Tadafumi Adachi

Tumor Thickness and Paralingual Distance of Coronal MR Imaging Predicts Cervical Node Metastases in Oral Tongue Carcinoma

BACKGROUND AND PURPOSE: The presence of cervical lymph node metastases is an important prognostic factor for oral tongue cancer. The accurate preoperative assessment is essential for treatment. Several studies have suggested that histologic tumor thickness is related to the metastases. The aim of this study was to determine whether MR images of oral tongue tumor have the potential to predict cervical lymph node metastases. MATERIALS AND METHODS: A total of 43 patients with squamous cell carcinoma of the oral tongue were investigated. Tumor thickness, sublingual distance between tumor and sublingual space, and paralingual distance between tumor and paralingual space, as determined from coronal MR imaging, were preoperatively estimated. Logistic regression analysis was used to identify independent predictors of lymph node metastases. RESULTS: Univariate logistic regression analysis showed that T classification, N classification, and 3 measured MR imaging distances (millimeters) were significantly associated with lymph node metastases. Multivariate logistic regression analysis showed that tumor thickness (odds ratio, 1.34; 95% confidence interval [CI], 1.11–1.63; P < .005) and paralingual distance (odds ratio, 0.53; 95% CI, 0.35–0.82; P < .005) were significant predictors for lymph node metastases. The probability of metastases was estimated with these models. The preoperative decision (20% probability) as to whether to perform neck dissection could be based on tumor thickness of >9.7 mm and paralingual distance of <5.2 mm. CONCLUSION: MR images provide satisfactory accuracy for the preoperative estimation of the tumor thickness and the paralingual distance, which are valuable for predicting cervical lymph node metastases.

Reliability of novel multidirectional lip‐closing force measurement system

This study aimed to quantify the directional specificity of multidirectional lip-closing force (LCF) and evaluate the reliability of multidirectional LCF measurements made using a novel system. In fourteen healthy subjects (seven females, seven males, median age = 28 years), LCFs in eight directions and electromyograms (EMGs) from four parts of the orbicularis oris muscles (OOM) were recorded during voluntary pursing-like lip closure tasks. The quantitative reliability was assessed from repeated measurements of the LCFs in the eight directions and from summed values for all eight directions [total lip-closing force (TLCF)]. The intra- and inter-investigator reliabilities for TLCF were assessed by the interclass correlation of the measurements by the same investigator and two investigators, respectively. Lip-closing forces showed directional specificity in vertical, horizontal and oblique directions but those in oblique and horizontal directions were symmetrical bilaterally. The quantitative reliability of measurements was between 0·735 and 0·948 in the eight directions and that of TLCF was 0·934. Interclass correlations of intra- and inter-investigator reliabilities were 0·96 [lower limit of 95% confidence interval (95% LL), 0·87] and 0·96 (95% LL, 0·91), respectively. The intra- and inter-investigator differences of measurements were randomly distributed in the whole range of measurements. The 95% confidence intervals of these differences were significantly narrower than those of the limits of agreement (mean ± 1·96 s.d.). In 13 subjects, Pearsons correlation coefficients between LCF and EMGs from OOM were above 0·95. We conclude that this system has a reasonable quality and reliability for quantitative measurements of multidirectional LCF for evaluating lip functions.

Induction chemotherapy is Associated with an increase in the incidence of locoregional recurrence in patients with carcinoma of the oral cavity

This study was conducted to determine long term survival rates and the pattern of failure in patients with carcinoma of the oral cavity treated with induction chemotherapy or preoperative radiotherapy followed by surgery.

Early two-stage double opposing Z-plasty or one-stage push-back palatoplasty?: comparisons in maxillary development and speech outcome at 4 years of age.

