5.1 Oral Surgery & Extractions

Assessment of Difficulty & Informed Consent

Before any extraction the clinician must assess difficulty and obtain informed consent that satisfies the Supreme Court's Montgomery v Lanarkshire Health Board (2015) ruling. Under Montgomery, a clinician must take reasonable care to ensure the patient is aware of any material risks of the proposed treatment and of reasonable alternatives. A risk is material if a reasonable person in the patient's position would attach significance to it, or the clinician is or should be aware that this particular patient would.

Factors Assessing Extraction Difficulty

Material Risks to Discuss for Lower Third Molar Surgery

• Inferior alveolar nerve (IAN) injury — the inferior alveolar nerve runs in the mandibular canal close to the mesial root of lower third molars; temporary altered sensation is reported in roughly 1-5% of surgical removals and permanent injury in well under 1%.
• Lingual nerve injury — lies immediately lingual to the mandible at the reflection of the floor of mouth; at particular risk during lingual flap retraction or sectioning.
• Dry socket (alveolar osteitis) — 1-4% routine extractions, 25-30% impacted lower third molars.
• Bleeding, infection, fracture of tuberosity or jaw, oro-antral communication (upper molars).

A patient who is a professional singer may attach particular significance to lingual nerve risk; that individualised significance must be recorded in the notes.

Forceps vs Surgical Extractions & Local Anaesthetic Techniques

Forceps (Closed) Extraction

The principles of forceps extraction are to expand the buccal bone and sever the periodontal ligament using controlled apical pressure and rotation. The beaks are applied to the cementum, not the enamel, to grip the root. Rotation is safest on single-rooted teeth with conical roots (upper incisors, upper canines); multi-rooted teeth require buccopalatal expansion followed by a figure-of-eight motion in the upper arch.

Surgical (Open) Extraction

Indications for a surgical extraction include impacted or submucosal teeth, divergent or ankylosed roots, brittle endodontically treated teeth, and teeth at risk of fracture. The technique uses a mucoperiosteal flap (envelope or three-cornered with a relieving incision), bone removal with a bur, and tooth sectioning to deliver roots individually. A release incision should be placed at a line angle, avoid the mental nerve, and have a broad base to preserve blood supply.

Local Anaesthetic Techniques for Extractions

For a failed block, intra-ligamentary injection or intra-osseous injection can supplement. An inferior alveolar nerve block normally contacts bone at about 20-25 mm of insertion; if bone is not contacted, withdraw and re-orientate rather than advancing further, and never insert a 35 mm needle to the hub.

Complications of Extraction

Alveolar Osteitis (Dry Socket)

Alveolar osteitis is a post-extraction complication occurring 3-4 days after surgery, characterised by severe throbbing pain, a socket empty of clot with exposed bone, and halitosis, without marked swelling or systemic features. Incidence is 1-4% of routine extractions and 25-30% of impacted lower third molars. Risk factors include smoking, oral contraceptive use, traumatic extraction, and pre-existing pericoronitis.

SDCEP Management of Acute Dental Problems and the FGDP/RCS Antimicrobial Prescribing in Dentistry (3rd edition, 2020) both advise:

1. Irrigate the socket gently with sterile saline to remove debris (chlorhexidine is not recommended for irrigation — anaphylaxis risk and insufficient evidence).
2. Place a dressing such as Alvogyl (eugenol-based) to obtund pain; this may delay healing so it should be lightly packed.
3. Advise analgesia (ibuprofen or paracetamol) and warm salt-water mouthwashes.
4. Do NOT prescribe antibiotics unless there is evidence of spreading infection, systemic involvement, or the patient is immunocompromised.

Nerve Injury

• Inferior alveolar nerve (IAN) injury — paraesthesia or dysaesthesia of the lower lip and chin on the affected side. Risk is increased when the tooth is close to the mandibular canal on cross-sectional imaging (distorted lamina dura, loss of the inferior alveolar canal cortex, J-shaped root).
• Lingual nerve injury — affects the tongue and floor of mouth; often relates to lingual flap retraction or the lingual splitting technique.

Nerve injuries are classified as neuropraxia (recoverable, conduction block), axonotmesis (axon disruption, endoneurium intact) and neurotmesis (complete transection). Most post-extraction injuries are neuropraxias resolving within weeks; referral to an oral surgery unit is indicated if symptoms persist beyond 3 months.

Oro-Antral Communication (OAC)

A communication between the oral cavity and the maxillary antrum most often follows extraction of an upper molar or premolar with close root proximity to the antral floor. A Valsalva test (nose-blow with the nostrils pinched) reveals air escape. Small communications (<2 mm) may close spontaneously; larger ones require buccal advancement flap closure or a palatal rotation flap. Post-operative advice includes avoiding nose-blowing and sneezing with the mouth open, and prescribing an antihistamine and nasal decongestant.

Spreading Odontogenic Infection & Ludwig's Angina

Odontogenic infection spreads along fascial planes of least resistance, and the route depends on the relationship of muscle attachments to the root apex.

Fascial Space Pathways

Ludwig's Angina

Ludwig's angina is a rapidly progressing, bilateral cellulitis of the submandibular, sublingual and submental spaces, classically arising from a lower second or third molar infection. The tongue is elevated and displaced posteriorly, the floor of mouth is firm and woody, and airway compromise is the immediate threat. Signs of airway risk include dysphagia, dyspnoea, drooling, trismus and a muffled ('hot potato') voice.

Management follows an ABC approach: protect the airway (may require awake tracheostomy rather than crash intubation), give high-flow oxygen, establish intravenous access, and start empirical IV antibiotics (e.g. amoxicillin with metronidazole, or co-amoxiclav). Urgent referral to the on-call oral and maxillofacial surgery (OMFS) or ENT team is mandatory; delay in securing the airway is the most common cause of death.

Discharge Advice After Extraction

Standard written and verbal advice after an extraction should include:

• Bite on gauze for 15-20 minutes; replace if soaked.
• Avoid rinsing for 24 hours to protect the clot, then use warm salt water after meals.
• Avoid smoking for at least 24-48 hours (reduces dry socket risk).
• Avoid vigorous exercise, hot drinks and alcohol for the rest of the day.
• Analgesia: ibuprofen 400 mg (or paracetamol if contraindicated), taken regularly for 24-48 hours.
• Red flags warranting urgent review: bleeding not controlled by pressure, increasing facial swelling after 48 hours, difficulty breathing or swallowing, fever, or a bad taste or pain worsening at day 3-5 (dry socket).