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- Herausgeber: Thieme
- Kategorie: Fachliteratur
- Sprache: Englisch
- Veröffentlichungsjahr: 2020
<p><strong><em>Dentistry at its finest</em></strong></p><p>As a veterinarian and dentist in one, Dr. Markus Eickhoff has practiced high-level canine and feline dentistry for over 20 years. He now shares his fund of experience in this book with over 1500 images.</p><p>What equipment do I need? What treatment options are available and how do I perform them? This book provides detailed, systematic and generously illustrated instructions.</p><p>Over 1500 illustrations present details of many fascinating cases, allowing the practitioner to follow procedures in detail. The myriad practical tips and step-by-step instructions for performing common dental procedures provide security when performing dental treatment on small animals. Supported by the images, Dr. Eickhoff introduces the practitioner to commonly performed procedures such as the extraction of root fragments or the placement of fillings.</p><p>The focus on dogs and cats allows not only conventional treatment options but also less common ones to be presented in detail. Benefit from the latest insights for treating exceptional cases such as cleft palate or dental ankylosis.</p>
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Atlas of Dentistry in Cats and Dogs
Markus Eickhoff
1525 figures
Preface
After over 20 years of veterinary medical practice, I feel that the only way to share helpful insights about diagnosing and treating conditions in the oral cavity is with images. Owners are not usually the proper audience for sharing images that can contain graphic details; on the other hand, veterinarians can learn the proper procedure for treating individual conditions through these images and image series.
Dentistry requires the use of diverse medical devices and instruments, and dentists must be prepared to offer a wide range of options to meet the specific requirements comprising highly variable parameters and conditions with suitable equipment. They also need the proper expertise in dental procedures, which extends far beyond the normal range required for a general practitioner. Thus, dentistry in human medicine has become a medical discipline in its own right. In veterinary medicine, however, such a development is unlikely, so appropriate dental treatment for cats and dogs will remain in the domain of veterinarians, who have to become specialized. This book does not aim to enable all veterinarians to treat all dental conditions, but rather to acquaint them with the problems and possible treatments. This in turn can permit veterinarians to offer the proper treatment or refer the client to a specialist; this approach can prevent years of suffering and pain and initiate a healing process.
Although dealing with fractures, bleeding and pain can be stressful for the veterinary dentist, it brightens the future for many animals.
Weissach, Spring 2017
Markus Eickhoff
Most importantly, this book is dedicated to my wife Sandra and my children Dana and Jared, who were so patient with me while I wrote this book. I am grateful to you.
