|Year : 2015 | Volume
| Issue : 2 | Page : 123-128
Pattern of dental anomalies in nonsyndromic clefts and its relationship to neural crest developmental fields
Sridhar Premkumar, Gayathri Mohan
Department of Orthodontics and Dentofacial Orthopedics, Tamil Nadu Government Dental College and Hospital, Chennai, Tamil Nadu, India
|Date of Web Publication||17-Aug-2015|
Dr. Sridhar Premkumar
B-3, Block 2, Jains Ashraya Phase III, 199, Arcot Road, Virugambakkam, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Objectives: To correlate dental anomalies in different cleft groups with that of the neural crest developmental fields. Materials and Methods: The study was performed at the Department of Orthodontics, Tamil Nadu Government Dental College and Hospital, Chennai on 60 subjects with cleft of lip, palate in the age group of 12-25 years of both genders. Subjects were divided into two major groups. Group A consisted of 30 subjects with unilateral cleft lip and palate (UCLP) and Group B comprised of 30 subjects with bilateral cleft lip and palate (BCLP). For assessment purpose both right and left side UCLP patients were grouped together. The subjects were classified by cleft type into one of three groups as unilateral left cleft lip and palate, unilateral right cleft lip and palate, BCLP. Results: Statistical analysis using Chi-square test yielded significant differences in agenesis of tooth (P < 0.001), ectopic eruption (P < 0.001), rotated tooth (P < 0.001), and impacted tooth (P < 0.001). The other dental anomalies did not yield any significant differences. Conclusion: Agenesis of the lateral incisor was the most common dental anomaly in the frontonasal field area. The ectopic eruption was the prevalent dental anomaly in the maxillary field area and agenesis of second premolar in the palatine field area.
Keywords: Cleft lip, palate and dental anomalies/pattern of dental anomalies and cleft lip, palate
|How to cite this article:|
Premkumar S, Mohan G. Pattern of dental anomalies in nonsyndromic clefts and its relationship to neural crest developmental fields. J Cleft Lip Palate Craniofac Anomal 2015;2:123-8
|How to cite this URL:|
Premkumar S, Mohan G. Pattern of dental anomalies in nonsyndromic clefts and its relationship to neural crest developmental fields. J Cleft Lip Palate Craniofac Anomal [serial online] 2015 [cited 2021 Oct 16];2:123-8. Available from: https://www.jclpca.org/text.asp?2015/2/2/123/162967
| Introduction|| |
The neural crest, which is a transient component of the ectoderm, is located in between the neural tube and epidermis of an embryo during neural tube formation. Appearance of the notochord causes thickening of the overlying ectoderm to form the neural plate. By the end of the 3 rd week of gestation, the lateral ends of the neural plate thicken to form neural folds and the depressed central region forms a neural groove. The neural folds elevate and fuse, forming the neural tube. This process of closure of the neural tube is called as neurulation. The cells at the lateral border of the neural folds called neural crest cells dissociate from the neuroectoderm. The induced neural crest cells, which get separated from the embryonic epithelial layer, migrate as mesenchymal cells into the facial and pharyngeal regions.
Loss of cell adhesion molecules (CAMs) between the neural tube and the migrating neural crest cells play a critical role in the migration of neural crest cells. Following the completion of craniofacial crest cell migrations and differentiation into specific structures (such as bones of the facial skeleton) CAMs are re-expressed. Neural crest populations along the rostrocaudal length of neural axis have been designated as cranial, vagal, trunk, and lumbosacral. The cranium develops from six different developmental fields namely, cerebellar and cervicals, theca, frontonasal, maxillary, palatine and mandibular.
The frontonasal field forms the lower part of the frontal bone, external nose, maxillary incisors and surrounding alveolar bone and soft tissue. The maxillary field forms the cranial part around the eyes and extends laterally to the upper lip, hard palate, sella turcica, and intervening tissue. The palatine field covers external aspects, the posterior bony palate, soft palate, and alveolar bone in the molar region. The mandibular field forms the entire mandible, lower lip and the lower part of the cheek.
