- Unerupted tooth (retained tooth): is that fail to erupt into the oral cavity at the normal time and age.
- Impacted tooth: is a retained tooth that is completely or partially buried in the soft tissue or the bone.
- Aberration: is a tooth that develop distant from its normal location.
- Ectopic eruption: eruption of a tooth outside the arch line based on clinical evaluation.
- Agenesis: failure of a tooth to develop due to many reasons and genetic factor is highly contributed.
- Mandibular third molars
- Maxillary canines
- Mandibular second premolars
- Maxillary second premolar
- Mandibular canines
Etiology of failure of eruption
- Tooth agenesis.
- Injury to tooth germ and displacement of tooth follicle.
- Crowding and disproportion between teeth size and jaw.
- Premature loss of a deciduous predecessor and gingival fibromatosis
- Presence of supernumerary teeth
- Presence of tumors or cysts
- Cleft palate and alveolus
- Cleidocranial dysostosis
- Conginital brevicollis dystrophy
- Klipped feil syndrome
- Cretinism (infantile hypothyrodism)
Indications-(Rational for treatment)
- Majority removed because of pain or being a foci of infection.
- Involvement in pathology like cyst and tumors.
- Resorption of roots of adjacent teeth.
- Interference in line of osteotomies and fractures.
- Infection of surrounding soft or hard tissue.
- For prophylactic reasons.
Asymptomatic unerupted teeth that removal is possibly complicated by an injury to inferior dental or lingual nerve during surgery treatment.
Teeth of favorable position that can be monitored at time intervals to detect the development of any complications.
Recognition of the problem:
The existence, position, orientation of the impaction and diagnosis of associated problems are based on:
- Clinical examination
Missing tooth or teeth with or without history of pain and swelling of underlying mucosa (agenesis??)
In case of pain, effort must be paid to eliminate other possible causes of dental pain from another tooth such as pulpitis and periodontitis.
Pain at posterior aspect of the mouth that can be a refereed type of pain such as earache, eye pain, artherolgia, etc.)
Inflammation around the crown of the tooth that make more acute symptoms (pericoronitis).
- Recording of missing teeth.
- Recording of retained deciduous teeth.
- Identify caries and periodontal diseases.(pain might be from adjacent carious tooth, this would influence the proposed treatment planning)
- Vitality test of all teeth in doubt.
- Examination for sign of infection.(swelling, discharge, trismus and enlarged lymph nodes)
- Facial asymmetry and jaw bone expansion.
- To disclose the unerupted tooth and the texture of the surrounding bone.
- To disclose the position in the jaw and its relation to adjacent teeth and other vital structures (sinuses, IDC,).
- To disclose the crown-root ratio and roots configuration.
- (curvature, numbers, hypercemntosis, bulbous, fused or diverged)
- To disclose the degree and orientation of impaction.
- To disclose atrophy of dental follicles and existence of pathological development.
Asymptomatic unerupted teeth most often discovered following radiographical screening (accidental findings).
Partially erupted teeth might be associated with pain and infection.
Impacted lower wisdom tooth may cause crowding upon anterior teeth.
Impacted tooth may erode or cause cavitation of adjacent teeth.
Impacted teeth may be associated with pathological cyst development.
- Infection involves the soft tissue surrounding the crown of partially erupted tooth.
- Usually caused by streptococci and anaerobic bacteria.
- It may presented as an acute or chronic infection.
- Acute infection developed over hours and days and associated possibly with systemic manifestation.
- Chronic infection distinguished by redness and or discharge of pus with few acute symptoms lasting over weeks to months.
- It may be associated with poor oral hygiene and upper respiratory infection.
