|Year : 2014 | Volume
| Issue : 1 | Page : 21-24
Prevalence of cervical enamel projection in human molars
Maria Regina Lima de Souza1, André Augusto Franco Marques1, Emilio Carlos Sponchiado2, Taíra Amazonas de Vargas1, Lucas da Fonseca Roberti Garcia3
1 Department of Endodontics, State University of Amazonas, Manaus, Amazonas, Brazil
2 Department of Endodontics, Federal University of Amazonas, Manaus, Amazonas, Brazil
3 Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
|Date of Web Publication||3-Mar-2014|
Lucas da Fonseca Roberti Garcia
Rua Siró Kaku, n°72, apto. 73, Bairro Jardim Botânico, CEP-14021-614, Ribeirão Preto, São Paulo
Source of Support: None, Conflict of Interest: None
Introduction : One of the developmental anomalies of dental enamel is cervical enamel projection (CEP). The aim of this study was to assess the prevalence of CEP in maxillary and mandibular human teeth. Materials and Methods: A total of 234 human molars obtained from the tooth bank of the State University of Amazonas were used in the present study. CEP was classified as Grade 0 (absence of projection), Grade I (discrete extension of cementoenamel junction toward the furcation), Grade II (closer to furcation without invasion), and Grade III (extending to the furcation area). The evaluation was performed using macroscopic inspection of teeth faces (buccal, lingual/palatal, mesial, and distal) with at least one-third of the crown on each face. Results: It was found that 17.1% of the teeth evaluated had CEP, but neither of the projections occurred on the proximal faces. Higher prevalence of CEP was found on the buccal faces and the most commonly grade of CEP found was Grade I (10.3%). Conclusions: It may be concluded that CEP occurs more frequently in mandibular molars and its diagnosis is extremely important since these projections may difficult bacterial plaque removal, leading to an inflammatory process and unnecessary endodontic treatment.
Keywords: Cervical enamel projection, dental anatomy, endodontics, periodontics
|How to cite this article:|
de Souza ML, Marques AF, Sponchiado EC, de Vargas TA, Garcia LR. Prevalence of cervical enamel projection in human molars. Dent Hypotheses 2014;5:21-4
| Introduction|| |
Cervical enamel projection (CEP) is an anatomical anomaly in which the enamel in the cervical region is projected toward the furcation area in different extensions.  In normal periodontium, the epithelial junction is approximately 0.97 mm. , In CEP, due to the extension in the apical direction toward the enamel, the epithelial junction becomes larger as this region of the enamel in the root prevents the insertion of conjunctive fibers and consequently, separates the bone margin. , Thus, when the epithelial junction ruptures and a deep periodontal pocket is formed, favoring the deposition of bacterial plaque which cannot be removed by the patient, the result is periodontitis. , Therefore, CEP is highly associated to chronic periodontal infection in furcation sites and buccal bifurcation cysts.  In the acute stage, conventional periodontal therapy frequently fails and the clinician/periodontist performs endodontic therapy believing that a possible endoperiodontal reaction will occur, which might lead to unnecessary endodontic treatment. ,,
Several developmental anomalies affect the morphology of the cervical region of the molars in which the cervical extension of enamel toward the furcation area modifies the contour of the cementoenamel junction changing the root anatomy.  These anomalies may be enamel pearls or CEPs that affect one or more tooth faces and they could occur simultaneously or not. ,
The endodontist plays a key role in diagnosing CEP, for when pulp vitality is tested unnecessary endodontic treatment is prevented and it may be verified that non-regression of the periodontal problem is due to the presence of CEP. 
CEP can be detected on routine clinical examination with a probe, radiograph examination, or during surgical procedure.  The knowledge of this anomaly as well as early diagnosis is fundamentally important for the maintenance of teeth with this morphological change since its prevalence in mandibular molars is of great significance, particularly on the buccal faces. ,
Therefore, the aim of this study was to assess the prevalence of CEP and its degree of extension in the maxillary and mandibular first, second, and third permanent molars.
| Materials and Methods|| |
To conduct this study, a total of 234 human molar teeth from the tooth bank of the State University of Amazonas (UEA) were used, of which 39 were maxillary first molars, 17 maxillary second molars, 68 maxillary third molars, 56 mandibular first molars, 28 mandibular second molars, and 26 mandibular third molars. The study was approved by the Research Ethics Committee at this institution, allowing the use of human teeth.
The teeth were first disinfected by immersing them in a 0.5% chloramine solution at a temperature of 4°C for 48 h and then washed under running water for 24 h for complete disinfection. The teeth were then dried with sterile absorbent paper and submitted to analysis and evaluation for CEP under adequate light by macroscopic inspection of the tooth faces (mesial, distal, buccal, and lingual/palatal faces). The examination was performed, with the aid of a magnifying loupe (Intex do Brasil Instrumentos Ópticos Ltda., Valinhos, SP, Brazil) for magnification of the image and better visualization of CEP.
The analysis was performed by one observer (specialist), and the method used to classify the CEPs was the division into the grades [Figure 1], according to Masters and Hoskins  classification, as follows:
|Figure 1: Classification of cervical enamel projection (CEP), according to Master and Hoskins|
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- Grade 0 - no CEP;
- Grade I - discrete extension of cementoenamel junction toward the furcation;
- Grade II - CEP is closer to furcation, but without invasion;
- Grade III - enamel progresses into the furcation area.