Contents
Titelei
Preface
Section I Fundamentals
1 Patient History
2 Examining the Head and Oral Cavity
2.1 Anatomy and Morphology of the Oral Cavity
2.2 Canine Oral Cavity
2.3 Feline Oral Cavity
2.4 Intraoral Radiography
2.5 Dental Probing
3 Interpreting Clinical Signs
3.1 Interpreting Clinical Signs of Pediatric Disorders
3.2 Interpreting Clinical Signs of Periodontal Disorders
3.3 Interpreting Clinical Signs of Trauma-related Conditions
3.4 Interpreting Clinical Signs of Resorptive Disorders
3.5 Interpreting the Clinical Signs of Mucosal Inflammatory Diseases
3.6 Interpreting Findings in Tumor Diseases
4 Treatment Aspects
4.1 Instruments and Equipment
4.1.1 Technical Resources
4.1.2 Instruments
4.2 Handling Instruments
4.3 Local Anesthesia
Section II Recurring Procedures
5 Dental Prophylaxis
5.1 Oral Hygiene Status
5.2 Dental Cleaning
5.2.1 Preparation
5.2.2 Ultrasonic Scaling
5.2.3 Dental Cleaning with Manual Tools
5.2.4 Polishing and Antiseptic Application
5.3 Toothbrushes
6 Tooth Extraction
6.1 Closed Extraction – Step by Step
6.1.1 Step 1
6.1.2 Step 2
6.1.3 Step 3
6.1.4 Step 4
6.2 Open Extraction of a Single-rooted Tooth – Step by Step
6.2.1 Step 1
6.2.2 Step 2
6.2.3 Step 3
6.2.4 Step 4
6.2.5 Step 5
6.2.6 Step 6
6.2.7 Step 7
6.3 Open Extraction of a Multirooted Tooth – Step by Step
6.3.1 Step 1
6.3.2 Step 2
6.3.3 Step 3
6.3.4 Step 4
6.3.5 Step 5
6.3.6 Step 6
6.3.7 Step 7
6.3.8 Step 8
6.3.9 Step 9
7 Retrieving Root Fragments
7.1 Retrieving Root Fragments – Step by Step
7.1.1 Step 1
7.1.2 Step 2
7.1.3 Step 3
7.1.4 Step 4
7.1.5 Step 5
7.1.6 Step 6
7.1.7 Step 7
7.1.8 Step 8
7.1.9 Step 9
8 Composite Fillings
8.1 Composite Fillings – Step by Step
8.1.1 Step 1
8.1.2 Step 2
8.1.3 Step 3
8.1.4 Step 4
8.1.5 Step 5
8.1.6 Step 6
9 Vital Pulpotomy
9.1 Crown Reduction – Step by Step
9.1.1 Step 1
9.1.2 Step 2
9.1.3 Step 3
9.1.4 Step 4
9.1.5 Step 5
9.1.6 Step 6
10 Crown Amputation
10.1 Crown Amputation – Step by Step
10.1.1 Step 1
10.1.2 Step 2
10.1.3 Step 3
10.1.4 Step 4
10.1.5 Step 5
11 Root Canal Fillings
11.1 Single-rooted Tooth – Step by Step
11.1.1 Step 1
11.1.2 Step 2
11.1.3 Step 3
11.1.4 Step 4
11.1.5 Step 5
11.1.6 Step 6
11.1.7 Step 7
11.1.8 Step 8
11.1.9 Step 9
11.1.10 Step 10
11.2 Multirooted Tooth 108 – Step by Step
11.2.1 Step 1
11.2.2 Step 2
11.2.3 Step 3
11.2.4 Step 4
11.2.5 Step 5
11.2.6 Step 6
11.2.7 Step 7
11.3 Multirooted Tooth 208 – Step by Step
11.3.1 Step 1
11.3.2 Step 2
11.3.3 Step 3
11.3.4 Step 4
11.3.5 Step 5
11.3.6 Step 6
12 Apicoectomy
12.1 Apicoectomy – Step by Step
12.1.1 Step 1
12.1.2 Step 2
12.1.3 Step 3
12.1.4 Step 4
12.1.5 Step 5
12.1.6 Step 6
13 Attaching Brackets
13.1 Attaching Brackets – Step by Step
13.1.1 Step 1
13.1.2 Step 2
13.1.3 Step 3
13.1.4 Step 4
13.1.5 Step 5
13.1.6 Step 6
14 Plate/Bite Plate
14.1 Acrylic Plate with Screw – Step by Step
14.1.1 Step 1
14.1.2 Step 2
14.1.3 Step 3
14.1.4 Step 4
14.1.5 Step 5
14.1.6 Step 6
14.1.7 Step 7
14.1.8 Step 8
Section III Case Studies
15 Young Animals
15.1 Missing Teeth
15.1.1 Multiple Missing Teeth (Hypodontia) and Reduced Tooth Development in Dogs
15.1.2 Hypodontia and Dental Fracture in Cats
15.1.3 Undeveloped Canines in Dogs
15.1.4 Retained Mandibular Premolar in a Dog and Severe Osteolysis
15.1.5 Bilateral Retained Mandibular Premolars in a Dog
15.1.6 Retained Maxillary Canine Tooth in a Dog
15.1.7 Orthodontic Treatment of a Retained Maxillary Canine Tooth in a Dog
15.2 Supernumerary Teeth
15.2.1 Persistent Deciduous Canines and Malpositioned Permanent Teeth in a Dog
15.2.2 Siblings with Hyperdontia
15.2.3 Double Maxillary Canines in a Cat
15.2.4 Malpositioned Incisors Due to Odontoma in a Dog
15.3 Dental Anomalies
15.3.1 Enamel Hypoplasia of Canines and Molars in a Dog
15.3.2 Generalized Enamel Hypoplasia with Root Deformity in a Dog
15.3.3 Dental Anomaly in a Dog
15.3.4 Double Crown of the Mandibular Premolars in a Cat
15.4 Malocclusions
15.4.1 Linguoversion and Mandibular Distoclusion
15.4.2 Rostral and Caudal Crossbite
15.4.3 Mesioverted Canine (Lance Canine)
15.5 Abrasions in a Young Animal
15.6 Tooth Fractures in Young Animals
15.6.1 Fractured Teeth 504 and 604.
15.6.2 Fractured Tooth 504
15.7 Persistent Deciduous Teeth
15.7.1 Persistent Deciduous Teeth
15.7.2 Shark Teeth in a Small Dog
15.8 Cleft Palate
15.8.1 Complete Cleft Palate in a Dog
15.8.2 Complete Cleft Palate Closure in a Dog, Two-stage Procedure
15.8.3 Trauma-induced Cleft Palate in a Cat
15.8.4 Cleft Lip and Palate in a Dog
15.9 Craniomandibular Osteopathy (CMO)
16 Teeth
16.1 Abrasion and Attrition
16.1.1 Severe Attrition of the Incisors
16.1.2 Severe Abrasion of the Front Teeth
16.1.3 Discoloration of the Maxillary Canine after Abrasion
16.1.4 Periapical Osteolysis of the Maxillary Carnassial Tooth after Abrasion
16.1.5 Abrasion of the Maxillary Canine with Fistula Formation
16.2 Tooth Fractures and Related Conditions
16.2.1 Tooth Discoloration
16.2.2 Tooth Fracture
16.2.3 Isolated Apical Process
16.2.4 Root Remnants
16.2.5 Vital Pulpotomy
16.2.6 Apexification
16.2.7 Bleaching
16.3 Caries
16.3.1 Caries on the Maxillary Cheek Teeth with Filling and Extraction
16.4 Fillings
16.4.1 Deformed Maxillary Canine Crown
16.4.2 Chipping of the Cusp and Buccal Surface on a Maxillary Carnassial Tooth
16.5 Crown Replacement
16.5.1 Metal Crown for Canine Tooth
16.5.2 Ceramic Canine Crown
16.5.3 Carnassial Tooth Crown
16.6 Feline Tooth Resorption
16.6.1 Schematics for Feline Tooth Resorption
16.6.2 Multiple Feline Resorptive Lesions
16.6.3 Tooth Resorption on Canine Roots
16.6.4 Development of Feline Tooth Resorption after Crown Amputation
16.7 Canine Tooth Resorption
16.7.1 Canine Tooth Resorption on Tooth 309
16.8 Tooth Displacement
16.8.1 Displacement of the Maxillary Left Canine
16.8.2 Avulsion of the Maxillary Right Canine Tooth
16.9 Tooth Extraction
16.9.1 Open Extraction of the Maxillary Canine Tooth in a Dog
16.9.2 Open Extraction of the Maxillary Canine Tooth in a Cat
16.9.3 Extraction of Multiple Maxillary Cheek Teeth in a Cat
16.9.4 Extraction of a Root Fragment of a Maxillary Carnassial Tooth in a Cat
16.9.5 Extraction of Teeth with Root Resorption in a Dog
16.10 Dental Implant of a Canine Tooth
17 Periodontium
17.1 Periodontium: Physiology and Pathology
17.1.1 Evaluating the Periodontium in a Dog
17.1.2 Evaluating the Periodontium in a Cats
17.2 Periodontitis
17.2.1 Gingivitis in the Dog
17.2.2 Effect of Dental Cleaning on the Canine Gingiva
17.2.3 Gingivectomy in a Cat with Gingival Hyperplasia
17.2.4 Generalized Periodontitis in a Dog
17.2.5 Generalized Periodontitis in a Cat
17.2.6 Fistula Formation in Association with Periodontitis
17.2.7 Symmetrical Advanced Periodontitis at the Maxillary Cheek Teeth
17.2.8 Local Interdental Periodontitis
17.2.9 Labial Gingivoplasty in a Dog with Local Periodontitis
17.2.10 Malocclusion-induced Local Periodontitis
17.2.11 Local Periodontitis due to a Crossbite of the Front Teeth
17.2.12 Local Periodontitis and Kissing Ulcers
17.2.13 Lasers
17.2.14 Laser Applications in Periodontology
17.2.15 Laser Gingivectomy in Cats
17.2.16 Dissecting Periodontal Mucosa
17.2.17 Covering Gingival Recession at the Maxillary Carnassial Tooth in a Cat
17.2.18 Guided Tissue Regeneration and Guided Bone Regeneration
17.3 Gingival Hyperplasia
