Prevalence and patterns of permanent tooth agenesis in patients with nonsyndromic Pierre Robin sequence

Patterns and sexual dimorphism of non-syndromic hypodontia among a French orthodontic population

OBJECTIVES

This retrospective study aimed to estimate the prevalence of non-syndromic congenitally missing teeth (CMT) and to explore the frequency of CMT patterns in a French orthodontic population. In addition, the study sought to assess sex-based differences in CMT patterns.

DESIGN

Panoramic radiographs of 4569 orthodontic patients between 9 and 21 years-old performed over a 16-year period (2006-2022) were examined to identify non-syndromic tooth agenesis, excluding third molars. A chi-square test or a Fisher exact test were used to determine the difference in the prevalence of tooth agenesis between sex and between arches.

RESULTS

Tooth agenesis was observed in 7.3% of the sample (7.9% for females and 6.6% for males). Approximately 86% of the included subjects presented 1 or 2 missing teeth. Single tooth agenesis was significantly more frequent in females than males (p = 0.002, χ2). In total, 23 of the 67 different patterns of CMT observed, were present more than once. 75.5% of male patients and 79.5% of female patients presented one or both missing lateral incisors or second premolars, rarely affected at the same time. This study showed no sex difference in the patterns of tooth agenesis.

LIMITATIONS

This study has limitations due to its retrospective nature and our findings apply solely to an orthodontic population from a white ethnic background.

CONCLUSIONS

Clinicians should be aware of this particular incisor/premolar phenotype regardless of biological sex. Issues associated with congenitally missing teeth can be managed more effectively with early teenage diagnosis.

Comprehensive Long-Term Outcomes Following Mandibular Distraction Osteogenesis

OBJECTIVE

To describe long-term outcomes and complications following mandibular distraction osteogenesis (MDO) in a diverse patient cohort.

DESIGN

Cross-sectional study.

SETTING

Single tertiary-care pediatric center.

PATIENTS

Forty-eight patients previously undergoing MDO with minimum 4-year follow-up.

MAIN OUTCOME MEASURES

Respiratory outcomes, feeding patterns, dental development, motor/sensory nerve function, temporo-mandibular joint function, and postsurgical scarring.

RESULTS

Forty-six patients with a median age of 7 years were evaluated. Of 20 nonsyndromic patients, none required additional airway procedures, none required continuous positive airway pressure (CPAP) during sleep, and 19 (95%) fed exclusively by mouth. Among 26 syndromic patients, 7 (27%) required CPAP and 8 (31%) were tube fed. Permanent first molar differences were seen in the majority of subjects; patterns of damage interfering with function were more common in syndromic (13/28, 46%) compared to nonsyndromic (5/24, 21%; P = .014) subjects. MDO prior to age two was associated with more frequent and worse dental damage (P = .001). Inferior alveolar nerve and marginal mandibular nerve function were fully intact in 37 (80%) and 39 (85%) of patients, respectively. Three patients (6%), all with associated genetic syndromes, demonstrated severe nerve impairment. By the Vancouver scar scale, ≥ 80% of surgical scars were rated in the most favorable category for each quality assessed. Temporomandibular joint dysfunction was rare.

CONCLUSIONS

MDO shows highly favorable long-term respiratory, feeding, nerve, and scar outcomes in nonsyndromic patients, although permanent molar changes not precluding tooth viability are commonly seen. Patients with associated syndromes demonstrate respiratory and feeding benefits, but higher rates of dental and nerve abnormalities.

Rare and Multiple Hypodontia in Van der Woude Syndrome: Case Report

Van der Woude syndrome (VWS) is a rare syndrome of genetic etiology, commonly occasioned by mutations in the IRF6 gene and that causes disorders in craniofacial development. VWS is characterized by the presence of paramedian fistulas in the lower lip and cleft lip and / or cleft palate. Although some dental phenotypes have been reported in this syndrome, multiple and rare hypodontias were not described. Through this case report, we present a case of Van der Woude Syndrome (VWS) with rare and multiple hypodontia in which clinical data and radiographic exams were evaluated. The patient presented hypodontia of eight permanent teeth (lateral incisors, second premolars and second molars). So, when the dentist recognizes multiple and/or rare hypodontias, for an accurate diagnosis, detailed examination of the lower lip is indicated, as well as a survey of the family history and referral for genetic counseling, since the syndrome presents high penetrance. The patient is expected to be rehabilitated to have a good quality of life. Rehabilitation in these cases requires alveolar bone graft, orthodontics and prosthesis to replace missing teeth.

