PEDIATRICDENTISTRY/Copyright © 1982 by AmericanAcademy of Pedodontics SpecialIssue/Radiology Conference Radiology in the diagnosis of oral pathology in children Henry M. Cherrick, DDS, MSD Introduction As additional information becomes available about that the possibility of caries or pulpal pathology the adverse effects of radiation, it is most important exists. that we review current practices in the use of radio- Pathological conditions excluding caries and pulpal graphs for diagnosis. It should be remembered that pathology, that do occur in the oral cavity in children the radiograph is only a diagnostic aid and rarely can can be classified under the following headings: a definitive diagnosis can be madewith this tool. Rou- 1. Congenital or developmental anomolies; 2. Cysts of tine dental radiographs are often taken as a screening the jaws; 3. Tumors of odontogenic origin; 4. Neo- procedure m frequently this tool is used to replace plasms occurring in bone; 5. Fibro-osseous lesions; 6. good physical examination techniques. A review of Trauma. procedures often employed in the practice of dentistry A good understanding of the clinical signs and reveals that a history is elicited from the patient (usu- symptoms, normal biological behavior, radiographic in- ally by an auxiliary) and then radiographs are taken terpretive data, and treatment of pathological condi- before a physical examination is completed. This tions which occur in the oral cavity will allow us to be sequence should be challenged inasmuch as most moreselective in the use of radiographs for diagnosis. pathologic conditions that occur in the facial bones It is not the purvue of this presentation to cover all present with clinical symptoms. The following ques- of the disease entities that occur in the jaws. The more tions should be addressed before a diagnostic radio- commonor significant conditions which effect the wel- graph is taken. fare of the child will be presented. 1. Whenwas the last screening radiograph taken? 2. Is there a clinical finding that suggests under- Congenital or DevelopmentalAnomolies lying osseous pathology? The early recognition of congenital or developmen- 3. Does the medical or dental history suggest tal anomolies often determines whether the eventual underlying osseous pathology? treatment is successful or not. It is imperative that 4. Will a radiograph augment the physical findings? the clinician know the physical symptoms and radio- 5. What type of radiograph will be most helpful? graphic features of these conditions. Diagnostic radiographs should only be taken when one of the following conditions exist: "Dens in Dente" 1. A physical or history finding would suggest an It is most important to identify the condition underlying pathological condition, knownas "dens in dente" as soon as possible. Recogni- 2. Whenthe physical finding is inadequate to make tion of this condition before the tooth erupts into the a differential diagnosis or to allow treatment. oral cavity maysave the patient the loss of this ante- Employmentof the above procedures would signifi- riot tooth. cantly reduce the number of diagnostic X rays taken. As the term indicates, "dens in dente" implies a It is recognized that screening radiographs {exclud- tooth within a tooth and is caused by an invagination ing bite-wing radiographs) in children are generally of all layers of the enamel organ into the dental papil- nonproductive without positive, physical findings. lae. As the hard tissues ave formed, the invaginated With this fact in mind a child should probably have enamel organ produces a small ,tooth within the future one screening radiograph (panorex) during the initial pulp chamber. It occurs in above 5%of the population visit and not have another until the permanent denti- and can best be diagnosed by radiographic examina- tion has erupted. Bitewing radiographs should be tion. The maxillary lateral incisors are most fre- taken whenever the physical examination suggests quently involved and the pulp is usually exposed due PEDIATRICDENTISTRY: Volume 3, Special Issue 2 423 to defects in the enamel and dentin. If this condition sebaceous glands, temperature elevation, dry skin, de- is recognized before the eruption of the tooth, surgical pressed bridge of the nose, protrusion of the lips and exposure and an appropriate restoration will often complete or partial endodontia. avoid loss of the tooth or endodontic therapy. Not in- A commoncause for partial endodontia is the expo- frequently, after the tooth has erupted, a periapical sure of the developing tooth germ to X radiation. lesion is associated with this condition. Supernumerary Teeth Dilaceration and Supernumerary Roots Teeth in excess of the normal compliment are re- Dilaceration is a term used to describe angulation ferred to as accessory or supernumerm’y. Supernumer- or a sharp bend or curve in the root or crown of a ary teeth frequently inhibit the normal compliment of forming tooth. The condition is thought to occur due teeth to erupt. An accessory tooth between the maxil- to trauma during