Volume 3, Issue 2 US $6.00

Editor: Panoramic radiologic appraisal of Allan G. Farman, BDS, PhD (odont.), DSc (odont.), anomalies of dentition: Chapter #2 Diplomate of the By Dr. Allan G. Farman entiated from compound odonto- American Board of Oral mas. Compound odontomas are and Maxillofacial The previous chapter , Professor of encapsulated discrete hamar- Radiology and Imaging higlighted the sequential nature of tomatous collections of den- Sciences, Department of developmental anomalies of the ticles. Surgical and Hospital dentition in general missing teeth Recognition of supernumerary , The University of in particular. This chapter provides teeth is essential to determining Louisville School of discussion supernumerary teeth appropriate treatment [2]. Diag- Dentistry, Louisville, KY. and anomalies in size. nosis and assessment of the Supernumeraries: mesiodens is critical in avoiding Featured Article: Supernumeraries are present when complications such as there is a greater than normal impedence in eruption of the Panoramic radiologic complement of teeth or tooth maxillary central incisors, cyst appraisal of anomalies of follicles. This condition is also formation, and of the dentition: Chapter #2 termed hyperodontia. The fre- permanent incisors. Collecting quency of supernumerary teeth in data for diagnostic criteria, In The Recent Literature: a normal population is around 3 % utilizing diagnostic radiographs, [1]. Most supernumeraries are found and determining when to refer to Impacted canines in the anterior (mesiodens) a specialist are important steps in or occur as para- and distomolars the treatment of mesiodens [2]. Space assessment in that (see Fig. 1). These are Early diagnosis and timely surgical followed in frequency by intervention can reduce or Age determination premolars in both (Fig. 2, 3). eliminate the need for orthodon- Pre-, post- or para-dentition tic treatment and reduce compli- supernumeraries are possible cations to the regular dentition in depending on the timing of Apical root resorption such cases. As a good rule of development of the supernumer- thumb, if a permanent tooth is Third molar eruption ary teeth in relation to that of the erupted to half its height assessment regular teeth. Most supernumerar- and the contralateral equivalent ies are rudimentary or conical in tooth in the same arch is not seen shape; however, some are regular clinically, a radiograph should be FAQs: in shape and are then termed made to investigate the cause. supplemental teeth. Supernumer- Infection control In a series of 10 cases of ary premolars are frequently supernumerary premolars treated Reading films supplemental. Complications from in Barcelona only one case supernumerary teeth include altered the normal eruption of the impactions and displacement or regular premolars; two evidenced delayed eruption of regular teeth. follicular cyst development [3]. Most individual supernumerary This is consistent with the teeth are sporadic in occurance; supernumerary premolars com- however, multiple supernumeraries monly being post-dentition in can occur in association with onset and being impeded from cleidocranial dysplasia or eruption by the regular teeth. Gardner’s syndrome. Multiple Panoramic is an supernumeraries should be differ- important step toward the identi- “ Cleidocranial dysplasia is an autosomally dominant condition characterized by defective ossification of cranial and clavicles.”

fication, localization and surgical removal of these supernumerary teeth [4]. (a) Cleidocranial dysplasia: Cleidocranial dysplasia is an autosomally dominant condition characterized by defective ossification of cranial bones and clavicles. It is associated with multiple supernumerary teeth, especially anterior to the first permanent molars, retained primary teeth and unerupted permanent teeth (Fig. 4). There is also delayed fontanelle closure, and hypolasia or aplasia of the clavicles [5]. Fig. 1: Unerupted mesiodens McNamara et al. (1999) (arrowed on ) reported the effectiveness of is causing displacement of the adjacent regular central incisors. dental panoramic radiography in Uncommonly (photograph) there is identifying features pathogno- room for the mesiodens to erupt monic for cleidocranial dysplasia and “function”. [6]. In addition to the established dental complications of failure of eruption of the permanent dentition and multiple supernu- merary teeth, morphological abnormalities of the maxilla and , particularly in the ascending ramus and coronoid process are present. While there often are numerous supernumer- ary teeth present in cleidocranial dysplasia this might not be apparent clinically. Failures in tooth eruption often results in apparent hypodontia. It is often necessary to fabricate overdentures for the prosthodontic treatment of such Fig. 2: Post-dentition supplemental patients. supernumerary premolars are illustrated Dentigerous cysts may form in the panoramic radiograph. The clinical photograph shows dental around the crowns of unerupted occurring in a patient regular and supernumerary teeth having three such supplemental teeth weakening the structure of the that have erupted. The dried jaw jaw and predisposing it to patho- specimen is of an ancient Indian jaw logic fracture. Dental panoramic more than 1000 year old (Mississippian) radiography is a valuable adjunct showing an erupted supplemental in confirming the diagnosis of premolar tooth.

