Occlusal Evaluation Using Modified Huddart and Bodenham Scoring System Following 2-Stage Palatoplasty With Hotz Plate: A Comparison Among 3 Different Surgical Protocols.

OBJECTIVE: This study aimed to determine if the change in technique of soft palate closure or timing of hard palatal repair induced occlusal changes in patients with complete unilateral cleft lip and palate (CUCLP). DESIGN: Retrospective study. SETTINGS: A medical and dental hospital in Japan. SUBJECTS: A total of 96 patients with CUCLP treated with 2-stage palatoplasty were included in the study and categorized into 3 groups (G1, G2, and G3) according to the protocol used. INTERVENTIONS: G1 underwent soft palate repair using Perko method at 1.5 years of age and hard palate repair using vomer flap procedure at 5.5 years of age. Furlow method was used for soft palate repair in G2 at 1.5 years of age and hard palate repair using vomer flap procedure at 5.5 years of age. The Furlow method was used to repair the soft palate in G3 at 1.5 years of age and vomer flap procedure was used to repair the hard palate at 4 years of age. MAIN OUTCOME MEASURES: Two evaluators assessed the dental arch relationship using the modified Huddart/Bodenham (mHB) index on 2 separate occasions. RESULTS: Intra- (intraclass correlation coefficient [ICC]: 0.962) and inter-examiner (ICC: 0.950) reliability showed very good agreement. The frequency of crossbite present in the major and minor segments gradually decreased with each change in protocol. Mean segmental scores showed no significant difference between 3 protocols (P > .05). Good inter-arch alignment occurred with all 3 surgical protocols (G1:82.6%, G2:89.8%, and G3:91.7%). CONCLUSIONS: There was no significant difference in the dental arch relationship outcomes between the 3 surgical protocols. The dentition status was comparable with all surgical protocols, even after the changes.

Endurance measurement of hyoid muscle activity and hyoid-laryngeal position during tongue lift movement.

BACKGROUND: Tongue lift movement (TLM) is used as a therapy to improve tongue pressure against the hard palate for dysphagic patients. OBJECTIVE: The present study aimed to characterize the time-dependent endurance changes in hyoid muscle activity and hyoid-laryngeal displacement during TLM in different ways. METHODS: Sixteen young healthy volunteers were instructed to perform TLM at maximum effort (100%) against the anterior and posterior parts of the hard palate using a balloon-type tongue pressure instrument, followed by a 10-second recording during anterior 80% TLM, anterior 100% TLM, posterior 80% TLM and posterior 100% TLM with visual feedback. Electromyography (EMG) of suprahyoid (S-Hyo) and infrahyoid (I-Hyo) muscles and videofluorography were simultaneously recorded. To evaluate temporal changes, the recording period was divided into three substages: early, middle and late. Tongue pressure, integrated EMG (iEMG), power frequency of EMG burst and hyoid-laryngeal position were compared among the conditions (80% vs 100%, anterior vs posterior and early vs middle vs late). RESULTS: Tongue pressure was stably maintained for 10 seconds in all conditions. S-Hyo iEMG and I-Hyo iEMG were significantly greater at 100% than at 80%, while no significant difference was observed between positions. S-Hyo iEMG and I-Hyo iEMG significantly increased at the late stage, while power frequency of EMG burst gradually decreased. Significant temporal changes in laryngeal elevation were observed only in posterior 100% TLM. CONCLUSION: The current results suggested that isometric posterior TLM may be more useful compared with anterior TLM in clinical situations for dysphagic patients to elevate the hyolaryngeal complex.

Properties of hyoid muscle contraction during tongue lift measurement.