Kjaer in a study spanning over 17 years stated that certain areas or fields are exposed to certain types of malformations.  An example of such malformations in the cranium, is a cleft lip. Borderlines between fields in the jaw regions are also borderlines between areas with different peripheral innervation. Cleft lip occurs due to defect in the borderline between frontonasal and maxillary fields and cleft palate occur as a result of defects in the borderline between the two maxillary fields and the two palatine fields [Figure 1].
|Figure 1: Frontonasal (orange), maxillary (green), palatine (blue) and mandibular (purple) fields schematically illustrated in an operated cleft lip patient. Note that the cleft lip occurs at the region of confluence between frontonasal and maxillary field|
Click here to view
The occurrence of dental anomalies is more common in cleft lip and palate individuals when compared to general population.  Though postnatal events have been implicated in tooth anomalies, dental abnormalities are mostly caused by prenatal and genetic influences.  Most previous studies investigating dental deformities among individuals with clefts have included different types of cleft cases among their samples and have not differentiated their results, according to the corresponding neural crest fields. A search of literature provides very little information regarding the prevalence of various dental anomalies in different cleft groups relating them to the neural crest fields. In the light of the lacunae present with regard to patterning of dental anomalies in different cleft groups and its relationship to neural crest developmental fields, the current study aimed to correlate dental anomalies in different cleft groups with that of the neural crest developmental fields.
| Materials and Methods|| |
Sixty subjects with a cleft of the lip, palate in the age group of 12-25 years of both the gender were included for the study. Patients' data were collected from the existing records of patients and also from new patients reporting to Department of Orthodontics and Dentofacial Orthopedics during the period January 1, 2010-May 5, 2013. Sixty samples were chosen from a total of 132 subjects. Subjects were divided into two major groups. Group A consisted of 30 subjects with unilateral cleft lip and palate (UCLP) and Group B comprised of 30 subjects with bilateral cleft lip and palate (BCLP). For assessment purpose both right and left side UCLP patients were grouped together. The subjects were classified by cleft type into one of three groups as unilateral left cleft lip and palate, unilateral right cleft lip and palate, BCLP. UCLP consisted of unilateral involvement of lip and alveolar process, the palate was involved, unilaterally. BCLP consisted of bilateral involvement of lip and alveolar process, the palate was involved, either unilaterally or bilaterally.
Medically compromised, any other syndromes, history of previous extraction of permanent teeth, endodontic or prosthodontic treatment and trauma to any tooth were excluded from the study. A written informed consent was obtained from all the patients after explaining the procedure. The study was approved by the Institutional Ethical Committee.
Standardized diagnostic records such as panoramic, occlusal and periapical radiographs, dental casts, and dental records were collected. All the mentioned standard records were present for all subjects included in the study. In order to eliminate inter-examiner differences, all records were examined by one observer principal investigator (PI). Intra examiner reliability was tested using kappa statistics. The anomalies investigated are given in [Table 1].
A Chi-square test to determine differences by gender and a Mann-Whitney U-test to determine whether or not significant differences existed in the occurrence of dental anomalies by age and within and outside clefts were used for the study. Differences in the incidence rates of each dental anomaly by cleft type were analyzed using Wilcoxon's test.
| Results|| |
Among the dental anomalies, agenesis rated for 88.3% occurrence followed by ectopic eruption with 41.7% [Table 2]. The teeth most commonly missing were lateral incisors, and the ectopic eruption was common among premolars. The incidence of agenesis is comparatively less in females (Fisher's exact test showed P = 0.004), while ectopic eruption showed increased occurrence, but with no statistical significance. The occurrence of dens invaginatus also showed significant gender difference. Overall, the vast majority of patients were found to have at least one dental anomaly.
|Table 2: Overall prevalence and prevalence of the dental anomalies by gender|
Click here to view
A significant amount of dental anomalies were seen in the frontonasal field when compared to the other two fields [Table 3]. 93.3% showed defects in the frontonasal field, 63.3% had some defects in the maxillary field while only 1.7% showed defects in the palatine field. In the frontonasal field, agenesis ranked with the most number of occurrence, followed by rotated tooth and ectopic eruption. In the maxillary field, the ectopic eruption is the most common anomaly (Chi-square test - P < 0.001) to be seen followed by impaction. Palatine field showed negligible defects with agenesis reported in one patient. Rotation is more prevalent in the frontonasal field with Chi-square test - P < 0.001. Frontonasal field exhibited maximum types of dental anomalies. Another interesting observation is that maxillary field showed more incidences of impactions (Chi-square test- P < 0.001).
