• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.375-401
• /
• 1995

Cause of skeletal Class III malocclusion in growing patients can be classified into maxillary deficiency, mandibular overgrowth, and combination of the two. Use of Protraction Head Gear(P.H.G.) has been recommended for treatment of growing Class III malocclusion patients, for it results in forward & downward movement of maxilla and backward & downward rotation of mandible. Numerous animal experiments were performed and clinical study data have been reported ; nevertheless, studies on soft tissue profile change and comparison of treatment effects among the patients who had undergone treatment are considered to be somewhat insufficient. The author selected 93 patients, who had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with P.H.G. ; the sample group was divided according to sex, treatment beginning age, palatal suture opening(intraoral appliance), and facial growth pattern. For each group, changing patterns of hard and soft tissue profile observed, and comparision with 20 normal group(Angle's Class I) patients of statistical significance in amount of growth and treatment of hard and soft tissue was done. The following results were obtained. 1. Skeletal, dental, and soft tissue measurements indicated that more growth changes was induced in the sample group that used P.H.G. compared to the growth amount of normal group. 2. No statistical significance was observed in the amounts of maxillary forward movement and mandibular backward & downward rotation depending on treatment beginning age in both sex group. 3. R.P.E. showed more significant maxillary forward movement and less protrusion of upper incisor than La-Li. 4. There was no statistical significance in the amount of maxillary forward movement depending on facial growth pattern. On the other hand, measurements indicating mandibular downward & backward rotation indicated greater change in counterclockwise growth pattern group than the clockwise. 5. Changes in upper and lower lip thicknesses showed a close relationship with positional changes in underlying bone tissue and upper and lower teeth, and upper lip height and nasolabial angle increased and mentolabial angle decreased.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.1
• /
• pp.70-78
• /
• 2016

Many types of orthopedic appliances have been developed and used for the treatment of class II malocclusion in pediatric dentistry. Headgear is one of the extraoral appliances, which is used for the purpose of preventing the overgrowth of maxilla. Hotz appliance is used in couple with a cervical headgear for the expansion of maxilla and retraction of maxillary incisors. This case report is about the orthodontic treatment of three patients with class II division I malocclusion. These young patients were given orthopedic treatment in combination with a cervical headgear and Hotz appliance. After the treatment using these extraoral and intraoral appliances, succeeding treatments were practiced considering individual needs as follows: fixed orthodontic appliance for mandibular anterior crowding, Class II activator for retention and additory orthopedic treatment and the retention with Hotz appliance. Young patients with Class II division I malocclusion reported in this study received the orthodontic treatment using a cervical headgear and Hotz appliance as well as appropriate succeeding treatment afterward. All patients received improved convex profiles and lip protrusions by retracting maxilla and maxillary incisors.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.2
• /
• pp.248-261
• /
• 1999

In order to define a current set of Korean children norm with mixed dentition, following study was done. The subjects were 102 healthy dentition contestants(48boys, 54girls). Standardized lateral head roentgenograms were taken, and Ricketts analysis was done. Results were as follows: 1. Length of anterior cranial base, posterior facial height, corpus length were longer in male than in female(p<0.05), and Porion was located posteriorly in male than in female(p<0.01). 2. Through facial depth, Pogonion of male was more forwardly positioned(p<0.05), mandible was significantly steeper in female, and maxillary anterior teeth were significantly tipped forward in male(p<0.05). 3. Variables such as length of anterior cranial base, upper molar position(p<0.01) and corpus length(p<0.05) were significantly changed by age. 4. Maxillary height, facial depth, mandibular plane angle, convexity were changed by age, but not significantly(p>0.05).

