(BQ) Part 1 book “Textbook of general and oral surgery” has contents: History taking, complications of surgery, fluid balance, metabolism and nutrition, general anaesthesia, conscious sedation techniques, orthognathic surgery, salivary gland surgery, plastic surgery, temporomandibular joint investigation and surgery,… and other contents.
This page intentionally left blank TEXTBOOK OF GENERAL AND ORAL SURGERY Commissioning Editor: Michael Parkinson Project Development Manager: Hannah Kenner Project Manager: Nancy Arnott Designer: Erik Bigland TEXTBOOK OF GENERAL AND ORAL SURGERY CHURCHILL LIVINGSTONE EDINBURGH LONDON NEW YORK PHILADELPHIA ST LOUIS SYDNEY TORONTO 2003 CHURCHILL LIVINGSTONE An imprint of Elsevier Science Limited © 2003, Elsevier Science Limited All rights reserved The right of David Wray, David Stenhouse, David Lee and AJ Clark to be identified as editors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior permission of the publishers or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London W1T 4LP Permissions may be sought directly from Elsevier's Health Sciences Rights Department in Philadelphia, USA: phone: (+1) 215 238 7869, fax: (+1) 215 238 2239, e-mail: healthpermissions@elsevier.com You may also complete your request on-line via the Elsevier Science homepage (http://www.elsevier.com), by selecting 'Customer Support' and then 'Obtaining Permissions' First published 2003 ISBN 4430 7083 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book is available from the Library of Congress Note Medical knowledge is constantly changing As new information becomes available, changes in treatment, procedures, equipment and the use of drugs become necessary The editors and the publishers have taken care to ensure that the information given in this text is accurate and up to date However, readers are strongly advised to confirm that the information, especially with regard to drug usage, complies with the latest legislation and standards of practice ELSEVIER SCIENCE your source for books, journals and multimedia in the health sciences www.elsevierhealth.com The publisher's policy is to use paper manufactured from sustainable forests Printed in China Preface The scope of dental practice has evolved enormously since the era of the barber surgeon Oral surgery remains, however, not only a traditional skill in dentistry but also a core skill for all dental surgeons regardless of their area of specialism, and therefore it is an important part of the undergraduate curriculum and general professional training Over the years, as the medical status of the population has become more complex and surgical expertise has increased, oral surgery has evolved into identified subspecialties These include maxillofacial surgery, which, in the UK, is a specialty of medicine; oral surgery, which embraces maxillofacial trauma and orthognathic surgery; and dentoalveolar surgery, which is designated surgical dentistry by the General Dental Council in the UK The first two - maxillofacial surgery and oral surgery - are the remit of specialists, whereas all dentists are expected to be competent in dentoalveolar surgery A sound knowledge of basic surgical principles is a prerequisite to the practice of any of these areas of surgery This text includes a consideration of general surgical principles, specialist surgical areas and minor oral surgery The section on general surgical principles has been written mainly by general surgeons and provides core knowledge that informs the safe practice of surgery It will be of practical help to those working as senior house officers in maxillofacial surgery wards This section also considers cross-infection control and provides an overview of both general anaesthesia and conscious sedation The second section includes chapters on individual areas of specialist surgical practice of interest to oral and maxillofacial operators, written by experts These are written to provide insight into these relevant areas of surgical practice so that the dentist can be confident in the information he or she provides to patients and can also make appropriate referrals This section is not intended to inform practice in these areas and so it is short and readable The third section - oral surgery - is a practical guide to the practice of dentoalveolar surgery or surgical dentistry It provides core information required to complete the undergraduate curriculum The integrated nature of this text, which includes general and oral surgery, is a companion to the Textbook of General and Oral Medicine, and is recommended for students studying human disease earlier in the undergraduate curriculum and, subsequently, oral surgery in the clinical years Although intended primarily for undergraduate students, the book also