Determining the optimal timing and procedure of palatal surgery for children with cleft lip and palate has long raised a major controversy. An early two-stage palatoplasty protocol has been a recent trend in an attempt to obtain preferable maxillary growth without compromising adequate speech development. In this study, we aim to address whether the resulting maxillofacial growth and speech development obtained by an early 2-stage palatoplasty protocol are better than those obtained by conventional 1-stage push-back palatoplasty. Seventy-two nonsyndromic children with complete unilateral cleft lip and palate were enrolled in this study. They were divided into 2 groups: 30 children, who were treated with early 2-stage palatoplasty, in which soft palate closure was performed using a modified Furlows procedure at 12 months of age and hard palate closure was performed at 18 months of age (Early Tow Stage [ETS] group: 22 boys, 8 girls), and 42 children, who underwent 1-stage Wardill-Kilner push-back palatoplasty at 12 months of age (Push Back [PB] group: 31 boys, 11 girls). Cephalometric analysis for maxillofacial growth and assessments of speech development were performed for each child at 4 years of age. The ETS group showed a lager maxillary length than the PB group [anterior nasal spine (ANS)-ptm′: ETS, 46.7 ± 2.0 mm; PB, 43.6 ± 2.3 mm]. The ANS in the ETS group was positioned more anteriorly than that in the PB group (N′-ANS: ETS, 2.5 ± 1.8 mm; PB, 0.26 ± 2.5 mm), whereas the posterior edge of the maxilla positioned anteroposteiorly was comparable between the 2 groups. The anterior facial height was significantly greater in the ETS group than in the PB group (N-N′: ETS, 43.3 ± 2.9 mm; PB, 40.1 ± 2.3 mm, S-S′: ETS, 29.7 ± 3.2 mm; PB, 31.0 ± 3.2 mm). No statistically significant differences were observed in the incidence of either velopharyngeal incompetence or articulation errors between the 2 groups at 4 years of age. Our results show that the early 2-stage protocol is advantageous with regard to maxillary growth compared with 1-stage push-back palatoplasty without compromising speech development as evaluated for all children at 4 years of age.

Early Two-Stage Palatoplasty Using Modified Furlow's Veloplasty

Objective To achieve sufficient velopharyngeal function and maxillary growth for patients with unilateral cleft lip and palate (UCLP), the authors have designed a new treatment protocol for palate closure involving early two-stage palatoplasty with modified Furlow veloplasty. Details of the surgical protocol and the outcomes of the dental occlusion of patients at 4 years of age are presented. Design and Setting This was an institutional retrospective study. Patients Seventy-two UCLP patients were divided into two groups based on their treatment protocols: patients treated using the early two-stage palatoplasty protocol (ETS group; n = 30) and patients treated using Wardill-Kilner push-back palatoplasty performed at 1 year of age (PB group; n = 42). Interventions The features of the ETS protocol are as follows: The soft palate is repaired at 12 months of age using a modified Furlow technique. The residual cleft in the hard palate is closed at 18 months of age. Lip repair is carried out at 3 months of age with a modified Millard technique for all subjects. Results The ETS group showed a significantly better occlusal condition than the PB group. The incidence of normal occlusion at the noncleft side central incisor was 7.1% in the PB group; whereas, it was 66.7% in the ETS group. Conclusion The results indicate that the early two-stage protocol is advantageous for UCLP children in attaining better dental occlusion at 4 years of age.

Effect on Maxillary Arch Development of Early 2-Stage Palatoplasty by Modified Furlow Technique and Conventional 1-Stage Palatoplasty in Children With Complete Unilateral Cleft Lip and Palate

PURPOSE The purpose of this study was to evaluate the palatal morphology of patients with complete unilateral cleft lip and palate after early 2-stage palatoplasty (ETS) consisting of soft palate closure by a modified Furlow palatoplasty at 12 months of age and hard palate closure at 18 months of age. We compared the result with the palatal morphology obtained by Wardill-Kilner push-back palatoplasty (PB) at 12 months of age with that of children with noncleft palate. In the present study we investigated whether ETS can result in better palatal development than conventional PB. MATERIALS AND METHODS Thirty subjects were treated by ETS and 42 underwent PB. We also included cross-sectional data obtained from 66 children with noncleft palate as control. We measured the arch length, width, and cleft width using dental cast models that were consecutively taken at 3 months to 4 yrs of age and compared the results among the 3 groups. RESULTS At 4 years of age, the anteroposterior palatal length of ETS was significantly longer than that of PB by 9.8%, and the transversal palatal width of ETS was also markedly wider than that of PB at every point measured. Furthermore, ETS showed potential catch-up growth in the anteroposterior palatal length from 12 months to 4 years of age. CONCLUSION These results demonstrate that ETS has a considerable benefit for the palatal development of patients with complete unilateral cleft lip and palate compared with PB.

High Incidence of Blood Exposure Due to Imperceptible Contaminated Splatters During Oral Surgery