Tooth Agenesis Patterns in Orofacial Clefting Using Tooth Agenesis Code: A Meta-Analysis

Individuals with orofacial clefting (OFC) have a higher prevalence of tooth agenesis (TA) overall. Neither the precise etiology of TA, nor whether TA occurs in patterns that differ by gender or cleft type is yet known. This meta-analysis aims to identify the spectrum of tooth agenesis patterns in subjects with non-syndromic OFC and controls using the Tooth Agenesis Code (TAC) program. An indexed search of databases (PubMed, EMBASE, and CINAHL) along with cross-referencing and hand searches were completed from May to June 2019 and re-run in February 2022. Additionally, unpublished TAC data from 914 individuals with OFC and 932 controls were included. TAC pattern frequencies per study were analyzed using a random effects meta-analysis model. A thorough review of 45 records retrieved resulted in 4 articles meeting eligibility criteria, comprising 2182 subjects with OFC and 3171 controls. No TA (0.0.0.0) was seen in 51% of OFC cases and 97% of controls. TAC patterns 0.2.0.0, 2.0.0.0, and 2.2.0.0 indicating uni- or bi-lateral missing upper laterals, and 16.0.0.0 indicating missing upper right second premolar, were more common in subjects with OFC. Subjects with OFC have unique TA patterns and defining these patterns will help increase our understanding of the complex etiology underlying TA.

Tooth agenesis in German orthodontic patients with non-syndromic craniofacial disorder: a retrospective evaluation of panoramic radiographs

Objectives

The study objective was to evaluate the tooth agenesis in German orthodontic patients with non-syndromic cleft lip and/or palate and Robin sequence compared to a control group without craniofacial disorder.

Materials/methods

A total of 108 panoramic radiographs were examined using the binary system of Tooth Agenesis Code (TAC) (excluding the third molar). Patients were divided into the craniofacial disorder group 1 (n = 43) and the healthy control group 2 (n = 65). Parameters such as skeletal class malformation, sex, localization of the cleft, craniofacial disorder, and interobserver reliability were assessed.

Results

Permanent tooth agenesis was observed in 44% of group 1 and 14% in group 2 with a statistically significant higher prevalence (p = 0.00162 (χ²)). Fourteen different TAC patterns were observed in group 1, ten of these occurring only once in separate patients. The distribution of the TAC codes in group 2 showed nine different possibilities of TAC code patterns; seven TACs were unique. In group 1, the most frequently absent teeth were the maxillary lateral incisor of the left side (30%); in group 2, the second premolar of the lower jaw on the right side (9%). Male patients with craniofacial disorder showed a higher percentage of tooth agenesis than female.

Conclusion

The data presented here shows a statistically significant higher prevalence of tooth agenesis in German patients with non-syndromic craniofacial disorder.

Clinical relevance

Radiographic evaluation enables the diagnosis of tooth agenesis. Recognizing early on the higher prevalence of tooth agenesis in patients exhibiting a craniofacial disorder is an important issue when developing long-term and comprehensive interdisciplinary treatment.

Dental anomalies in non-syndromic orofacial clefts: a clinical approach

Orofacial clefts (OC) represent some of the most common congenital malformations and affect multiple structures in the craniofacial region. There are a wide range of morphological OC types within the spectrum of both non-syndromic OC (NSOC) and syndromic OC, including cleft lip (CL); cleft lip and palate (CLP) and cleft palate (CP). Here, we describe the most frequent dental anomalies seen in the permanent dentition of individuals with NSOC, comparing them between the three main cleft types (CL, CLP, CP). We present these findings from the perspective of prevalence relating to each anomaly, as well as the clinical characteristics and potential impact in the rehabilitation process. The investigation of dental anomalies associated with NSOC is important, helping to expand the phenotypic characterization of NSOC, improve initial diagnostics and establish appropriate rehabilitation and counseling.

A Retrospective Longitudinal Treatment Review of Multidisciplinary Interventions in Nonsyndromic Robin Sequence With Cleft Palate

Objective:

To document and analyze the overall longitudinal institutional treatment experience of children with nonsyndromic Robin sequence (RS) from infancy to early adulthood.

Design:

Retrospective longitudinal treatment review.

Setting:

A tertiary-care, referral, teaching hospital.

Patients:

Children with nonsyndromic RS and cleft palate (N = 117) born between December, 1985, and January, 2012.