provides a comprehensive range of information for those preparing for membership examinations and will be a useful bench book in a dental practice environment The authors have taken great pleasure and satisfaction in compiling this text, which is unique in bringing together succinct knowledge on the whole scope of surgical practice in dentistry It is hoped that the reader will also be pleased and satisfied Finally, I would sincerely like to thank Dr Declan Millett, Senior Lecturer in Orthodontics, for providing his expertise in the areas where there is an interface with orthodontics I would also like to record my thanks to Mrs Grace Dobson and Mrs Betty Bulloch for the manuscript, and to Mrs Kay Shepherd and Mrs Gail Drake of the Dental Illustration Department, in addition to those who have contributed to this text D Wray Glasgow, 2003 VII This page intentionally left blank Contributors Professor Jeremy Bagg, PHD, BDS, FDS RCS(Ed), FDS RCPS(Glasg), FRC Path Professor of Clinical Microbiology, University of Glasgow Honorary Consultant Microbiologist, North Glasgow University Hospitals NHS Trust Mr Philip Barlow, MPhii, BSC, MB ChB, FRCS(Ed) Consultant Neurosurgeon, South Glasgow University Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Dr Andrew J E Clark, BSc(Hons), MB ChBMRCS(Ed) Clinical Research Fellow in General Surgery Western General Hospital, Edinburgh and Arran Acute Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Mr David Lee, BSC, MB ChB, FRCS(Ed) Consultant General and Endocrine Surgeon, Lothian University Hospitals NHS Trust, Royal Infirmary, Edinburgh Member of Council, Royal College of Surgeons of Edinburgh Mr Jason A Leitch, BDS, FDS RCS(Eng) Lecturer in Oral Surgery, University of Glasgow Honorary Associate Specialist, North Glasgow University Hospitals NHS Trust Mr Gerald W McGarry, MD, MB ChB, FRCS(Ed), Mr Howard A Critchlow, BDS, FDS RCS(Eng), FDS FRCS(Glasg) RCPS(Glasg) Consultant Otolaryngologist, North Glasgow University Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Consultant Oral Surgeon, South Glasgow University Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Professor Khursheed F Moos, BDS, MB BS, FDS RCS(Eng), Mr Hugh Harvie, BDS, FDS RCS(Ed), FDS RCPS(Glasg), Dip FDS RCS(Ed), FDS RCPS(Glasg), FRCS(Ed) For Med Honorary Professor, University of Glasgow Honorary Consultant in Oral Surgery, North Glasgow University Hospitals NHS Trust Head of Dental Division, Medical and Dental Defence Union of Scotland Honorary Senior Lecturer, University of Glasgow Dr James R I R Dougall, MB ChB, FFA RCSI Consultant in Anaesthesia and Intensive Care, North Glasgow University Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Mr W Stuart Hislop, BDS, MB ChB, FDS RCS(Ed), FRCS(Ed), FDS RCPS(Glasg) Consultant Oral and Maxillofacial Surgeon, Ayrshire Mr Arup K Ray, MS, MB BS, FRCS(Ed), FRCS(Glasg) Consultant Plastic and Reconstructive Surgeon, North Glasgow University Hospitals NHS Trust Honorary Senior Lecturer, University of Glasgow Mr R J Sanderson, MB ChB, FRCS(Eng), FRCS(Ed) Consultant Otolaryngologist and Head and Neck Surgeon, West Lothian and Lothian University Hospitals NHS Trust IX Table 19.2 The Glasgow Coma Scale and score Feature Scale responses Score notation Eye opening Spontaneous To speech To pain None Orientated Confused conversation Words (inappropriate) Sounds (incomprehensible) None Obeys commands Localises pain Flexion - normal Flexion - abnormal Extend None Verbal response Best motor response Total Coma score 164 eye opening to speech should be looked for before testing eye opening to pain The correct way to test for a motor response often causes some difficulty If a patient does not obey simple commands, a localising (purposeful) response is tested for By convention, painful pressure is applied to the supraorbital margin and if the patient brings a hand up to the site of the pain, then the patient is localising Both arms are tested by holding one arm down at a time If the patient does not localise, the other responses are tested by applying pressure to the fingernail bed A flexion or extension response refers to movement at the elbow The intermediate response, abnormal (or spastic) flexion is charted if there is either preceding extension movement in arm, or extension in a leg, or two of the following: stereotyped flexion posture, extreme wrist flexion, adduction of arm or fingers flexed over thumb Because of the difficulty of describing this response, spastic flexion can be omitted from the Coma Scale, but is important to record, if present, as a focal sign (Fig 19.1) If in doubt, record normal flexion When recording conscious level, the 'best' motor response is taken This means the arm with the best response, not the best response over time So if a patient