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Featured researches published by Tadashi Mikoya.


The Cleft Palate-Craniofacial Journal | 2010

Monocortical mandibular bone grafting for reconstruction of alveolar cleft.

Tadashi Mikoya; Nobuo Inoue; Yusuke Matsuzawa; Yasunori Totsuka; Takashi S. Kajii; Tomoyuki Hirosawa

Objective To assess and develop a monocortical mandibular bone grafting procedure for reconstruction of alveolar cleft. Design Prospective study. Setting Hokkaido University Hospital. Patients Forty-two consecutive Japanese patients who had been treated for a total of 48 clefts according to a strict clinical protocol. Mean age at bone grafting was 6 years 11 months. Interventions Bone grafting was performed by harvesting lateral cortical bone plates from the symphysis and/or body and then placing them on the labial and palatal openings of the alveolar process defect. No particulate bone grafts were packed into the bony cavity. Mean follow-up after bone grafting was 37 months. Main Outcome Measures Status of the grafted area and eruption of cleft-adjacent teeth were assessed prospectively using computed tomography and periapical radiography. Results At 6 months postoperatively, computed tomography showed sufficient bone bridge formation at the cleft site in 85.4% of clefts. Periapical radiography showed ≥75% of the root surfaces of cleft-adjacent teeth were covered with spanning bone in 83.3% of clefts. In 92.6% of clefts in which the cleft-adjacent canine was uncovered with bone during follow-up, the canines erupted spontaneously. Conclusions Monocortical mandibular bone grafting appears extremely effective for sufficient bone bridge formation and facilitation of cleft-adjacent teeth eruption. The procedure is advantageous in that the quantity of bone required per unit volume of cleft defect is relatively reduced, and larger clefts can thus be treated.


The Cleft Palate-Craniofacial Journal | 2015

Dental Arch Relationship Outcomes in One- and Two-Stage Palatoplasty for Japanese Patients With Complete Unilateral Cleft Lip and Palate

Tadashi Mikoya; Toyoko Shibukawa; Takafumi Susami; Yoshiaki Sato; Toshimoto Tengan; Hirotaka Katashima; Akihiko Oyama; Yusuke Matsuzawa; Yumi Ito; Emi Funayama

Objective To compare dental arch relationship outcomes following one- and two-stage palatal repair. Design Nonrandomized, clinical trial with concurrent control. Setting Hokkaido University Hospital. Patients Sixty-eight consecutively treated Japanese patients with complete unilateral cleft lip and palate. Interventions Thirty-one of the 68 patients underwent two-stage palatoplasty with delayed hard palate closure, and 37 patients underwent one-stage pushback palatoplasty. Main Outcome Measures Dental casts were taken at 4.9 to 6.3 (mean: 5.2) years of age in the two-stage group and at 4.0 to 6.3 (mean: 5.1) years of age in the one-stage group, and dental arch relationships were assessed using the 5-Year-Olds’ Index (5-Y) by four raters and the Huddart/Bodenham Index (HB) by two raters. Results Intrarater and interrater reliabilities evaluated using weighted kappa statistics were good or better for the 5-Y and HB ratings. The mean 5-Y score was 2.94 in the two-stage group and 3.13 in the one-stage group (P value was not significant). However, there was a significant difference in distributions between the groups (P < .05). The HB scores of molars were significantly greater in the two-stage group than in the one-stage group (P < .05). The rank correlation coefficients between the 5-Y and total HB score (ρ = −0.840, P < .01) and between the 5-Y and the score of the incisors in the HB (ρ = −0.814, P < .01) were significantly increased. Conclusions These results suggest that the anteroposterior relationship was not significantly different between the groups, but the transversal relationship was better in the two-stage group than in the one-stage group.


