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Review Article Plastic and Aesthetic Research

Neurovascular plexus theory for “escape

pain phenomenon” in lower third molar

surgery

Gururaj Arakeri , Mandeep Gill Sagoo , Peter A. Brennan 3
2
1
1 Department of Oral and Maxillofacial Surgery, Navodaya Dental College and Hospital, Raichur 584101, Karnataka, India.
2 Department of Anatomy and Human Sciences, King’s College, London WC2R 2LS, UK.
3 Department of Oral and Maxillofacial Surgery, Queen Alexandra Hospital, Portsmouth PO6 3LY, UK.
Address for correspondence: Dr. Gururaj Arakeri, Department of Oral and Maxillofacial Surgery, Navodaya Dental College and Hospital,
Raichur 584101, Karnataka, India. E-mail: gururaj.arakeri@gmail.com

ABSTRACT
Pain during extraction of impacted mandibular third molars which can occur despite adequate local
anesthesia is termed as “escape pain phenomenon”. Recently, it was described during elevation of
a mesioangular impacted mandibular third molar and also while curetting an extracted third molar
socket. This phenomenon has been overlooked, as it was previously considered secondary to pressure
effect on the inferior alveolar neurovascular bundle (IANB). However, it is unlikely that the pain
impulses originate from direct pressure on the IANB, as the nerve is blocked more proximally at
its entry into the mandible. The authors speculated that the occasional presence of a neurovascular
plexus (NVP) independent of the IANB causes the escape of a pain impulse upon stimulation by
root pressure or instrumentation. To validate the presence of such a plexus, a meticulous literature
search and review were performed. The search revealed evidence of the occasional presence of a NVP
consisting of auriculotemporal and/or retromolar neural filaments. The plexus may be present around
the inferior alveolar artery or embedded within the IANB, and does not innervate the tooth. This
plexus likely propagates pain impulses only upon stimulation by compression or instrumentation in
the apical area of the tooth socket. This theory explains the absence of pain during tooth sectioning and
bone guttering in the presence of a complete inferior alveolar nerve block.
Key words:
Inferior alveolar nerve, inferior dental plexus, escape pain phenomenon, third molar surgery

INTRODUCTION during elevation of the tooth and even during curettage
of the extraction socket at the apical region. This pain was
The concept of the “escape pain phenomenon” (EPP) thought to be an alert for the proximity of root apices to
[2]
[1]
was described first by Carter and Keen in 4-5% of the inferior alveolar canal. However, the pain was absent
patients following an inferior alveolar nerve block. This during soft tissue retraction, bone guttering, and tooth
phenomenon was observed during the entire course of section procedures. [3]
[1]
the extraction procedure. Recently, a concern was raised The purpose of the present article was to postulate a
regarding the incidence of pain upon the elevation of an theory which explains the EPP while elevation or curettage
impacted third molar. [2,3] The pain typically manifested
steps of third molar surgery based on a systematic
literature search.
Access this article online
Quick Response Code: A literature search was conducted through the MEDLINE
Website: database using PubMed Central, Science Direct Search,
www.parjournal.net
Scopus, and Google. The keywords “neurovascular
plexus” (NVP), “lower third molar”, “inferior dental
DOI: artery”, “inferior alveolar nerve”, “variation”, “impaction
10.4103/2347-9264.157098 and neurovascular complications” were used in all
combinations. All papers are scrutinized for relevancy by a
Plast Aesthet Res || Vol 2 || Issue 3 || May 15, 2015 107