Hideharu Yamaguchi

Health-related quality of life and psychosocial function 5 years after orthognathic surgery

This prospective, multisite, randomized clinical trial evaluated the long-term health-related quality of life and psychosocial function of 93 patients after bilateral sagittal split osteotomy to correct Class II malocclusion. Patients were evaluated approximately 2 weeks before surgery, and 2 and 5 years after surgery. Scores from the Sickness Impact Profile psychosocial dimension and all of its components showed significant improvement from presurgery to 2 and 5 years postsurgery (P <.05). The overall dimension score also showed significant improvement (P <.05). Change between 2 and 5 years postsurgery was not significant, demonstrating that the improvement was stable between 2 and 5 years. The Oral Health Status Questionnaire showed significant improvement at 2 and 5 years relative to presurgery (P <.05). These improvements also remained stable between 2 and 5 years, with the exception of general oral health. The Symptom Checklist 90 Revised demonstrated significant improvements from presurgery to 2 and 5 years after surgery (P <.05) in all areas except somatization. Results other than somatization did not change significantly between 2 and 5 years, showing that improvements were stable. The 7-point satisfaction scale showed that patients were satisfied with postsurgical results, and their satisfaction was maintained 5 years after surgery. It is concluded that general health-related quality of life, oral health-related quality of life, and psychosocial function show significant improvements after bilateral sagittal split osteotomy, and the improvements are stable between 2 and 5 years after surgery.

Influence of extraoral lateral force loading on the mandible in the mandibular development of growing rats

INTRODUCTION The objective of this study was to elucidate the influence of extraoral lateral force loading of the mandible on mandibular development. METHODS Thirty growing Wistar rats were divided into 3 groups: control, sham, and experimental. To determine longitudinal developmental changes, each animal was placed under anesthesia and immobilized in a custom-built body retainer to allow microcomputed tomography to be performed before and after the experiment. In the experimental group, a fixing device of aluminum was fitted to the zygomatic arch. Lateral force was then applied to the mandible with an open coil for 2 weeks. Stereoscopic images were constructed from 3-dimensional microcomputed tomography images. Absolute lengths and perpendicular heights from the baseline of the lower border of the mandible were measured. The images were superimposed at the baseline planes in each animal. After the final observation, the rats were killed, and the bilateral condyles excised. The condyles were decalcified by the standard method, stained with hematoxylin and eosin and toluidine blue, and observed under a microscope. RESULTS Lateral force induced the mandible to shift toward the nonloaded side; absolute mandibular length at menton-condylion on the side where the load was applied was greater than that in the control group. No difference from the control group was noted on the nonloaded side, and there were no significant differences in perpendicular heights. Lateral loading on the mandible resulted in histopathologic changes: (1) on the side where the load was applied, the cartilaginous zone hypertrophied in the highest margin of the condylar head, the erosive zone expanded, and the width of the mandibular neck decreased; (2) the chondrocyte layer shifted to the medial side on the nonloaded side, and cartilaginous ossification occurred in the lateral direction immediately below the chondrocyte layer, which deformed the mandibular neck toward the medial side and caused asymmetric development of the mandible. CONCLUSIONS These results demonstrate that extraoral lateral force loading during the growth stage causes asymmetrical mandibular development.

Expression of BMP7 is associated with resistance to diabetic stress: Comparison among mouse salivary glands

We determined mRNA levels of bone morphogenetic protein 7 (BMP7), a growth and differentiation factor belonging to the transforming growth factor-beta superfamily, in the salivary glands of mice with streptozotocin (200 mg/kg, i.p.)-induced diabetes. We also examined the effects of BMP7 on secretion of saliva and degenerative change in salivary glands in diabetic mice. In normal mice, BMP7 mRNA levels were high in the submandibular gland and low in the parotid gland, while in diabetic mice, levels were significantly decreased in the parotid gland, but not in the submandibular gland. No significant difference was observed in mRNA levels of BMP receptors between normal and diabetic mice. In diabetic mice, pilocarpine (4 mg/kg, i.p.)-stimulated salivary secretion showed a remarkable decrease in both parotid and submandibular gland, although degree of reduction was smaller in the latter. Notable degeneration with vacuolation and atrophy was also found in parotid gland, whereas degeneration of submandibular gland was slight. Administration of BMP7 (50 and 100 microg/kg, i.v.) in diabetic mice induced a significant increase in salivary secretion, with rate of recovery higher in parotid gland than in submandibular gland. In diabetic mice, BMP7 also exhibited a powerful protective effect in degenerated salivary gland, especially in parotid gland. These results suggest that BMP7 acts to prevent diabetic damage in salivary gland, and that its cytoprotective effect is closely correlated with mRNA levels in tissue.

