• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.2
• /
• pp.119-128
• /
• 2011

In the process of assessing the children with anterior crossbite in early mixed dentition, it has frequently been detected that the stronger the skeletal pattern of the malocclusion is, the more markedly delayed the development and eruption of maxillary teeth are. If the anteroposterior characteristics of craniofacial skeleton has any relationship with dental maturation, the evaluation of dental development and eruption was thought to be able to contribute to early diagnosis of crossbite in children. This study was performed for the purpose of elucidating the relationship between dental maturation of maxillary teeth and some cephalometric values in children with anterior crossbite of maxillary undergrowth type in early mixed dentition. Among the children in Hellman dental age IIA and IIC who attended the Pediatric Dental Clinic of Pusan National University Hospital with orthodontic problems, cases with Class III malocclusion were classified and 50 cases of maxillary undergrowth type and type with normal maxilla respectively were randomly selected and studied as subjects. From their lateral cephalographs and panoramic radiographs, their anteroposterior skeletal features, the dental maturity and eruption rate were obtained of each group and data were analyzed to yield the results as follows: 1. Comparing the maturity of maxillary teeth of both groups, only the first molars of maxillary undergrowth group showed significantly slower development and eruption (p<0.05). 2. There was high correlation between maturation of maxillary 1st molar and chronological age(p<0.05). 3. Among the parameters of anteroposterior relationship of skeletal pattern in maxilla and mandible. Wits was revealed as a useful index to predict both the calcification and eruption rate of the 1st molars whereas SNA was to eruption rate(p<0.05).

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.3
• /
• pp.232-240
• /
• 2008

Purpose: This study was performed to evaluate transverse changes of proximal segment after bilateral sagittal split ramus osteotomy (BSSRO) using 3-D CT in mandibular prognathism. Patients and methods: Twenty-two patients who underwent BSSRO for mandibular set-back in class III malocclusion without facial asymmetry were examined. Miniplates were used for the fixation after BSSRO. Facial CT was taken before and after BSSRO within 3 months. Frontal-ramal inclination (FRI), inter-gonial width (IGW) and intercondylar width (ICW) were measured in 3-D CT images using V-works $4.0^{TM}$ program. Student t-test was used to compare the changes between pre- and post-operative measurements using SPSS 10.0 program. Results: 1. Mean peroperative FRI value ($12.87{\pm}3.43^{\circ}$) was slightly increased to postoperative value ($14.13{\pm}3.72^{\circ}$) (p < 0.05). The average FRI increased 10.42% and the range was from $-2.46^{\circ}$ to $3.34^{\circ}$. 2. Mean peroperative IGW ($99.01{\pm}5.36$) was slightly decreased to postoperative IGW ($96.51{\pm}5.88mm$) (p < 0.05). The average IGW decreased 2.52 % and the range was from $-6.61^{\circ}$ to 0.91 mm. 3. Mean preoperative ICW ($125.01{\pm}5.30mm$) was slightly decreased to postoperative ICW ($125.40{\pm}5.45mm$) (p < 0.05). There is no significant difference between pre- and post-operative ICW. 4. There was significant correlationship between FRI difference and IGW difference (p < 0.05). Conclusions: These results indicate that the lower ramus of the proximal segment is moved inward after BSSRO procedure for mandibular set-back.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.18 no.1
• /
• pp.87-108
• /
• 1996

This study was intended to perform cephalometric analysis of the facial soft tissue profile after surgical correction of skeletal Class III malocclusion after SSRO in 29 patients (Males 12, females 17). Lateral cephalograms were taken in centric occlusion before and immediate, long term after surgeries. 1. Counter-clockwise rotation of mandible was observed after the surgery, average relapses of mandibular set back were 1.23-1.28mm. The net effects of the mandibular set-back after surgeries were 81.7-82.2%. Because these relapse tendencies may reduce the effects of the surgical outcomes, surgeon must consider these net before the surgical treatment planning. 2. The ratio of horizontal changes of hard tissue to soft tissue at lower lip, mentolabial sulcus, pogonion were 72.7-93.7%, 100.3%, 99.1-102.1% respectively. There were little changes at upper lip position anteroposteriorly. 3. The relationship of upper and lower lips were improved after surgery. Lower lip was posteriorly repostioned and upper lip was flattend and elongated in conjunction with deepening of inferior lobial sulcus. But profile of chin was still prominent after surgery. 4. Hard tissue horizontal changes and tissue vertical changes were significantly correlated with each other and there were reverse correlations with hard tissue vertical changes and soft tissue horizontal changes.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.20 no.3
• /
• pp.256-262
• /
• 1998

