Dental abnormalities and ectopic eruption in patients with isolated cleft palate

Retrospective evaluation of the orthodontic treatment needs in primary school children with Robin sequence following Tübingen palatal plate therapy in infancy

INTRODUCTION

The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls.

METHODS

The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls.

RESULTS

In 21 children with RS (n = 23; 19 non-syndromic, 4 syndromic; average age 9.9 years) showed high OTN, which was significantly higher than in controls (n = 21). The latter of 9 controls had minor OTN, followed by 8 participants with borderline OTN. Regarding the intraoral picture, patients with RS had an increased open bite tendency. Without considering the presence of a cleft palate, 16 children with RS had high or very high OTN, compared to 4 of controls.

CONCLUSIONS

Patients with RS have significantly higher OTN than healthy controls, independent of cleft occurrence. RS is associated with dental anomalies and special skeletal growth patterns, both increasing malocclusion and negatively affecting dentoalveolar growth. This should raise awareness for identifying these needs and provide a comprehensive orthodontic treatment, where functional rehabilitation should be favored over aesthetic results.

How Does Hypodontia Compare in Nonsyndromic Pierre Robin Sequence Versus Isolated Cleft Palate and Isolated Cleft Lip?

OBJECTIVE

To assess the prevalence and patterns of hypodontia in nonsyndromic Pierre Robin sequence (PRS) and compare it with hypodontia in nonsyndromic isolated cleft palates and isolated cleft lips.

DESIGN

Retrospective cohort study.

SETTING

Alder Hey Children's Hospital, United Kingdom.

PATIENTS

Patients with nonsyndromic PRS (group 1), isolated cleft palate (group 2), and isolated cleft lip (group 3).

MAIN OUTCOME MEASURES

Hypodontia in the permanent dentition assessed from orthopantomographs.

RESULTS

A total of 154 patients were included. Group 1 had the highest incidence of hypodontia with 47% having at least one tooth congenitally absent. Groups 2 and 3 had reduced rates of hypodontia with 27% and 19% of the groups missing teeth, respectively; 93% of cases of hypodontia in group 1 involved the absence of at least one second premolar. Of these patients, there was found to be bilateral agenesis of second premolars in 50% of cases.

CONCLUSIONS

Patients with PRS and cleft palates are more likely to have hypodontia than those with isolated cleft palates or unilateral cleft lips. Patients with PRS have more severe hypodontia than those with isolated cleft palates or unilateral cleft lips. Bilateral agenesis of lower second premolars is a commonly seen pattern among patients with PRS. In this large UK study, a similar prevalence and pattern of hypodontia to other nonsyndromic PRS populations worldwide has been demonstrated.

Dental anomalies frequency in submucous cleft palate versus complete cleft palate

BACKGROUND/OBJECTIVES

This retrospective study evaluated the prevalence of dental anomalies of number in different subphenotypes of isolated cleft palate.

MATERIALS/METHODS

The sample comprised 26 individuals with submucous cleft palate (group S) and 68 individuals with complete cleft palate (group C) aged between 9 and 12 years from a single centre. Panoramic radiographs were evaluated regarding the presence of dental anomalies of number in permanent teeth. Intergroup comparison was performed using chi-square tests (P < 0.05).

RESULTS

Tooth agenesis was found in 34.61 and 36.76 per cent of group S and group C, respectively. The most commonly missing teeth were the maxillary second premolar, maxillary lateral incisor, and mandibular second premolar. Supernumerary teeth were found in none and 1.47 per cent of the individuals with submucous and complete cleft palate, respectively. No statistically significant difference was found between groups for the frequency of tooth agenesis and supernumerary teeth.

LIMITATIONS

Only dental anomalies of number were evaluated.

CONCLUSIONS/IMPLICATIONS

Individuals with submucous and complete cleft palate showed similar prevalence for tooth agenesis and supernumerary teeth. Dental anomalies frequency seems not to be a discriminator for subphenotypes of cleft palate.

Phenotypes, Developmental Basis, and Genetics of Pierre Robin Complex

The phenotype currently accepted as Pierre Robin syndrome/sequence/anomalad/complex (PR) is characterized by mandibular dysmorphology, glossoptosis, respiratory obstruction, and in some cases, cleft palate. A causative sequence of developmental events is hypothesized for PR, but few clear causal relationships between discovered genetic variants, dysregulated gene expression, precise cellular processes, pathogenesis, and PR-associated anomalies are documented. This review presents the current understanding of PR phenotypes, the proposed pathogenetic processes underlying them, select genes associated with PR, and available animal models that could be used to better understand the genetic basis and phenotypic variation of PR.

Prevalence of ectopic eruption of first permanent molars in a Turkish population

Purpose

The aim of this study was to investigate the prevalence and characteristics of ectopically erupting first permanent molars (FPMs) in children attending the clinics of the Pediatric Dentistry Department at İstanbul University.

Materials and methods

This retrospective study was performed using panoramic radiographs of 7,649 patients (3,506 females and 4,143 males) aged from 5 to 11 years. The age and gender of the subjects, the number and location of the ectopic molars, bilateral versus unilateral occurrence, the degree of resorption of the roots of the primary molars, and other associated dental anomalies were assessed. Ectopic eruption was categorized according to a grading system based on the resorption rates of the primary molars.

