Characterization of dental phenotype in patients with cleidocranial dysplasia using longitudinal data

Genotype-phenotype analysis of selective failure of tooth eruption-A systematic review

Tooth eruption is an important and unique biological process during craniofacial development. Both the genetic and environmental factors can interfere with this process. Here we aimed to find the failure pattern of tooth eruption among five genetic diseases. Both systematic review and meta-analysis were used to identify the genotype-phenotype associations of unerupted teeth. The meta-analysis was based on the characteristics of abnormal tooth eruption in 223 patients with the mutations in PTH1R, RUNX2, COL1A1/2, CLCN7, and FAM20A respectively. We found all the patients presented selective failure of tooth eruption (SFTE). Primary failure of eruption patients with PTH1R mutations showed primary or isolated SFTE1 in the first and second molars (59.3% and 52% respectively). RUNX2 related cleidocranial dysplasia usually had SFTE2 in canines and premolars, while COL1A1/2 related osteogenesis imperfecta mostly caused SFTE3 in the maxillary second molars (22.9%). In CLCN7 related osteopetrosis, the second molars and mandibular first molars were the most affected. While FAM20A related enamel renal syndrome most caused SFTE5 in the second molars (86.2%) and maxillary canines. In conclusion, the SFTE was the common characteristics of most genetic diseases with abnormal isolated or syndromic tooth eruption. The selective pattern of unerupted teeth was gene-dependent. Here we recommend SFTE to classify those genetic unerupted teeth and guide for precise molecular diagnosis and treatment.

Detection and diagnosis of cleidocranial dysplasia by panoramic radiography: a retrospective study

BACKGROUND

Cleidocranial dysplasia (CCD) is a rare and underdiagnosed congenital disorder in dentistry. The purpose of this study was to illustrate and quantify the maxillofacial bone abnormalities detected on panoramic radiographs from a relatively large retrospective case series and to provide a series of diagnostic references for dentists to indicate the presence of disease and help in making an early and accurate diagnosis.

METHODS

The dental panoramic radiographs of thirty CCD patients aged 11 to 45 years (18 males and 12 females) were examined retrospectively. The dentition states, including supernumerary teeth and impacted teeth, were recorded. Twelve quantified measurements were adopted to determine the abnormalities of maxillofacial bones, including the degree of the zygomatic arch downward bend, bicondylar breadth, ramal height, mandibular height, mandibular aspect ratio, mandibular body height, condylar height, coronoid height, distance between the coronoid process and the condyle, bigonial width, gonial angle and best-fit gonial circle diameter. The Wilcoxon rank-sum test was used to compare the findings of the CCD patients with those of their matched controls (n = 300).

RESULTS

Supernumerary teeth were detected in 27 patients (90.0%), and all 30 patients presented impacted teeth. Compared to the matched controls, the CCD patients had a significantly larger degree of zygomatic arch downward bend (ZAD), a larger diameter of the best-fit gonial circle (BGC), and a shorter distance between the coronoid process and the condyle (DCC) in panoramic radiographs (P < 0.001). According to the reference cutoff values established from the 5th or 95th percentile of the measurements in the control group, ZAD higher than 6.90 mm, DDC less than 22.37 mm and BGC higher than 52.41 mm were significantly associated with the CCD features identified. Other panoramic measurements were not significantly different between the two groups.

CONCLUSIONS

Panoramic radiographs had great value in the diagnosis of CCD. In this study, we identified some dental and maxillofacial features on panoramic radiographs from a relatively large retrospective case series of CCD. A series of reliable quantitative indicators were provided for dentists that can indicate the presence of disease and improve the diagnostic specificity.

An overview of the intraoral features and craniofacial morphology of growing and adult Japanese cleidocranial dysplasia subjects

BACKGROUND

Orthodontic treatment for cleidocranial dysplasia (CCD) requires an understanding of the nature of the retained deciduous teeth, supernumerary teeth, delayed eruption of the permanent teeth, and craniofacial morphology from childhood to adulthood. This study aimed to provide an overview of the intraoral and craniofacial characteristics of growing and adult Japanese CCD subjects.

METHODS

We assessed cross-sectionally the intraoral features of 28 CCD subjects (males, 15.3 ± 7.0 years; females, 15.2 ± 5.1 years) using orthopantomograms and photographs. Mean facial diagrams (profilograms) of 3 age groups (5-10 years, 11-14 years, over 15 years: adult) were constructed, and linear and angular measurements of 2 age groups (under 15 years, adult) were performed by using cephalograms. The data were compared with Japanese standards.

RESULTS

A mean of 11.7 and 8.4 retained deciduous teeth, 10.4 and 15.8 erupted permanent teeth were observed in the adult males and females, and a mean of 6.8 and 5.3 supernumerary teeth were observed in all males and females, respectively. A positive correlation was found between the number of supernumerary teeth and the age at initial visit. Cephalometric analysis showed an average to anteriorly positioned maxilla, a tendency for counter-clockwise rotation of the ramus, and a prognathic mandible in all groups.

CONCLUSIONS

The number of supernumerary teeth increased with age. The maxilla was average to anteriorly positioned, and the mandible was counter-clockwise rotated and prognathic for all groups. These characteristic craniofacial morphologies and changes of intraoral conditions at different ages in CCD patients should be considered when proposing rational orthodontic treatment plans.

Supernumerary teeth of permanent dentition in patients with neurofibromatosis type 1

PURPOSE

The purpose of the study was the investigation of supernumerary teeth (ST) in the permanent dentition of patients with neurofibromatosis type 1 (NF1).

MATERIAL AND METHODS

The panoramic radiographs of 200 NF1 patients were analysed for ST. The potential impact of certain neurogenic facial tumours on the measured variable was investigated separately. The results were compared to dental findings in panoramic radiographs of 200 age- and sex-matched controls.

RESULTS

The total number of ST in all individuals was 23 in 12 patients (3% of total population). However, all ST had developed in the group of NF1 patients (6%), (p = 0.0004). ST were particularly common distal to the molar region. Although ST occur in the region of facial plexiform neurofibroma, the numerical aberrations of the dentition are independent of specific type of facial nerve sheath tumour.

CONCLUSION

The unusual accumulation of ST in the terminal sections of molar development could be an indicator of preferred points of developmental disorder, in which the genetic predisposition of the patient is involved. Reviewing the results of other NF1 patient collectives is desirable.