International Journal of Pediatric Otorhinolaryngology | 2014

Important points for primary cleft palate repair for speech derived from speech outcome after three different types of palatoplasty

Emi Funayama; Yuhei Yamamoto; Noriko Nishizawa; Tadashi Mikoya; Toru Okamoto; Satoko Imai; Naoki Murao; Hiroshi Furukawa; Toshihiko Hayashi; Akihiko Oyama

OBJECTIVE This study was performed to investigate speech outcomes after three different types of palatoplasty for the same cleft type. The objective of this study was to investigate the surgical techniques that are essential for normal speech on the basis of each surgical characteristic. METHODS Thirty-eight consecutive nonsyndromic patients with unilateral complete cleft of the lip, alveolus, and palate were enrolled in this study. Speech outcomes, i.e., nasal emission, velopharyngeal insufficiency, and malarticulation after one-stage pushback (PB), one-stage modified Furlow (MF), or conventional two-stage MF palatoplasty, were evaluated at 4 (before intensive speech therapy) and 8 (after closure of oronasal fistula/unclosed hard palate) years of age. RESULTS Velopharyngeal insufficiency at 4 (and 8) years of age was present in 5.9% (0.0%), 0.0% (0.0%), and 10.0% (10.0%) of patients who underwent one-stage PB, one-stage MF, or two-stage MF palatoplasty, respectively. No significant differences in velopharyngeal function were found among these three groups at 4 and 8 years of age. Malarticulation at 4 years of age was found in 35.3%, 10.0%, and 63.6% of patients who underwent one-stage PB, one-stage MF, and two-stage MF palatoplasty, respectively. Malarticulation at 4 years of age was significantly related to the presence of a fistula/unclosed hard palate (P<0.01). One-stage MF palatoplasty that was not associated with postoperative oronasal fistula (ONF) showed significantly better results than two-stage MF (P<0.01). Although the incidences of malarticulation at 8 years of age were decreased in each group compared to at 4 years of age, the incidence was still high in patients treated with two-stage MF (45.5%). On the whole, there was a significant correlation between ONF/unclosed hard palate at 4 years of age and malarticulation at 8 years of age (P<0.05). CONCLUSION Appropriate muscle sling formation can compensate for a lack of retropositioning of the palate for adequate velopharyngeal closure. Early closure of the whole palate and the absence of a palatal fistula were confirmed to be essential for normal speech. To avoid fistula formation, multilayer repair of the whole palate may be critical.


Journal of Human Genetics | 2010

A type of familial cleft of the soft palate maps to 2p24.2–p24.1 or 2p21–p12

Masayoshi Tsuda; Takahiro Yamada; Tadashi Mikoya; Izumi Sogabe; Mitsuko Nakashima; Hisanori Minakami; Tatsuya Kishino; Akira Kinoshita; Norio Niikawa; Akiyoshi Hirano; Koh-ichiro Yoshiura

Cleft of the soft palate (CSP) and the hard palate are subtypes of cleft palate. Patients with either condition often have difficulty with speech and swallowing. Nonsyndromic, cleft palate isolated has been reported to be associated with several genes, but to our knowledge, there have been no detailed genetic investigations of CSP. We performed a genome-wide linkage analysis using a single-nucleotide polymorphism-based microarray platform and successively using microsatellite markers in a family in which six members, across three successive generations, had CSP. A maximum LOD score of 2.408 was obtained at 2p24.2–24.1 and 2p21–p12, assuming autosomal dominant inheritance. Our results suggest that either of these regions is responsible for this type of CSP.


Oral Science International | 2018

A rare case of glial choristoma of the tongue associated with cleft palate

Tamaki Yamada; Yusuke Matsuzawa; Izumi Sogabe; Masaki Donen; Kanchu Tei; Tadashi Mikoya

Abstract Glial choristoma is considered a developmental malformation characterized by brain heterotopias without connection to the central nervous system. In this article, we report a rare case of glial choristoma occurring on the dorsum of the tongue with cleft palate in a 3-month-old male infant. Complete surgical excision was performed prior to palatoplasty. There were no postoperative complications or evidence of recurrence after 5 years of follow-up.