Results

Of the 7,649 reviewed subjects, 203 (118 males and 85 females) were diagnosed with ectopic eruption of the FPMs, resulting in a frequency of 2.65%. The mean age of the subjects with ectopic FPMs was 6.82±1.25 (range: 5-11) years. Of the 273 ectopic FPMs, 157 (57.5%) were detected in the maxilla and 116 (42.5%) in the mandible. Severe and very severe degrees of ectopic eruption were found to be more common in the maxilla than in the mandible, whereas a moderate degree of ectopic eruption was more prevalent in the mandible (p=0.251).

Conclusion

To our knowledge, this is the first study in a Turkish population reporting the prevalence of ectopic eruption of FPMs. Although the difference between the right and the left sides was not significant, the severity of ectopic eruption was different between the maxilla and the mandible.

Congenitally Missing Teeth in the Israeli Cleft Population

Objective

The purpose of the study was to determine the prevalence of congenitally missing teeth in a group of Israeli children with various types of clefts.

Design

Prevalence of congenitally missing teeth was determined for 179 children with cleft lip, cleft lip and alveolar ridge, cleft lip and palate, and cleft palate. Subgroupings were assessed according to patient sex, origin, cleft type, tooth type, and the side of hypodontia. The diagnosis of congenitally missing teeth (CMT) was based on initial and follow-up panoramic roentgenograms. In case of doubt, occlusal or periapical roentgenograms as well as clinical dental photographs were also used.

Setting

Data collection was conducted at the Rambam Medical Center, Orthodontic and Craniofacial Unit, Haifa, Israel.

Results

In the total cleft group, 67.6% of the patients presented with hypodontia, totaling 246 missing teeth. A statistically significant difference was found in the distribution of patients with CMT of Jewish and minority origin according to sex. Cleft lip and palate was the most frequently affected group in which 195 teeth were missing. The most frequently missing tooth among the cleft population was the maxillary incisor. The order of frequency of the other missing teeth was the same as in the normal population. Hypodontia and malformations of permanent teeth were most common on the cleft side.

Conclusion

The frequency of CMT in the Israeli cleft population studied was higher than in the intact population. This confirms findings in other populations worldwide.

Permanent tooth agenesis in individuals with non-syndromic Robin sequence: a systematic review and meta-analysis

OBJECTIVES

To evaluate prevalence rates and patterns of permanent tooth agenesis in individuals with non-syndromic Robin sequence (ns-RS).

MATERIAL AND METHODS

Two investigators independently carried out a literature search, using PubMed, Web of Science, Ovid, EMBASE and the Cochrane Library, identifying articles relating to permanent tooth agenesis, diagnosed using panoramic radiographs, in individuals with ns-RS. The outcomes desired were prevalence rates and patterns of permanent tooth agenesis. The final search was carried out in January 2017.

RESULTS

Six articles were selected for inclusion, with a total of 448 individuals with ns-RS. Data available in each study varied which allowed conducting further specific meta-analyses only on sample sizes of 339 or 378 individuals from three or four of the six included articles. The overall estimated prevalence rate of permanent tooth agenesis was 42% (95% CI: 35%-48%), excluding third molars, with no sex predilection. In individuals with tooth agenesis, approximately 30% had one missing tooth while 40% had two missing teeth. Tooth agenesis was more commonly bilateral (Relative Risk 2) and found in the mandible (Relative Risk 1.6). The highest prevalence of permanent tooth agenesis was found for mandibular second premolars (26%) followed by maxillary second premolars (14%). The most common tooth agenesis patterns were the agenesis of both mandibular second premolars, followed by the agenesis of all second premolars.

CONCLUSION

Individuals with ns-RS have high prevalence rates of permanent tooth agenesis. The most prevalent tooth agenesis patterns are bilateral symmetric tooth agenesis, most commonly agenesis of both mandibular second premolars.

Permanent tooth agenesis in non-syndromic Robin sequence and cleft palate: prevalence and patterns

Objectives

Partial tooth agenesis is frequently observed in Robin sequence. Tooth anomalies are increasingly considered as an extended phenotype of the cleft palate population. The study objective was to compare the prevalence and patterns of tooth agenesis in a group of patients with non-syndromic Robin sequence (ns-RS) and a group with non-syndromic cleft palate (ns-CP).

Materials and methods

The panoramic radiographs of 115 ns-RS and 191 ns-CP patients were assessed for agenesis of the permanent dentition (excluding third molars) and the patterns recorded using the Tooth Agenesis Code.

Results

Partial tooth agenesis was observed in 47.8% of ns-RS and 29.8% of ns-CP patients with a greater prevalence in the mandibula than in the maxilla, particularly in ns-RS. The teeth most frequently absent in both groups were the mandibular second premolars and maxillary lateral incisors. Tooth agenesis was bilateral in two-thirds of affected ns-RS patients and one-half of ns-CP patients. In ns-RS, bilateral agenesis of the mandibular second premolars was more frequently observed in female than that in male patients. Completely symmetrical patterns of hypodontia were found in around 45% of ns-RS patients with tooth agenesis compared to 35% in ns-CP. No association was found between the extent of the palatal cleft and the severity of hypodontia.