|Table 3: Prevalence of dental anomalies in frontonasal, maxillary and palatine fields|
Click here to view
When the dental anomalies were compared between unilateral and bilateral cleft patients [Table 4], all the patients with bilateral cleft showed some form of dental anomaly, while only 90% of unilateral cleft patients demonstrated dental anomalies. In the frontonasal field, 96.7% of subjects with bilateral cleft had agenesis of the tooth while only 66.7% with unilateral cleft had agenesis of the tooth. Similarly, the prevalence of other dental anomalies was also more in bilateral cleft patients when compared to subjects with unilateral clefts. In the maxillary field ectopic, eruption and impaction showed the highest number of occurrence, while in the palatine field only agenesis was reported. In general, BCLP showed highest rates of dental anomalies.
|Table 4: Comparison of dental anomaly between unilateral and bilateral clefts in frontonasal field, maxillary field and palatine fields|
Click here to view
[Table 5] gives the comparison of dental anomalies among the three different areas. Statistical analysis using Chi-square test yielded significant differences in agenesis of tooth (P < 0.001), ectopic eruption (P < 0.001), rotated tooth (P < 0.001) and impacted tooth (P < 0.001). The other dental anomalies did not yield any significant differences.
| Discussion|| |
The developmental field has been defined as "A region or part of an embryo which responds as a coordinated unit to embryonic interaction and results in complex or multiple anatomical structures by Spranger et al. They further stated that an intrinsic, nondisruptive disturbance of a developmental field will lead to a field defect." Kjaer classified craniofacial developmental fields into frontonasal, maxillary, palatine and mandibular fields.  The frontonasal field gives rise to the maxillary incisors, canines; the premolars arise from the maxillary field, and the molars arise from the palatine field [Figure 2]. Several studies have been done in the past regarding the various dental anomalies found in cleft lip and palate patients. But little information exists relating them to the craniofacial developmental fields. The present study represents the first such examination of an abnormal population afflicted with cleft lip and palate in India. The present paper reports the first such report on not only the anomalies in numbers but also in the morphologic structural abnormalities seen in subjects with cleft lip and palate.
|Figure 2: Diagrammatic representation of the three fields namely frontonasal (orange), maxillary (green) and palatine (blue) in the human palate|
Click here to view
The prevalence of dental anomalies has been found to vary among different patients. The present study investigated the frequency of anomalies in a sample of Chennai population and classified them, according to cleft type. The relationship was found between dental anomalies and gender in the present investigation. This is in contrast with the findings of Ribeiro et al., The incidence of agenesis was comparatively less in females (Fisher's exact test showed P = 0.004), while ectopic eruption showed increased occurrence, though statistically insignificant. Demirjian et al. in 1973 observed that the mechanisms controlling dental development are independent of somatic and sexual maturity but appear to be highly influenced by etiological factors.  The number of male subjects was higher than females in the present study. This is in contrast to the report of Akcam et al. Agenesis in the anterior region on the cleft-side was found to be the most frequently occurring dental anomaly, followed by ectopic eruption, rotations, impaction, supernumerary tooth, short roots, microdontia, dilacerations, pulp stones, hypoplasia and invaginatus in order of frequency.
When the dental defects were analyzed in the three different craniofacial fields, the frontonasal field showed the maximum number and type of dental anomalies. Congenital absence of the cleft-side permanent lateral incisor happened to be the most common finding in children with a cleft lip and palate. Various authors have suggested that the high rate of agenesis near the cleft may be due to a deficiency in blood supply, either congenital or secondary to surgery, or to a deficiency in the mesenchymal mass. ,, In the current study, the rate of agenesis in the field outside cleft area was only 2.9% on the other hand, Dewinter et al. reported agenesis outside the cleft area in 27.2% of patients, and Brattström and McWilliam,  a 27.8% rate of agenesis outside the cleft area in UCLP patients. In the maxillary field ectopic eruption was the most common anomaly (Chi-square test - P < 0.001) to be seen followed by impaction. The findings of the current study showed a significantly higher rate of impaction in the maxillary field regions in the cleft lip and palate groups.