2 cleidocranial dysplasia and in subsequently checking for formation. (b) Gardner’s syndrome: Gardner’s syndrome (famial adenomatosis coli; intestinal polyposis type II ) is character- ized by the occurrence of multiple impacted supernumer- ary teeth, osteomas of the long bones, and jaws, multiple polyposis of the large intestines and multiple epidermoid or dermoid cysts Significantly, the intestinal polyps are premalig- nant. Detection of osteomas in Fig. 3: Multiple unerupted supernumerary the jaws and multiple supernu- teeth in the mandible that are not merary teeth (Fig. 5) on pan- interfering with the regular dentition. In oramic radiology may lead to such cases a syndrome such as cleidoc- the early determination of the ranial dysplasia should be ruled out. syndrome and preventive management of a potentially fatal malignancy [7]. In a matched study 82 % of patients having this syndrome showed osteomatous changes com- pared to 10 % of controls. Super- numerary teeth, compound odontomas and impacted teeth were found in 30 % of patients having Gardner’s syndrome compared to 4 % of controls. Anomalies in Tooth Size (a) Macrodontia involves a tooth or teeth being larger than normal in size with proportional enlarge- ment of pulp chamber, crown and root (Fig 6). This condition Fig. 4: Cleidocranial dysplasia is may be general or localized. associated with multiple supernu- General true macrodontia can merary teeth (panoramic radio- be associated with pituitary graph). Affected patients often giantism. Unilateral relative have hypoplastic or absent clavicles and have the flexibility to macrodontia can occur in bring their shoulders close together . Macro- in the midline (e.g. photograph). dontia is often sporadic, but can also be a feature of Ekman- Westborg-Julin syndrome [8, 9]. There is usually a normal

3 complement of teeth. Macro- Fig. 5: Gardner’s dontia needs to be differenti- syndrome: multiple ated from connation (gemina- osteomas are tion or fusion) and concres- present in both jaws cence. In germination there is and there are also division of a tooth with an retained primary attempt to make an additional teeth and multiple tooth. In fusion there is combina- impacted perma- tion of two or more teeth with a nent teeth. Such patients are also reduction in number. For fusion, prone to develop this number count presupposes intestinal cancer. that the combination does not involve a supernumerary tooth or teeth. is the joining of adjacent teeth through cementum. Early detection of macro- dontia is of importance for orthodontic planning of space and cosmetic intervention. Certainly if space is not avail- able for eruption of all of the teeth due to macrodontia, impaction or malocclusion is likely to ensue. Panoramic radiology can help in early diagnosis. Caution needs to be applied; however, as the crown of a tooth that is lingually or palatally displaced will appear magnified horizontally on stan- dard panoramic views. Moreover care needs to be made to ensure the patient was posi- tioned symmetrically in the cephalostat. Rotation or lateral displacement of the head during panoramic radiology can cause Fig. 6: Sporadic macro- one side of the jaws and teeth dontia results in a to be minified, while the other disproportionately large side is magnified. tooth crown in compari- (b) son with the contralat- eral counterpart tooth Microdontia implies the abnor- (radiograph). The mal smallness of a single or photograph illustrates a case of multiple teeth. This is most macrodont lateral incisior in which the commonly an isolated anomaly tooth was similar in size to a maxillary such as a peg lateral or diminu- central incisor tooth. tive third molar tooth (Fig. 7). The

4 “ Microdontia implies the abnormal smallness of a single or multiple teeth. This is most commonly an isolated anomaly such as a peg lateral or diminutive third molar tooth.”

Fig. 7: Bilateral microdont mandibular intervention to assure optimal second permanent molar teeth. In such a function dental occlusion and situation preservation of the third molars stomatognathic function. The should be a consideration. panoramic radiograph is an important adjunct in the assess- ment of normal growth and development. In the future, Panoramic Imaging News will cover anomalies in tooth mor- phology and dental structure. References 1. Yanagida I, Mori S. Statistical studies on numerical anomalies of teeth in children using orthopantomograms-congenital hypodontia. Osaka Daigaku Shigaku Zasshi 1990;35:580-593.