Conclusion

Tooth agenesis is more prevalent in ns-RS than that in ns-CP, demonstrates a much greater predilection for the mandible in ns-RS, and bears no relation to the extent of the palatal cleft.

Clinical relevance

When compared to ns-CP, additional developmental disturbances are likely involved in the etiology of tooth agenesis in ns-RS. Future research could help identify the underlying genetic traits and aid in classifying patients in those with and without expected tooth agenesis in order to facilitate orthodontic management strategies.

Dental Anomalies in a Brazilian Cleft Population

Objective

The aim of this study was to radiographically investigate the prevalence of dental anomalies outside the cleft area in a group of Brazilian patients with nonsyndromic cleft lip and/or palate (NSCL/P).

Design, Participants, and Setting

A retrospective analysis of 207 panoramic radiographs of patients with NSCL/P aged 12 to 45 years without history of tooth extraction and orthodontic treatment was performed.

Results

Dental anomalies were found in 75.4% of the patients, and tooth agenesis (29.2%) and supernumerary tooth (2.6%) were the most common anomalies. The risk of agenesis was higher among the individuals with cleft palate (CP) compared with individuals with cleft lip (CL) and cleft lip and palate (CLP) (agenesis: CP versus CL: odds ratio 6.27, 95% confidence interval 2.21-17.8, P = .0003; CP versus CLP: odds ratio 2.94; 95% confidence interval 1.27-6.81, P = .01). The frequency of dental agenesis was higher in patients with unilateral complete CLP (agenesis: P < .0001), incomplete bilateral CLP (agenesis: P = .0013), complete CP (agenesis: P < .0001), and incomplete CP (agenesis: P < .0001). The frequency of supernumerary teeth was higher in patients with bilateral complete CLP ( P < .0001). The frequency of dental agenesis ( P < .0001) and ectopic tooth ( P = .009) was higher than the frequency estimated for general population.

Conclusions

The prevalence of dental anomalies in patients with NSCL/P was higher than that reported in overall population. This study found preferential associations between dental anomalies and specific extensions of NSCL/P, suggesting that dental agenesis and ectopic tooth may be part of oral cleft subphenotypes.

Radiographic Study of the Prevalence and Distribution of Hypodontia Associated with Unilateral and Bilateral Clef Lip and Palate in a Hungarian Population

Background

Cleft defects are one of the most frequent birth-deformities of the orofacial region and they are commonly associated with anomalies of the tooth structure, size, shape, formation, eruption, and tooth number. The aim of our study was to evaluate the prevalence, distribution, and potential association of combined hypodontia in cleft-affected patients with regard to all types of teeth in both jaws in the permanent dentition.

Material/Methods

This retrospective radiographic analysis included patients with various types of clefts treated orthodontically in the Department of Orofacial Orthopedics and Orthodontics at Heim Pàl Children’s Hospital, Budapest. There were 150 patients (84 males, 66 females) with non-syndromic unilateral (UCLP; n=120 patients) or bilateral (BCLP; n=30 patients) cleft formation (lip, alveolus and palate) who met the inclusion criteria. Statistical analysis was performed using the chi-square test and Fisher’s exact test (significance level p<0.05).

Results

Hypodontia was significantly more frequent in patients with cleft-sided lateral incisor (104 patients, 69%), with a total of 235 missing teeth, followed by the second premolars of the upper and lower jaw. A significant correlation of congenital missing teeth was observed in left-sided clefts between the upper and lower second premolar in the cleft area.

Conclusions

Hypodontia inside and outside the cleft area was frequently observed. This should affect the therapy plans, especially if the cleft-sided premolar is also absent. Further comprehensive research including numerous random samples is necessary for better estimating other possible associations.

Cleft sidedness and congenitally missing teeth in patients with cleft lip and palate patients

Background

The aim of this study was to investigate the prevalence of cleft sidedness, and the number of congenitally missing teeth in regard to cleft type and gender.

Methods

The charts, models, radiographs, and intraoral photographs of 201 cleft patients including 131 males with the mean age of 12.3 ± 4 years and 70 females with the mean age of 12.6 ± 3.9 years were used for the study. T test, Chi-square, and binomial tests were used for assessment of the data.

Results and conclusions

One hundred forty-eight of the subjects suffered from cleft lip and palate followed by 41 subjects who suffered from cleft lip and alveolus. Chi-square test did not show any significant difference between the genders. Binomial test showed that left-sided cleft was more predominant in unilateral cleft lip and palate patients (P < 0.001). This study also showed that the upper lateral incisors were the most commonly missing teeth in the cleft area.

Bilateral Hypodontia in Adolescents with Pierre Robin Sequence

Objective

To describe the frequency of hypodontia and left-right symmetry of hypodontia in the permanent dentition of children with Pierre Robin sequence (PRS).

Patients and Method

The sample consisted of 78 children born with PRS between 1980 and 2006 and referred to the Oslo Cleft Lip and Palate Team (OCLPT). Data were collected retrospectively from the archives of the OCLPT. Panoramic radiographs were evaluated to document hypodontia; third molars were excluded.

