Otras razas de maíz no reportadas en Michoacán de Ocampo

I. Periodontal disease

A. Pathophysiology: Most common disease diag- nosed in dogs and very common disease in cats. Periodontal disease increases signifi cantly with increasing age and is more severe in small-breed dogs. Periodontal disease is caused by an accu- mulation of bacteria in the form of plaque on the surface of the teeth, which causes infl ammation of the surrounding tissues. As periodontal disease progresses, the periodontal ligament that attaches the root of the tooth to the alveolar bone is destroyed and attachment of the tooth to the bone is lost, the gingiva recedes, the furca- tion of multirooted teeth are exposed, and ulti- mately the attachment of the tooth is severely compromised, which results in tooth loss

B. Stages of periodontal disease and diagnostic evaluation

1. Stage I (gingivitis): Gingiva is infl amed but there is no attachment loss

2. Stage II (early periodontal disease): Periodon- tal probing and dental radiographs may indi- cate attachment loss of up to 25%, with the teeth remaining stable

3. Stage III (moderate periodontal disease): Peri- odontal probing and dental radiographs may indicate attachment loss between 25% and 50% of the root length, and teeth may begin to be- come mobile

4. Stage IV (severe periodontal disease): Peri- odontal probing and dental radiographs may indicate attachment loss greater than 50%, and there is severe loss of supporting tooth struc- tures and teeth become loose

C. Clinical presentations of periodontal disease 1. Common clinical presentations of periodontal

disease: Mobile teeth, periodontal and periapi- cal abscesses with secondary facial swelling, gingival recession, mild to moderate gingival hemorrhage, and deep periodontal pockets with secondary oronasal fi stula formation with secondary chronic rhinitis

2. Uncommon clinical presentations of periodon- tal disease: Severe gingival sulcus hemorrhage, pathologic mandibular fractures, painful contact mucosal ulcers, intranasal tooth migration, osteomyelitis, and ophthalmic problems

Figure 4-1 A, Anatomy of the tooth. B, Gingival anatomy. (From Birchard SJ, Sherding RG. Saunders Manual of Small Animal Clinical Practice, 3rd ed.

St Louis, 2006, Saunders.)

A

B

Crown Root Dentin Pulp Periodontal ligament Furcation Interradicular bone Alveolar mucosa Mucogingival line Attached gingiva

D. Treatment

1. Dental charting with the patient anesthetized using a periodontal probe and dental radio- graphs to assess attachment loss

2. Supragingival and subgingival scaling 3. Root planning and subgingival curettage 4. Polishing or irrigation

5. Gingivectomy

6. Open-fl ap curettage with augmentation of bony defects

7. Perioceutics

8. Exodontia (extractions) 9. Oronasal fi stula repair 10. Home care

II. Endodontic disease

A. Pathophysiology: Endodontic disease refers to disease of the pulp of the tooth or the inner aspect of the tooth that contains the blood ves- sels and nerves of the tooth. The most common cause of endodontic disease in small animals is dental trauma. A series of events may occur in some fractured teeth with exposed pulp, which can result in signifi cant clinical problems. This series of events includes pulpal exposure, bacte- rial pulpitis, pulp necrosis, periapical granuloma, periapical abscess, acute alveolar periodontitis, osteomyelitis, and sepsis

B. Teeth most commonly fractured

1. Dogs: Canine teeth, incisors, and maxillary fourth premolars

2. Cats: Canine teeth

3. Any tooth in a dog or cat may be fractured, although less frequently

C. Stages, clinical signs, and evaluation of endodon- tic disease

1. Acute pulpal exposure (acute endodontic dis- ease): Animals may hypersalivate, they may be reluctant to eat, and the tooth will bleed at the site of the pulpal exposure. A dental explorer under anesthesia can be inserted into the pulp canal and the pulp will bleed

2. Chronic pulpal exposure: Facial swelling, sneezing, nasal discharge, or mucosal or cuta- neous fi stulas. A dental explorer under anes- thesia can be inserted into the pulp canal, but the pulp is necrotic and will not bleed

D. Radiographic changes associated with chronic endodontic disease

1. Periapical lysis (radiolucency around apex or dark halo around root tip)

2. Apical lysis (radiographic loss of the apex) 3. Large endodontic canals compared with con-

tralateral tooth (when teeth are affected with endodontic disease when a dog is young, the pulp remains large and dentin is not deposited in the tooth)