BACKGROUND: Tongue lift movement (TLM) task is considered a treatment strategy in dysphagic patients. However, there is no evidence of effect of sustained tongue movements on the related muscle contraction. OBJECTIVES: The present study aimed to characterise the properties and time-dependent changes of the electromyographic (EMG) features of suprahyoid muscles during TLM. METHODS: Twenty young healthy volunteers were instructed to perform TLM at maximum effort in either the anterior or the posterior position, during measurement of tongue pressure for 7 s. Supra- (S-hyo) and infra-hyoid (I-hyo) EMGs were recorded. The area and power frequency of EMG burst and the area under the curve of tongue pressure were compared among the conditions: trials (1st, 2nd vs 3rd trials); anterior vs posterior TLM; and early vs late 3 s of each trial. RESULTS: There was no difference in the tongue pressure among trials or between the early and late 3 s. Anterior tongue pressure was significantly higher than posterior tongue pressure (P < .001). The area of I-hyo EMG burst was significantly larger (P = .044), and the power frequency of I-hyo EMG burst was significantly smaller (P = .042) during posterior TLM than anterior TLM. A significant difference in the power frequency of both EMG bursts was observed between early and late stages during both anterior (P < .05) and posterior (P < .01) TLM. CONCLUSION: Hyoid muscles may compensate for rapid fatigue of the tongue muscle to maintain tongue pressure by changing their activity pattern during tongue pressure generation.

Autotransplantation or replantation of cryopreserved teeth: a case series and literature review.

BACKGROUND: The aim of this report was to evaluate the outcome of autotransplantation or replantation of cryopreserved teeth clinically and radiographically. Donor teeth were slowly frozen in a controlled-rate freezer using 5% dimethylsulfoxide (DMSO) and 6% hydroxyethyl starch (HES) as protectants. Seven cryopreserved teeth, with duration of storage ranging from 4 to 36 months, were autotransplanted or replanted at Niigata University Medical and Dental Hospital. Endodontic treatment involving root canal debridement followed by interim root canal filling with calcium hydroxide was started 3 weeks after the operation and continued with replacement of the calcium hydroxide filling at 2-week to 3-month intervals. Three transplants showed periodontal regeneration clinically and radiographically, whereas replacement root resorption was observed in the remaining transplants. From the results, it can be concluded that cryopreserved tooth autotransplantation has potential for clinical use; however, the risk of replacement root resorption remains.

Alterations in intermediate filaments expression in disc cells from the rat temporomandibular joint following exposure to continuous compressive force.

The articular disc in the temporomandibular joint (TMJ) that serves in load relief and stabilizing in jaw movements is a dense collagenous tissue consisting of extracellular matrices and disc cells. The various morphological configurations of the disc cells have given us diverse names, such as fibroblasts, chondrocyte-like cells and fibrochondrocytes; however, the characteristics of these cells have remained to be elucidated in detail. The disc cells have been reported to exhibit heterogeneous immunoreaction patterns for intermediate filaments including glial fibrillary acidic protein (GFAP), nestin and vimentin in the adult rat TMJ. Because these intermediate filaments accumulate in the disc cells as tooth eruption proceeds during postnatal development, it might be surmised that the expression of these intermediate filaments in the disc cells closely relates to mechanical stress. The present study was therefore undertaken to examine the effect of a continuous compressive force on the immunoexpression of these intermediate filaments and an additional intermediate filament - muscle-specific desmin - in the disc cells of the TMJ disc using a rat experimental model. The rats wore an appliance that exerts a continuous compressive load on the TMJ. The experimental period with the appliance was 5 days as determined by previous studies, after which some experimental animals were allowed to survive another 5 days after removal of the appliance. Histological observations demonstrated that the compressive force provoked a remarkable acellular region and a decrease in the thickness of the condylar cartilage of the mandible, and a sparse collagen fiber distribution in the articular disc. The articular disc showed a significant increase in the number of desmin-positive cells as compared with the controls. In contrast, immunopositive cells for GFAP, nestin and vimentin remained unchanged in number as well as intensity. At 5 days after removal of the appliance, both the disc and cartilage exhibited immunohistological and histological features in a recovery process. These findings indicate that the mature articular cells are capable of producing desmin instead of the other intermediate filaments against mechanical stress. The desmin-positive disc cells lacked α-smooth muscle actin (α-SMA) in this study, even though desmin usually co-exists with α-SMA in the vascular smooth muscle cells or pericytes. Because the precursor of a pericyte has such an immunoexpression pattern during angiogenesis, there is a further possibility that the formation of new vessels commenced in response to the extraordinary compressive force.