Results

Of the 78 children with PRS, hypodontia was found in 33 (42%). Of the 33 children with hypodontia, 27 (82%) showed hypodontia in the micrognathic lower arch, 24 (73%) were missing two or more permanent teeth, and 2 (6%) had oligodontia. The teeth most often missing were the mandibular second premolar (72%), followed by the maxillar second premolar (29%). Most cases of hypodontia 21 (64%) occurred bilaterally. Bilateral hypodontia of the mandibular second premolar occurred in 27 (73%) of the patients.

Conclusion

Hypodontia was found in 33 (42%) of the children with PRS, which is seven times higher than the prevalence among children without PRS (6%). Unlike in the general population, bilateral hypodontia was more common than unilateral hypodontia in the micrognathic mandible of children with PRS.

Presurgical Unilateral Cleft Lip Anthropometrics and the Presence of Dental Anomalies

Objective

To investigate associations between cleft lip anthropometrics and dental anomalies in the permanent dentition in unilateral cleft lip patients.

Design

Retrospective cross-sectional study.

Patients

Children with unilateral clefts of the lip, with or without cleft palate.

Methods

Anthropometric lip measurements, made immediately prior to lip repair, were available for each patient. The presence of dental anomalies in the permanent dentition was assessed radiographically. The presence of associations between anthropometric lip measurements and prevalence rates of different dental anomalies were determined using logistic regression analyses.

Results

In the 122 included patients, the cleft lateral lip element was deficient in height in 80% and in transverse length in 84% of patients. Patients with more deficient cleft side lateral lip height and less deficient cleft side lateral lip transverse length were more likely to present with cleft side maxillary lateral incisor agenesis. On the other hand, patients with a less deficient cleft side lateral lip height and more deficient cleft side lateral lip transverse length were more likely to present with a cleft side supernumerary maxillary lateral incisor. When looking only at incomplete clefts, the cleft side lateral lip transverse length deficiency was more predictive of the presence of supernumerary maxillary lateral incisors (P= .030), while for complete clefts, the cleft side lateral lip height deficiency was more predictive of the presence of maxillary lateral incisor agenesis ( P = .035).

Conclusions

In patients with unilateral clefts, cleft lip anthropometrics have a predictive role in determining the occurrence of dental anomalies.

Prevalence of dental anomalies of number in different subphenotypes of isolated cleft palate

Objective

This study aimed at carrying out a radiographic analysis on the prevalence of dental anomalies of number (agenesis and supernumerary teeth) in permanent dentition, in different subphenotypes of isolated cleft palate pre-adolescent patients.

Methods

Panoramic radiographs of 300 patients aged between 9 and 12 years, with cleft palate and enrolled in a single treatment center, were retrospectively analyzed. The sample was divided into two groups according to the extension/severity of the cleft palate: complete and incomplete . The chi-square test was used for intergroup comparison regarding the prevalence of the investigated dental anomalies (P < 0.05).

Results

Agenesis was found in 34.14% of patients with complete cleft palate and in 30.27% of patients with incomplete cleft palate. Supernumerary teeth were found in 2.43% of patients with complete cleft palate and in 0.91% of patients with incomplete cleft palate. No statistically significant difference was found between groups with regard to the prevalence of agenesis and supernumerary teeth. There was no difference in cleft prevalence between genders within each study group.

Conclusion

The prevalence of dental anomalies of number in pre-adolescents with cleft palate was higher than that reported for the general population. The severity of cleft palate did not seem to be associated with the prevalence of dental anomalies of number.

The prevalence of specific dental anomalies in a group of Saudi cleft lip and palate patients

Objective

The aims of this study were to investigate the prevalence and distribution of dental anomalies in a group of Saudi subjects with cleft lip and palate (CLP), to examine potential sex-based associations of these anomalies, and to compare dental anomalies in Saudi subjects with CLP with published data from other population groups.

Design

This retrospective study involved the examination of pre-treatment records obtained from three CLP centers in Riyadh, Saudi Arabia, in February and March 2010. The pre-treatment records of 184 subjects with cleft lip and palate were identified and included in this study. Pre-treatment maxillary occlusal radiographs of the cleft region, panoramic radiographs, and orthodontic study models of subjects with CLP were analyzed for dental anomalies.

Results

Orthopantomographs and occlusal radiographs may not be reliable for the accurate evaluation of root malformation anomalies. A total of 265 dental anomalies were observed in the 184 study subjects. Hypodontia was observed most commonly (66.8%), followed by microdontia (45.6%), intra-oral ectopic eruption (12.5%), supernumerary teeth (12.5%), intra-nasal ectopic eruption (3.2), and macrodontia (3.2%). No gender difference in the prevalence of these anomalies was observed.

Conclusions

Dental anomalies were common in Saudi subjects with CLP type. This will complicate the health care required for the CL/P subjects. This study was conducted to epidemiologically explore the prevalence of dental anomalies among Saudi Arabian subjects with CLP.

Clefts of the secondary palate referred to the Oslo Cleft Team: epidemiology and cleft severity in 994 individuals

OBJECTIVE

To describe Norwegian individuals born with cleft of the secondary palate (CP) in relation to cleft severity, Pierre Robin sequence, associated anomalies, syndromes, and hypodontia and to present estimated longitudinal prevalences.

PATIENTS

Nine hundred ninety-four individuals with CP born between 1960 and 2002 referred to the Oslo Cleft Team (OCT).