• The korean journal of orthodontics
• /
• v.28 no.4 s.69
• /
• pp.499-515
• /
• 1998

The purpose of this study was to examine the associations of head posture the position of the tongue or the hyoid bone to craniofacial structure. Cephalograms taken in Natural head position(NHP) of 90 dental students (50 in male, 40 in female, 20 to 30 years in age) were traced and measured using the extracranial true horizontal and vertical lines. The obtained results were as follows; 1. There was no sex difference in head posture, but the hyoid bone was placed anteroinferiorly in male more than in female and anteroinferior inclination of the hyoid bone showed greatly in male. 2. The more inclined was the cervical column, the less prognathic was the face in natural head posture, and the larger cervical curvature, the more vertical pattern of the face. 3. The less small showed craniocervical angulation, the more anteriorly placed was the hyoid bone to the cranial base, and there was no significantly association between craniocervical angulation and the vertical position of the hyoid bone. 4. The more prognathic was the mandible, the more anteriorly placed was the hyoid bone, and there was slightly association between the craniofacial morphology and the vertical position of the hyoid bone.

• The korean journal of orthodontics
• /
• v.25 no.2 s.49
• /
• pp.129-142
• /
• 1995

The purpose of this study was to estimate correlations of craniocervical posture and craniofacial morphology in Korean young adults. The sample consisted of 50 young adults (25 males and 25 females) who had good profile and Class I molar relationship. The analysis of craniocervical posture and craniofacial morphology was performed on lateral cephalograms taken in natural head position. The results were as follows, 1. The mean and the standard deviation of postural and morphologic variables were obtained. 2. Korean young adult had cervical lordosis of which degree between OPT and CVT shows $3.55{\pm}2.58^{\circ}$ 3. Craniocervical posture and each of vertical ratio, facial prognathism, mandibular rotation showed high correlation. 4. Correlation coefficients between postural variables and each of intermaxillary relation, anteroposterior ratio were low. 5. The head positioning error of natural head position was smaller than the inter-individual variability of postural variables.

• The korean journal of orthodontics
• /
• v.28 no.2 s.67
• /
• pp.189-201
• /
• 1998

The purpose of this study was to evaluate the characteristics of craniofacial skeleton on orthognathic surgical cases with skeletal Class III malocclusion. For this study, 74 students at the dental college of Chosun University volunteered as a normal occlusion group. They had well-balanced faces and good occlusions with acceptable Class I molar relationship. They had not received orthodontic treatment and had no signs or symptoms of temporomandibular joint dysfunction. 45 malocclusion patients enrolled for orthognathic surgical treatment with skeletal Class III malocclusion at the Department of Orthodontics, College of Dentistry, Chosun University. On the basis of this study. the results of this study were as follows: 1. Skeletal Class III malocclusion was largely due to the overgrowth of mandible in man and the undergrowth of maxilla in woman. 2. The mandible was antero-inferiorly overgrown by large MP-HP angle and large genial angle in orthognathic surgical cases with skeletal Class III malocclusion. And also, upper incisors were severely labioversioned, but on the other hand lower incisors were linguoversioned. 3. In female, lower-third facial height was characteristically shortened in comparison with middle-third facial height and also, lower facial throat angle was small in male.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.12 no.1
• /
• pp.1-5
• /
• 2016

Robinow syndrome is skeletal dysplasia with both autosomal dominant and recessive inheritance patterns. It is characterized by short-limbed dwarfism, abnormalities in the head and face, as well as vertebral segmentation. A 2-year-7-month old boy with Robinow syndrome had visited Seoul National University Dental Hospital, for the evaluation of tooth palatal eruption on maxilla. He had micrognathia, delayed tooth eruption, cleft lip with bifid uvula. He also had an erupted mesiodens on the palatal side of maxillary primary incisors, which was tuberculated and 8mm in major diameter. The patient was scheduled for mesiodens extraction under general anesthesia. He was a young child with delayed development, so general anesthesia was inevitable. General anesthesia was induced and maintained with inhalation agent, Sevoflurane. There were no postoperative complications related to anesthesia and dental treatment. Robinow syndrome patients have craniofacial dysmorphism and eruption disorders. Therefore, he requires regular check-ups as well as dental managements.