the period in which the tooth is lary central incisor is called a mesiodens. Supernumer- forming. Consequently, the position of the calcified ary teeth which develop distal to the third molar are portion of the tooth is changed and the remainder of called a distomolar and one which is located buccal or the tooth is formed at an angle. Most teeth have some lingual to the molar is called a p~ramolar. Super- degree of dilaceration. It is most important to identify numerary teeth occur nine times more frequently in this condition prior to the extraction of any tooth. As the maxilla than in the mandible. It is estimated that a general rule of thumb it is wise to take a preopera- 5% of the caucasian population of this country exhibit tive radiograph on any tooth to be extracted. one or more supernumerary teeth. Numerous supernumerary and impacted teeth are seen in a condition called cleidocrs, nial dysostosis. Concrescence Concrescence occurs when two independently form- This symptomfrequently leads to the diagnosis of the disease. Cleidocranial dysostosis is characterized by ing teeth become fused by either cementum or bone. delayed closure of the fontanelles, delayed closure of Microscopically, these teeth are found to have sepa- cranial sutures and presence of wormian bones, under- rate pulp canals and roots. Both of the teeth may be development of the upper face -- :particularly the erupted or unerupted or one tooth may be imbedded maxilla, underdevelopment of the pssanasal sinuses, and the other erupted. It has been estimated that .5% and prognathism. There is frequently an absence or of all teeth have someform of concrescence. It is gen- hypoplasia of the clavicals so that the patient can erally thought that this condition occurs when two approximate the shoulders with ease. teeth are forced together after they have completely formed. Clinically these teeth give a dull sound when they are tapped. If this condition is not identified Cycts of the Jaws before an extraction it is possible the adjacent, non- The cysts of the jaws fall into two major categories. offended tooth will also be extracted. The odontogenic cysts which develop from epithelium of odontogenic origin are more frequently seen in the Anodontia child than the developmental cysts which come from True anodontia implies the absence of teeth. It may entrapped epithelium in fissures and sutures. The be total involving, both the deciduous and permanent cysts of the jaws present with a clinical sign of swell- dentitions, as in some patients with ectodermal dys- ing or with secondarily infected pain. When these plasia, or it may be partial (hypodontia) and limited cysts enlarge to any degree there is usually expansion to a single tooth or group of teeth. It is estimated that of the cortical bone and migration of adjacent teeth 7%of the population exhibit at least one congenitally (Chart I, next page). missing tooth. In a study by Dolder the mandibular second premolar was the most commonly missing Primordial Cyst tooth followed by the maxillary premolar and then The primordial cyst comprises approximately 2% of the maxillary lateral incisor. Wheneverthere is a miss- all odontogenic cysts. It arises from a tooth germ ing tooth or delayed eruption of a tooth it is wise to which, instead of forming a tooth, degenerates into a take a diagnostic radiograph. The early identification cyst. Clinically this lesion is always associated with a of numerous missing or impacted teeth may facilitate missing tooth. The mandible is involved much more the early diagnosis of ectodermal dysplasia, or clei- frequently than the maxilla and the lesion most fre- docranial dysostosis. quently occurs during the second decade of life. The Ectodermal dysplasia is a hereditary disease that lesion is generally asymptomatic unle~ it is secondar- involves all structures derived from the ectoderm. ily infected. Most frequently the lesion causes expan- Males are affected much more freqently than females. sion of the cortical plates of bone and may produce Clinical findings are the absence or reduction in the migration of adjacent teeth. The teeth in the area are amount of hair (Hypotrichosis) an absence of sweat generally vital. Radiographic examination reveals a 424 RADIOLOGY/ORALPATHOLOGY IN CHILDREN: Cherrick PEDIATRICDENTISTRY: Volume 3, Special Issue 2 425 well-delineated area of radiolucency generally sur- matic. Occasionally when the nonvital tooth becomes rounded by a thin radiopaque line. The cyst is gener- infected this cyst may create a draining fistula and ally not associated with an erupted or unerupted may also cause pain. This cyst is always associated tooth. Treatment is surgical removal. with a nonvital tooth which frequently may be darker Dentigerous Cyst in color than adjacent teeth. The patient will always Dentigerous cysts comprise 34%o~ all odontogenic give a history of pain in the infected tooth. Ra- cysts. They are slightly more commonin males than in diographically, the apical periodontal cyst is charac- females and usually occur in the second decade of life.