Orthodontic evaluation of eight cases in Beckwith-Wiedemann syndrome

Abstract Beckwith–Wiedemann syndrome is a congenital anomaly. It was reported by Beckwith [Beckwith JB. Macroglossia, omphalocele, adrenal cytomegaly, gigantism and hyperplastic visceromegaly. In: Bersma D, editor. Part II. Malformation syndromes, birth defects: original article series, vol. 5, no. 2. White Plains: The National Foundation—March of Dimes; 1969. p. 188–96] in 1969 and Wiedemann [Wiedemann HR. Familial malformation complex with umbilical Aherina and macroglossia—a “NEW SYNDROME”? Genet Hum 1964;13:223–32] in 1964, and is characterized by the triad of exomphalos, macroglossia, and gigantism and hypoglycemia in newborns. This syndrome is, therefore, also known as EMG syndrome [Niikawa N, Ishikiriyama S, Takahashi S. The Wiedemann–Beckwith syndrome: pedigree studies on five families with evidence for autosomal dominant inheritance with variable expressivity. Am J Med Genet 1986;24:41–55]. Orthodontically, open bite and reversed occlusion are often observed effects of gigantism and macroglossia, although a number of studies have found no common maxillofacial morphological characteristics between these two disorders [Kamogashira K, Itoh T, Nakagawa M. Orthodontic findings in a case of Beckwith–Wiedemann syndrome. J Jpn Orthod Soc 1984;43:564–72; Friede H, Figueroa A. The Beckwith–Wiedemann syndrome: a longitudinal study of the macroglossia and dentofacial complex. J Craniofac Genet Dev Biol Suppl 1985;1:179–87]. We analyzed intraoral findings and lateral cephalograms (cephalometric analysis) obtained at initial consultation in eight patients with Beckwith–Wiedemann syndrome who visited our department. We found the common maxillocraniofacial problem among them to occur solely in the vertical plane (increased gonial angle and open bite). There were no common anteroposterior problems. These differences in the anteroposterior growth of the mandibular body may be closely associated with whether macroglossia, as an external factor, was improved by surgery before eruption of the permanent teeth. In terms of dental problems, the only common finding observed was open bite. The position and function of the tongue and perioral muscles during speech and swallowing may differ among patients, thus resulting in maxillocraniofacial morphology characteristic to each patient.

Chewing Movements in Near Ideal Occlusion With and Without TM Symptoms

Orthodontic models hand-articulated into maximum intercuspation of 720 untreated subjects were evaluated by 17 criteria for grading an ideal anatomic occlusion including good dental interdigitation and alignments. Of the 720 subjects screened, the best 17 subjects were divided into three groups that contained 11 near ideal occlusions scored with 92-98%, three lower evaluated occlusions scored with 86-88% and three near ideal occlusions with TM signs or symptoms scored with 90-94%. Border and chewing movements were recorded using incisor tracking instrument (Visitrainer, model 3). Border movements in asymptomatic subjects demonstrated a well-defined intercuspal position, smooth and equal lateral excursions, and straight opening/closing movements. However, one subject with pain of right joint recorded an inconsistent intercuspal position, restricted excursions and a deviated path corresponding to a reciprocal click in opening/closing movements. Chewing movements in asymptomatic subjects with near ideal occlusion demonstrated either no or a lower rate of opening gliding tooth contact along the lateral border movement on non-working side, and a higher rate of closing gliding tooth contact along border movement on the working side. Chewing movements in symptomatic subjects with near ideal occlusion showed opening and closing without gliding along the lateral excursions, and closing point was inconsistent with maximum intercuspal position in the pain subject. In examining these near ideal occlusion subjects, the different characteristic chewing and border movements were defined for subjects with and without TM symptoms, respectively. Asymptomatic subjects with near ideal occlusion and lower evaluated occlusion showed almost the same chewing function. The goal of orthodontic treatment might be anatomic ideal occlusion with good chewing and border movements indicated in this study.

Evaluation of Chewing Movement in Skeletal Class III Patients with Orthognathic Treatment

The objective of this study was to clarify the influence of improvement in morphology on chewing movement in patients with skeletal reversed occlusion following orthognathic treatment. A total of 10 patients with skeletal class III reversed occlusion undergoing orthognathic treatment were included in the study. A number of parameters, including chewing rhythm, maximum opening and closing velocities, and opening distance during chewing of gum, were measured in a pre- (Pre) and post-treatment (Post) group. The laterality and stability of the measured items were then compared between the two groups and with those in another group of subjects with normal occlusion (Control). Laterality of chewing movement was greater in the Pre group than in the Control group, and significant differences were noted in all parameters, apart from closing Vmax and opening distance. No significant difference was noted in any parameter between the Post and Control groups. The coefficient of variation was significantly higher in the Pre group than in the Control group, apart from for opening phase. All parameters showed a significant decrease in the Post group compared with in the Pre group, yielding a stable chewing movement. Comparison of the Post and Control groups revealed no significant difference in any of the parameters, apart from in the occluding phase. These findings suggest that orthognathic treatment of skeletal class III malocclusion improves chewing movement to levels close to those in subjects with normal occlusion.

Patient perception of jaw functional stability after orthodontic treatment

Abstract The purpose of this study was to investigate numerical evaluations of patient perceptions related to jaw functional stability before and after orthodontic treatment. One hundred and fifteen subjects were assessed by 12-item questionnaire regarding self-perception with a visual analog scale from 0 to 100 (VAS). Comparing the questions before and after treatment showed significant differences regarding the satisfactory jaw functions in all items. The highest scores after treatment were biting feeling (Q1) and biting stability (Q2) in posterior teeth, indicating that the subjects had a greater degree of satisfaction after treatment. The highest correlation coefficients were Q1 and Q2 before and after treatment, respectively. The result of stepwise multiple regression analysis indicated that Q2 seemed to accompany Q1, biting feeling during meals (Q3), and jaw movements while singing and talking before treatment. After treatment, Q2 seemed to accompany Q1 and Q3. These factors explain to be a significant prediction in functional stability response before and after treatment.