International Journal of Oral and Maxillofacial Surgery | 2018

Incidence of anterior disc displacement without reduction of the temporomandibular joint in patients with dentofacial deformity

Kazuhiro Ooi; Nobuo Inoue; Kazuhiro Matsushita; Hiro-o Yamaguchi; Tadashi Mikoya; Kazuyuki Minowa; Shuichi Kawashiri; S. Nishikata; Kanchu Tei

The aim of this study was to investigate the incidence of anterior disc displacement without reduction (ADDwoR) of the temporomandibular joint (TMJ) in patients with dentofacial deformity. Eighty-eight female patients (176 joints) with skeletal class III malocclusion and 33 female patients (66 joints) with skeletal class II malocclusion, with or without anterior open bite and asymmetry, were evaluated. Magnetic resonance imaging (MRI) of the TMJ was used to diagnose ADDwoR. A statistical analysis was performed to examine the relationship between ADDwoR and skeletal structure. ADDwoR was present in 37 of the 66 joints (56.1%) in class II compared to 34 of the 176 joints (19.3%) in class III (P<0.05). In class III, ADDwoR was significantly more common in joints with mandibular asymmetry (24/74; 32.4%) than in joints with open bite (9/62; 14.5%) and joints with open bite and without mandibular asymmetry (1/38; 2.6%). In class II, ADDwoR was significantly less common in joints with mandibular asymmetry and without open bite (1/8; 12.5%). ADDwoR was only observed on the deviated side in both class III and class II with mandibular asymmetry. The prevalence of ADDwoR differed according to the dentofacial morphology.


Journal of Maxillofacial and Oral Surgery | 2015

Post-operative Stability After Bimaxillary Surgery in Patients with Facial Asymmetry: Comparison of Differences Among Different Original Skeletal Class Patterns.

Kazuhiro Matsushita; Nobuo Inoue; Hiro-o Yamaguchi; Tadashi Mikoya; Kanchu Tei

AbstractPurpose When improving jaw deformity by two-jaw surgery, we are of the opinion from our clinical experience that a certain degree of undercorrection is occasionally beneficial from the perspective of stability. Functional deterioration is not always seen with undercorrection. We conducted this retrospective study to assess post-operative stability in patients with facial asymmetry, with the aim of both clarifying differences between the original three skeletal class patterns, and confirming the efficacy of surgery performed on the basis of our concept. Patients and MethodsAll patients received optimal orthognathic treatment before and after surgery. Surgery was performed by our concept that undercorrection is not always bad. Nineteen patients were enrolled, and separated into three skeletal classes according to the ANB angle, because of the difference of the treatment modalities between them. Evaluations were performed by cephalometric measurements taken at least two-year post-operatively. Transverse occlusal cant, chin deviation, point A, point B, overjet and overbite were assessed.ResultsIn all patients, transverse occlusal cant improved to <4°, which has been reported as the threshold for visual recognition of facial symmetry. Chin deviation was also improved to the degree at which soft tissue can sufficiently mask the asymmetry. The changes remained stable throughout follow-up and satisfaction was obtained from all patients.ConclusionsIrrespective of original skeletal class patterns, post-operative stability of patients with facial asymmetry was achieved. Undercorrection is thus by no means problematic from the clinical perspective of stability and our concept of approach appears valid.


Japanese Journal of Oral and Maxillofacial Surgery | 2015

A case of spontaneous regression of multiple congenital epulis

Toyoko Shibukawa; Tadashi Mikoya; Yusuke Matsuzawa; Yumi Ito; Izumi Sogabe; Kanchu Tei


北海道歯学雑誌 | 2013

Dental arch relationships in children with complete unilateral cleft lip and palate following two-stage palatoplasty

Toyoko Shibukawa; Tadashi Mikoya; Yusuke Matsuzawa; Yumi Ito; Izumi Sogabe; Eiji Yamamoto; Yasunori Totsuka; Kanchu Tei


The Japanese Journal of Jaw Deformities | 2013

A Case of Mandibular Prognathism with Edentulous Maxilla treated by Orthognathic Surgery

Masaki Donen; Yuji Murakami; Mitsutaka Oda; Yoshinori Kobori; Kazuhiro Matsushita; Hiro-o Yamaguchi; Tadashi Mikoya; Osamu Takamichi; Kenjiro Shibata; Fumio Saito; Yuri Tsukamoto; Yoshiaki Sato; Junichiro Iida; Nobuo Inoue

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