Relationship between tongue pressure and maxillofacial morphology in Japanese children based on skeletal classification

During childhood, perioral muscle function is closely associated with malocclusion. To clarify the effects of tongue function on maxillofacial morphology in children, tongue pressure and maximum lip‐closing force (LCF) were measured and the relationship between perioral muscle function and maxillofacial morphology was evaluated according to the skeletal classification. Maximum tongue pressure (MTP) and swallowing tongue pressure (STP) were measured on the anterior palatine rugae in 100 children (Hellman's dental stages IIIA‐IIIC) using a balloon‐type tongue pressure measurement device. Lip‐closing force was measured using an LCF measurement device. Lateral cephalograms were examined to classify subjects into skeletal (S)‐I, S‐II and S‐III groups. Correlations of skeletal classification with tongue pressure and LCF were examined. Correlations of lateral cephalometric measurements with palatal volume (PV), measured using a three‐dimensional optical scanner, were evaluated. Maximum tongue pressure was significantly lower in the S‐II group than in other groups. Swallowing tongue pressure was significantly lower in the S‐II group than in the S‐III group. Lip‐closing force was significantly higher in the S‐III group than in other groups. Swallowing tongue pressure was positively correlated with MTP and PV. Correlations between tongue pressure and anteroposterior skeletal classification indicated the importance of quantitative tongue function assessment.     

Effects of lip‐closing training on maximum voluntary lip‐closing force during lip pursing in healthy young adults

To investigate the effect of lip‐closing training, the time‐course of multidirectional lip‐closing forces during training was evaluated. The subjects were healthy young adults with no systemic disease. Ten subjects each were allocated to the training and non‐training (control) groups. The subjects were instructed to use a lip muscle strength fixation device (M Patakara) for lip‐closing training. Regarding closing the upper and lower lips against this force for 3 min as one task, the subjects were instructed to perform three tasks a day for 4 weeks. The multidirectional lip‐closing forces were measured before, during and after training every week. In the control group, the forces were measured under the same schedule without training. After the initiation of training, the total lip‐closing force significantly increased at 3 and 4 weeks in the training group compared with that in the control group (P = 0·003 at 3 weeks, P < 0·001 at 4 weeks). After the completion of training, the force decreased from 1 week and no significant difference from the control group was noted. When the lip‐closing force was evaluated by direction, significant increases in the upward and downward directions were noted in the training group compared with those in the control group (P = 0·034 at 3 weeks for upwards; P = 0·027 at 4 weeks for downwards). Quantitative analysis confirmed that lip‐closing training enhanced the lip‐closing force regionally.     

Multidirectional lip‐closing force in adult females after short‐term lip training

The purpose of this study was to investigate the multidirectional lip‐closing force in adult females before and after short‐term lip training. Sixty‐six Japanese females participated in this study. The subjects performed lip training that involved maintaining 200 or 400 g of bottled water in the oral vestibule. The signals of directional lip‐closing force were investigated in eight directions before training and 5 and 7 days after the lip training. The differences in the closing force between pre‐ and post‐training were then analysed statistically. The lip‐closing force increased in the following order: pre‐training, 5 days post‐training and 7 days post‐training in every direction (P < 0·05). The patterns of the increase in the lip‐closing force in the upper, lower, right and left directions as a result of the repetitions were similar. No significant differences were noted between the training effects with loads of 200 and 400 g. Our findings demonstrated that the lip‐closing force was influenced by the short‐term lip training.     

唇裂术后上唇压力对上颌骨发育影响的有限元分析

目的:探讨唇裂术后上唇压力对上颌骨的影响及抑制机制.方法:利用ANSYS 17.0软件在腭裂上颌骨有限元模型上添加上唇软组织,赋予材料属性,形成含上唇的唇腭裂上颌骨三维有限元模型,对模型分组,施加上唇压力并进行受力分析.试验组:施加唇裂术后上唇压力,对照组:施加同龄正常儿童上唇压力.结果:试验组形变值大于对照组,在三维...     

Pressure production in oral vestibule during gum chewing

The aim of this study was to record oral vestibule pressure (OVP) by the lip and cheek contraction during gum chewing, to examine the characteristics of these pressures and coordination between the OVP and jaw movement. The subjects were eight healthy adult men (mean age of 29·3 ± 3·3 years). An experimental plate that incorporated four pressure sensors on the midline of the upper jaw (Ch. 1), upper right canine (Ch. 2), upper right first molar (Ch. 3) and upper left first molar (Ch. 4) was used for measuring OVP. The right masseter electromyogram (EMG) was recorded simultaneously. Subjects chewed gum on the right side 20 times, and eight consecutive strokes were used for the analysis of the sequential order, maximal magnitude and duration of each OVP. Onset of OVP was observed at the molar on the non‐chewing side (Ch. 4) before chewing side (Ch. 3), and offset was largely simultaneous at each site. On the chewing side (Chs. 1–3), OVP onset during the interval of EMG activity reached to the peak around the end of interval and offset in the duration of EMG activity. The maximal pressure was significantly larger at Chs. 1–3 than at Ch. 4, but no significant differences were observed in duration of pressure among each site. These results suggest that OVP is coordinated with jaw movement during gum chewing, and larger pressure is produced on the chewing side than on the non‐chewing side. Our findings are quantitative indices for the evaluation of lip and cheek function during mastication.     

