Classification, recording, and cleft palate surgery at the Uppsala Cleft Palate Centre

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.

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.

Outcomes of Cleft Palate Repair in Patients with Pierre Robin Sequence: A Matched Case-Control Study

BACKGROUND

Pierre Robin sequence results from a cascade of events that occur during embryologic development and frequently presents with cleft palate. Some studies have shown speech outcomes to be worse in patients with Pierre Robin sequence after cleft palate repair.

METHODS

A cohort of Pierre Robin sequence patients who all required an airway intervention and nasogastric feeding in the neonatal period were identified and speech outcomes assessed at 5 years of age. A cleft- and sex-matched non-Pierre Robin sequence, cleft palate-only comparison group was also identified from the same institution and study period.

RESULTS

A total of 24 patients with Pierre Robin sequence that required airway and nutritional support in the neonatal period were matched for age, sex, and cleft type to a group of 24 non-Pierre Robin sequence cleft patients. There was no significant difference in the incidence of oronasal fistula between the groups. Secondary surgery for velopharyngeal incompetence was significantly more (p = 0.017) in the Pierre Robin sequence group, who also had significantly greater nasality (p = 0.031) and cleft speech characteristic (p = 0.023) scores.

CONCLUSIONS

The authors hypothesize that other factors may exist in Pierre Robin sequence that may lead to poor speech outcomes. The authors would suggest counseling parents of children with Pierre Robin sequence that have required a neonatal airway intervention, that speech development may be poorer than in other children with cleft palate, and that these children will have a significantly higher incidence of secondary speech surgery.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

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.

Left-sided predominance of hypodontia irrespective of cleft sidedness in a French population

OBJECTIVE

Individuals with oral clefts exhibit considerably more dental anomalies than do individuals without clefts. Our aim was to evaluate the prevalence of tooth agenesis in a sample composed of 124 children (81 boys and 43 girls, mean age 12.5 years) with clefts registered with the Cleft Palate Center in Strasbourg (France).

DESIGN

Cleft types and dental agenesis were assessed by clinical and radiographic examination. Cleft types were divided into four groups according to the clinical extent of the cleft (cleft lip only [CL, 12.9%], cleft lip and alveolus [CLA, 4%], cleft lip and palate [CLP, 49.2%], and cleft palate only [CP, 33.9%]).

RESULTS

Of the subjects 63% had evidence of hypodontia: maxillary lateral incisors (54%) and upper and lower premolars (32%) were the most common missing teeth. The number of dental ageneses associated with CP (54%) and CLP (79%) was significantly higher than that with CL (33%). All these anomalies were found in proportionately higher frequencies as the severity of the cleft increased, and we found left side predominance for hypodontia (p < .01) irrespective of cleft sidedness.

CONCLUSIONS

Both right-sided and left-sided clefts were more frequently correlated with left-sided dental agenesis. This left-sided prevalence suggests that common signaling malfunctions might be involved, both in dental development anomalies and cleft genesis.

Length of the cleft in relation to the incidence of hypodontia of the second premolar and to inheritance of cleft lip and palate in children with isolated cleft palate

We studied severity of the isolated cleft palate expressed as the length of the cleft in relation to hypodontia in the second premolar regions and known inheritance of any type of cleft lip and palate. The material consisted of 47 children at 10 years of age born with non-syndromic isolated cleft palate of varying extent, who all had hypodontia of at least one second premolar, and had panoramic radiographs taken at 10 years of age. Information about length of cleft and inheritance of cleft lip and palate was collected from surgical files initiated at birth. The higher the number of missing second premolars, the more extended was the length of the cleft. More children had hypodontia of the second premolar in the mandible than in the maxilla. The family history had little influence on the length of the cleft.

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).

Altered mandibular development precedes the time of palate closure in mice homozygous for disproportionate micromelia: an oral clefting model supporting the Pierre-Robin sequence

BACKGROUND

Development of the human craniofacial anatomy involves a number of interrelated, genetically controlled components. The complexity of the interactions between these components suggests that interference with the spaciotemporal interaction of the expanding tongue and elongating Meckel's cartilage correlates with the appearance of cleft palate. Mice homozygous for the semi-dominant Col2a1 mutation Disproportionate micromelia (Dmm), presenting at birth with both cleft palate and micrognathia, provide the opportunity to test the hypothesis that mandibular growth retardation coincides with formation of the secondary palate as predicted from our understanding of the Pierre Robin sequence. The present study was conducted in embryonic day 14 (E14) mice, 1 day before palate closure, to describe the relationship between growth of the lower jaw/tongue complex versus genotype of the embryo.

METHODS

Whole heads, isolated from E14.25, E14.5 and E14.75 wild-type and homozygous mutant embryos, were fixed in Bouin's solution, embedded in paraffin, and serially sectioned. Mid-sagittal sections, stained with toluidine blue, were used to estimate growth of both tongue and lower jaw (Meckel's cartilage length) during a 12-hr period preceding palate closure.

RESULTS

In control embryos, the largest increase in Meckel's cartilage length occurred between E14.5 and E14.75. Compared to control, the mean Meckel's cartilage length in the mutant was similar at E14.25, but was significantly less at E14.5 and E14.75. Absolute tongue size in control embryos increased linearly during this period of E14.25 to E14.75. Relative to the rapidly growing Meckel's cartilage, however, relative tongue size in control embryos actually decreased over time. Absolute tongue size in the mutant was not significantly different from that of control at any of the embryonic stages examined, however, relative tongue size in the mutant was significantly greater at E14.75 compared to control.

CONCLUSION

Mandibular growth retardation, coupled with relative macroglossia in E14 Dmm/Dmm mice, suggests that the concerted development of the palate and lower jaw complex in the mutant is aberrant. Detection of micrognathia and pseudomacroglossia in homozygotes, before the time of palate closure, supports the hypothesis that a relationship exists between growth retardation of Meckel's cartilage and malformation of the secondary palate, as predicted by the Pierre-Robin sequence.