Characteristics of craniofacial morphology and factors affecting them in patients with isolated cleft palate.

BACKGROUND: Myriad maxillo-mandibular occlusal relationships are observed in patients with isolated cleft palate (ICP), unlike in patients with other cleft types, such as cleft lip and palate. OBJECTIVES: This study aimed to categorise the characteristics of craniofacial morphology in patients with ICP, and investigate the clinical factors affecting these categorised morphological characteristics. METHODS: Thirty-six girls with ICP (age (mean ± SD): 5.36 ± 0.36 years) underwent cephalometric measurement. Their craniofacial morphology was categorised using cluster analysis. Profilograms were created and superimposed onto the standard Japanese profilograms to visualise the morphological characteristics of each group (cluster). The mean values and variations in the linear and angular measurements of each group were compared with the Japanese standards and statistically analysed using Dunnett's test after the analysis of variance. Fisher's exact test was used to analyse the differences between the cleft types (cleft in the hard and/or soft palate) and skills of the operating surgeons in the groups. RESULTS: Cluster analysis of craniofacial morphologies in patients with ICP resulted in the formation of three categories: the first cluster exhibited a relatively harmonious anteroposterior relationship between the maxilla and the mandible (22.2%); the second cluster exhibited crossbite owing to a significantly smaller maxilla (33.3%); and the third cluster exhibited a smaller mandible with posterior rotation showing skeletal class II malocclusion (44.4%). Differences in cleft types and surgeons were not associated with the distribution of patients in each cluster. CONCLUSIONS: Patients with ICP exhibited characteristic morphological patterns, such as bimaxillary retrusion or severe mandibular retrusion, besides the anterior crossbite frequently found in patients with cleft lip and palate . Understanding the typical morphological characteristics could enable better diagnostic categorisation of patients with ICP, which may eventually improve orthodontic treatment planning.

Cleft-lip-plate patient with tracheobronchomalacia: A case report and review of the literature in Japan.

BACKGROUND: Tracheobronchomalacia (TBM) is a severe life-threatening perioperative complication. It is a rare condition caused by congenital and developmental anomalies of the trachea and/or the bronchus. It is often difficult to diagnose TBM before surgery as this congenital disease presents very few symptoms preoperatively and most often appears postoperatively. CASE PRESENTATION AND REVIEW: The study describes a case of cleft-lip-plate (CL/P) in a 7-month-old Japanese female with TBM and Tetralogy of Fallot syndrome. Before undergoing cleft-lip surgery, her TBM was not fully elucidated by preoperative examinations, and the operation was completed uneventfully. After the surgery, however, she started showing severe respiratory distress and developed hypoxia and bradycardia in the operating room. CPR was performed successfully, but a bronchoscopy revealed a severely collapsed airway, and the pathological condition was diagnosed as TBM occurred postoperatively. Eight months later, she died of sudden respiratory failure similar to that of the postoperative event caused by TBM. A literature review was conducted on the complications of CL/P from 1990 to 2017 in Japan. CONCLUSIONS: It was hypothesized that CL/P with congenital heart disease (CHD) and TBM with CHD may crossover in relatively high rates. Currently, there are very few solutions available to treat severe airway obstruction related to TBM. This highlights the need for preoperative diagnosis of TBM as an important step in overcoming severe airway complications.

Surface vacuolar ATPase in ameloblastoma contributes to tumor invasion of the jaw bone.