METHOD

Data were collected retrospectively from the archives of the OCT.

RESULTS

Among all CP, 7.6% had recognized syndromes, 30.5% had associated anomalies, and in 61.9%, CP was the only malformation. Pierre Robin sequence was recorded in 11.7%. Female predominance was observed both in general and in each cleft severity subgroup. Of 610 individuals with CP, only 25.1% were diagnosed with a submucous cleft palate, 45.9% had a cleft of the soft palate only, and in 29%, the cleft extended into the hard palate. Among 309 individuals over the age of 10 years with CP only, hypodontia was found in 28.5%, and in individuals with Pierre Robin sequence, hypodontia was found in 44.1%. During the period 1965 to 1999, the estimated prevalence of individuals with CP in the OCT uptake area was found to be 0.59 per 1000 live births. The estimated prevalence increased slightly over time, both overall and within the cleft severity subgroups.

CONCLUSION

A large proportion of a Norwegian population with CP had syndrome or additional anomalies. The estimated prevalence of CP in this population increased slightly during the observation period.

Association between cleft size and crossbite in children with cleft palate and unilateral cleft lip and palate

OBJECTIVE

To investigate the association between cleft size in infancy and crossbite at 5 years of age in children with cleft palate (CP) and unilateral cleft lip and palate (UCLP).

DESIGN

Retrospective study.

SETTING

University Hospital, Uppsala, Sweden.

PATIENTS

Dental study models of 80 consecutive children, 51 children with CP and 29 children with UCLP, born between 1990 and 1999 were analyzed.

INTERVENTIONS

Lip repair at 3 to 4 months in UCLP children. Primary soft palate repair at 6 to 10 months and secondary hard palate closure at 25 to 26 months of age.

MAIN OUTCOME MEASURES

Maxillary arch dimensions and cleft size were measured on infancy dental casts. At follow-up at 5 years, crossbite scores were registered on dental study models.

RESULTS

The cleft dimensions in infancy showed large interindividual variation. Mean posterior cleft width was larger in UCLP children than in children with CP. The UCLP group also had significantly more crossbite at 5 years than the CP group. No significant association was noted between initial cleft size and crossbite scores at 5 years in the CP group. For the UCLP group, larger cleft widths at the level of the cuspid points were significantly associated with less anterior and posterior crossbite.

CONCLUSIONS

The findings support the hypothesis that cleft size in infancy affects early outcome with respect to crossbite in children with UCLP, but not in children with CP.

Prevalence of second premolar hypodontia in the Polish cleft lip and palate population

Background

Cleft lip and/or palate is the most frequent congenital abnormality occurring in the craniofacial region and is often associated with numerous dental defects such as tooth agenesis, supernumerary teeth, microdontia, taurodontism, crown malformations, or delay in eruption. The prevalence of hypodontia in cleft-affected patients is much higher in comparison with a healthy population. The aim of this study was to evaluate the prevalence of second premolar hypodontia in patients with cleft lip and/or palate.

Material/Methods

We performed a retrospective, evaluation of panoramic radiographs and dental casts in the Department of Dentofacial Orthopeadics and Orthodontics, Wroclaw Medical University. Two independent observers evaluated the records of 469 patients with various types of clefts and analyzed dental casts and panoramic radiographs.

Results

202 individuals met inclusion criteria. The sample comprised 120 UCLP patients, 38 BCLP patients, 28 CP patients, and 17 CLA patients. Hypodontia in the premolar region was observed in 39 individuals (19.3%). A total number of 58 second premolars were missing, of which 35 were maxillary second premolars (U5) and 23 were mandibular second premolars (L5).

Conclusions

Estimated hypodontia in the Polish CL/P sample was considerably higher than the hypodontia in permanent dentition reported for a European healthy population. The number of congenitally missing second premolars was higher in the maxillary arch than in the mandibular.

Developmental and genetic perspectives on Pierre Robin sequence

Pierre Robin sequence (PRS) is a craniofacial anomaly comprising mandibular hypoplasia, cleft secondary palate and glossoptosis leading to life-threatening obstructive apnea and feeding difficulties during the neonatal period. The respiratory issues require careful management and in severe cases may require extended stays in neonatal intensive care units and surgical intervention such as lengthening the lower jaw or tracheotomy to relieve airway obstruction. These feeding and respiratory complications frequently continue well into childhood, affecting not only growth and development but also impacting on long term educational attainment. The diagnosis of PRS depends on readily recognizable clinical features but the phenotypic similarity of many PRS individuals conceals considerable etiological heterogeneity. Defects in the growth of the mandible sit at the core of PRS and the natural history of PRS can be classified into two major streams: primary defects of mandibular outgrowth and elongation and issues that are external to the mandibular skeleton but that secondarily impact on its growth. These altered developmental trajectories appear to be driven by a range of influences including defects in cartilage growth, neuromuscular function and fetal constraint. Various genetic and cytogenetic associations have been made with PRS and the diversity of these associations highlights the fact that there are numerous ways to arrive at this common phenotypic endpoint.

Prevalence of Dental Anomalies in Patients with Nonsyndromic Cleft Lip and/or Palate in a Brazilian Population

Objective

Many studies have demonstrated a high frequency of dental anomalies in patients with cleft lip and/or palate. Because dental anomalies may complicate dental treatment, we investigated the prevalence of dental anomalies in a group of Brazilian patients with nonsyndromic cleft lip and/or palate.

