• The korean journal of orthodontics
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• v.43 no.6
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• pp.302-310
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• 2013

Orthodontic closure of old, edentulous spaces in the mandibular posterior region is a major challenge. In this report, we describe a method of orthodontic closure of edentulous spaces in the mandibular posterior region accelerated by piezoelectric decortication and alveolar ridge expansion. Combined piezosurgical and orthodontic treatments were used to close 14- and 15-mm-wide spaces in the mandibular left and right posterior areas, respectively, of a female patient, aged 18 years and 9 months, diagnosed with skeletal Class III malocclusion, hypodontia, and polydiastemas. After the piezoelectric decortication, segmental and full-arch mechanics were applied in the orthodontic phase. Despite some extent of root resorption and anchorage loss, the edentulous spaces were closed, and adequate function and esthetics were regained without further restorative treatment. Alveolar ridge expansion-assisted orthodontic space closure seems to be an effective and relatively less-invasive treatment alternative for edentulous spaces in the mandibular posterior region.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.246-251
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• 2012

Purpose: The purpose of the study is to evaluate the effectiveness of anterior segmental osteotomy (ASO) in bimaxillary protrusion (BP) patients by comparison between the mandibular soft and hard tissue changes from orthodontic treatment and ASO. Methods: All 44 patients were diagnosed with BP in Kyung-Hee Medical Center. Orthodontic treatment with teeth extractions were underwent by 23 patients (Group A) and 21 patients underwent ASO (Group B). Mandibular soft and hard tissue changes were measured and evaluated, which were based on the vertical and horizontal reference line in lateral cephalometric radiographs. Statistical significance between the changes and correlation between each measurement were analyzed. Results: The amount of B point movement was lesser than that of the lower incisal tip (LIT) retraction, and LIT was tilted lingually in group A. The posterior movement discrepancy between LIT and B point was insignificant, and the inclination of lower incisor was not changed in group B. The soft tissues, including the lower lip, showed a posterior movement and reduction in the depth of mento-labial groove. According to the correlation analysis, the movement of the lower incisor was significantly related to the movement of the lower lip in group A, and the movement of the lower incisor was significantly related to that of the movement of lower lip, B point and Pog in group B. Conclusion: The orthodontic treatment in BP patients results in posterior tilting movement of the lower incisor, but ASO results in the bodily movement of the lower incisor. Consequently, ASO is more effective in BP cases because it ensures the controlled movement of the lower incisors.

• Journal of Oral Medicine and Pain
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• v.12 no.1
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• pp.85-93
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• 1987

The author studied on the effect of TMJ sounds to the patterns and ranges of mandibular border movements in horizontal plane with Pantograph (Denar Corp.). For study, 19 patients with TMJ sounds only and 16 students with no TM disorder were selected and classified as experimental group and control group, respectively. The subject performed right lateral movement, left lateral movement, and forward movement. Each movement were performed 3 times and the movement trajectory obtained with mechanical pantograph were observed for accordance of centric relation position, reproducibility and/or restriction of lateral movement paths, deviation of protrusive path in anterior table, restriction of protrusive condylar movement path in posterior horizontal table, presence of Fisher angle in posterior vertical table. And pantographic reproducibility Index (PRI) were obtained with pantronic by the same movement method as in the mechanical pantograph record. The obtained results were as follows : 1. In experimental group, PRI scores in those who show accordance of centric relation position were 14.4, and were 26.53 in those who did not show accordance of centric relation position. However, the PRI scores of the two subgroups show no statistically significant difference in control group. Therefore, in experimental group, the capability of accordance of centric relation position affected largely the PRI scores than in control group. 2. Deviation of protrusive path was opposite to the affected side in experimental group, and was left side in control group. 3. Restriction side of condylar movement in protrusion was ipsilateral to the deviation side in experimental group, but in control group, restriction side was not related to the deviation side. 4. PRI scores in experimental group were 23.2 (moderate dysfunction category), and in control group, were 17.8 (slight dysfunction category). The PRI scores in control group, however, implies that the evaluation of temporomandibular disorders by the PRI scores only may be unreasonable.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.2
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• pp.137-143
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• 2001

• The Journal of the Korean dental association
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• v.15 no.9
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• pp.732-737
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• 1977

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.82-88
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• 2005

Treatment methods of mandibular condylar fracture were conservative and surgical method. Surgical method of mandibular high condylar fracture was very difficult because approach and internal fixation of small size fracture fragment were difficult. So there is a tendency to select conservative method over surgical method for guiding a stable occlusion and avoiding TMJ disorder and growth disturbance, minimizing pain and deviation during function. But, in case of mandibular high condylar fracture patient who has no biting teeth on posterior teeth area, guiding a stable occlusion and conservative functional treatment were very difficult. In this case, patient was 62years old male. He had fracture of mandibular symphysis, right mandibular body, left mandibular high condyle. We treated the patient for mandibular symphysis and right mandibular body fracture area with surgical method. But left mandibular high condylar fracture area was difficult to treat with surgical method. So we selected a conservative functional method on left mandibular high condylar fracture area. We intended recovery of vertical dimension and stable occlusion with implantation of immediate provisional implant on maxillar and mandibular posterior teeth area, and temporary crown. And then patient did mandibular functional movement and his mandibular function was recoverd.