When unilateral and bilateral cleft patients were compared for the prevalence of dental anomalies, BCLP showed more prevalence of agenesis, ectopic eruption, hypoplasia, and microdontia. Rotations, short roots, dens invaginatus, supernumerary tooth, and pulp stones were more prevalent in UCLP. Following agenesis, the presence of a supernumerary tooth in the cleft region has been stated to be the second most common dental anomaly.  The current study found high rates, from 13.3% in the UCLP and cleft palate groups. A higher rate, 10% of supernumerary permanent teeth in the cleft area was observed in children with a UCLP in the frontonasal field while BCLP showed a higher rate of supernumerary teeth in the maxillary field. The frequency of supernumerary teeth in this study was greatest in the UCL group and decreased as the severity of the cleft increased. This correlates with the findings of previous studies. , Tsai et al. hypothesized that the odontogenic region of the lateral incisor comes from the medial nasal and maxillary processes and that nonfusion of these two processes results in two separated lateral incisors.  Another hypothesis is that the supernumerary teeth come from the postfusion rupture of the cleft in the lateral incisor area, and the tooth germ of the lateral incisor is split into two separate teeth.  Bondemark and Tsiopa in 2007, reported that ectopic eruption depends on systemic or local factors  and the population average for ectopic teeth has been reported to range between 2% and 6% for the maxillary first molars and 1.5-2% for the permanent canines. , In the current study, the rate of ectopic eruption varied from 3.3% to 16.7% in the frontonasal field for unilateral and bilateral cleft patients. In the maxillary field, UCLP patients showed 40% while BCLP had reduced 23.3%. Surprisingly lower rates of dens invaginatus (1%) were observed in the present study. Comparison of prevalence of dental anomalies revealed that 95.1% had defects within the cleft area, 78.7% had defects outside the cleft area but within the concerned field. 21.3% exhibited defects outside the concerned the craniofacial field which implies that structures not involved in the formation of the cleft are also affected suggesting a multifactorial etiology for cleft lip and palate.
This study is somewhat limited in that it is retrospective, and the missing data, therefore, affects the results due to the decreased sample size. Combining the information sources of the medical chart, intra-oral photos, panoramic, and intra-oral occlusal X-ray films was able to reduce errors and helped to obtain more accurate data.
| Conclusion|| |
A significant proportion of individuals with a cleft was found to have at least one dental anomaly. Agenesis was the most common dental anomaly (81.7%) in this overall study sample. The rates of dental anomalies varied among the unilateral and bilateral cleft groups. 93.3% of the sample showed defects in the frontonasal field with agenesis of lateral incisor being the most common dental anomaly, followed by rotation of central incisors. This is in accordance with the study of Riis et al. who found the dental deviations to be predominant in the frontonasal field. In the maxillary field area, 63.3% had some defects in the maxillary field with ectopic eruption as the most common dental anomaly followed by impacted tooth. Only 1.7% showed defects in the palatine field area with agenesis of second premolar as the only defect. The face, jaws, and teeth develop from areas on the neural crest, formerly located in the brain. This association between the brain and cranium will be an interesting field of focus for dental surgeons and neurologists in the future.
The authors wish to acknowledge the Indian Council of Medical Research (ICMR) for approving and funding this study as short-term study with reference number 2013-01049.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kjaer I. Orthodontics and foetal pathology: A personal view on craniofacial patterning. Eur J Orthod 2010;32:140-7.
Ranta R. A review of tooth formation in children with cleft lip/palate. Am J Orthod Dentofacial Orthop 1986;90:11-8.
Kotsomitis N, Dunne MP, Freer TJ. A genetic aetiology for some common dental anomalies: A pilot twin study. Aust Orthod J 1996;14:172-8.
Hamasha AA, Al-Khateeb T, Darwazeh A. Prevalence of dilaceration in Jordanian adults. Int Endod J 2002;35:910-2.
McCulloch KJ, Mills CM, Greenfeld RS, Coil JM. Dens evaginatus from an orthodontic perspective: Report of several clinical cases and review of the literature. Am J Orthod Dentofacial Orthop 1997;112:670-5.