4. Radiographic loss of tooth structure to pulp canal

E. Treatment

1. Vital pulpotomy: Limited to very recent pulpal exposure in young dogs with very large pulp canals and is an attempt to maintain the viabil- ity of the pulp until at least the tooth is mature

and the pulp canal is more narrow and the dentin is thicker and stronger, at which time a conventional root canal procedure may be per- formed if necessary

2. Conventional endodontic therapy or nonsurgi- cal root canal therapy: Most common form of endodontic therapy involving removal of the pulp tissue through the crown of the tooth and placement of an inert material in pulp canal to prevent infection associated with necrotic pulp 3. Surgical endodontic therapy: Rarely performed endodontic therapy and involves conventional endodontic therapy and amputation of the apex of the tooth with closure of the remaining apical portion of the root

III. Feline tooth resorptive lesions

A. Pathophysiology: The cause of feline tooth re- sorptive lesions is unknown; however, proposed theoretical contributing factors in feline tooth re- sorption include excess vitamin D and excessive occlusal stress caused by eating large, dry kibble. Feline tooth resorptive lesions are caused by odontoclasts and can develop anywhere on the root surface, not just close to the cementoenamel junction; resorption on the enamel as the initial event is rarely observed. Resorptive lesions that occur at the cementoenamel junction are fi lled with highly vascular and infl amed granulation tissue. These lesions are often painful and bleed when probed with a dental explorer. Tooth re- sorption in cats is frequently progressive, and the resorptive lesions continue to enlarge until the roots of affected teeth are completely resorbed or the crown of the tooth breaks off, leaving behind remnants of resorbing roots

B. Teeth affected by feline tooth resorptive lesions: All types of teeth may be affected, but the man- dibular 3rd premolars are the most frequently af- fected teeth

C. Clinical signs and evaluation of feline tooth re- sorptive lesions

1. Resorptive lesions are often painful when the lesion involves the crown

2. Lesions may be hidden from view by plaque, dental calculus, or infl amed gingival tissue 3. Dental explorer used to localize lesions: when

explorer encounters a resorptive lesion, it will fall into the irregular area of resorption

4. Dental radiographs necessary to determine the full extent of the resorptive process and to de- termine the appropriate treatment plan D. Treatment options

1. Restoration: Lesions that extend into the den- tine but do not involve pulp tissue were previ- ously restored; however, restoration of these teeth has been shown to be unsuccessful, so no longer recommended

2. Conservative management: Resorptive le- sions involving only the root and not the crown can be monitored both clinically and radiographically

3. Whole tooth extraction: Ideal but often not possible with advanced lesions

34 SECTION I GENERAL DISCIPLINES IN VETERINARY MEDICINE

4. Coronal amputation: Indicated when the crown is affected and the root has been extensively resorbed

IV. Feline gingivostomatitis

A. Pathophysiology: The cause of feline gingivosto- matitis, also referred to as lymphoplasmacytic stomatitis or lymphocytic plasmacytic gingivitis stomatitis, is unknown; however, there may be an immunologic basis for this condition and poten- tial involvement of various viral agents

B. Oral pathologic fi ndings: Severe infl ammation may be focal or diffuse, including gingivitis, stomatitis, and infl ammation of the palatoglossal folds C. Diagnosis

1. Feline immunodefi ciency virus (FIV) and FeLV tests: Often negative

2. Complete blood cell count (CBC) and serum chemistry: Hypergammaglobulinemia

3. Histopathology: Submucosal infl ammatory infi l- trate of plasma cells, lymphocytes, macro- phages, and neutrophils

4. Dental radiographs: To rule out resorptive le- sions and bone loss secondary to periodontitis or oral tumors

D. Treatment options

1. Initial treatment: Periodontal therapy and home care with corticosteroid and antibiotic therapy as needed

2. Medical management alone often inadequate 3. In refractory cases, extraction of the teeth is the treatment of choice (including all the pre- molars and molars, and in some cases all the teeth may require extraction)

4. Other treatment options: Laser thermoablation combined with cyclosporine therapy if extrac- tion of teeth is not desired

V. Miscellaneous small animal dental or oral diseases A. Normal occlusion and malocclusions

1. Normal scissors bite: The upper incisors are rostral to the lower incisors

2. Undershot (mandibular prognathic bite): The mandible is longer than the upper jaw, and the lower incisors are rostral to the upper incisors 3. Overshot (mandibular brachygnathic bite):

The mandible is shorter than normal, and the upper incisors are signifi cantly rostral to the lower incisors

B. Abnormal number of teeth

1. Persistent or overly retained deciduous teeth: Common in small-breed dogs, and retained de- ciduous teeth should be extracted as soon as possible to help prevent the permanent teeth from erupting in abnormal locations