17.3.1 Gingival Hyperplasia and Gingivectomy
17.3.2 Gingival Hyperplasia and Pseudopockets
17.3.3 Gingival Hyperplasia in a Cat
17.3.4 Feline Gingival Hyperplasia and Extractions
17.4 Oronasal Fistula
17.4.1 Symmetrical Oronasal Fistulas of the Maxillary Canine Teeth
17.4.2 Closing an Oronasal Fistula at the Maxillary Left Canine Tooth
17.5 Gingivostomatitis
17.5.1 Gingivostomatitis with Extraction of All Cheek Teeth
17.5.2 Gingivostomatitis in a Young Cat
17.5.3 Delayed Recovery from Gingivostomatitis
17.5.4 Gingivostomatitis Before and After Extraction of All Teeth
17.6 Stomatitis in a Dog
17.6.1 Polypoid Stomatitis
17.6.2 Mucositis
18 Oral Mucosa
18.1 Immunogenic Inflammation
18.1.1 Contact Ulcer
18.1.2 Eosinophilic Granuloma Complex
18.1.3 Systemic Lupus Erythematosus (SLE)
18.1.4 Eosinophilic Myositis
18.1.5 Lip Fold Dermatitis
18.2 Trauma
18.2.1 Stick Injury to the Palate
18.2.2 Fistula Formation after a Stick Injury to the Palate
18.2.3 Avulsion of the Skin over the Mandible after an Accident
19 Oral Masses
19.1 Cysts
19.1.1 Follicular Cyst in the Mandible Near a Partially Retained Premolar
19.1.2 Symmetrical Follicular Cysts in the Mandible
19.1.3 Symmetrical Ranula Formation
19.2 Tumors
19.2.1 Squamous Cell Carcinoma at the Mandibular Front Teeth of a Dog
19.2.2 Squamous Cell Carcinoma in the Maxilla of a Cat
19.2.3 Squamous Cell Carcinoma in the Mandible of a Cat
19.2.4 Diagram of Jaw Resection
19.2.5 Acanthomatous Ameloblastoma at the Caudal Body of the Mandible in a Dog
19.2.6 Acanthomatous Ameloblastoma at the Mandibular Front Teeth of a Dog
19.2.7 Papilloma in a Young Dog
19.2.8 Odontoma in a Dog
19.2.9 Odontoma in a Cat
19.2.10 Symmetrical Tissue Granulation in the Mandible of a Cat
19.2.11 Treatment of Inflammatory Oral Masses through Crown Reduction of the Carnassial Teeth in a Cat
19.2.12 Other Diagnostic Imaging
20 Jawbone
20.1 Jaw Fractures
20.1.1 Noninvasive Repair of a Fractured Body of the Mandible in a Dog
20.1.2 Nasal Fracture
20.1.3 Nasal Avulsion
20.1.4 Symphyseal Separation in a Cat
20.1.5 Fracture of the Caudal Body of the Mandible in a Cat
20.1.6 TMJ Fracture in a Cat
20.1.7 Carnassial Tooth in the Fracture Gap
20.2 TMJ Luxation
20.2.1 TMJ Luxation in a Dog
20.2.2 TMJ Luxation in a Cat
20.3 TMJ Dysplasia
20.3.1 TMJ Dysplasia in a Dog
20.3.2 TMJ Dysplasia in a Cat
Section IV Appendix
21 Selected References
About the Authors
Contact Information
Index
Imprint
Section I Fundamentals
1 Patient History
2 Examining the Head and Oral Cavity
3 Interpreting Clinical Signs
4 Treatment Aspects
1 Patient History
When examining the oral cavity of an uncooperative animal, the veterinarian generally has to work quickly. Before the actual examination, the veterinarian must pay careful attention while taking the history in order to pinpoint the region of focus. Dental issues in adult dogs can originate when they are young ( ▶ Fig. 1.1). When puppies bite each other while tussling, for example, their very sharp deciduous canine teeth can cause problems in later dental development that are not apparent until their permanent teeth erupt.
Fig. 1.1Puppies tussling. Puppies’ tussling is sometimes so aggressive that it leads to injuries of the deciduous teeth or the dental follicles of the permanent teeth.
Abrasive toys, such as a tennis ball, can lead to exposure of the pulp of the deciduous teeth. The open channel then enables opportunistic oral bacteria to reach the deeper-lying jawbone ( ▶ Fig. 1.2).
Fig. 1.2Smooth rubber toy. For puppies, smooth rubber toys are preferred, since rough materials such as the felt covering of a tennis ball can abrade the teeth. In the worst-case scenario, such abrasion can impact the dental pulp of a deciduous tooth.
In contrast to blunt or abrasive toys, the main problem of dogs playing with sticks ( ▶ Fig. 1.3) is the potential for acute injury where the stick penetrates the soft tissue, causing injuries that are often hidden below the tongue or behind the molars. The injury is not always immediately detectable. For example, the first signs may be a restricted jaw opening that can be observed when the dog yawns, plays, or eats ( ▶ Fig. 1.4).
Fig. 1.3Dog with stick. Playing with sticks can lead to penetration injuries of the oral cavity. While the foreign body does not always remain in the wound, the stick fragments or the initial inflammatory response can cause problems.
Fig. 1.4Relaxed yawning with maximum jaw opening. Relaxed, contented yawning is usually a sign that jaw opening is unhindered. If jaw opening is restricted by an inflammatory process resulting from a stick injury, for example, further examination and treatment are warranted.
Abnormal behaviors may result from the way an animal is kept. For example, an animal may bite on the metal bars of an enclosure, which can damage the teeth. Signs include metallic deposits on the surface of the teeth, as well as dental abrasion or even fractures ( ▶ Fig. 1.5). The type of food also influences dental health. In animals fed dry food, the food tends to remove some of the dental calculus but it may cause teeth to fracture; in animals fed only wet food, this cleaning effect is absent.
Fig. 1.5Metallic abrasion in a dog kept in a kennel. Dark, flat, firmly adhered metallic deposits on teeth suggest the dog’s unfulfilled need to play or lack of activity. This piques the dog’s interest in the grid of its enclosure or the bars of its car crate, which may lead to biting that damages the teeth. A “cage biter” typically exhibits abrasion of the distal surfaces of the canine teeth.
In many cases, specific breeds have particular characteristics that predispose them to certain dental issues. Depending on the breed and the skull type, the animal may be prone to certain disorders. For example, Boxers are strong candidates for retained first premolars and “epulis” ( ▶ Fig. 1.6), while Shetland Sheepdogs tend to develop mesioverted canine teeth (lance canine teeth) and young Maine Coon cats are predisposed to hyperplastic gingivitis.
Fig. 1.6Skull shape. Boxers, with their characteristic skull shape, have breed-typical dental disorders. In many cases, they have unerupted, retained first premolars, often with follicular cysts, as well as teeth that are completely covered by gum tissue.
While an asymmetrical jaw generally results from a dental disorder, the cause in older animals may be neoplastic ( ▶ Fig. 1.7
Fig. 1.7Swelling on the upper jaw of a cat. With the massive changes to the front of the skull, as in this cat, a pathological growth is suspected. A biopsy is needed for diagnostic purposes.
Squamous cell carcinoma in the oral cavity of cats commonly occurs on the floor of the mouth or at the base of the tongue ( ▶ Fig. 1.8). If it causes the entire mandible to swell, the area of concern is obvious. Unfortunately, however, these tumors commonly hide in the submandibular space. A typical clinical sign is hardening of the entire floor of the mouth, which can cause problems with eating.
Fig. 1.8Sublingual enlargement. During the clinical examination for suspected squamous cell carcinoma at the base of the tongue, the veterinarian should be able to lift the tongue by palpating the submandibular space. Any significant hardening generally warrants biopsy.