Levitan ME, Himel VT. Dens evaginatus: literature review, pathophysiology, and comprehensive treatment regimen. J Endod 2006;32:1-9.
Thilander B, Jakobsson SO. Local factors in impaction of maxillary canines. Acta Odontol Scand 1968;26:145-68.
Darwazeh AM, Hamasha AA, Pillai K. Prevalence of taurodontism in Jordanian dental patients. Dentomaxillofac Radiol 1998;27:163-5.
Lai PY, Seow WK. A controlled study of the association of various dental anomalies with hypodontia of permanent teeth. Pediatr Dent 1989;11:291-6.
Apajalahti S, Hölttä P, Turtola L, Pirinen S. Prevalence of short-root anomaly in healthy young adults. Acta Odontol Scand 2002;60:56-9.
Toutountzakis N, Katsaris N. Ectopic eruption of the maxillary first permanent molar. Orthod Epitheorese 1990;2:117-28.
Spranger J, Benirschke K, Hall JG, Lenz W, Lowry RB, Opitz JM, et al.
Errors of morphogenesis: Concepts and terms. Recommendations of an international working group. J Pediatr 1982;100:160-5.
Ribeiro LL, das Neves LT, Costa B, Gomide MR. Dental development of permanent lateral incisor in complete unilateral cleft lip and palate. Cleft Palate Craniofac J 2002;39:193-6.
Lourenço Ribeiro L, Teixeira Das Neves L, Costa B, Ribeiro Gomide M. Dental anomalies of the permanent lateral incisors and prevalence of hypodontia outside the cleft area in complete unilateral cleft lip and palate. Cleft Palate Craniofac J 2003;40:172-5.
Demirjian A, Goldstein H, Tanner JM. A new system of dental age assessment. Hum Biol 1973;45:211-27.
Akcam MO, Evirgen S, Uslu O, Memikoğlu UT. Dental anomalies in individuals with cleft lip and/or palate. Eur J Orthod 2010;32:207-13.
Jiroutova D, Mullerova Z. The occurrence of hypodontia in patients with cleft lip and palate. Acta Chir Plast 1994;36:53-6.
Vichi M, Franchi L. Abnormalities of the maxillary incisors in children with cleft lip and palate. ASDC J Dent Child 1995;62:412-7.
Dewinter G, Quirynen M, Heidbüchel K, Verdonck A, Willems G, Carels C. Dental abnormalities, bone graft quality, and periodontal conditions in patients with unilateral cleft lip and palate at different phases of orthodontic treatment. Cleft Palate Craniofac J 2003;40:343-50.
Brattström V, McWilliam J. The influence of bone grafting age on dental abnormalities and alveolar bone height in patients with unilateral cleft lip and palate. Eur J Orthod 1989;11:351-8.
da Silva AP, Costa B, de Carvalho Carrara CF. Dental anomalies of number in the permanent dentition of patients with bilateral cleft lip: Radiographic study. Cleft Palate Craniofac J 2008;45:473-6.
Vallino LD, Zuker R, Napoli JA. A study of speech, language, hearing, and dentition in children with cleft lip only. Cleft Palate Craniofac J 2008;45:485-94.
Tsai TP, Huang CS, Huang CC, See LC. Distribution patterns of primary and permanent dentition in children with unilateral complete cleft lip and palate. Cleft Palate Craniofac J 1998;35:154-60.
Kitamura H. Evidence for cleft palate as a postfusion phenomenon. Cleft Palate Craniofac J 1991;28:195-210.
Bondemark L, Tsiopa J. Prevalence of ectopic eruption, impaction, retention and agenesis of the permanent second molar. Angle Orthod 2007;77:773-8.
Fox NA, Fletcher GA, Horner K. Localising maxillary canines using dental panoramic tomography. Br Dent J 1995;179:416-20.
Barberia-Leache E, Suarez-Clúa MC, Saavedra-Ontiveros D. Ectopic eruption of the maxillary first permanent molar: Characteristics and occurrence in growing children. Angle Orthod 2005;75:610-5.
Riis LC, Kjær I, Mølsted K. Dental anomalies in different cleft groups related to neural crest developmental fields contributes to the understanding of cleft aetiology. J Plast Surg Hand Surg 2014;48:126-31.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]