Ameloblastoma is the most common benign odontogenic tumor in Japan. It is believed that it expands in the jaw bone through peritumoral activation of osteoclasts by receptor activator of nuclear factor kappa-B ligand (RANKL) released from the ameloblastoma, as in bone metastases of cancer cells. However, the clinical features of ameloblastoma, including its growth rate and patterns of invasion, are quite different from those of bone metastasis of cancer cells, suggesting that different underlying mechanisms are involved. Therefore, in the present study, we examined the possible mechanisms underlying the invasive expansion of ameloblastoma in the jaw bone. Expression levels of RANKL assessed by western blotting were markedly lower in ameloblastoma (AM-1) cells than in highly metastatic oral squamous cell carcinoma (HSC-3) cells. Experiments coculturing mouse macrophages (RAW264.7) with AM-1 demonstrated low osteoclastogenic activity, as assessed by tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cell formation, probably because of low release of RANKL, whereas cocultures of RAW264.7 with HSC-3 cells exhibited very high osteoclastogenic activity. Thus, RANKL release from AM-1 appeared to be too low to generate osteoclasts. However, AM-1 cultured directly on calcium phosphate-coated plates formed resorption pits, and this was inhibited by application of bafilomycin A1. Furthermore, vacuolar-type H+-ATPase (V-ATPase) and H+/Cl- exchange transporter 7 (CLC-7) were detected on the surface of AM-1 cells by plasma membrane biotinylation and immunofluorescence analysis. Immunohistochemical analysis of clinical samples of ameloblastoma also showed plasma membrane-localized V-ATPase and CLC-7 in the epithelium of plexiform, follicular and basal cell types. The demineralization activity of AM-1 was only 1.7% of osteoclasts demineralization activity, and the growth rate was 20% of human normal skin keratinocytes and HSC-3 cells. These results suggest that the slow expansion of several typical types of ameloblastomas in jaw bone is attributable to its slow growth and low demineralization ability.

Upward Advancement of the Nasolabial Components at Unilateral Cleft Lip Repair Prevents Postoperative Long Lip.

OBJECTIVE: To prevent the occurrence of postoperative long lip, longitudinal postoperative changes in nasolabial forms of patients with unilateral cleft lip who underwent primary lip repair with or without upward advancement of the nasolabial components were compared. PATIENTS: Forty-three subjects (24 unilateral cleft lip and palate [UCLP] and 19 unilateral cleft lip solely, and cleft lip and alveolus [UCL/UCLA]) who underwent primary lip repair with upward advancement of the nasolabial components (NA group) and 30 subjects (16 UCLP and 14 UCL/UCLA) without upward advancement (LA group) were enrolled. OUTCOME MEASURES: Postoperative photos taken at 1 and 6 months and at 1, 2, and 3 years were used for measuring the heights of the nasal alar base (NBH), the columellar base (CBH), Cupid's peak (CPH), and the upper lip (ULH). The ratios of these measurements between the affected and unaffected sides were calculated in both groups. RESULTS: In the LA group, the 3-year postoperative all-items ratios of UCLP were significantly larger than those at 1 month postoperatively, demonstrating drooping of the nasolabial tissues in the affected side (all P < .01). Furthermore, the 3-year postoperative CPH and ULH ratio of UCL/UCLA was significantly larger than that at 1 month postoperatively, demonstrating the long lip (P < .01). In the NA group, the NBH, CBH, and CPH ratios of both UCLP and UCL/UCLA did not show significant differences between 1 month and 3 years postoperatively. CONCLUSION: Upward advancement of the nasolabial components prevents postoperative long lip.

Can occlusal evaluation of children with unilateral cleft lip and palate help determine future maxillofacial morphology?