Design, Participants, Setting

Retrospective analysis was performed using clinical records of 296 patients aged between 12 and 30 years with repaired nonsyndromic cleft lip and/or palate without history of tooth extraction and orthodontic treatment. Associations between oral clefts and presence of dental anomalies outside the cleft area were investigated.

Results

Dental anomalies were identified in 39.9% of the nonsyndromic cleft lip and/or palate patients, and tooth agenesis (47.5%), impacted tooth (13.1%), and microdontia (12.7%) were the most common anomalies. Cleft lip patients were less affected by dental anomalies compared with cleft palate or cleft lip and palate patients ( p = .057). Specifically, patients with unilateral cleft lip and palate were significantly more affected by dental anomalies than those with bilateral cleft lip and palate ( p = .00002), and individuals with unilateral complete cleft lip and palate ( p = .002) and complete cleft palate ( p = .01) were significantly more affected by tooth agenesis than other cleft types. Agenesis of the premolars ( p = .043) and maxillary lateral incisors ( p = .03) were significantly more frequent in patients with unilateral complete cleft lip and palate.

Conclusions

The present study revealed a high frequency of dental anomalies in nonsyndromic cleft lip and/or palate patients and further demonstrated that patients with unilateral cleft lip and palate were frequently more affected by dental anomalies than those with bilateral cleft lip and palate. Moreover, our results demonstrate that dental anomalies should be considered during dental treatment planning for individuals affected by nonsyndromic cleft lip and/or palate.

Prevalence of Dental Anomalies in a Population of Cleft Lip and Palate Patients

Objective

The aim of our study was to investigate radiographically the prevalence of dental anomalies in a group of Jordanian cleft lip and/or palate subjects.

Design

This is a retrospective review of panoramic radiographs of 78 subjects with cleft lip and/or palate that were evaluated from their file records and investigated for possible dental anomalies.

Results

Dental anomalies were found frequently in cleft lip and/or palate subjects. Missing teeth were found in 66.7% of the patients; the tooth most commonly missing was the maxillary lateral incisor. Supernumerary teeth were found in 16.7% of patients; 37% had microdontia; 70.5% had taurodontism; 30.8% had transposition and/or ectopic teeth; 19.2% had dilacerations; and 30.8% had hypoplastic teeth. There was no statistically significant difference in the above anomalies’ prevalence between males and females. However, it was found that subjects with bilateral cleft lip and/or palate had significantly more microdontia ( p = .005), dilaceration ( p = .002), and hypoplastic teeth ( p = .0001) than subjects with unilateral cleft lip and/or palate.

Conclusions

The prevalence of dental anomalies in cleft lip and/or palate patients was higher than what had been reported in the normal Jordanian population. This emphasizes the relation of cleft lip and/or palate to all dental anomalies studied. Although our study represents a thorough and complete description of dental anomalies present in a sample of cleft lip and/or palate subjects, larger samples are required to effectively determine the relationship of each dental anomaly with cleft type.

Dental age in 6-year-old children with submucous cleft palate and cleft of the soft palate

OBJECTIVE

To evaluate dental age in 6-year-old children with submucous cleft palate (SMCP) and to compare this in age-matched and sex-matched children with clefts of the soft palate (CPs).

MATERIAL AND METHODS

The dental maturity of 73 children (39 girls) with SMCP was evaluated from panoramic radiographs and compared in age-matched and sex-matched controls with CPs. Mean biological age of the children was 6.1, ranging from 5.5 to 6.8 (boys 6.2 years, range 5.7-6.8; girls 6.1 years, range 5.5-6.7). Dental stages were assessed following the method of Demirjian, and dental age was calculated in accordance with the Finnish dental maturity reference values. Student's paired t-test was used in the statistical analysis.

RESULTS

There were no significant differences in dental age between the sexes, such that boys and girls were combined in the further analyses. Dental age of the children with SMCP (6.2 years, range 4.9-7.4) was similar to their biological age (NS). Dental age of those with CPs was 0.2 years delayed (dental age 5.9 years, range 4.6-7.5; p<0.001) compared to their biological age. Children with CPs had a lower dental age than children with SMCP (p<0.001).

CONCLUSION

Dental maturation in 6-year-old children with submucous cleft palate is not delayed, whereas in children with clefts of the soft palate dental age is slightly delayed.

Dental Anomalies as Part of the Cleft Spectrum

Objective:

The aim of this study was to determine subphenotypes of clefts based on tooth development. Dental phenotypes (tooth agenesis, supernumerary and impacted teeth, transposition, and structural anomalies) outside the cleft area in the permanent dentition of oral cleft individuals were investigated.

Design:

Evaluation of dental records of cleft patients.

Setting:

National Museum of Health and Medicine, Washington, D.C.

Patients, Participants:

A collection of dental casts, radiographic and clinical records of 146 patients with oral clefts was evaluated.

Main Outcome Measure:

Association of dental anomalies with preferential subtypes of clefts.