Phenotypes of articular disc cells in the rat temporomandibular joint as demonstrated by immunohistochemistry for nestin and GFAP.

The articular disc is a dense collagenous tissue containing disc cells that are phenotypically described as chondrocyte-like cells or fibrochondrocytes. Despite the possible existence of these phenotypes in systemic joints, little is known about the detailed classification of the articular disc cells in the temporomandibular joint. In this immunocytochemical study we examined the localization and distribution patterns of nestin and glial fibrillary acidic protein (GFAP) in the articular disc of the rat temporomandibular joint at postnatal day 1, and weeks 1, 2, 4 and 8, based on the status of tooth eruption and occlusion. Nestin and GFAP are intermediate filament proteins whose expression patterns are closely related to cell differentiation and cell migration. Both types of immunopositive cell greatly increased postnatally to a stable level after postnatal week 4, but they showed different distribution patterns and cell morphologies. Nestin-reactive disc cells, which were characterized by a meagre cytoplasm and thin cytoplasmic processes, were scattered in the articular disc, whereas GFAP-positive cells, characterized by broader processes, existed exclusively in the deeper area. In mature discs, the major proportion of articular disc cells exhibited GFAP immunoreactivity. Furthermore, a double-immunostaining demonstrated that the nestin-negative cells, consisting of GFAP-positive and -negative cells, exhibited immunoreactions for heat shock protein 25. These findings indicate that the articular disc cells comprise at least three types in the rat temporomandibular joint and suggest that their expressions closely relate to mechanical loading forces within the joint, including occlusal force, as observed through postnatal development.

Relapse tendency in maxillary arch width in unilateral cleft lip and palate patients with different maxillary arch forms.

OBJECTIVE: The aim of this study was to investigate the relapse tendency in the maxillary dental arch widths in unilateral cleft lip and palate patients with different types of maxillary arch form. SUBJECTS: Thirty-two unilateral cleft lip and palate patients treated by one-stage surgical palatal closure were included. The subjects were divided into three groups according to the types of the maxillary arch forms: group A, symmetrical arch form; group B, collapse of minor segment; group C, collapse of both segments. METHODS: Using dental casts obtained at three different times, relapse in the intercanine, interpremolar, and intermolar widths in each group was assessed and differences between groups were investigated. RESULTS: Patients in group A showed stable results in all measurements. Patients in group B showed posttreatment relapse in the intercanine width only, whereas patients in group C demonstrated significant posttreatment relapses in the interpremolar and intermolar widths. Comparison between groups showed more significant relapse in the interpremolar and intermolar widths of group C than in those of group B. CONCLUSION: The types of the maxillary arch forms in unilateral cleft lip and palate patients might play a stronger role in the stability of the maxillary dental arch widths after orthodontic treatment in patients with collapse of both segments and a severe degree of maxillary narrowness.

Localization of CD44 and hyaluronan in the synovial membrane of the rat temporomandibular joint.

Previous studies have pointed out a lack of adhesion structures in the synovial lining layer of the rat temporomandibular joint (TMJ) despite showing an epithelial arrangement. CD44, a major cell adhesion molecule, plays crucial roles as an anchor between cells and extracellular matrices by binding hyaluronan (HA) for the development of organs or the metastasis of tumors. The present study examined the localization of CD44 in the synovial membrane of the rat TMJ by immunocytochemistry for OX50, ED1, and Hsp25, which are markers for the rat CD44, macrophage-like type A, and fibroblast-like type B synoviocytes, respectively. Histochemistry for HA-binding protein (HABP) was also employed for the detection of HA. OX50 immunoreactions were found along the cell surface and, in particular, accumulated along the surface of the articular cavity. Observations by a double immunostaining and immunoelectron microscopy revealed that all the OX50-immunopositive cells were categorized as fibroblastic type B cells, which had many caveolae and a few vesicles reactive to intense OX50. However, the macrophage-like type A cells did not have any OX50 immunoreaction in the synovial lining layer. A strong HABP reaction was discernable in the extracellular matrix surrounding both OX50-positive and -negative cells in the synovial lining layers, exhibiting a meshwork distribution, but weak in its sublining layer. This localization pattern of CD44 and HABP might be involved in the formation of the epithelial arrangement of the synovial lining layer. Furthermore, OX50 immunonegativity in the type A cells suggests their low phagocytotic activity in the rat TMJ under normal conditions.