Interventions:

Data regarding airway management, nutritional management, audiological interventions, orthodontic treatment, and surgical interventions were documented and analyzed in different growth/developmental stages. Comparative data from other international centers were collected from the literature.

Results:

Airway management during infancy involved prone positioning (92%), nasopharyngeal airway (6%), tracheostomy (2%), and mandibular distraction osteogenesis (1%). Feeding with nasogastric, gastrostomy, and/or gastrojejunostomy tubes was used in 44%, Haberman feeders in 53%, and Mead Johnson feeders in 3%. Gastroesophageal reflux disease was documented in 6% of the sample. During childhood and early adolescent years, pharyngeal flap surgery was carried out in 22% of the children, while 11% had secondary palatal surgery. Audiological management included the use of tympanostomy tubes in 62%, with several children needing multiple tube replacements. At least 18% were diagnosed with obstructive sleep apnea. Adenoidectomy or adenotonsillectomy was undertaken in 4%. Analysis of data pertaining to middle childhood and adolescent years showed that orthodontic treatment was conducted for most children for crowding, tooth agenesis, and skeletal and/or dental dysplasia. Orthognathic surgery frequency (<18%) was low.

Conclusions:

Institutional treatment experience of children with nonsyndromic RS involves multidisciplinary care at different ages and stages of their development.

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.

Association between agenesis and root morphology of anterior teeth

Abstract Introduction Tooth agenesis is likely to affect the root teeth and should be considerated in orthodontic tratament. Objective The aim of this study was to assess the association between agenesis and root morphology of anterior teeth. Material and method The anterior teeth of 51 individuals were evaluated on 102 periapical radiographs and then divided into three groups: Group 1 (n=16) – no tooth agenesis; Group 2 (n=17) – only third molar agenesis; and Group 3 (n=18) – tooth agenesis of premolars or lateral incisors. Root morphology of anterior teeth was evaluated and the roots were classified as short, blunt, apically bent, and pipette-shaped. Fisher’s exact test was used to compare root shapes, the chi-square test was used to obtain the distribution of sexes between the groups, and ANOVA was performed to compare the ages between the groups. The significance level was set at 5% for all analyses. Result There was significant difference in root shapes (P<0.05) between the groups. Blunt roots were the most prevalent in all groups, but their rate was higher in Group 3 (83%). Conclusion There was association between agenesis and root morphology of anterior teeth.

Novel dental phenotype in non-syndromic Pierre Robin Sequence: A retrospective study

OBJECTIVE

The objective was to investigate dental phenotypes in individuals with non-syndromic Pierre Robin Sequence (ns-PRS) and compare the prevalence of these phenotypes with subjects with non-syndromic cleft palate (ns-CP) and a control group with subjects without any craniofacial anomalies.

METHODS

A total of 760 panoramic radiographs of 330 individuals (110 with ns-PRS; 110 with ns-CP and 110 without any malformations) were digitized and evaluated regarding the diagnosis of taurodontism, tooth agenesis, root dilaceration and tooth transposition. Chi-square test was applied to compare the occurrence of dental phenotypes between groups. A P value of less than 0.05 was considered statistically significant.

RESULTS

Total prevalence of dental phenotypes was 94.5% of ns-PRS; 54.5% of ns-CP and 59.1% of the control group subjects with a statistically significant difference for the ns-PRS when compared to the other two groups. Two dental phenotypes, taurodontism and dental agenesis were identified with statistically significant higher prevalences in subjects with ns-PRS when compared with the ns-CP group and the control group (p < 0.001). Taurodontism was the most prevalent dental phenotype, with 92.73% in the ns-PRS group, 40.91% for ns-CP and 44.55% in the control group. Tooth agenesis had a prevalence of 22.7% for ns-PRS, 4.5% for ns-CP and no case in the control group. For the prevalence of root dilaceration and tooth transposition, no statistically significant differences were observed between the three groups.

CONCLUSIONS

Due to the high frequency of taurodontism in individuals with ns-PRS, we suggested that this novel phenotype would be important in the phenotypic screening of ns-PRS and could be considered as a phenotype associated with ns-PRS.

Prevalence of Hypodontia in a Sample of Spanish Dental Patients

Objectives

The aim of this retrospective study was to evaluate the prevalence of hypodontia in a sample of dental patients, aged between seven and eleven years at University Alfonso X in Madrid (Spain).