Results:

Forty-seven individuals (32.19%) presented at least one dental anomaly outside the cleft area. Individuals with complete cleft lip and palate (CLP) presented more dental anomalies than individuals with incomplete CLP (p  =  .04). Cleft palate individuals presented more dental anomalies than CLP individuals (p  =  .048). Maxillary lateral incisors and premolars were the most affected teeth. High incidence of maxillary second premolar agenesis was observed in individuals with bilateral CLP (p  =  .04). In cases with unilateral CLP, 12.5% presented dental anomalies of the maxillary lateral incisors on the noncleft side. Cleft palate individuals presented a high incidence of mandibular premolar anomalies (p  =  .004).

Conclusion:

Future studies should consider the inclusion of a complete dental description to aid in the definition of cleft subphenotypes to be studied.

Studies of dental anomalies in a large group of school children

The identification of specific patterns of dental anomalies would allow testing the hypothesis that certain genetic and environmental factors contribute to distinct dental anomaly subphenotypes. A sexual dimorphism in tooth agenesis and its association with other dental anomalies has been suggested. The aim of this study was to investigate a large group of children to define dental anomaly subphenotypes that may aid future genetic studies. Orthopantamograms of 1198 subjects were examined and 1167 were used in this study. The frequency of tooth agenesis in the studied population was 4.8%. Male:female ratios varied from 2:1 in the agenesis of upper lateral incisors to 0.5:1 in premolar agenesis. The risk of infra-occlusion of primary molars and double formation of primary incisors was increased in individuals with tooth agenesis.

Prevalence of Abnormalities in Dental Structure, Position, and Eruption Pattern in a Population of Unilateral and Bilateral Cleft Lip and Palate Patients

Objective:

To evaluate the dental characteristics of patients subjected to a protocol that included early secondary gingivoalveoloplasty (ESGAP).

Design:

Panoramic radiographs of 87 patients with unilateral cleft lip and palate (UCLP) and 29 with bilateral cleft lip and palate (BCLP) were evaluated. Missing and supernumerary teeth were also quantified on the cleft and noncleft side and in the maxilla and mandible. Crown and root malformations and tooth rotations were quantified. A subsample in permanent dentition was extrapolated to analyze canine eruption patterns.

Results:

A total of 48.8% of the UCLP patients presented with missing permanent lateral incisors in the cleft area and 6.1% contralaterally. A total of 4.9% presented with missing second maxillary premolars on the cleft site and 1.2% contralaterally. A total of 7.3% presented with supernumerary lateral incisors, and 45% of the BCLP cleft sites presented with missing lateral incisors, while 25% of the cleft sites presented second maxillary premolars agenesis. Five percent of the cleft sites presented with supernumerary lateral incisors. Evaluation of the subsample in permanent dentition showed that 15.5% had a canine retention and 4.4% of the canines had to be surgically exposed. A significant association was observed between canine inclination and retention but not with absence of the lateral incisor.

Conclusions:

The frequency of dental anomalies in this sample was similar to other cleft populations. As surgical trauma has been suggested to damage forming teeth, the results of this study indicated that ESGAP has no detrimental influence on subsequent dental development.

Dental arches in submucous cleft palate: comparison of six-year-old boys with unoperated submucous cleft palate, with operated cleft of the soft palate, and without a cleft

OBJECTIVE

To evaluate the dental arch dimensions in 6-year-old boys with unoperated submucous cleft palate (SMCP), and to compare their dental arch dimensions with those of boys without clefts and boys with clefts of the soft palate (CP).

MATERIAL AND METHODS

The sizes of dental arches in 97 boys were compared retrospectively from dental casts taken at a mean age of 6.4 years (range 5.2-8.4). The material included 34 boys without clefts, 30 with unoperated SMCP, and 33 with CP. In children with CP, palatal closure had been done by the pushback technique at a mean age of 1.5 years.

RESULTS

The dental arch dimensions of the boys with SMCP were similar to those of boys without clefts, except for a decreased maxillary arch length. There was no difference in maxillary arch length between the boys with SMCP and those with CP. The boys with CP had smaller maxillary and mandibular dental arch widths than the boys without clefts and with SMCP. There were no differences in the number of boys with permanent incisors between the three groups.

CONCLUSION

Six-year-old boys with unoperated SMCP have similar dental arch dimensions as boys without clefts, except for a decreased maxillary arch length.

Interferon regulatory factor 6 (IRF6) and fibroblast growth factor receptor 1 (FGFR1) contribute to human tooth agenesis

Phenotypic characteristics expressed in syndromes give clues to the factors involved in the cause of isolated forms of the same defects. We investigated two genes responsible for craniofacial syndromes, FGFR1 and IRF6, in a collection of families with isolated tooth agenesis. Cheek swab samples were obtained for DNA analysis from 116 case/parent trios. Probands had at least one developmentally missing tooth, excluding third molars. In addition, we studied 89 cases and 50 controls from Ohio to replicate any positive findings. Genotyping was performed by kinetic polymerase chain-reaction or TaqMan assays. Linkage disequilibrium analysis and transmission distortion of the marker alleles were performed. The same variants in the IRF6 gene that are associated with isolated orofacial clefts are also associated with human tooth agenesis (rs861019, P = 0.058; rs17015215-V274I, P = 0.0006; rs7802, P = 0.004). Mutations in IRF6 cause Van der Woude and popliteal pterygium syndromes. The craniofacial phenotypic characteristics of these syndromes include oral clefts and preferential tooth agenesis of incisors and premolars, besides pits on the lower lips. Also it appears that preferential premolar agenesis is associated with FGFR1 (P = 0.014) and IRF6 (P = 0.002) markers. There were statistically significant data suggesting that IRF6 interacts not only with MSX1 (P = 0.001), but also with TGFA (P = 0.03).