is localising pain with the right arm but flexing to pain with the left arm, the conscious level is judged as localising However, the flexion response in the left arm is an important focal sign, indicating a lesion probably affecting the right hemisphere 3 /15 to 15 /15 It is common, especially in trauma patients, to be unable to record one or more aspects of the Coma Scale The patient's eyes might be closed by swelling, or directly injured, making eye opening not possible The patient may be dysphasic, or have an endotracheal tube or tracheostomy, making verbal response unrecordable There may be a high spinal injury, brachial plexus lesion, or limb fracture, making motor response unreliable In all these situations it is important simply to give the reason for not recording the response, rather than to guess at what it might be (see Fig 19.1) Coma is defined as not obeying commands, not eye opening even to pain, and not uttering recognisable words A severe head injury is one where coma, as defined, is present for h or more Each component of the Glasgow Coma Scale can be allocated a numerical value, the sum of which can give the Glasgow Coma (GC) Score (see Table 19.2) The GC Score was devised in the 1970s to allow information on large numbers of head-injured patients to be stored and analysed by computer The GC Score is useful for grouping head-injured patients by severity, for displaying risk factors, and as a form of shorthand used in producing guidelines Despite widespread practice to the contrary, the GC Score should never be used to describe an individual patient's conscious level in a clinical situation To so often results in confusion and significant loss of information In clinical practice, always use the verbal description of the three components of the GC Scale Fig 19.1 Stylised neurosurgical observation chart of a patient deteriorating with a left-side extradural haematoma who improves following surgical evacuation The Glasgow Coma Scale (GCS) uses the best motor response but limb asymmetry is also charted; if a response is inaccessible, the reason is given (e.g C, eyes closed by swelling; DYS, dysphasic) The GC Score is not used for individual patients in a clinical situation Neurosurgical investigations and procedures The purpose of neurosurgical history taking and examination is to determine anatomical localisation and, if possible, general pathology This in turn guides the investigations that are most likely to assist in further diagnosis (of special pathology) and management Lumbar puncture This is used to diagnose infection of the CSF, in which case the white cell count will be raised Bleeding into the CSF (from, for example, a ruptured intracranial aneurysm) is diagnosed by frank blood-staining of the CSF and/or xanthochromia in the supernatant Lumbar puncture (LP) is contraindicated in the presence of an intracranial mass lesion; an LP in this circumstance may lead to a pressure differential and subsequent downward herniation of the brain (coning) This can result in rapid death Nerve conduction studies and electromyography These are tests performed by neurophysiologists and may be very useful in distinguishing nerve root abnormalities from peripheral nerve entrapment or peripheral neuropathy Plain radiography Plain radiographs of the head or spine can be particularly useful in cases of trauma Radiographs of the skull can 165 show a fracture, a depressed fracture, air in the head or foreign bodies following a penetrating wound Many head injuries are associated with spinal injury, particularly of the cervical spine, and cervical spine radiograph is almost routine following any significant head injury Some brain tumours contain calcification or cause bone erosion, which is visible on a skull radiograph Many pituitary tumours show erosion or expansion of the pituitary fossa on a lateral skull radiograph In babies or children a skull radiograph can show premature fusion of the sutures (craniosynostosis), and chronic raised ICP gives patchy thinning of the skull vault - the copperbeaten appearance Some spinal cord tumours or cysts may cause expansion and erosion of adjacent vertebra CT scan This investigation has revolutionalised neurosurgery No longer neurosurgeons need to rely on careful, detailed neurological examination to identify the exact site of, for example, a brain tumour MRI scan This gives exquisite anatomical images The two main advantages of the MRI scan over the CT scan are, first, that it is not affected by thick bone and is therefore useful for imaging the posterior fossa and spine Second, it can image in any plane, and this is particularly informative in sagittal images of the spine The disadvantages of the MRI scan is that it is expensive and time consuming It is contraindicated