When a cat is involved in a car accident or falls from a greater height (high-rise syndrome), the jaw is often involved. These situations generally include tooth and/or bone fractures that prevent normal closure of the jaw and normal eating. In addition to obvious fractures, such as in the rostral jaw ( ▶ Fig. 1.9), the other sections of the jaw and area of the temporomandibular joint should also be radiographed.
Fig. 1.9Cat involved in accident. This cat was involved in an accident with a rostral mandibular fracture involving the teeth and jawbone.
2 Examining the Head and Oral Cavity
2.1 Anatomy and Morphology of the Oral Cavity
Even after the crown of a tooth has erupted, the development of the tooth is far from complete. A mature root takes several months to develop. Initially, development is dominated by a large pulp cavity and an open apical foramen ( ▶ Fig. 2.1). During this period, dental injuries with subsequent pulpitis usually cannot be treated, which is why stress on the teeth should be minimized in the animal’s first year of life. The development of an individual tooth is not complete until the root apex has formed and the tooth has reached its full height ( ▶ Fig. 2.2). The development periods vary due to the differences in eruption patterns.
Fig. 2.1Diagram of a young tooth. The pulp of the crown and root occupies a great deal of space, while the tooth walls are still very thin. The Hertwig epithelial root sheath is soft and the apical foramen provides a wide point of entry to the dental pulp.
Fig. 2.2Diagram of a mature tooth. The “adult” tooth has a closed pulp chamber that narrows and shrinks inward as the animal ages, forming normal dentin.
The junctional gingival epithelium ( ▶ Fig. 2.3, ▶ Fig. 2.4) creates the epithelial attachment, the first barrier in the gingival sulcus. Attached via hemidesmosomes, this barrier prevents bacteria and their toxins from entering the fibrous, desmodontal attachment. However, the epithelial attachment is susceptible to trauma, which is why dental health requires good dental care to preserve this structure. The bacteria in the soft plaque and the development of a biofilm impair the epithelial attachment and destroy the desmodontal attachment. The next step is the deterioration of the periodontal ligament and resorption of the alveolar bone ( ▶ Fig. 2.5).
Fig. 2.3Junctional gingival epithelium. In a medium-sized dog, the normal gingival sulcus is approximately 2 mm deep and in cats, it is approximately 1 mm deep. Near the sulcus floor, special non-keratinized cells attach the gingiva to the tooth at the cementoenamel junction.
Fig. 2.4Cells of the junctional gingival epithelium. The cells of the junctional gingival epithelium employ hemidesmosomes for attachment to the tooth surface. The epithelial cells are connected via desmosomes. Because they are non-keratinized, these cell layers are permeable and permit the host’s immune factors and cells to penetrate the gingiva at the sulcus.
Fig. 2.5Comparison of healthy and diseased periodontium. The periodontium on the left is healthy. The inner lining of the gingival sulcus, along with the junctional gingival epithelium, seals off the periodontium on the oral cavity side, forming a gingival cuff. The periodontium on the right is diseased. The junctional gingival epithelium (orange) has migrated apically. Normal gingival mucosal cells have shifted into the sulcus, but are unable to provide a barrier. The gingival sulcus has deepened due to the damaged epithelium and desmodontal attachment and the loss of the fibrous and bony support of the alveolar bone.
The maxilla ( ▶ Fig. 2.6) consists of the maxillary, premaxillary and palatine bones, all of them paired, which are connected by sutures.
Fig. 2.6Maxilla. The incisors are located in the premaxillary bone, and the canine teeth and cheek teeth are embedded in the maxillary bone. The palatine bone does not contain any teeth. The two large rostral openings between the maxillary and premaxillary bones are the palatine fissures, through which the vomeronasal organ communicates with the oral cavity.
The mandible ( ▶ Fig. 2.7) consists of the paired mandibular bones, which are connected rostrally in the band-like symphysis. Unlike in humans, no solid bony structure is formed at the symphysis.
Fig. 2.7Mandible. The mandible consists of the horizontal body of the mandible and the vertical ramus of mandible. While the maxilla increases in size appositionally and along the sutures, the mandible widens caudally. Each mandibular condyle articulates with the base of the skull at the mandibular fossa of the temporal bone.
The teeth can be classified by function ( ▶ Fig. 2.8). The mandibular teeth are all embedded in the alveolar part of the mandible while the maxillary incisors are embedded in the alveolar part of the premaxillary bone, and the canine teeth and cheek teeth are embedded in the alveolar part of the maxillary bone.
Fig. 2.8Tooth classification. The different groups of teeth are color-coded as follows: incisors: blue; canine teeth: green; premolars: orange; molars: yellow.
In dogs and cats, the salivary glands are grouped caudally to the angle of the mandible. Only the zygomatic gland is located separately behind the zygomatic arch ( ▶ Fig. 2.9, ▶ Fig. 2.10).
Fig. 2.9Lateral view of the salivary glands. The parotid gland (green) is situated directly below the base of the ear with one rostral and one caudal part. Directly below the parotid glands, in the area of Viborg’s triangle, is the mandibular gland (red), which is covered by a capsule that includes the caudal part of the sublingual gland (blue). The zygomatic gland (magenta), is located separately, behind the zygomatic arch.
Fig. 2.10Ventral view of the salivary glands. The ducts of the mandibular and sublingual glands open at the frenulum of the tongue. The duct of the parotid gland opens on the buccal mucosa at the level of the buccal surface of the maxillary carnassial teeth. The short duct of the zygomatic gland opens just caudally to this.
Dental charts ( ▶ Fig. 2.11, ▶ Fig. 2.12) are used for diagnostics and follow-up. They are for recording information on the animal and findings from examination of the mouth. Calculus and the degree of gingivitis are recorded and a legend is used to record other changes such as fractures, oral masses, etc. Changes to the jaw or planned orthodontic appliances can also be outlined in the overview section. The cut-out ( ▶ Fig. 2.13) shows how periodontal pocket depth is assigned for each tooth.
Fig. 2.11Canine dental chart, dentition. Dogs have a total of 42 permanent teeth. The only teeth with cusps for grinding are the molars. The chart has a separate box for each tooth.
Fig. 2.12Feline dental chart, dentition. Cats have 30 teeth, all of which have only a cutting function.
Fig. 2.13Canine dental chart, detail. The boxes containing an “x” are used to record the individual pocket depths of each area. The veterinarian can also record planned and past treatments here.
In dogs and cats, normal occlusion involves close interdigitation of the upper and lower teeth, so even small anomalies in an individual tooth or minimal changes in position can alter the jaw’s closure. The powerful coronoid process of the caudal ramus of the mandible, which attaches to the powerful mouth-closing muscles, controls movement. The close anatomical proximity of the dental roots to the adjacent structures of the head is illustrated in ▶ Fig. 2.14, ▶ Fig. 2.15 and ▶ Fig. 2.16.