After collecting the data, the teeth were statistically analyzed according to CEP frequency. Pearson's chi-square test was used for the comparison of proportions at a level of significance of 5%.
| Results|| |
[Figure 2] shows the frequency of CEP found in the human molar teeth evaluated. CEP occurred more frequently in mandibular molars (22.7%) and it was statistically significant in comparison with the maxillary molars (P < 0.05) [Figure 3]. No statistically significant difference was found (P > 0.05) with regard to the presence of CEP in different tooth groups [Figure 4]. When assessing the presence of CEP, taking into consideration the tooth face and the classification of the anomaly, a significant difference (P < 0.05) and a higher prevalence of CEP were found on the buccal face and Grade I projection [Figure 5].
|Figure 2: Distribution according to the frequency of CEP in human molars obtained from the tooth bank of the State University of Amazonas|
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|Figure 3: Presence of CEP in relation to the position of the tooth in the dental arch|
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|Figure 5: Percentage of projection found in different classifications and tooth faces|
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| Discussion|| |
Although the identification and description of the CEP date from the last century, it was only in 1964 in classic work of Masters and Hoskins  that the clinical significance of the anomaly was evidenced. In the same study, the authors noted the presence of CEP in 90% of cases in which the periodontal disease was found, thus proving its pathogenesis. At present, most studies use the classification of Master and Hoskins  to determine the extension of CEP. ,,,,,,,,
Lima and Hebling  reported that CEP structure is very peculiar for not to have connective tissue attachment, but a long junctional epithelium, which facilitates the development of inflammatory periodontal disease, and furcation involvement of molars.
Also, Leite et al.,  demonstrated that the incidence of CEP was greater on the buccal and lingual surfaces than the mesial and distal surfaces of permanent molars. Furthermore, the incidence was more frequently in maxillary molars than in mandibular molars.
Studies indicate higher prevalence of the Grade I projection on the buccal face of mandibular molars in a continuous and triangular shape. , The origin of the projection is due to an increase in the functional activity of ameloblasts, probably due to the absence of apoptosis, and it may be pathogenically related to paradental cysts, contributing to the formation of endoperiodontal lesions and making the site propitious for the induction of furcation and endodontic lesions. ,,
By knowing the possible direct communication between the dental pulp and periodontium through accessory canals that connect the pulp chamber floor to the furcation, the risks of inducing inflammatory changes in the dental pulp through this passage is also evident. , CEP difficult bacterial plaque removal, becoming a local factor in the development of gingivitis, and after, periodontal disease.  Therefore, such anomaly should be removed down to the crestal bone level by cauterization to facilitate periodontal maintenance.  Moreover, odontoplasty, osteoplasty, and regenerative procedures may be required to treat several bone defects promoted by CEP. ,
Although the dental anatomy is fundamentally important in clinical practice, it seems that little attention has been paid to the anatomical factors of the external root surfaces. , In general, greater emphasis is placed on the coronal anatomy, whereas the root anatomy is usually limited to the number and shape of the roots and/or number and anatomy of the root canals. However, profound knowledge of the external root anatomy also seems to be imperative for performing adequate periodontal instrumentation.  The region in which lies the CEP presents numerous natural irregularities that when exposed may facilitate the accumulation of plaque and hinder root scaling procedures, contributing to the progression of the periodontal disease. , The condition of periodontal disease in the acute phase can lead to unnecessary endodontic treatment and the correct diagnosis of the presence of CEPs is necessary to perform appropriate treatment. ,
In the present study, mandibular and maxillary molars were used as they are the group of teeth with the highest incidence of CEP. These findings are explained by the root anatomy, according to some authors, because the molars have shorter root trunks, which anatomically favor the incidence of CEP. ,
It was found that the frequency of CEP in all the molars studied was 17.1%, irrespective of the degree of anomaly, being these findings, similar to the results found in several other studies. , However, Zee and Bratthal  reported the prevalence of CEP and its relation with furcation involvement in Eskimo people. The results demonstrated a prevalence of 72% of CEP in the molars studied, a value much higher than the one presented in this study, which leads us to believe that ethnicity plays a relevant role on the prevalence of this anomaly. The study demonstrated that mandibular molars had a higher prevalence of CEP (78%) than maxillary molars (67%). Moreover, Grade III was the most common (53%), followed by Grade II (9%), and Grade I (11%).
Several studies have reported conflicting results regarding CEP prevalence.  Swan and Hurt  demonstrated that Grade I is the most common manifestation of CEP. However, Machtei et al.,  reported that Grade II is the most frequent.
In the present study, no statistical difference of the presence of CEP was found in different tooth groups, different from a recent study  that found a higher incidence in the maxillary second molars (61.02%) and another study that noted a higher incidence in the mandibular first molars. 
Despite the limitations of this study, it may be concluded that the knowledge of this anomaly by the clinician as well as early diagnosis is crucial for the maintenance of teeth as the prevalence of CEP interferes with the clinical treatment, which could lead to unnecessary endodontic treatment.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]