are used to extract tooth roots in the mandible.
- Angular elevator — has a beak deflected from the long axis of the instrument by an average of 60°, available in paired sets (with left- and right-turned beaks).
- Side elevator — used for extracting molar roots; the working (concave) surface of the beak is inserted into the periodontal space or between two roots.
What local postoperative complications occur after tooth extraction?
Local postoperative complications after tooth extraction include alveolitis and socket hemorrhage.
- Alveolitis — an inflammatory process that develops when blood clot retention is disturbed or the clot disintegrates in the socket; accompanied by constant pain, and the socket may be empty or covered with a grayish fibrinous coating.
- Socket hemorrhage may occur, for example, upon fracture of a portion of the alveolus.
Odontogenic neuralgia is described as a condition occurring after traumatic tooth extraction, but in the cited sources it is not classified directly as a local postoperative complication. Normal postoperative pain is not a complication.
What instruments are used to extract teeth in the mandible?
Falcon-beaked forceps and various elevators are used to extract teeth in the mandible.
- Falcon-beaked forceps bent on the edge — the primary instrument, subdivided into forceps with converging (for roots) and non-converging beaks. Forceps with narrow beaks are used for incisors.
- Falcon-beaked forceps bent on the flat — used for extracting mandibular molars when the patient has limited mouth opening.
- Elevators — straight (for luxating the lower wisdom tooth), angular, side, and bayonet-shaped (Lecluse elevator) are used.
In some cases, universal bayonet forceps may be used to extract the roots of mandibular incisors and canines.
Class and exam questions
Why is the maxillary first molar luxated in the palatal direction?
Unlike second and third molars, whose luxation proceeds in the buccal direction, the first molar is luxated palatally. This is due to the presence of a very dense bone formation—the zygomaticoalveolar crest—on the vestibular surface in this zone.
What most commonly causes a root fracture during surgery?
In addition to severe caries destruction, a frequent cause is a technical error: the physician does not advance the forceps beaks deep enough under the gingiva, fails to observe the tooth axis, or makes overly sharp movements.
What forceps are needed if the patient cannot open their mouth wide during mandibular third molar extraction?
Under conditions of limited mouth opening, when it is impossible to properly apply standard forceps along the tooth axis, special falcon-beaked forceps bent on the flat are used.
What else to study on this topic
- Technique for using elevators in the mandible
- Methodology for using a dental bur in apical root fractures
- Emergency care algorithms for syncope and collapse in the dental chair
- Differential diagnosis of early postoperative local complications
Master the entire topic in the course "Surgical Dentistry"
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Tooth Root Extraction" 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 5. Tooth Extraction Surgery (A.M. Panin, V.V. Afanasyev)"
Entire section "Chapter 5. Tooth Extraction Surgery (A.M. Panin, V.V. Afanasyev)"Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.