Successful prevention of oral self‐mutilation using a lip guard: a case report

Self‐injurious behavior (SIB) is causing deliberate harm to the body without suicidal intent; this problem occurs in a number of psychiatric, behavioral, and developmental disorders. This report describes the case of a girl, aged 19 months, whose lower lip injuries due to SIB were successfully treated through the use a combination of extraoral and intraoral prostheses. A custom‐made lip guard with a custom‐made adjustable head strap was effective in the management of the lip trauma. SIB was prevented and there was no recurrence even at the 17‐month follow‐up appointment.     

Multidirectional lip‐closing force in adults with mandibular deviation

The purpose of this study was to investigate the relationship between multidi‐rectional lip‐closing force and facial soft tissue morphology in adults with mandibular deviation. Fifteen Japanese adults with mandibular deviation participated in this study. The deviation value was defined as the horizontal distance between soft tissue menton and the facial midline. The side of the soft tissue menton relative to the facial midline was defined as the deviated side and the opposite side as the non‐deviated side. The signals of directional lip‐closing force (DLCF) were investigated in 8 directions. Total lip‐closing force (TLCF) was calculated by adding DLCFs in 8 directions. Correlations and differences between the variables were analysed statistically. Significant positive correlations between TLCF and DLCFs were determined in six directions with the exception of the horizontal direction. Significant positive correlations for seven pairs of opposing DLCFs were found. The lower non‐deviated DLCF was smaller than the three pairs of opposing lip‐closing forces. Negative significant correlation was found between the deviation value and the upper deviated DLCF (P < 0·05). In individuals with mandibular deviation, lip‐closing force in the lower non‐deviated direction was found to be smaller than the opposing lip‐closing forces. When mandibular deviation was greater, the upper deviated lip‐closing force was smaller.     

Lip closing pressure and spoon management in passive spoon feeding

To determine the sources of lip closing pressure (P(LC) ) generation during passive spoon feeding, we used a fine pressure transducer glued into a wooden spoon, as well as electromyography (EMG) of the upper and lower lips and the submental muscle complex, in normal adult volunteers (average age 24·5 years). An assistant fed a seated subject 0·6 mL of yogurt and then withdrew the spoon from the subject's closed mouth. The spoon was held at an angle of 0° (i.e. in the naso-auricular plane) during serving and at either 0° or 60° during withdrawal. We detected simultaneous increases in P(LC) and in EMG activity in the lips and the submental muscle complex. The maximum P(LC) was significantly higher at 60° [65 ± 11 g cm(-2) (mean ± s.e.m)] than at 0° (42 ± 8 g cm(-2)). The former was correlated with the maximum EMG amplitude, which was analysed by using the mean of the root-mean-square EMG and presented as a percentage of the maximum EMG obtained in the lower lip region and the submental muscle complex during subsequent swallowing in each subject. In conclusion, in healthy adult subjects, perioral muscles of the lower lip region and the submental muscle complex participate in P(LC) generation, particularly at a steep spoon withdrawal angle. The results suggest that a steep withdrawal angle not only increases P(LC) but also promotes these muscles' activities in passive spoon feeding.     

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.     

Commissural lip pits in Israeli Jews of different ethnic origin

The prevalence of commissural lip pits in a group of 2462 Israeli Jews was determined, and a relation of commissural lip pits to ethnic background was noted. Results showed the presence of commissural lip pits in 17.4% of the entire sample; 9.7% were unilateral and 7.7% were bilaterally located. The Ashkenazi group showed a significant higher prevalence of commissural lip pits (19.4%) when compared to the prevalence in the Sephardic group (14.1%) and the Eastern group (21.1%).     

Asymmetric lip-closing forces in children with repaired unilateral cleft lip and/or palate

The objectives of this study were to estimate the effects of cleft lip and/or palate (CLP) repair on the multidirectional lip-closing forces (LCF) produced during maximum voluntary pursing-like lip-closing movement in children. Thirty Japanese children were divided into the control group and repaired unilateral CLP (RUCL) group, which was subdivided into the unilateral cleft lip and/or alveolus (UCLA) and the unilateral cleft lip and cleft palate (UCLP) groups. The maximum voluntary LCF were recorded in eight directions. No significant differences in any of the directional LCF (DLCF) or total LCF were observed between RUCL and control groups. Symmetrical DLCF were seen in the oblique directions on both sides of the upper lip in the control group, while the oblique DLCF on the non-cleft side was significantly greater than that on the cleft side in RUCL group. Furthermore, symmetrical vertical DLCF were observed in the upper and lower directions in control and UCLA groups, while the vertical DLCF obtained from the lower direction was significantly greater than that obtained from the upper direction in UCLP group. These results indicate that children with repaired CLP display impaired directional specificity, which may cause secondary deformities. These findings aid our understanding of the pathology of secondary deformities in CLP patients after primary surgery for cleft lip or palate. We propose that quantitative assessments of lip-closing function based on the directional specificity of the multidirectional LCF produced during maximum voluntary pursing-like lip-closing movement are useful for assessing the nature of lip-closing dysfunctions.     