2. Atwan SM, Turner D, Khalid A. Early intervention to remove mesiodens and avoid orthodontic therapy. Gen Dent 2000;48:166-169. diminutive tooth tends to be of one primarily diagnosed dental 3. Valmaseda-Castellon E, Berini-Aytes L, somewhat conical in shape. anomaly was compared to the Gay-Escoda C. Supernumerary Such teeth need to be differ- prevalence for the examined premolars. Report of 10 cases. Bull Group Int Rech Sci Stomatol Odontol entiated from rudimentary dental anomalies in a control 2001;43:19-25. supernumerary teeth, and group of 1,000 subjects, deriving 4. Yeung KH, Lau YW, Lee KH. Mandibular abnormally shaped teeth due from a common initial sample of supernumerary premolars: orthodontic to ectodermal dysplasia or 4,850 subjects. Significant recipro- and surgical considerations. Prim Dent Care 1997;4:115-117. in childhood. Early cal associations (p < 0.008) were detection of microdontia can found among the dental anoma- 5. Farman AG, Nortjé CJ, Wood R. Oral and Maxillofacial Diagnostic Imaging. 1993; be effected by use of pan- lies studied. The statistically Mosby: St Louis. oramic radiology for evalua- demonstrated existence of 6. McNamara CM, O’Riordan BC, Blake M, tion of growth and develop- associations among different Sandy JR. Cleidocranial dysplasia: ment. tooth anomalies was felt to be radiological appearances on dental panoramic radiography. Baccetti (1998) examined clinically relevant, since the Dentomaxillofac Radiol 1999;28:89-97. patterns of association diagnosis of a dental anomoly 7. Wolf J, Jarvinen HJ, Hietanen J. Gardner’s among five types of dental may indicate an increased dento-maxillary stigmas in patients with anomalies (aplasia of second chance for later developmental familial adenomatosis coli. Br J Oral Maxillofac Surg 1986;24:410-416. premolars, small size of tooth and eruption disturbances. maxillary lateral incisors, Panoramic Radiology: an 8. Ekman-Westborg B, Julin P. Multiple anomalies in dental morphology: infraocclusion of primary important adjunct in the assess- macrodontia, multituberculism, central molars, ectopic eruption of ment of dental anomalies cusps, and pulp invaginations. Oral Surg Oral Med Oral Pathol 1974;38:217-222. first molars, and palatal This and the previous chapter displacement of maxillary reviewed anomalies in the number 9. Yoda T, Ishii Y, Honma Y, Sakai E, Enomoto S. Multiple macrodonts with odontoma canines) in an untreated and size of teeth. These condi- in a mother and son – a variant of orthodontic population, aged tions are of importance for Ekman-Westborg-Julin syndrome. Oral Surg Oral Med Oral Pathol Oral Radiol 7-14 years [10]. The prevalence patient esthetics – and conse- Endod 1998;85:301-303. of associated tooth anoma- quently may affect perceptions 10. Baccetti T. A clinical and statistical lies in five groups of 100 of self-worth. Early detection of study of etiologic aspects related to subjects each and character- dental anomalies isof importance associated tooth anomalies in number, size, and position. Minerva Stomatol ized by the constant presence for planning timely orthodontic 1998;47:655-663.

5 “ Panoramic radiographs can be used to assess eruption patterns and space availability for posterior teeth.”