Blepharo-cheilo-dontic (BCD) syndrome: case report.

OBJECTIVE: To report a case of blepharo-cheilo-dontic (BCD) syndrome, to compare with the previous cases, and to discuss the possible treatment. PATIENT: The patient was a 14-day-old boy born uneventfully on August 7, 2002. His scalp hair was sparse and curly. A tumor on the top of his head, which was thought to be a dermoid cyst, and a nevus on the back of his left hand were observed. All typical symptoms of blepharo-cheilo-dontic syndrome, such as euryblepharon with ectropion of the lower eyelids, distichiasis, bilateral cleft lip and palate, severe oligodontia, and conical teeth, were observed. Because there was no fatal complication, and growth and development were about normal, it was recommended that a long and active treatment plan be considered for this patient.

Development of the articular cavity in the rat temporomandibular joint with special reference to the behavior of endothelial cells and macrophages.

Previous developmental studies on the temporomandibular joint (TMJ) have proposed several hypotheses on the formation of its articular cavity. However, detailed information is meager. The present study examined the formation process of the articular cavity in the rat TMJ by immunocytochemistry for CD31, RECA-1, and ED1, which are useful cellular markers for endothelial cells and monocyte/macrophage lineages, respectively. The upper articular cavity formation had begun by embryonic day 21 (E21) and was completed at postnatal day 1 (P1) in advance of the lower cavitation; the latter took place from P1 to P3. The occurrence and distribution pattern of the CD31-, RECA-1-, and ED1-positive cells differed between the upper and lower articular cavity-forming areas: the ED1-positive cells exclusively occurred in the area of the prospective upper articular cavity prior to its formation, while no ED1-positive cell appeared in the lower cavity-forming area. In contrast, the CD31- and RECA-1-positive endothelial cells were restricted to the lower cavity-forming area (never the prospective upper cavity) at E19 and diminished thereafter. Throughout the cavity formation, we failed to find any apoptotic cells in the cavity formation area, indicating no involvement of apoptosis in the cavity formation in TMJ. The present findings on the behaviors of endothelial cells and ED1-positive cells show a possibility of different mechanism in the cavity formation between the upper and lower articular cavities in the rat TMJ. The appearance of ED1-reactive cells and temporal vascularization may play crucial roles in the upper and lower articular cavity formation, respectively.

Long-term results of the two-stage palatoplasty/Hotz' plate approach for complete bilateral cleft lip, alveolus and palate patients.

PURPOSE: To investigate the effects of the two-stage palatoplasty combined with the Hotz' plate on craniofacial development in patients with bilateral complete clefts. MATERIAL AND METHODS: Lateral and frontal cephalograms of two-stage palatoplasty/Hotz' plate group (n=10), one-stage palatoplasty group (n=11), and a non-cleft group (n=11), were evaluated at 6, 8, 10 and 12 years of age. The unpaired Student's t-test and Scheffe's F test (p<0.05) were applied. RESULTS: At 6 years the posterior upper facial height (PUFH) and PUFH/PFH ratio were greater in the two-stage group. At 10 years the PUFH, maxillary depth, convexity and ANB angle were greater in the same group. At 12 years, maxillary depth and ANB angle were also greater in this group. In the one-stage group, the L1/Mp. angle, PUFH and PUFH/PFH ratio were smaller when compared with the non-cleft group, whereas the palatal plane/SN angle was greater. In both cleft groups, the I.I. angle and tongue-PTM' distance were greater, and the U1/SN angle was smaller when compared with non-clefts. The UC-UC' and the ratios UC/MAX and UC/LC of both cleft groups were also smaller when compared with non-clefts. The ratio UM/MAX of the one-stage group was smaller when compared with the non-cleft group. CONCLUSION: The two-stage palatoplasty in combination with application of the Hotz' plate had good effects on the maxillary growth up to the age of 12 years.