Fig. 2.14Canine skull, frontal view. The frontal view of the canine skull shows the close anatomical proximity of the maxillary canine roots to the nasal cavity. The mesial surface of the maxillary canine root is separated from the nasal cavity by only a paper-thin bony cover.
Fig. 2.15Canine maxilla, lateral view. The lateral view shows the proximity of the caudal maxillary cheek teeth and the orbital cavity. The orbital floor is not protected by a bony structure, but consists of soft tissue. Firmness of the orbital floor thus may indicate inflammatory changes in the caudal maxilla or in the space caudal to the molars.
Fig. 2.16Canine mandible, lateral view. The most powerful mandibular cheek tooth is the first molar, which is called the carnassial tooth. In the maxilla, the opposing carnassial tooth is the fourth premolar.
The modified Triadan system of dental charting allows veterinarians to unequivocally designate canine and feline teeth. Feline evolution has caused the appearance of gaps between teeth in the system, because only the existing teeth are assigned the relevant three-digit number. The first digit identifies the quadrant, where the numbering starts from the examiner’s perspective in the patient’s right maxilla and continues in a clockwise fashion. The second digit starts at the median between the central incisors, counting caudally. Because dogs can have more than nine teeth per quadrant, a third digit is required, and digits two and three are read as a single number ( ▶ Fig. 2.17).
Fig. 2.17Tooth number in dogs. The teeth are numbered in sequence, beginning in the patient’s right upper quadrant from the examiner’s perspective, going in a clockwise fashion, and from the medians between the central incisors, going in a caudal direction.
In cats too, the anatomical proximity between the oronasal cavity and the orbital cavity is readily apparent ( ▶ Fig. 2.18). In cats, the upper and lower teeth occlude very closely together and the jaw joints are restricted, permitting only a pure hinge-like movement and precluding any lateral movements for grinding food.
Fig. 2.18Feline skull, frontal view. In cats, the skull shape is significantly more uniform than in dogs because there is less variation among the different cat breeds.
As in dogs, Triadan tooth numbering in cats also uses a three-digit system ( ▶ Fig. 2.19), although a two-digit system would actually suffice for the total number of cat teeth per jaw quadrant.
Fig. 2.19Tooth numbering in cats. Tooth numbering in cats is similar to that in dogs. However, unlike in dogs, gaps in the numeric sequence (e.g., 304 followed by 307, with no 305 or 306) represent the teeth that are no longer present.
2.2 Canine Oral Cavity
Canine deciduous teeth may undergo changes that require treatment and influence the development of the permanent teeth. Dogs have a total of 28 deciduous teeth, with 7 teeth per quadrant ( ▶ Fig. 2.20). If teeth are absent or malpositioned, the cause and possible impact on the permanent teeth should be investigated.
Fig. 2.20Maxillary deciduous teeth. Deciduous teeth in dogs comprise three incisors, one canine tooth and three molars per quadrant. The deciduous teeth are significantly smaller than the permanent teeth, and the interdental gaps of the deciduous teeth widen as the jaw grows.
If the jaw is wide enough, the teeth can stand in a row ( ▶ Fig. 2.21). In dogs with a short jaw, however, rotated premolars are common, as is crowding in the mandibular incisors, signs of which may already appear in the deciduous teeth and become more obvious as the number of permanent teeth increases.
Fig. 2.21Mandibular deciduous teeth. Wear and tear from use of the deciduous teeth presents in forms such as the abrasion of the canine tooth cusps depicted here. Treatment is not needed as long as the pulp is not involved.
Exfoliation does not always occur in the sequence of “deciduous tooth falls out and permanent tooth appears.” In the transitional period, deciduous teeth or deciduous teeth remnants may remain in place parallel to the eruption of the permanent teeth ( ▶ Fig. 2.22). If malalignment may result from the deciduous teeth remaining in place, they must be removed immediately.
Fig. 2.22Crown of a deciduous molar. While during mixed dentition, the roots of the deciduous teeth are physiologically resorbed, the crowns may remain until the permanent tooth causes them to fall out. These crowns can generally be easily removed or fall out on their own.
A dog has 42 permanent teeth. Each maxillary quadrant has 10 teeth, while each mandibular quadrant has 11 teeth. They are classified as brachydont teeth with short crowns and long roots. Dogs are considered to be heterodont, because they have different tooth morphology for performing different functions. The upper teeth, with their incisal edges or buccal cusps ( ▶ Fig. 2.23) are located labial to the mandibular teeth, with the mandibular arch somewhat narrower.
Fig. 2.23Maxillary molars. The maxillary molars are designed to perform the grinding function in carnivore dentition. Cusps and fossae of the maxillary molars create a surface for grinding.
The carnassial teeth are the most important teeth for processing food ( ▶ Fig. 2.24). This stress on the carnassial teeth unfortunately also makes them prone to fracture.
Fig. 2.24Maxillary carnassial tooth. The maxillary carnassial tooth is situated at the center of the dog’s masticatory force. In conjunction with the mandibular carnassial teeth, lumps of food are bitten into pieces.
Initially, the smaller premolars ( ▶ Fig. 2.25) do not appear to be particularly important; however, in conjunction with the interaction of the mandible and maxilla, they allow objects to be immobilized. If a guard dog behaves abnormally while training with a bite sleeve, the behavior may be due to pain in the premolar region.
Fig. 2.25Maxillary premolars. The small maxillary premolars (the fourth, large maxillary premolar functions as a carnassial tooth) generally are not in contact with the mandibular dental arch. The teeth in this area are too small to completely bite through objects.
The canine teeth ( ▶ Fig. 2.26) are responsible for grasping and holding food, prey or other objects.
Fig. 2.26Maxillary incisors and canine teeth.The canine teeth are the most exposed maxillary teeth and are thus commonly predisposed to fracture. The occlusion of the canine teeth of the mandible and maxilla is very tight, ensuring their function for holding prey.
The mandibular carnassial teeth are less commonly fractured than the maxillary carnassial teeth due to their larger size and better stability ( ▶ Fig. 2.27).
Fig. 2.27Mandibular carnassial. The mandibular carnassial tooth is the first molar of the lower jaw and sits opposite the maxillary carnassial tooth. Its location is lingual to the maxillary carnassial tooth. When the dog bites, the strong shearing force often causes the tip and/or buccal lamella of the maxillary carnassial tooth to break off, since the mandibular carnassial tooth is more compact.
In addition to the last molars, the first premolar in the canine mandible is not always present ( ▶ Fig. 2.28). This is a continuation of evolutionary development rather than a dental abnormality.
Fig. 2.28Mandibular premolars.If the position of the jaw and teeth is normal, the mandibular premolars interdigitate with the maxillary premolars. In the context of normal evolutionary development, the first premolar is often retained, reduced in form, or not developed at all. Such variations should be radiographed to check for pathological processes in the jaw.
For many breeders a scissor bite ( ▶ Fig. 2.29) is important for meeting a breed standard. However, phenotypically correct occlusion is not always an indication of genetic perfection, and evaluating the incisors alone is insufficient.