Signs and symptoms:
- Swelling of retro-molar tissue
- Erythemia of overlaying soft tissue or operculum
- Facial swelling of the affected side
- Raised temperature
- Regional lymphodenopathy
- General malaise
- Trauma from an opposing over-erupted wisdom tooth
- Entrapment of food debris and bacterial infection under the operculum
- Physical and mental stress
- Pregnancy and suppression of the immune system
- Upper respiratory tract infection
Management of pericoronitis
- Local irrigation by hot salt mouthwash. chlorhexidine mouthwash
- Antibiotics if signs of spreading infection are evident. (amoxycillin, metronidazole)
- Analgesic and non-steroidal anti-inflammatory agent.
- Extraction of upper opposing wisdom tooth if traumatizing the lower operculum.
- Removal of lower wisdom tooth when acute infection is resolved.
- Hospital admission in case of severe infection that may compromise the airway.
Considerations in clinical examination of an impacted/ partially erupted tooth
- Patient age and tooth eruption
- Associated infection
- Caries and restoration
- Dental status of the adjacent tooth
- Periodontal status
- State of the TMJ
Status of tooth in question
- Based on clinical evaluation
- Erupted but non-functional (no opposing, tilted, carious, etc.)
- Partially erupted (covered partially with soft tissue)
- Partially erupted with sign of recurrent infection
- Truly impacted (bony or soft tissue)
- Association with pathological lesions
Methods of radiographical examination
Radiographs in two planes at right angles are needed to show clearly the position of the tooth and the degree of impaction
- Orthopantomogram (OPG)
- Preapical radiograph
- Lateral oblique view of the jaw
- Vertex occlusal view
- Parellex method of Clark
- Orientation (mesioangular, vertical, distoangular and transalveolar)
- Depth below the occlusal plane
- Crown size and follicular width
- Root morphology (number, length, shape: fused or separate, curved apex, bulbous, ankylosis).
- Condition of the crown and the adjacent tooth
- Approximation of an ascending ramus, IDC, maxillary sinus, ptrygoid plates and pyriform fossa.
Management of impacted/ partially erupted teeth
Options of management
- No treatment
- Conservative management
- Surgical repositioning and transplantation
- Exposure of the teeth with or without orthodontic application
- Surgical removal
No treatment-(Choices of putting tooth in probation)
- Asymptomatic tooth
- When it acts as a buttress for the root of adjacent tooth
- When vital structures are at risk of injury in the course of operation
- In case of acute preicoronitis
- Tooth that might be brought into occlusion provided that space is adequate in the arch line.
- When adjacent tooth is carious, heavily filled or missing.
- Mesial drifting may allow tooth to replace poorly prognosis or missing anterior one
Surgical repositioning and transplantation
- Aimed to move tooth bodily into the dental arch
- Careful surgical extraction is required to minimize the damage to the apical vessels and periodentium
- Imobilization within the prepared socket for 4 weeks
- Success determined by the dental age (unclosed apices), patient age and atrumatic surgery
- Resorption of root might be evident in 2-5 years
- Early endondontic treatment might be of help to minimize the failure
Third molar transplantation
Surgical aids to orthodontics
- It is mostly prescribed for impacted canine
- Other teeth might be considered as well
- Aimed to help in establishing optimum occlusion orthodontically
- The canine is very important esthetically
- The success is very high
- Surgery for exposure is much easier than for removal of the impaction
Surgery-assisted orthodontic traction
- Reflection of mucoperiosteal flap
- Crown is to be freed to its greatest circumference
- Preservation of attached ginigiva for labially and buccally placed teeth
- Orthodontic device ( button, hock and ligature wire) is to be applied
- Flap is to be then sutured back in position
- For palatal placed teeth, soft tissue excision for exposure is to be packed with whitehead’s varnish, BIPS, coepack
- Orthodontist visit to be arranged one week post op for traction application
- The procedure:
Removal of unerupted teeth
- Earlier to sclerosis of bone
- Earlier to follicle atrophy
- When it is infection-free
- Before fully development of roots