• The korean journal of orthodontics
• /
• v.26 no.5 s.58
• /
• pp.487-495
• /
• 1996

The purpose of this study was to evaluate the dentofacial characteristics and the fost-treatment dentofacial changes of those treated by four premolar extractions and to investigate the factors affecting extraction decision. The sample consisted of 35 patients (27 females, and 8 males) with no more than 7.0mm crowding, diagnosed as Class I protrusion. Pre-treatment and post-treatment lateral cephalograms were evaluated. Computerized statistical analysis was carried out using SPSS/PC+ program. The results were as follows. 1. There was no significant change in skeletal pattern after treatment while there was significant change in dentoalveolar and soft tissue pattern. 2. In pre-treatment skeletal pattern, a tendency toward vertical discrepancy was found. 3. In pre-treatment dental pattern, interincisal angle was $113.11^{\circ}$, U1 to FH was $117.78^{\circ}$ and L1 to A-Pog was 7.94mm. Pre-treatment upper and lower lip position was 2.88mm and 5.43mm to E line. 4. After treatment, interincisal angle increased $14.46^{\circ}$ and upper and lower lip moved back 2.45mm and 3.2mm to E line.(p<0.001) 5. The EI was 138.71 before treatment and 148.2 after treatment.

• The Journal of Korean Academy of Prosthodontics
• /
• v.60 no.3
• /
• pp.263-275
• /
• 2022

The loss of posterior occlusal support leads to further complications such as collapsed occlusal plane and reduced vertical dimension, and it may cause problems such as facial appearance change, reduced chewing efficiency, and temporomandibular joint disorders. In such case, it is necessary to re-establish occlusal plane and vertical dimension properly through accurate diagnosis and predictable treatment plan. This case report presents a 71-year-old female, whose occlusal plane was collapsed and posterior restorative space was insufficient. To perform a patient-friendly full mouth rehabilitation, proper vertical dimension and occlusal plane were decided by evaluation of interocclusal space at her physiologic mandibular rest position, swallowing, pronunciation, facial appearance, and the average length of anterior teeth. And then, the fixed provisional restorations were fabricated with the new occlusal position, and evaluated for 5 months with checking adaptation of masticatory muscles and any kind of clinical symptoms occurs or not. After confirmation of functional stability and esthetic satisfaction with the newly established occlusion, final definitive restorations were fabricated and inserted in the mouth. Through the above process, the treatment result was functionally and aesthetically satisfactory.

• The korean journal of orthodontics
• /
• v.40 no.6
• /
• pp.398-410
• /
• 2010

Objective: The purpose of this study was to investigate the changes in dentofacial morphology of non-orthodontically treated female patients with TMJ disk displacement. Methods: The sample consisted of 25 Korean female patients with bilateral TMJ disk displacement who visited the Department of Orthodontics, Seoul National University Dental Hospital from 1996 to 2006. Disk displacements were diagnosed using the magnetic resonance imaging (MRI) of both TMJs. Baseline (T1) and follow-up (T2) lateral cephalograms were analyzed. The mean age of samples at T1 was $18.1{\pm}3.5$ years (range 14.2 - 25.8 years) and at T2, $21.1{\pm}3.5$ years (range 16.2 - 28.0 years). The mean observation period was $3.0{\pm}1.9$ years. Descriptive statistics for each variable were calculated at baseline (T1) and follow-up (T2) stages, and during the observation period (T2-T1). Results: Skeletal changes were found in 64% of the non-orthodontically treated female patients with TMJ disk displacement during the observation period. The L1 to Mandibular plane distance (mm) increased significantly by 0.8 mm (p < 0.01). But there were no significant differences in the other dental relationship variables (overjet, overbite, U1 to palatal plane) during the observation period. Most patients with skeletal changes showed a backward rotation of the mandible. The ratio of the rotation was a decrease of SNB by $0.43^{\circ}$ for every $1^{\circ}$ increase of FMA (Spearman rho = -0.660, P < 0.01). A few patients showed a distal shift of the mandible without rotation or significant changes in the vertical dimension. Conclusions: During observation periods without orthodontic treatment, non-growing patients with TMJ disk displacement showed dentoskeletal changes, mainly backward rotation of the mandible.