Objective : To investigate the change in occlusal evaluations from the 5-year-olds' index to the Goslon Yardstick and to compare the relationship between the evaluations and maxillofacial growth in patients with complete unilateral cleft lip and palate (UCLP). Design : A prospective longitudinal study. Subjects : The sample consisted of 85 patients with complete UCLP who underwent surgery from 1969 to 1994 and were treated at the Kyushu University Hospital in Fukuoka, Japan. Subjects had two serial dental casts performed at the ages of 5 and 10 years. Furthermore, each patient had lateral cephalographs taken at the age of 5 years, 76 of 85 subjects had films taken at the age of 10 years, and 54 subjects also had lateral cephalograms taken after the age of 15 years. Methods : Every dental cast was evaluated by the 5-year-olds' index and the Goslon Yardstick, respectively. The lateral cephalographs were traced and digitized, and angular dimensions were calculated. Outcomes were compared using Spearman's rank-order correlation analysis and the Kruskal-Wallis analysis. Results and Conclusion : Dental arch relationships were evaluated and rated as 2.96 in the 5-year-olds' index and 2.85 in the Goslon Yardstick, respectively. Both groupings showed a significant relationship, and they showed no change in 36 out of 85 subjects (42.3%), significant improvement in 30 (35.3%), and deterioration in 19 (22.3%). Two occlusal groupings and maxillofacial morphology on the cephalographs indicated that the grouping reflected the anteroposterior position of the mandible. Moreover, both groupings showed some relation to previous maxillofacial growth, but they did not show any relationship with future growth. The Goslon Yardstick may not predict maxillofacial morphology in adulthood.

Fibroblast growth factors 7 and 10 are involved in ameloblastoma proliferation via the mitogen-activated protein kinase pathway.

Ameloblastoma is an epithelial benign tumor of the odontogenic apparatus and its growth mechanisms are not well understood. Fibroblast growth factor (FGF) 3, FGF7 and FGF10, which are expressed by the neural crest-derived ectomesenchymal cells, induce the proliferation of odontogenic epithelial cells during tooth development. Therefore, we examined the expression and function of these FGFs in ameloblastoma. We examined 32 cases of ameloblastoma as well as AM-1 cells (an ameloblastoma cell line) and studied the expression of FGF3, FGF7, FGF10 and their specific receptors, namely, FGF receptor (FGFR) 1 and FGFR2. Proliferation, mitogen-activated protein kinase (MAPK) signaling and PI3K signaling were examined in AM-1 cells after the addition of FGF7, FGF10 and these neutralizing antibodies. The expression of FGF7, FGF10, FGFR1 and FGFR2 was detected in ameloblastoma cells and AM-1 cells, while that of FGF3 was not. FGF7 and FGF10 stimulated AM-1 cell proliferation and phosphorylation of p44/42 MAPK. However, Akt was not phosphorylated. Blocking the p44/42 MAPK pathway by using a specific mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitor (U0126) completely neutralized the effects of FGF7 and FGF10 on AM-1 cell proliferation. However, Anti FGF7 and FGF10 neutralizing antibodies did not decrease cell proliferation and MAPK phosphorylation of AM-1 cells. These results suggested that FGF7 and FGF10 are involved in the proliferation of ameloblastoma cells through the MAPK pathway.

Anti-apoptotic role of the sonic hedgehog signaling pathway in the proliferation of ameloblastoma.

Sonic hedgehog (SHH) signaling pathway is crucial to growth and patterning during organogenesis. Aberrant activation of the SHH signaling pathway can result in tumor formation. We examined the expression of SHH signaling molecules and investigated the involvement of the SHH pathway in the proliferation of ameloblastoma, the most common benign tumor of the jaws. We used immunohistochemistry on ameloblastoma specimens and immunocytochemistry and reverse transcription-PCR on the ameloblastoma cell line AM-1. We also used the inhibitors of SHH signaling, SHH neutralizing antibody and cyclopamine, to assess the effects of SHH on the proliferation of AM-1 cells. We detected expression of SHH, patched, GLI1, GLI2 and GLI3 in the ameloblastoma specimens and AM-1 cells. The proliferation of these cells was significantly inhibited in the presence of SHH neutralizing antibody or cyclopamine; this was confirmed by BrdU incorporation assays. Furthermore, in the presence of SHH neutralizing antibody, nuclear translocation of GLI1 and GLI2 was abolished, apoptosis was induced, BCL-2 expression decreased and BAX expression increased. Our results suggest that the SHH signaling pathway is constitutively active in ameloblastoma and plays an anti-apoptotic role in the proliferation of ameloblastoma cells through autocrine loop stimulation.