Fig. 2.29Mandibular incisors and canine teeth. The mandibular incisors lie on a somewhat narrower arcade than the maxillary incisors, which results in a physiological scissor bite. The mandibular canine teeth occlude equidistantly between the interdental surfaces of the maxillary lateral incisor and the maxillary canine.
The tongue is a highly specialized structure that is reinforced by the hyoid bone (and contains the lyssa) in the dog. The tongue uses specialized processes, called papillae ( ▶ Fig. 2.30, ▶ Fig. 2.31) for protection, for grasping and tasting food, and for sensory perception.
Fig. 2.30Dorsal surface of the tongue. The dorsal surface of the tongue has different types of papillae, most of which are mechanically active filiform papillae with an extended, horn-like appearance. In addition, the tongue has gustatory papillae, which are closely associated with taste buds. Other papillae are the knob-like fungiform papillae (small red projections), as well as circumvallate papillae, which appear as wide, circular red spots surrounded by a circular fossa. Sweet taste receptors are located near the tip of the tongue. Salt receptors are located on the rostral sides of the tongue. Bitter receptors are in caudal area of the tongue, as a final control prior to the intake of toxic substances, which often taste bitter.
Fig. 2.31Lingual papillae. This close-up shows the horn-like extension of the filiform papillae.
Given the limits of two-dimensional radiography, computed tomography (CT) shows the spatial relations ( ▶ Fig. 2.32) and past pathological processes and permits assessment of the degree of disease.
Fig. 2.32CT image of the root of the maxillary canine tooth. The CT image clearly shows the proximity of the maxillary canine root to the nasal cavity. The only separation between the canine root and the nasal cavity is a thin bony wall that can become slightly eroded or detached in inflammatory processes; this can lead to typical unilateral nasal discharge.
CT images illustrate the critical role of the size and morphology of the teeth in forming the shape of the jaw ( ▶ Fig. 2.33).
Fig. 2.33CT image of the mesial root of the mandibular carnassial tooth. Like the roots of the maxillary canine tooth, the mesial roots of the mandibular carnassial teeth are space-occupying. The image shows the large buccolingual extent of the roots. Apical to the roots the translucent mandibular canal is visible. In smaller breeds of dog, the root extends to the ventral margin and is superimposed on the mandibular canal. This can lead to bleeding during extraction due to trauma to the inferior alveolar artery or vein. In addition, osteolysis and leverage forces during extraction can cause fracture. Thus, preoperative radiographic visualization prior to extraction helps to assess and record the current condition for forensic purposes.
Not all deviations from the norm are pathological. While elongated papillae of the tongue may appear unusual, they do not need to be treated ( ▶ Fig. 2.34).
Fig. 2.34Hairy tongue. Excessive elongation of the mechanical filiform papillae can cause hairy tongue, which is characterized by dark, hair-like elongation of the papillae. It occurs predominantly in the median sulcus and does not require treatment.
During tooth exfoliation, a distinction must be made between normal resorption of the deciduous tooth roots, the loss of deciduous teeth ( ▶ Fig. 2.35), and real pathological detachment processes and fractures.
Fig. 2.35Discolored deciduous canine tooth. During exfoliation, a brownish or purple discoloration without any other apparent cause is normal, because the root becomes resorbed by the erupting permanent canine tooth.
A typical soft biofilm is not always found on the teeth. The basic properties of saliva cause calculus to form relatively quickly as a result of the precipitation of minerals in the saliva, which then create a basis for crystallization ( ▶ Fig. 2.36).
Fig. 2.36Severe calculus accumulation. The cusps of the molars just barely protrude above the massive accumulation of calculus. Whether or not this has led to periodontal disease or bone damage is not apparent from the clinical findings alone. Diagnostic radiography is required for full assessment of the situation.
Suborbital swelling is a nearly pathognomonic sign of a dental disorder ( ▶ Fig. 2.37).
Fig. 2.37Suborbital swelling on the right. The most common cause of suborbital swelling is a bony process near the maxillary carnassial teeth or molars.
2.3 Feline Oral Cavity
A cat has 30 permanent teeth. Each maxillary quadrant has eight teeth ( ▶ Fig. 2.38), while each mandibular quadrant has seven teeth. The incisors are very small, surrounded by the very prominent canine teeth. The maxillary fourth premolar and the mandibular first molar are the carnassial teeth for breaking up food.
Fig. 2.38Feline maxilla. The variable dark and light-pigmented oral mucosa in this cat shows very clear palatine folds. The feline dentition consists of only cutting (secodont) teeth.
While in dogs the gingiva tends to be distinctly pink to pinkish-reddish, the gingiva in cats is usually pale pink ( ▶ Fig. 2.39).
Fig. 2.39Feline mandible. In contrast to the firm palatine mucosa, the sublingual mucosa is very thin and fragile.
In cats, a physiological “mass” that is not present in dogs is seen in the mandibular molar area ( ▶ Fig. 2.40).
Fig. 2.40Lingual molar gland. The molar gland, which is not present in dogs, is located lingual to the mandibular carnassial tooth. After extraction of the mandibular carnassial tooth, this gland may protrude more prominently. However, as a physiological structure, it does not require treatment.
When a cat’s incisors are extracted, the owner may suddenly notice a mass-like alteration at the front of the palate; however, this is normal and not pathological ( ▶ Fig. 2.41).
Fig. 2.41Incisive papilla. As in dogs, in cats the incisive papilla is located in the median directly caudally to the maxillary inner incisors. This is where the paired incisive ducts end and connect the oral cavity to the vomeronasal organ (Jacobson’s organ), which accounts for the heightened detection of scent, especially in dogs.
While in dogs, a clear scissor bite is preferred, feline occlusion is different ( ▶ Fig. 2.42).
Fig. 2.42Occlusion of the front teeth in cats. The incisors generally meet in the form of a pliers. The canine teeth occlude vertically very deeply. Therefore, when the jaw is completely closed, there may be very close contact between the teeth, especially the canine teeth, and the opposing soft tissue.
In the molar area too, the teeth are also shaped for cutting (▶ Fig. 2.43) and there are no teeth shaped for grinding nuggets of food. The bite is designed solely for breaking up food.
Fig. 2.43Molar occlusion in cats. The cutting effect of the molars is supported by the deep vertical occlusion.
Exfoliation occurs in a predetermined sequence ( ▶ Fig. 2.44, ▶ Fig. 2.45, ▶ Fig. 2.46, ▶ Fig. 2.47). Exceptions to this sequence are abnormal and call for further diagnostics.
Fig. 2.44Maxilla, early mixed dentition. This mixed dentition of a cat clearly shows that the incisors are the first permanent teeth to replace the deciduous teeth.
Fig. 2.45Mandible, early mixed dentition. In the mandible too, the first permanent teeth to appear are the incisors. The deciduous teeth are already discolored from root resorption.