• The Journal of Korean Academy of Prosthodontics
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• v.23 no.1
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• pp.137-144
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• 1985

This study was designed to investigate the side shift of orbiting condylar movement by direct measurements from tracings of Denar pantograph. It is well known that side shift has much influence on the articulating surface of teeth. In this study, after locating the ture hinge axis point with Denar hinge axis locatior, the recordings of Mandibular movement were obtained from Denar pantographic recording assembly, and immediate side shift and progressive side shift were measured. For this study, 20 dental studnts who have no missing teeth and no difficulties of mandibular movement and 4 patients who were, treated by occlusal therapy were selected. The results obtained were as follows, 1. The prevalence of immediate side shift was 42%, and the immediate side shift of greater than 0.5mm was only 17%. 2. The mean of immediate side shift (20 of 48) was 0.38mm, that of right lateral excursion (7 of 24) was 0.27mm, and that of left lateral excursion (13 of 24) was 0.44mm. 3. The mean of progressive side shift was $7.21^{\circ}$ that of right lateral excursion was $6.46^{\circ}$, and that of left lateral excursion was $7.96^{\circ}$.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.2
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• pp.113-123
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• 2001

The success of complete denture prosthesis is to satisfy three basic requirements for the edentulous patient : maximum comfort, efficiency, and esthetic appearance. This can be achieved only if the dentures are both stable and retentive. When the residual alveolar ridge has resorbed significantly, stability and retention are more dependent on the correct position of the teeth and external surfaces of the denture. The stability and retention of the denture can be improved by locating the denture in the neutral zone and reproducing exact mandibular border movement for balanced occlusion. The neutral zone philosophy is based upon the concept that there exists a specific area where the musculature function will not unseat the denture in the mouth. In here, forces generated by the tongue are neutralized by the forces generated by the lips and cheeks. One of the simplest methods for recording border movements in three dimensions is to make stereographic record of condylar movement. Stereographs are made in the mouth during mandibular movement with intraoral clutches and central bearing point, and used in dictating the condylar movement on the articulator later by generating the condylar paths in doughy acrylic resin. Its procedure is simpler and more convenient than that of Pantograph. In this clinical report, we introduce the concept of neutral zone and stereograph in complete denture fabrication.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.115-131
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• 2000

In the study of craniofacial deformity, it is very important that identifying the factor which can affect the morphology and which is closely related to the morphology, because it can not only improve the comprehension of growth and developmental process but also be applied in growth prediction and treatment modality. Several investigators have already mentioned the characterstics of head posture and airway space in relations to morphologic difference. But it is very meaningful work in clarifying the correlation between morphology, head posture and airway space that observing the change of head posture after morplologic change caused by operation and the change of airway space after same procedure. To investigate above correlation, I selected normal group which is consisted of 43 adults and mandibular prognathism group which is consisted of 47 adults who had been operated by sagittal split ramus osteotomy and were followed up more than 1 year. With their lateral skull radiograghs, reference lines which can evaluate each measuring points and areas without effect of postural change were first determined. And using above reference lines, change of airway space, positional change of tongue and hyoid, change of cranial and cervical angulations were measured. The results obtained from the study were as follows 1. In the change of head posture, the position of tongue and hyoid neighboring to pharynx is more closely related to the reference line of cervical column than to reference line of cranium. 2. After mandibular setback operation, the airway dimension was decreased to 81.6% of preoperative state at 1 month postoperatively and was slightly increased to 89.7% at 1 year postoperatively. 3. Posterior movement of tongue plays important role in decrease of airway dimension and inferior movement of hyoid was closely correlated with posterior movement of tongue. 4. Postoperative anterior movement of mandible, namely, morphologic relapse had correlation with relapse phenomenon of airway dimension. 5. Craniocervical angulation increased postoperatively. Especially in the postoperative early state, there was increased foreward inclination of cervical angulation rather than increase of cranial angulation. But at postoperative 1 year it was observed that cervical inclination was returned to preoperative state and cranial angulation was increased gradually. 6. Increase rate of airway dimension was correlated with the increase of cranial angulation from postoperative 1 month to 1 year. In conclusion, relapse tendency of airway dimension following increase of cranial angulation was found after mandibular setback operation and it is considered that increase of cranial angulation is one of compensatory mechanism in airway maintenance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.5
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• pp.185-191
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• 2014

Purpose: Although there have been several studies of reduced airway space after mandibular setback surgery using the sagittal split ramus osteotomy technique, research on the risk factors for changes of the airway space is lacking. Therefore, this study was performed to examine airway changes and the position of the hyoid bone after orthognathic surgery, and to assess possible risk factors. Methods: In this retrospective study, 50 patients who underwent posterior displacement of the mandible by the bilateral sagittal split ramus osteotomy technique were included. Changes of the position of the hyoid bone and the airway space were analyzed over various follow-up periods, using cephalometric radiography taken preoperatively, immediately after surgery, eight weeks after surgery, six months after surgery, and one year after surgery. To identify risk factors, multiple regression analysis of age, gender, body mass index (BMI), posterior mandibular movement, and the presence of genioplasty was performed. Results: Inferor and posterior movement of the hyoid bone was observed postoperatively, but subsequent observations showed regression towards the anterosuperior aspect. The airway space also significantly decreased after surgery (P<0.05), and increased slightly up until six months after surgery. The airway space significantly decreased (${\beta}=0.47$, P<0.01) as the amount of mandibular setback increased. However, age, sex, BMI, and presence of genioplasty were not associated with airway reduction. Conclusion: The amount of mandibular set back was significantly associated with postoperative reduction of airway space. It is necessary to establish a treatment plan considering this factor.