Marsupialization for odontogenic keratocysts: long-term follow-up analysis of the effects and changes in growth characteristics.

OBJECTIVE: This study evaluated the effects of marsupialization on odontogenic keratocysts (OKCs) and its role in conjunction with enucleation and curettage. STUDY DESIGN: Twenty-eight primary OKCs, treated by marsupialization before enucleation and curettage, were examined in this study. The effect of marsupialization and recurrence data after a follow-up period of at least 3 years were evaluated. The changes of growth characteristics during marsupialization were analyzed by means of histopathologic and immunohistochemical studies with monoclonal anti-Ki-67 antibody. RESULTS: The effect of marsupialization was evaluated as extremely effective (64.3%), moderately effective (32.1%), and poorly effective (3.6%). In 5 lesions, the cysts disappeared macroscopically and further surgery was not done. Recurrence was observed in 6 lesions (21.4%), and there was no significant difference in recurrence rates between the lesions treated with or without marsupialization. There appeared to be a predilection for recurrence in the lesions in the mandibular ramus region and also for radiographically multilocular lesions. Microscopic examination showed substantial changes from a parakeratinized or orthokeratinized epithelium into a hyperplastic, stratified, nonkeratinizing squamous epithelium after marsupialization in many cases. There was no significant difference in labeling index between premarsupialization (20.2% +/- 12.0%) and postmarsupialization (15.3% +/- 10.3%). CONCLUSION: Marsupialization was found to be effective as a preliminary treatment for large OKCs. This procedure does not appear to affect the recurrence tendency of OKCs, and the probable changes in growth characteristics become rather less aggressive.

Comparison of long-term results between different approaches to ameloblastoma.

OBJECTIVE: The long-term results of different surgical approaches to ameloblastoma were compared to develop a more rational surgical approach to this tumor. STUDY DESIGN: Seventy-eight primary ameloblastomas, including 27 unicystic, 21 multicystic, and 30 solid-type tumors, were examined in this study. The methods of treatment consisted of radical surgery (ie, resection-both segmental and marginal) and conservative treatments (ie, marsupialization alone, marsupialization followed by enucleation with sufficient bone curettage if necessary, and enucleation with bone curettage). The effect of marsupialization on recurrence data after a follow-up period of at least 5 years was evaluated with respect to clinical type and histologic pattern. RESULTS: Marsupialization was performed in 31 cystic ameloblastomas before surgery, and the effective rate of marsupialization was 74.2%. Recurrence was observed in 7.1% (3/42) after radical surgery and in 33.3% (12/36) in conservative treatments. Relatively higher tendencies of recurrence were observed in the multicystic type and follicular and/or plexiform pattern tumors. CONCLUSIONS: Conservative treatments including marsupialization and enucleation followed by sufficient bone curettage were thought to be useful, reducing the need for jaw resection. This result extends the indications for conservative treatment of ameloblastoma.

Epithelial stem cells in teeth.

Many tissues and organs maintain a process known as homeostasis, in which cells are replenished as they die as a result of apoptosis or injury. The continuously growing mouse incisors are an excellent model for studying the molecular mechanisms of cell homeostasis, renewal, and repair. We elucidated these mechanisms in mouse incisors by detecting adult stem cells and analyzing the stem cell lineage by bromodeoxyuridine (BrdU) labeling analysis. The stem cells divide slowly, giving rise to a daughter cell that remains in the cervical loop and a second daughter cell that enters the zone of rapidly dividing inner enamel epithelial cells (transit-amplifying cell population). During subsequent rounds of cell division, the latter cells move toward the incisal end and differentiate into ameloblasts that form the enamel matrix. Recent evidence from gene knockout mice suggests that fibroblast growth factor (Fgf10) plays an important role in the formation and maintenance of stem cells in the development of mouse incisors. The role of dental stem cells in odontogenic tumors is discussed.