in patients with pacemakers, implanted stimulators or ferromagnetic implants or foreign bodies Some claustrophobic patients cannot tolerate lying in the scanner Angiography Carotid and vertebral angiograms are used to visualise intracranial aneurysms, arteriovenous malformations (AVMs), and the vascular supply of tumours Access is usually via the femoral artery, threading the tracker catheter along the aorta under X-ray control Craniotomy 166 This refers to a flap of bone that is removed with a saw and replaced at the end of the procedure The craniotomy flap may be of any size but is usually greater than cm diameter A craniotomy may be an osteoplastic flap, where the temporalis muscle is left attached to the bone, or a free flap A craniotomy is the standard neurosurgical procedure to gain access to the intracranial contents Neurosurgicai conditions Trauma No head injury is so trivial that it can be ignored, or so serious that it should be despaired of These words are as true today as when written by Hippocrates Head injuries are common and the majority are minor and not require investigation or hospital admission Nevertheless, the potential for complications is always present Head injuries can be classified anatomically according to the structure(s) affected (scalp, skull, dura, brain), pathologically, depending on the type of brain damage (primary, secondary, focal, diffuse), or aetiologically, according to the mechanism of injury (blunt, penetrating, acceleration/deceleration, missile) Isolated scalp injuries are common but not usually serious Blood loss may look frightening but is rarely enough to cause shock, with the exception sometimes in babies The history is always important and may alert the examiner to the possibility of a penetrating wound or a depressed fracture, both of which will normally require neurosurgical exploration First aid treatment of a scalp laceration is to stop the bleeding by direct pressure Thereafter direct primary suture is usually possible A skull fracture may be of the vault or the skull base A closed (or simple) skull fracture has no overlying scalp laceration A compound (or open) fracture implies communication of the fracture with the atmosphere A compound depressed fracture of the skull vault usually requires an operation to debride the wound, elevate the fracture and inspect the underlying dura and brain for lacerations The main aim of this procedure is to reduce the risk of intracranial infection by removing all foreign material and repairing the dural defect Penetrating wounds are dealt with in the same way Simple depressed fractures not require surgery Fractures of the skull base are difficult to see with radiographs but can be diagnosed clinically by the presence of well-defined periorbital haematomas (racoon eyes) and subconjunctival haemorrhage with no posterior Table 19.3 Risk of an operable intracranial haematoma in head injured patients GCS (/15) Risk Other features Risk 15 in 3615 9-14 in 51 3-8 in None Post-traumatic amnesia (PTA) Skull fracture Skull fracture and PTA No fracture Skull fracture No fracture Skull fracture 1 1 1 1 in 31 300 in 6700 in 81 in 29 in 180 in in 27 in GCS, Glasgow Coma scale Adapted from Teasdale et al 1990 British Medical Journal, 300: 363-367 limit (in anterior fossa fractures), or bruising over the mastoid process (Battle's sign) in fractures of the petrous bone Petrous fractures can damage the middle or inner ear and may have associated bleeding from the external meatus, deafness, dizziness or facial nerve palsy If the dura underlying a base of skull fracture is torn, there may be a CSF leak through the nose or the ear, or air many enter the subarachnoid space (pneumocephalus) In either event there is a risk of bacterial meningitis If the dural tear does not heal within 1-2 weeks, surgical repair is usually indicated Recently published guidelines not recommend prophylactic antibiotics for a CSF leak The main significance of a skull fracture is that it indicates a greatly increased risk of the patient harbouring an intracranial haematoma that requires surgical removal Table 19.3 illustrates the risks that form the basis for guidelines on the early management of head injuries Table 19.4 lists the criteria for referral of a head injury to hospital Further guidelines on the indications for a skull radiograph, admission to hospital, a CT scan, and referral to a neurosurgeon can be found in the Scottish Intercollegiate Guidelines Network (SIGN) publication entitled 'Early management of patients with a head injury (No 46)', published in August 2000 Table 19.4 Indications for referral of a head injured patient to hospital A head injured patient should be referred to hospital if any of the following is present: Impaired consciousness (GCS