A cross-sectional analysis of the prevalence of tooth agenesis and structural dental anomalies in association with cleft type in non-syndromic oral cleft patients

Konstantonis et al. Progress in Orthodontics (2017) 18:20 DOI 10.1186/s40510-017-0169-x RESEARCH Open Access A cross-sectional analysis of the prevalence of tooth agenesis and structural dental anomalies in association with cleft type in non-syndromic oral cleft patients Dimitrios Konstantonis1,2* , Alexandros Alexandropoulos1, Nikoleta Konstantoni3 and Maria Nassika1 Abstract Background: The aim of this study was to investigate the prevalence of tooth agenesis, microdontia, and tooth malformation among non-syndromic oral cleft patients and their potential association with cleft type and gender. Methods: Intraoral records and radiographs of 154 patients (97 males and 57 females) were examined. The variables assessed were tooth agenesis, microdontia, dental malformations, and cleft types. The statistics included chi-square and Fisher’s exact tests as well as logistic regression to assess any mutual effects of gender and cleft type on the dental variables. Results: Tooth agenesis occurred in 50% of the sample and microdontia in 18%. Non-statistically significant odds ratios for the association of gender and cleft type with tooth agenesis were obtained. Tooth agenesis was substantially higher at the unilateral right CL + P and the bilateral CL + P in quadrant 1 and at the unilateral left CL + P and bilateral CL + P in quadrant 2. It was also higher, at the isolated cleft palate (CP) in quadrants 3 and 4. These results were attributed to teeth 22 (31.8%) and 12 (21.6%) in the maxilla and to teeth 35 (6.1%) and 45 (5.4%) in the mandible. In unilateral CL + P patients, the cleft quadrant that presented tooth agenesis was associated with the side of the cleft. Conclusions: Interdisciplinary treatment of the oral cleft patients should take into consideration the high prevalence of tooth agenesis and their association with the different cleft types. The most frequently affected teeth by cleft are by far the upper lateral incisors. Results indicate that tooth agenesis appears to be a genetically controlled anomaly related to the orofacial cleft development through various genetic links and not caused by the cleft disruptive process. Keywords: Cleft lip and palate, Dental anomalies, Tooth agenesis, Microdontia Background Cleft lip and palate (CL + P) is the most common craniofacial birth defect in the world [1]. The average prevalence of cleft lip with or without cleft palate is 7.75 and 7.94 per 10,000 live births in the USA and worldwide, respectively, [2]. * Correspondence: 1 Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, 2 Thivon st, 115 26 Athens, Greece 2 Clinic of Orthodontics and Pediatric Dentistry, University of Zurich, Zurich, Switzerland Full list of author information is available at the end of the article The most frequent dental anomaly among cleft patients is tooth agenesis [3–7]. The occurrence of tooth agenesis among cleft patients is markedly increased in comparison to the general, non-cleft population [3, 6–11]. Additionally, dental anomalies appear more commonly in the cleft rather than the non-cleft area [4, 10, 12–14]. It is reported that the prevalence of left-sided clefts is higher than rightsided clefts; the cause still remaining unknown [9, 15]. Data from the literature indicate that isolated cleft lip patients (CL) seem to be less affected by dental anomalies outside the cleft area compared to CP or CL + P patients [7]. Furthermore, the permanent dentition seems to be © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Konstantonis et al. Progress in Orthodontics (2017) 18:20 more affected than the primary dentition in patients with unilateral and bilateral CL + P [13]. Other investigations suggest a link between the severity of the cleft type and the number of missing teeth as well as the incidence of dental anomalies [4, 12]. Still, the lateral incisor is reported as the most frequently missing tooth in cleft patients [3, 6, 13, 15, 16]. Also, according to a recent study, the prevalence of lateral incisor agenesis increases in respect to the severity of the cleft [16]. A much higher incidence of agenesis of second premolars was found in the maxilla rather in the mandible in CL + P patients [14, 17]. This agenesis was more frequently observed in the left side and was not gender- or jaw-dependent [9]. Also, contradictory results are reported regarding gender-dependent patterns in the distribution of dental anomalies [4, 18]. It is the aim of this study to identify a contemporary sample of cleft lip and/or palate patients and investigate the prevalence of tooth agenesis and structural dental anomalies and their possible association to the cleft type or gender. Therefore, the null hypothesis of this study was that tooth agenesis and dental structural anomalies are not different between the various types of oral clefts and gender. Methods The data of this study consisted of consecutive cleft patient records obtained from the graduate clinic of the Department of Orthodontics and Pediatric Dentistry of the School of Dentistry of the National and Kapodistrian University in Athens, Greece. An ethics and research committee approval was also obtained (ref. 312/21.09.2016). Considering that the proportion of patients with tooth agenesis and structural dental anomalies approaches 60%, we found that approximately 160 individuals are needed to ensure that a 99% confidence interval estimate of the proportion is within 10% of the true proportion [19]. By the end of 2016, a total of 154 cleft patient records were thoroughly examined for tooth agenesis and structural dental anomalies. All patients were born between 1977 and 2006 in Greece. Of them, 97 were males and 57 were females. The inclusion criteria were Caucasian male or female non-syndromic patients with complete records including dental casts, photos, and panoramic xrays; no history of permanent teeth extractions prior to the initial orthodontic screening; and no previous orthodontic treatment received. Third molars were excluded from our assessment. All patient records were taken prior to secondary alveolar bone grafting. Additionally, no pre-surgical orthopedics, gingivoperiosteoplasty or primary bone grafting were performed so that tooth agenesis as well as structural dental anomalies presented in this sample of patients could not be considered iatrogenic. In order to make sure that the agenesis of second premolars was not mistakenly noted due to individual Page 2 of 9 variation, we evaluated all panoramic radiographs of patients older than 8 years of age. All patients recei (...truncated)