2. Abnormal number of teeth

a. Supernumerary teeth: Common in dogs and may be the result of either a genetic defect or a disturbance during tooth development and require extraction if causing dental crowding b. Oligodontia: A rare congenital absence of

many but not all teeth

c. Hypodontia: Absence of only a few teeth is a relatively common genetic fault often in- volving missing premolar teeth

C. Dental wear

1. Attrition: Dental wear caused by tooth-to-tooth frictional contact

2. Abrasion: Dental wear caused by frictional con- tact of a tooth with a non-dental material 3. Teeth respond to dental wear by laying down

tertiary or reparative dentin, which is visible as a dark solid brown spot that cannot be entered with a dental explorer

4. Very rapid dental wear may result in pulpal exposure that requires endodontic therapy or extraction

D. Enamel hypoplasia

1. Cause: A disruption of the ameloblasts during the fi rst several months of life while the teeth are developing, which may be associated with periods of high fever, infections (especially canine distemper), nutritional defi ciencies, disturbances in metabolism, systemic disor- ders, and trauma

2. Disturbance in enamel formation over a longer period results in a more generalized distribution of lesions affecting multiple teeth in a bilaterally symmetrical manner while a solitary tooth that is affected with enamel hypoplasia is most likely the result of a focal traumatic episode

3. Defective enamel is soft and porous, and the brittle enamel peels off exposing the underlying dentin, which is soon stained yellowish brown 4. Treatment: Individual lesions can be restored;

generalized lesions require diligent oral hy- giene, fl uoride treatment, and radiographic monitoring for endodontic disease

E. Dental caries

1. Cause: Demineralization of calcifi ed dental tissues when plaque bacteria use fermentable carbohydrates as a source of energy

2. Dental caries are rare in dogs compared with humans and have not been reported in cats; usually affect teeth with occlusal tables (molar teeth)

3. Early dental caries may appear as dark brown spots and have a sticky or slightly soft feel when probed with a dental explorer 4. Following perforation of the enamel, dental

caries progress rapidly in the dentin, resulting in extensive loss of tooth structure with secondary pulpitis and pain and may result in pulp necrosis and periapical pathology

5. Treatment: Restoration or extraction of af- fected teeth

F. Lip-fold pyoderma

1. Cause: Deep skin folds where the skin rubs against itself, causing irritation resulting in a pyoderma

2. Skin folds create a moist, dark, and warm envi- ronment that supports the growth of bacteria or yeast and subsequent infl ammation 3. Dogs are often presented because of severe

halitosis

4. Breed predisposition: Cocker spaniel, springer spaniel, Saint Bernard

5. Treatment: Medical management can include gentle exposure and cleansing of the skin fold with an antiseptic shampoo, drying the area, and application of a mild astringent. Surgical removal of the skin fold provides a more per- manent solution

G. Craniomandibular osteopathy 1. Cause unknown

2. Proliferative bone disease that results in the excessive deposition of periosteal new bone on the base of the skull and caudal aspect of the mandible

3. Breed predisposition: Most frequently seen in West Highland white terriers and Scottish terri- ers but occasionally seen in other breeds 4. Signalment and presenting signs include the

following: Young immature dogs with intermit- tent fever, pain associated with attempting to eat and pain when opening the mouth. If exces- sive bone proliferation occurs, inability to open the mouth may be a complicating factor 5. Once skeletal maturity is reached and the phy-

ses close, bone proliferation decreases H. Masticatory muscle myositis

1. Cause: Immune-mediated disease affecting muscles of mastication

2. Breed predisposition: German shepherd dogs and other adult large-breed dogs

3. Clinical presentation: Inability to open mouth with atrophy of muscles of mastication and se- vere temporal muscle atrophy

4. Diagnostics: Test for autoantibodies to type 2M myosin in muscle and serum and muscle bi- opsy demonstrates necrosis, phagocytosis, at- rophy with fi brosis

5. Treatment: Forceful opening of mouth under gen- eral anesthesia with aggressive immunosuppres- sive doses of steroids tapered over 6 months I. Common malignant oral tumors

1. Dogs: Melanoma, squamous cell carcinoma and fi brosarcoma

2. Cats: Squamous cell carcinoma (most common oral tumor in cats)

LAGOMORPH AND RODENT DENTISTRY

In document MICHOACÁN DE OCAMPO Su origen, relaciones fitogeográficas y filogenéticas (página 44-54)