In The Recent Literature: Impacted canines: Panoramic influenced the treatment deci- crown height = stage 4. The radiography combined with a sion, with palatally positioned mesiodistal crown width of lateral cephalometric image is impacted canines more likely to the first and second molars, useful in treatment planning be surgically exposed and those axial inclination and eruption impacted maxillary canines. in the line of the arch, or labially rate of these teeth, and the Stivaros N, Mandall NA. Radio- situated, removed (p < 0.05). space available for their graphic factors affecting the Additionally, as the canine angu- emergence was measured at management of impacted upper lation to the midline increased, each stage. Statistical analy- permanent canines. J Orthod the canine was more likely to be sis was performed to assess 2000 Jun;27(2):169-73. [From the removed (p < 0.05). The orthodon- changes in development. Orthodontic Department, Univer- tists’ decision to expose or Mandibular second molars sity Dental Hospital, Manchester, remove an impacted upper began to erupt at stage 3 UK.] permanent canine, based on and maxillary second molars radiographic information, seems at stage 2. The axial inclina- The investigators used a retro- to be primarily guided by two tion of the mandibular sec- spective, cross-sectional design factors: labio-palatal crown ond molars was essentially to evaluate radiographic factors position and angulation to the unchanged from stages 1 to 4 influencing the orthodontists’ midline. These can be readily but maxillary second molars decision whether to expose or assessed using a combination of uprighted gradually from remove an impacted upper panoramic radiography and a stage 1 to 4. The available permanent canine. Panoramic lateral cephalometric image. space increased significantly and lateral cephalometric radio- from stage 1 to 2 in both jaws. graphic records of patients Space assessment: Panoramic It is suggested that the space referred between 1994 and 1998 radiographs can be used to available for emergence of to the Orthodontic Department assess eruption patterns and the second molar is prepared at Manchester University Dental space availability for posterior before stage 2, and then the Hospital having impacted upper teeth. tooth begins to erupt. For the permanent canines (n = 44) were Tsai HH. Eruption process of the maxillary second molars, evaluated. Canine position second molar. ASDC J Dent there was a further increase in measurements made from the Child 2000 Jul;67(4):275-81. [From the available space after panoramic radiograph were the Department of Pedodontics, stage 3. A negative correla- angulation to the midline, vertical School of Dentistry, China Medi- tion was determined between height, antero-posterior position cal College, Taichung, Taiwan, the mesiodistal crown width of the root, overlap of the adja- Republic of China.] of the mandibular second cent incisor, and presence of root molar and the available jaw resorption of adjacent incisor(s). This study observed the eruption space at stage 2. A positive The labio-palatal position of the process of maxillary and man- correlation was seen be- impacted canine was assessed dibular second molars by evaluat- tween the mesiodistal crown from the lateral skull radiograph. ing 238 panoramic radiographs. width of maxillary second Whether the impacted canine The developmental of the second molars and the available jaw had been exposed and molars was divided into four space at stage 3. orthodontically aligned or re- stages: completion of crown moved was also recorded. calcified = stage 1; initial root Age determination: Standard Stepwise logistic regression formation = stage 2; initial forma- criteria have been devel- analysis showed that the labio- tion of the radicular bifurcation = oped using panoramic palatal position of the crown stage 3; and root length equal to radiographs for the assess-

6 ment of biologic age in Apical root resorption: Pan- than in matched individuals Swedish children and adoles- oramic radiographs made before without this condition. cents. and following orthodontic treat- Maruko E, Hayes C, Evans CA, Nystrom M, Aine L, Peck L, ment has been used to assess Padwa B, Mulliken JB. Hypodontia Haavikko K, Kataja M. Dental apical root resorption. in hemifacial microsomia. Cleft maturity in Finns and the McNab S, Battistutta D, Taverne Palate Craniofac J 2001 problem of missing teeth. A, Symons AL. External apical Jan;38(1):15-9. [From the Depart- Acta Odontol Scand 2000 root resorption following orth- ment of Oral Health Policy and Apr;58(2):49-56. [From the odontic treatment. Angle Orthod Epidemiology, Harvard School of Department of Pedodontics 2000 Jun;70(3):227-32. [From the Dental Medicine, Boston, USA.] and , University Faculty of Health, Queensland of Helsinki, Finland.] University of Technology, This study described the patterns Brisbane, Australia.] of missing teeth in patients Development of teeth was having hemifacial microsomia studied from 2483 dental The association of appliance (HFM) and compared the preva- panoramic radiographs of type and tooth extraction with lence of missing teeth in subjects 1651 healthy patients ranging the incidence of external apical with HFM with a group of unaf- in age from 2 to 25 years. root resorption of posterior teeth fected subjects. Missing teeth Dental maturity was assessed following orthodontic treatment were determined by evaluation of using a method based on was investigated using pre- and panoramic radiographs. Records developmental stages of post-treatment panoramic of 125 patients with HFM were seven left mandibular teeth. radiographs. The study comprised available from the Craniofacial Sex-specific tables were 97 patients. A 4-level ordinal scale Center at Boston’s Children’s developed of maturity as a was used to rate external apical Hospital. Seventy-six met inclusion function of chronological age root resorption. The analysis was criteria for radiographic analysis and of ages as a function of mutually adjusted for the effects of hypodontia. Fifty-two patients maturity scores. Percentile of age at the start of treatment, met inclusion criteria for compar- graphs for visual evaluations pre-treatment overbite and ing the prevalence of hypodontia of dental maturity in children overjet, use of headgear, tooth with a group of patients from the and adolescents were also extraction, and type of appli- Department of Orthodontics at developed. Since maturity ance. The incidence of such Harvard School of Dental Medi- scales do not tolerate any resorption was positively associ- cine. A Fisher’s exact test was missing data, the authors ated with tooth position (p < .001), conducted to test the hypothesis developed linear regression appliance type (p = .038), and that HFM patients have a greater models for predicting the extractions (p = .001). The inci- prevalence of missing teeth than formation stages of each of dence of resorption was 2.3 times individuals without the anomaly. A the seven mandibular teeth. It higher for Begg appliance treat- chi2 test for trend was conducted was easiest to predict the ment compared with edgewise, to determine whether hypodontia formation stage of the man- and it was 3.7 times higher where was more prevalent with increas- dibular first molars (correct in extractions had been performed ing severity of the mandibular 87% within the study material) than when they were not. deformity in HFM. Hypodontia was and most difficult to predict more prevalent among HFM the formation stage of sec- Hypodontia: Panoramic radio- patients (26.9%) versus the com- ond molars and second graphs showed that hypodontia parison group (p < .0001). Addi- premolars (correct in 69% and is more frequent in patients tionally, the degree of hy podontia 70%, respectively. having hemifacial microsomia was correlated with the grade of