- When 2/3 of the roots are formed
- Best timing for removal
- Localization of unerupted tooth
- Morphology of the tooth and roots
- Relationship to the inferior dental neurovascular bundle
- Buccolingual position
- Relationship to adjacent teeth
- Relationship to inferior border of the mandible and anterior border of the ramus
Planning for operation
- “Reverse in order”
- The tooth position in jaw
- The natural line of withdrawal
- Overcome obstacles (ascending ramus and adjacent tooth or teeth)
- Point of application for elevation
- Access by removing bone and design flap accordingly
Natural line of withdrawal
Teeth extracted by moving them away from sockets or bone along their pathway
The course of movement is dictated by the curvature of the roots
Unfavorable elevation refers to tooth goes deeper in bone or impacted against another tooth
Violation of the principles of line of withdrawal
Fracture of bone (the whole entity or part of it)
Displacement of tooth into soft tissue or anatomical spaces
Damage of inferior dental nerve
Obstacles to elevation
√ shape of the tooth and root
√ Constriction at the neck of the tooth
√ bone and depth of the tooth
√ adjacent tooth (impaction against a tooth )
√ adjacent vital structures (the inferior dental neurovascular bundle)
Overcoming the obstacles
Removing sufficient bone to allow tooth to be rotated and delivered
Division of the tooth horizontally or vertically or by both using:
√ drill and large fissure bur
Removal of lingual plate using:
√ chisels and mallet
Point of application
Dental elevators is the best for removal of buried teeth
Point of application must be determined during planning
Point of application is to be prepared simultaneously during access preparation
No tooth division until adequate point of application has been prepared.
Preparation for surgery
Hospital and general anesthesia
Outpatient clinic with either intravenous sedation or local anesthesia
- Flap must be sufficient enough to allow direct vision with no chance of tension and trauma
- Bone removal should permit tooth with its greatest crown dimension to pass freely (tooth division may minimize the need for more bone removal)
- Curved and bulbous root must be made free of bone
- Cutting of bone and tooth division must be completed before attempting elevation
- Flap is to be replaced and rests on bone before suturing
Closure of wound
- Debridment and smoothening of sharp edges of the socket
- Removal of dental follicle (sack) without endangering vital structure (lingual nerve)
- Primary closure as long as flap is not under tension is desirable
- Resorbable or non-resorbable suture may be used
- Suture notes should be kept to a minimum
Surgery of Mandibular Impacted/ Parially Erupted Teeth
- Transbuccally (crown facing lingually or buccally)
- Apparent position; ramus or close to inferior border of the mandible
Impacted mandibular canine and premolar tooth
- Surgical considerations
- Position of unerupted tooth (3rd molar or canine)
- Relationship to adjacent teeth
- Relationship to maxillary sinus
- Morphology of the roots
- Status of adjacent teeth
- Presence of supernumerary and supplemental teeth
Upper third molar Operative technique
- The flap
- The envelop flap
- Two sided flap (triangular type)
- Bone removal
- Establishment of OAF
Surgical exposure and surgical removal of impacted canine and anterior
Palatally positioned tooth
Labially positioned tooth
Removal of unerupted teeth from edentulous ridge
- Difficulty is owing to sclerotic bone and loss of periodontal space
- Gentle force via a well prepared point of application would minimize the risk of fracture of brittle bone
- Alveolar ridge preservation by accurate assessment and minimal bone removal
- Osteoplastic flap to preserve the alveolar bone in height and in width
- Bone reduction and fixation in the incident of atrophic jaw fracture
- Small mouth
- Narrow space between anterior border of the ramus and distal aspect of second molar tooth buried deeply in bone
- Approximation of inferior dental canal and sinuses
- Existence of fusion and ankylosis
- Devitalizations and cavitations
Complications associated with unerupted and impacted teeth surgery
√Fractured root, tuberosity
√Damage to adjacent tooth, tooth displacement
√ oroantral-oronasal communication
√ pain, swelling, bruising, trismus, aneathesis, infection