Surgical correction of hypertrophic upper lip in vascular malformations

Capillary malformations (CMs) and Lymphatic malformations (LMs) are vascular malformations that share a common tendency to cause soft and hard tissue hypertrophy, expressed in the three dimensions of the space. The middle third of the face is the most commonly involved area, with a predominance of the upper lip.To our knowledge, no paper has previously focused on the surgical technique to correct such deformities. We propose and illustrate a surgical protocol, consisting in merging an asymmetric bikini upper lip reduction and a unilateral bull horn resection technique, that allowed to reduce the overall volume of the hypertrophied lip thus restoring lip symmetry. We adopted this technique in 2 patients affected by CMs and 4 patients with LMs, with satisfactory results.     

口周力对唇腭裂患者牙颌发育影响的研究现状

唇腭裂患者常出现牙颌发育缺陷,其影响因素非常复杂。患者唇腭裂修复术前后的口周力都不同于正常人。多数学者认为,患者唇腭部术后软组织张力变化是导致患者牙颌生长受限的原因之一。现就唇腭裂患者口周力的研究现状及研究方法做一综述。     

Split zygomaticus major muscle sling reconstruction for significant lower lip defects

Defects to the lower lip remain surgically challenging to reconstruct. Restoration of aesthetics and function are crucial, of which the aims include restoring the tissues of the lower lip, maintaining oral competence, speech articulation, and restoring lip height and the vermillion. Further surgical techniques continue to be explored, with local flap surgery being the generally preferred method. However, many reconstructions leave the patient with pronounced deformity and morbidity. In this case report, we describe a new technique for the reconstruction of an 80% lower lip defect with an ipsilateral split zygomaticus major muscle sling, nasolabial flap, and facial artery musculomucosal flap. The reconstruction provided good oral competence, speech articulation and aesthetics, in addition to maintaining the oral commissure and lower lip height/length. Iatrogenic microstomia was avoided and zygomaticus functioning was normal. We are confident this technique will be useful to reconstructive surgeons in select cases of significant lip defects.     

Relationship between frontal craniofacial morphology and horizontal balance of lip‐closing forces during lip pursing

The objectives of this study were to quantitatively evaluate the relationship between frontal craniofacial morphology and the horizontal balance of the lip‐closing forces (LCF) generated during maximum voluntary pursing‐like movements in patients with mandibular deviation. Thirty‐one subjects (median age 25·4 ± 8·9 years) without a history of orthodontic treatment were randomly selected from among the orthodontic patients who visited our hospital. Lip‐closing forces was recorded in eight directions during maximum voluntary pursing‐like lip‐closing movements. The subjects were divided into the deviation (two males and 11 females) and non‐deviation groups (four males and 14 females). There was no significant difference in the total LCF between the deviation and non‐deviation groups. In the deviation group, the mean LCF value on the deviation side of the upper lip was significantly lower than that detected on the non‐deviation side of the upper lip, while the mean LCF value for the deviation side of the lower lip was significantly higher than that for the non‐deviation side of the lower lip. In contrast, no significant difference in upper or lower lip LCF was detected between the deviation and non‐deviation sides in the non‐deviation group. The difference in the LCF generated in the lower lip between the deviation and non‐deviation sides was significantly positively correlated with mandibular menton deviation and significantly negatively correlated with the difference in maxillary height between the deviation and non‐deviation sides. These results suggest that the horizontal balance of the upper and lower lip LCF produced during pursing‐like lip‐closing movements in patients with mandibular deviation is related to frontal craniofacial morphology.     

双侧不对称性唇裂的初步研究

目的：探讨双侧不对称性唇裂在先天性唇腭裂疾病中的发病比例并评价其目前的整复方法。方法：对自2007年1月～2012年10月收治的所有唇腭裂患者进行回顾性研究;同时对纳入研究标准的双侧不对称性唇裂患者通过3dMDpatient软件及SPSS17．0软件进行指标测量分析来评价双侧不对称性唇裂的各种整复方法。结果：在4467个唇腭裂患者中,双侧唇裂964人,其中双侧不对称性唇裂患者294人,约占先天性双侧唇裂的30．4％;采用单侧分期修复的患者有3项测量指标（除唇峰一人中点外）统计结果均为P〈0．05,存在显著性差异,而采用双侧唇裂修复方法同期整复及单侧唇裂的修复方法同期整复的患者,其4项测量指标的统计结果均为P〉0．05,无统计学意义。结论：双侧不对称唇裂在先天性双侧唇裂中占了相当大的比例,且采用单侧唇裂的修复方法同期整复获得的手术效果最好。