7 mandibular hypoplasia (p = .024). Panoramic radiographs from the came as upright as the Hypodontia was found to be more start and the end of active second molars they replaced. prevalent in patients with HFM treatment and three or more Mandibular third molar roots than in comparison subjects. years after treatment were were frequently curved assessed. Study models were distally, thus the third molar Third molar eruption assessment: used to compare the size of the crown position was invariably Sequential panoramic radio- second and third molar teeth and better than the overall tooth graphs can be used to evaluate to assess the final position of the angulation would suggest by eruption of third molars following third molars following eruption. All 16.5o on average. Model extraction of second molar teeth. third molars erupted; none be- analysis (Richardsons’ scoring Orton-Gibbs S, Crow V, Orton HS. came impacted. During eruption, system) showed 96 % of Eruption of third permanent maxillary third molar crowns mandibular and 99 % of molars after the extraction of uprighted and maintained their maxillary third molars erupted second permanent molars. Part angulation as they came into into an acceptable position. 1: Assessment of third molar occlusion. Mandibular third molar The mesiodistal size of third position and size. Am J Orthod crowns continued to upright molars was suitable to re- Dentofacial Orthop 2001 significantly mesiodistally after place second molars. On Mar;119(3):226-38. [From the active treatment, with space average, mandibular third St Helier Hospital, Surrey, UK.] closure being the result of hori- molars were 0.55 mm larger zontal translation rather than and maxillary third molars The eruptive path of third molars mesial tipping. Further uprighting were 0.70 mm smaller than after extraction of second molars occurred once occlusion was second molars. was examined in 63 patients. established although few be- Frequently Asked Questions: Q: What infection control disposable and is not the upper jaw and nasal cavity, precautions or practices should autoclavable. Discard and replace then working back in the maxilla be applied to the use of a after each use. When using the and zygomatic complex on each Panoramic Corporation PC-1000 cephalometric attachment, side. The soft tissue shadows of the X-ray machine? disposable rubber covers should be tongue and soft palate are placed over the rods. Surface incorporated at this stage. This is A: Universal precautions as disinfectants should be used on followed by evaluation of the recommended by the CDC, OSHA, any direct or secondary contact cervical spine and associated ADA and OSAP should be applied. surfaces. structure. I then evaluate the Wearing of exam gloves is contents of the mandible starting recommended. The hand grips, Q: Is there a method for reading from the midline and then chin rest, forehead support, temple panoramic radiograms to assure progressing posteriorly on each supports, and any surface that a thorough review of everything side. Any examination would be may potentially come in contact being shown? incomplete without a thorough with the patient, either directly or evaluation of the soft tissues secondary from the operator, A: One approach was suggested by anterior to the spine and inferior to should be disinfected with a hard Dr. Allan Farman, our editor, in the the mandible. The last part of the surface disinfectant such as initial Panoramic Imaging News evaluation should be the area of BIREXse or should be draped. The Vol 1. #1. “I approach the radiograph chief complaint and the dental bite-guide used to position the roughly in the numerical sequence arches. You can sequence your patient is designed to be shown, namely starting with the evaluation in many ways; however, bony landmarks from the midline of it is very important to develop a consistent approach that ensures that all diagnostic information in the radiograph is indeed read.”

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