Mandibular morphology and growth with and without hypodontia in subjects with Pierre Robin sequence

INTRODUCTION

Mandibular micrognathia is the hallmark of Pierre Robin sequence (PRS). A high prevalence of mandibular hypodontia has been reported in subjects with PRS. The hypothesis of this study is that the morphology of the mandible in subjects with PRS and mandibular hypodontia is different from that in subjects with PRS but without mandibular hypodontia.

METHODS

The study was conducted at the craniofacial center of The Hospital for Sick Children in Toronto. The study sample comprised 16 caucasian children with nonsyndromic PRS (7 boys, 9 girls) with mandibular hypodontia and 18 white children with nonsyndromic PRS (6 boys, 12 girls) without hypodontia. Longitudinal lateral cephalograms were available before orthodontic treatment (T1; mean age, 11.7 years) and after orthodontic treatment but before orthognathic surgery (T2; mean age, 16.6 years). A new, customized cephalometric analysis with additional landmarks and measurements to study mandibular morphology was performed. Differences in measurements were studied by using analysis of variance adjusted for age and sex.

RESULTS

Cephalometric measurements were smaller in the group with mandibular hypodontia at T1: mandibular length (3.36 mm, P = .04), ramal length (2.78 mm, P = .04), posterior facial height (3.97 mm, P = .03), and mandibular molar eruption (1.96 mm, P = .02). At T2, the differences increased: mandibular length (4.56 mm, P = .02), ramal length (4.04 mm, P = .002), posterior facial height (5.98 mm, P = .001), and mandibular molar eruption (2.08 mm, P = .04). Comparison of growth increments between the 2 groups from T1 to T2 showed a greater cranial base deflection increment in the group with mandibular hypodontia (0.88 degrees, P = .02) and a larger posterior facial height increment in the group without mandibular hypodontia (2.02 mm, P = .04).

CONCLUSIONS

Children with nonsyndromic PRS with mandibular hypodontia had smaller mandibles than children with nonsyndromic PRS and normal complements of mandibular teeth. Their patterns of growth did not improve during adolescence, and the magnitude of differences increased.

Genetic association studies of cleft lip and/or palate with hypodontia outside the cleft region

OBJECTIVE

The purpose of this study was to determine whether the candidate genes previously studied in subjects with cleft lip, cleft palate, or both are associated with hypodontia outside the region of the cleft.

SUBJECTS

One hundred twenty subjects from the Iowa Craniofacial Anomalies Research Center were selected based on the availability of both dental records and genotype information.

METHOD

The type of orofacial clefting and type and location of dental anomalies (missing teeth, supernumerary teeth, or peg laterals) were assessed by dental chart review and radiographic examination. Genotype analysis of candidate genes was performed using polymerase chain reaction/single-strand conformation polymorphism analysis.

RESULTS

The prevalence of hypodontia in this sample was 47.5%, with 30.0% of subjects having missing teeth outside the cleft. There was a positive association between subjects with cleft lip or cleft lip and palate who had hypodontia outside the cleft region (compared with noncleft controls) and both muscle segment homeo box homolog 1 (MSX1) (p =.029) and transforming growth factor beta 3 (TGFB3) (p =.024). It was not possible in this analysis to determine whether this association was specifically associated with orofacial clefting combined with hypodontia or whether it was due primarily to the clefting phenotype.

CONCLUSIONS

In this sample, there was a significantly greater incidence of hypodontia outside the cleft region in subjects with cleft lip and palate, compared with cleft lip only or cleft palate only. Cleft lip and/or palate with hypodontia outside the cleft region was positively associated with both TGFB3 and MSX1, compared with noncleft controls.

Oral clefts and syndromic forms of tooth agenesis as models for genetics of isolated tooth agenesis

Genetic defects responsible for tooth agenesis are only now beginning to be uncovered. MSX1 and PAX9 have been associated with tooth agenesis in mice and humans, but interestingly for humans, these genes are associated with specific missing teeth. Mouse models also show that specific genes contribute to the development of specific types of teeth. A precise description of the phenotype specifying which teeth are missing has become fundamental. Mendelian segregation can be identified in families with tooth agenesis, but heterogenous or multiple genes may be responsible for the development of specific types of teeth agenesis in humans. Data from animal models are still very complex, and the human embryology is still poorly understood. Oral clefts and syndromic forms of tooth agenesis may be the best models for isolated tooth agenesis. In the future, a precise description of the missing teeth in syndromes involving tooth agenesis may be useful.

Maxillofacial pathology and management of Pierre Robin sequence

Pierre Robin sequence affects 1:8500 newborns and is characterized by cleft palate, micrognathia, and airway obstruction. Evolution in the understanding of the causes and pathogenesis of this condition is reviewed. Clinical findings and treatment options are also addressed. An overview of syndromes commonly associated with Pierre Robin sequence is provided.