PURPOSE To evaluate the incidence of blood exposure during outpatient oral surgery from splattering caused by use of high-speed rotary instruments at the Referral and Teaching Center, University Dental Hospital. MATERIALS AND METHODS Twenty-five consecutive patients who had impacted mandibular third molars were selected. The attending surgeon wore an operation gown and visor mask, and carried out the tooth extraction with the regular procedure. We counted the number of bloodstains found on the operation gown and visor mask, and confirmed the presence of diluted and invisible bloodstains using a leucomalachite green presumptive test, which was able to detect dilutions up to 1:4,000. RESULTS There were 469 separate bloodstains on the gown and visor mask of oral surgeons, which came from 19 (76%) of 25 patients during impacted mandibular third molar surgery. Presumptive tests for invisible bloodstains resulted in 1,206 positive reactions, 2.57-fold greater than the visible stains, from 88% of the cases. All of the surgeons were right-handed and the common areas of staining were the right forearm, face, and thorax regions. CONCLUSIONS Dental procedures with high-speed instruments exposed surgeons to possible blood-borne infections by splashing in nearly 90% of the cases. Greater than 50% of the stains were invisible to the naked eye. Based on our results, strict compliance with barrier precautions, including routine use of an operation gown and visor mask, is recommended whenever oral surgery is carried out with high-speed rotary instruments.

Measurement of Velopharyngeal Movements Induced by Isolated Stimulation of Levator Veli Palatini and Pharyngeal Constrictor Muscles

The levator veli palatini (LVP) and superior pharyngeal constrictor muscles (PC) close the velopharynx. However, for the velopharyngeal movements to be understood in detail, each muscle contraction must be analyzed precisely. This study was performed to clarify the velopharyngeal movement which was induced by a single muscle contraction, LVP or PC. Using a nasopharyngeal fiberscope, we analyzed the velopharyngeal movement associated with the contraction of the LVP and PC muscles in mongrel dogs. To elicit the maximal contraction of each muscle, we applied repetitive electrical stimulation to each peripheral nerve efferent to the LVP or PC muscle. Stimulation with a frequency of 77 Hz and 83 Hz induced maximal tension in the LVP and PC muscles, respectively, in isometric contraction. In a second series of experiments, fiberscopic views of the velopharyngeal movements associated with each muscles maximal contraction were recorded. The degree of closure was calculated at several sections. The LVP muscle pulled the caudal fourth of the soft palate, while the PC projected the posterior wall at the level of the caudal end of the soft palate. The PC muscle also projected the lateral wall of the velopharynx. The effect of LVP contraction on the lateral wall was very small. These results show that the velopharyngeal movement associated with LVP contraction is very different from that with PC contraction.

Gender differences in maximum voluntary lip‐closing force during lip pursing in healthy young adults

The objectives of this study were to quantitatively evaluate the gender differences in the lip-closing force (LCF) generated during pursing-like lip-closing movement using a multidirectional LCF measurement system in healthy young adults. In 40 healthy subjects (20 women, 20 men; median age = 26·5 years, range = 22-41 years), LCF was recorded in eight directions during the performance of a voluntary pursing-like lip-closing task in four measurement sessions. The correlations between the total sum of the forces generated in all eight directions [total LCF (TLCF)] and each directional LCF (DLCF) and those between opposing DLCF were statistically analysed. The TLCF obtained from the highly reproducible measurements acquired in the four different sessions was normally distributed in both genders. The TLCF in men was significantly greater than that in women. Among the eight pairs of opposing DLCF, seven pairs of opposing DLCF showed significant correlations in men, while five pairs were significantly correlated in women. In men, no significant difference was observed between opposing DLCF; however, three pairs of opposing DLCF were significantly different in women. The present results quantitatively indicate that there are gender differences in the magnitude and directional specificity of the LCF produced during pursing-like lip-closing movement in healthy young adults.

Regulatory relationship between tactile sensation at the vermilion of the lips and lip-closing force.

The objectives of this study were to identify the regulatory relationship between tactile sensation at the vermilion of the lips and the output of pursing-like lip-closing force (LCF), as measured by a multidirectional LCF measurement system. Thirty-six healthy subjects were divided into Anaesthesia and Vaseline groups. The tactile detection threshold (TDT) at six sites on the vermilion and the maximum voluntary LCFs in eight directions were recorded before and during partial or whole application of the agent and 6 h after whole application (Recovery). Five per cent lidocaine gel and Vaseline was applied to the vermilion in the Anaesthesia and Vaseline groups, respectively. These agents were applied to either the right part of the vermilion of the lower lip (Partial) or the whole vermilion (Whole). Partial application of 5% lidocaine gel significantly decreased the magnitudes of six of eight directional LCFs, while it only increased the TDT at one site. The subsequent whole application of 5% lidocaine gel did not affect the magnitude of the LCFs in five of these six directions although its application increased the TDTs at all sites. These reductions in LCF were reversed after recovery from surface anaesthesia. Vaseline application did not affect either TDT or LCF in any conditions. We concluded that tactile sensation at the vermilion of the lips is related to the output of LCF, without any particular directional specificity. The present results suggest the presence of a common synaptic drive ordering the pursing of the relevant muscles.