Materials and Methods

The number of hypodontia cases and the most affected teeth were evaluated in 2500 panoramic radiographs in a random sample of dental patients consisting of 1235 females and 1265 males. We divided them according to age, number of hypodontia present in each patient (multiple or single), each side, each quadrant either in the upper jaw or in the mandible. The chi-square test (P <0.05) was used to compare the differences in agenesis among males and females.

Results

The sample of 2500 patients who were studied consisted of 1235 women, out of which 41 presented hypodontia (3.31%) and 1265 men, out of which 46 had at least a dental absence (3.63%). There was no significant difference in the proportion of hypodontia between men and women (p> 0.05).

Conclusion

The percentage of total agenesis of 2500 patients studied was 3.48%.

The ontogeny of Robin sequence

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms.

Update on 13 Syndromes Affecting Craniofacial and Dental Structures

Care of individuals with syndromes affecting craniofacial and dental structures are mostly treated by an interdisciplinary team from early childhood on. In addition to medical and dental specialists that have a vivid interest in these syndromes and for whom these syndromes are of evident interest, experts of scientific background-like molecular and developmental geneticists, but also computational biologists and bioinformaticians-, become more frequently involved in the refined diagnostic and etiological processes of these patients. Early diagnosis is often crucial for the effective treatment of functional and developmental aspects. However, not all syndromes can be clinically identified early, especially in cases of absence of known family history. Moreover, the treatment of these patients is often complicated because of insufficient medical knowledge, and because of the dental and craniofacial developmental variations. The role of the team is crucial for the prevention, proper function, and craniofacial development which is often combined with orthognathic surgery. Although the existing literature does not provide considerable insight into this topic, this descriptive review aims to provide tools for the interdisciplinary team by giving an update on the genetics and general features, and the oral and craniofacial manifestations for early diagnosis. Clinical phenotyping together with genetic data and pathway information will ultimately pave the way for preventive strategies and therapeutic options in the future. This will improve the prognosis for better functional and aesthetic outcome for these patients and lead to a better quality of life, not only for the patients themselves but also for their families. The aim of this review is to promote interdisciplinary interaction and mutual understanding among all specialists involved in the diagnosis and therapeutic guidance of patients with these syndromal conditions in order to provide optimal personalized care in an integrated approach.

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.

Patterns of non-syndromic permanent tooth agenesis in a large orthodontic population

OBJECTIVE

The aim of this study is to explore patterns of non-syndromic permanent tooth agenesis in a large orthodontic patient group.

DESIGN

A record review was performed in various orthodontic clinics to identify white patients with non-syndromic permanent tooth agenesis, excluding 3rd molars. Four hundred and fourteen subjects fulfilled the inclusion criteria.

RESULTS

In the 414 subjects with tooth agenesis, approximately 70% presented 1-2 missing teeth. Symmetric agenesis patterns were often observed in the sample (by jaw, by side, or crossed quadrants), with prevalence approaching 30% for cases with contralateral tooth agenesis within a jaw. In cases with 1 or 2 missing teeth, from the total number of potential tooth agenesis patterns in the sample, a certain part was evident, limiting the variation to 27.8% (44/158). In the entire sample, both in the maxilla and the mandible a certain incisor/premolar agenesis phenotype was observed in 59.0% of cases in isolated form.

CONCLUSIONS

Although there was variation in the tooth agenesis patterns, our findings suggest the involvement of particular genetic, epigenetic, and/or environmental factors in the formation of the entire dentition, which often lead to specific tooth agenesis phenotypes in cases where this process is disrupted. The present study provides a comprehensive categorization of orthodontic cases with tooth agenesis and can assist in planning future epidemiological and genetic studies.

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.

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.

Pierre Robin sequence: review of diagnostic and treatment challenges

Pierre Robin sequence is not a rare condition and paediatric specialists caring for respiratory related issues are likely to encounter cases in their practice. There have been a few recent reviews on the topic, mostly focusing on the surgical interventions performed for cases with severe airway obstruction. In the present review, we will highlight the different challenges that remain today in the global evaluation of infants afflicted with this condition through a thorough review of the medical literature, giving the clinician a full scope of the disease and of the various management options. The need for an improved objective evaluation of airway obstruction and for a better classification will be emphasized. We are therefore proposing a novel classification scheme that will better account for respiratory and feeding difficulties in these infants. Finally, many knowledge gaps persist regarding this condition, underlining the necessity for further research both in the genetic field and regarding the outcome of therapy.