Fig. 2.46Maxilla, late mixed dentition. In late mixed dentition of the maxilla, all of the deciduous teeth have fallen out but the permanent ones have not yet completely erupted. The gums are reddened and the teeth show multiple deposits. Exfoliation is often accompanied by inflammation of the surrounding gingiva. The associated pain prevents the cat from using its teeth properly. In most cases, once the permanent teeth fully erupt, they are used for eating, the deposits disappear, and the inflammation subsides.
Fig. 2.47Mandible, late mixed dentition. In the mandible, exfoliation occurs later than in the maxilla ( ▶ Fig. 2.46). Residual deciduous teeth persist buccal to the erupted teeth or teeth in the process of eruption. Persistent deciduous teeth are rare in cats, so exfoliation will likely progress as usual.
The cat’s rough tongue ( ▶ Fig. 2.48) is distinctly different from the satiny tongue of a dog.
Fig. 2.48Feline tongue. The feline tongue, with its pronounced filiform papillae directed toward the pharynx, is perfectly suited for grooming and for transporting food. When examining the tongue, it is very important to check the floor of the mouth. For some conditions, particularly in the case of squamous cell carcinoma at the base of the tongue, palpating the mandibular space can reveal hardening early on in the disease course. Considering the relatively high prevalence of such malignancies in older cats, the veterinarian should always check for them in hidden locations, especially if the owner reports any changes in eating habits.
2.4 Intraoral Radiography
To obtain evaluable radiographs of the teeth, intraoral radiographs are indispensable. The film or sensors are placed intraorally to ensure that the teeth, including their roots, are visualized with minimal superimposition. To ease orientation of the radiographic beams, the animal should be placed in sternal recumbancy when imaging the maxilla ( ▶ Fig. 2.49, ▶ Fig. 2.51) and in dorsal recumbancy when imaging the mandible ( ▶ Fig. 2.50, ▶ Fig. 2.54). The head should be placed such that the occlusal plane is horizontal or parallel to the table top.
Fig. 2.49Positioning a dog for radiography of the maxilla.
Fig. 2.50Positioning a dog for radiography of the mandible.
Fig. 2.51Position a cat for radiography of the maxilla. In this case, gauze sponges are used to hold the digital sensor in place.
The parallax technique is most commonly used in orthopedic radiology. However, given dog and cat anatomy, this technique can be used only for the mandibular molars ( ▶ Fig. 2.55). The radiographic film is placed parallel to the tooth to be imaged, and the radiographic beam hits both planes perpendicularly, thus ensuring an isometric projection. The other regions of the oral cavity do not allow this arrangement. Thus, the bisecting angle technique is required instead ( ▶ Fig. 2.52, ▶ Fig. 2.53, ▶ Fig. 2.54). With this technique, the radiographic beam is directed perpendicularly to the bisecting line between the film and long tooth axis in order to ensure an isometric projection. Using a standard position for the animal thus helps defined values to be used for applying the radiographic beam.
Fig. 2.52Frontal view of the setting of the radiographic beam for visualization of the maxillary molars in a cat. To prevent superimposition of the molars, the central radiographic beam must be set more horizontally when imaging the maxillary cheek teeth. In dogs, this angle is 45° and in cats, 30°.
Fig. 2.53Radiographic beam placement for visualization of the maxillary incisors. For an isometric projection of the teeth, the radiographic beam is set perpendicular to the line bisecting the space between the film and the long tooth axis.
Fig. 2.54Radiographic beam placement for visualization of the mandibular incisors. As a compromise, the placement is gradually shifted in the area of the mandibular front teeth in order to visualize incisors and canine teeth in the same radiograph and the values averaged.
Fig. 2.55Radiographic beam placement for visualization of the mandibular cheek teeth. The root apices in the mandible can be visualized with a ventral inclination of up to 15° . Visualizing the mandibular molars is generally easiest because the parallax technique can be used.
In order to orient the images, the film is embossed with a dot or other mark. For intraoral placement, the embossed dot is always placed on the mesial side. Once the maxilla and mandible have been identified on the image, the correct side can be identified because the convex embossed dot is always oriented mesially ( ▶ Fig. 2.56).
Fig. 2.56Film orientation. Consistent placement of the film during imaging allows for correct orientation of the film. The convex embossed dot on the side to be exposed is always oriented mesially, which allows subsequent identification of the quadrants.
The following figures illustrate the radiographic visualization of the transition from deciduous dentition to permanent dentition in a dog: ▶ Fig. 2.57, ▶ Fig. 2.58, ▶ Fig. 2.59, ▶ Fig. 2.60, ▶ Fig. 2.61, ▶ Fig. 2.62, ▶ Fig. 2.63, ▶ Fig. 2.64, ▶ Fig. 2.65, ▶ Fig. 2.66, ▶ Fig. 2.67, ▶ Fig. 2.68, ▶ Fig. 2.69, ▶ Fig. 2.70, ▶ Fig. 2.71, ▶ Fig. 2.72.
Fig. 2.57Radiograph of the maxillary right carnassial tooth in a dog. In orthogonal projection, the mesial roots are often superimposed during visualization of the maxillary carnassial tooth. To visualize the roots in the radiograph, the parallax method is used. Mesial and distal projections pull the roots apart in the image. The width of the vital pulp is a distinct sign of a young dog. Development has progressed to the point that a physiological periodontal ligament space appears as a black line around the roots.
Fig. 2.58Radiograph of the maxillary right canine tooth in a dog. The canine root apex is not yet fully developed. In young dogs, a fractured tooth cannot be treated with conventional root canal therapy because no apical stop is present and the root canal filling would be pressed onto the jawbone.
Fig. 2.59Radiograph of the maxillary incisors in a dog. The root apices of the maxillary incisors are still developing, and the apical stop is still fragile. The maxillary symphysis is located between the central incisors. The alveolar ridge line normally starts just below the cementoenamel junction.
Fig. 2.60Radiograph of the mandibular left carnassial tooth. Directly below the root apices of the tooth, the mandibular canal can be seen as a translucent area without cancellous bone.
Fig. 2.61Radiograph of the maxillary left carnassial tooth in an adult dog. The pulp chamber has decreased in size as the dentin layer has widened due to increasing “inward” growth.
Fig. 2.62Radiograph of the maxillary left canine tooth in an adult dog. The pulp is still present, no thicker than a thread. The apex is inconspicuous and the periodontal ligament space is even. Apically, a slight translucency is visible due to the type of projection and the presence of an apical delta, and this is physiological. The vessels and nerves enter and exit the pulp via a widely ramified network rather than a central channel found in humans.
Fig. 2.63Radiograph of the mandibular front teeth in a young dog. The root apices are not yet closed and the lumen of the dental pulp of the canine teeth is very wide.
Fig. 2.64Radiograph of the canine teeth in an adult dog. In adult dogs, the same teeth (cf. ▶ Fig. 2.63) have significantly smaller pulpal lumen and a closed root apex. The surrounding periodontal ligament space is unremarkable.
Fig. 2.65Radiograph of the maxillary right molars in mixed dentition in a dog. The completeness of the dog's permanent dentition can be visualized radiographically by the age of 3 months. By this stage of their development, the caudal molars are not yet fully developed. The mineralization of the crown is just barely detectable (in cut-out, highlighted by the contrast medium).
Fig. 2.66Radiograph of the maxillary right molar in mixed dentition in a dog. The deciduous teeth are still visible at the alveolar ridge, and the crown of the permanent carnassial tooth is under development.
Fig. 2.67Radiograph of the maxillary right premolar and canine tooth. During development, a distinct translucent space can be seen around the buds of the premolars. The cusp of the canine tooth is located as close to the deciduous root as the permanent premolar cusps are located to their deciduous precursor. The first premolar physiologically has no precursor tooth.
Fig. 2.68Radiograph of the maxillary incisors. The permanent maxillary incisors are located closely below the deciduous incisors. The actual dental arch cannot form until the jaw starts growing and the permanent incisors have erupted further.
Fig. 2.69Radiograph of the mandibular front teeth. Due to the tight anatomical circumstances, the veterinarian must carefully count the number of teeth on a radiograph in order to confirm that the correct number of teeth is present.
Fig. 2.70Radiograph of the mandibular right premolars. The subsequent permanent teeth are located between the widely spread roots of the deciduous teeth. The first premolar is already further developed and does not have a deciduous precursor tooth.
Fig. 2.71Radiograph of the mandibular right carnassial tooth. The mandibular right carnassial tooth does not have a deciduous precursor, since it develops from a distal extension of the dental ridge.
Fig. 2.72Radiograph of the last mandibular right molars. In this dog, at this point in time, the third molar, the last one to develop, can be identified solely by the presence of its cusp.
The following figures ( ▶ Fig. 2.73, ▶ Fig. 2.74, ▶ Fig. 2.75, ▶ Fig. 2.76) show radiographic visualization of individual teeth in the cat.
Fig. 2.73Radiograph of the maxillary right cheek teeth in a cat. The proximity of the molars to the zygomatic arch necessitates a more horizontal orientation of the radiographic beam in order to be able to visualize the teeth with as few superimpositions as possible.
Fig. 2.74Radiograph of the maxillary right canine tooth and incisors in a cat. Aiming the beam slightly laterally enables the canine teeth and incisors to be imaged. Imaging the left side in a similar fashion often eliminates the need to separately image the incisors.
Fig. 2.75Radiograph of the mandibular left cheek teeth in a young cat. With the parallax technique, the premolars and the molar can be visualized well. Here too, the wide pulp chamber is indicative of the cat’s youth. A wide pulp chamber in a mature animal indicates that the tooth is nonvital and requires treatment.
Fig. 2.76Radiograph of the mandibular front teeth in a cat. The mandibular symphysis of the cat normally appears as a distinct, irregular translucent area at the junction of the two bodies of the mandible.
2.5 Dental Probing
Probing is used to supplement a visual oral examination. To detect subtle structural changes at the crown, a dental probe with a pointed tip is quite useful ( ▶ Fig. 2.77, ▶ Fig. 2.78, ▶ Fig. 2.79). In contrast to the dental probes used at the supragingival level, a periodontal probe is used in the subgingival area. It is used to measure the gingival sulcus between the tooth and the gingiva. A periodontal probe is graduated ( ▶ Fig. 2.80) and the pocket depth is read directly. The pocket depth increases as periodontal disease progresses. When choosing among the wide range of probe types, an important criterion is good readability of the pocket depth ( ▶ Fig. 2.81). The individual measurements are recorded and taken together, they offer an assessment of periodontal health. Probing also reveals individual vertical infrabony pockets that are often overlooked during examination, particularly in the absence of inflammatory signs.
Fig. 2.77Dental probe. A dental probe has a sharp tip for detecting irregularities on the tooth surface.
Fig. 2.78IM3 dental probe. IM3 produces a combined dental and periodontal probe. The pointed dental probe reveals defects in the area of the crown such as fissure lines, fine exposure of the pulp or resorptive defects.
Fig. 2.79Using a dental probe to diagnose a fractured tooth. The dental probe can move the fractured buccal lamella of the mandibular carnassial tooth.
Fig. 2.80Periodontal probe. A periodontal probe has graduated markings for measuring the depth of the gingival sulcus and periodontal pocket. Pathological findings about the specific surface of a tooth are noted on the dental chart.
Fig. 2.81iM3 periodontal probe. The opposite end of the iM3 probe has a periodontal probe. The probe has a measuring scale in millimeters with special color markings at 5, 10, and 15 mm, making the pocket depth easy to read. The millimeter markings also make it easy to measure the pocket depths in cats.
The veterinarian must practice using a periodontal probe in order to develop a feel for proper handling and be able to measure the pocket depths accurately ( ▶ Fig. 2.82). In an awake animal, deep penetration of the periodontal probe in the damaged periodontium can help to explain to the owner that the animal requires treatment ( ▶ Fig. 2.83). The situation is particularly urgent when damage to the periodontium involves other structures of the skull, such as the nasal cavity ( ▶ Fig. 2.84, ▶ Fig. 2.85).
Fig. 2.82Probing at the sulcus. The dental probe is placed with the blunt tip between the tooth and the gingival margin.
Fig. 2.83Probing into the sulcus. The probe is introduced into the periodontal sulcus of the first molar of this dog without applying pressure. The damage to the bony periodontal apparatus allows the probe to be introduced to a depth greater than the normal depth of 2 mm.
Fig. 2.84Probing the periodontal pocket. The rounded tip is placed at the free margin of the palatal gingiva adjacent to the maxillary canine tooth.
Fig. 2.85Probing the periodontal pocket. The periodontal probe is introduced on the palatal side down to the distance at which it bends. This is only possible if a massive bony defect is present. In this periodontal pocket, destruction of the attachment fibers occurs with resorption of the surrounding alveolar bone. In many cases, an opening to the nasal cavity is found because of its proximity, so probing may trigger nasal bleeding of the affected side.
In addition to vertical insertion into a sulcus, the periodontal probe can be used to examine a furcation near the crown of a tooth ( ▶ Fig. 2.86).
Fig. 2.86Using a periodontal probe to probe a furcation defect. The periodontal probe is introduced horizontally on a dog’s maxillary left premolar. Due to the bone resorption in the area of the furcation, the probe penetrates completely and reappears on the palatal side.
If a pointed dental probe is too thick to palpate an exposed pulp cavity, finer instruments are available ( ▶ Fig. 2.87).
Fig. 2.87Endodontic needle as a probe.Instead of a dental probe, an endodontic instrument is used to explore pulp involvement. An extremely fine and rigid “pathfinder” is used to verify pulp exposure that was not identified with a dental probe.