The aim of this study was to evaluate treatment plan and treatment procedure such as bone graft material, timing of bone graft and orthodontic treatment in 31 alveolar cleft bone graft patients treated at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital from Jan. 1992 to Dec. 1996. Results obtained were as follows : In total 31 patients of alveolar bone grafts, males(64.5%) were more than females(35.5%). The patients' age ranged between 2 - 33 years of age. Secondary bone grafting was the highest incidence(58.1%) when procedures were undertaken in patients between 6 - 16 years of age. In distribution of cleft side, unilateral clefts(93.5%) were the major part with the left side was larger than the right side. The Missing teeth were found most in lateral incisor, the supernumary teeth were found most between lateral incisor and canine. The most common occlusion before operation was class III malocclusion and anterior cross-bite(65.1%), orthodontic treatment was performed similarly between before and after the bone graft. The most common combined operation with alveolar bone graft was secondary cheiloplasty. The complications were 6 cases of bone defect, a case of oronasal fistula, 3 cases of dehiscence. PMCB and DFDB were used bone graft materials. In marginal bone height after operation, PMCB grafts were higher than DFDB grafts and marginal bone level was increased in the PMCB group but not in the DFDB group.

• The korean journal of orthodontics
• /
• v.28 no.2 s.67
• /
• pp.237-253
• /
• 1998

Surgical-orthodontic treatment is performed for the skeletal Class III patients with no remaining growth and too big a skeletal discrepancy (or camouflage treatment, and two jaw surgery is needed in order to have maximum effect in such patients. In two jaw surgery cases, surgical alteration of the occlusal plane is necessary to establish optimal function, esthetics and postoperative sability, therefore the establishment of the occlusal plane is essential in diagnosis and treatment. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane bsaed on the architectural and structural craniofacial analysis of Delaires. Thus, the subjects of this study were 48 patients who underwent two jaw surgery, and divided in two groups. Each group were composed of 24patients, A group were operated with ideal occlusal plane and B group were not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. There was no significance in occlusal plane angulation between $T_2\;and\;T_3$. Average long term follow-up changes of occlusal Plane angle were $0.24^{\circ}{\pm}2.43$, with FH plane and $0.15{\circ}{\pm}2.16{\circ}$ with SN plane in all 48 patients. These results demonstrated that the occlusal plane after two jaw surgery in skeletal Class III malocclusion was stable. 2. There was no significance in postoperative stability of occlusal plane between A and B group. 3. There was no significance in postoperative stability of occlusal plane depending on surgeon and operative method within each group. 4. The postoperative changes of occlusal plane were correlated to the postoperative changes of jaw rather than tooth position. 5. There was no correlation between the postoperative changes of occlusal plane and maxillary impaction and mandibular setback with surgery.

• The korean journal of orthodontics
• /
• v.32 no.6 s.95
• /
• pp.413-424
• /
• 2002

Preadolescent children with deficient maxillae are suitable candidates for the maxillary protraction appliance(MPA). The theoretical effect of the MPA is protraction or anterior displacement of the maxilla. However, it is known that complex effects such as anterior displacement of the maxillary teeth, downward and backward rotation of the mandible, linguoversion of the mandibular anterior incisors, are known to play a role in improving the Cl III malocclusion. There have been much studies with regard to maxillary protraction, but the different effects of MPAs depending on the vertical facial pattern are not known precisely. This study was based on 67 patients (31 males, 36 females) aged from 6 years 6 months to 13 years 3months, who visited the Dept. of Orthodontics at Yonsei Univ., Dental Hospital and diagnosed as skeletal Class III with maxillary deficiency. They were divided into 3 groups (low, average, high angle groups) depending on genial angle and the SNMP (Go-Gn) angle, respectively. Pretreatment and post-treatment lateral cephalograms were used to compare the effects of MPA and the following conclusions were obtained: 1) A significantly large amount of backward movement of the B point was observed in patients with a low SNMP angle. Those with a high SNMP angle had significant forward movement at A point. 2) The patients with low genial angle had the least forward movement at the A point, and those with a high angle had more forward movement. 3) In comparing the arcTan of the A point, the high angle group showed more horizontal movement while the low angle group showed more vertical movement. 4) There was no significance between the treatment duration of the SNMP and the Genial angle groups.

• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.669-682
• /
• 1997

[$Bj\ddot{o}rk$] and Skieller concluded after following facial growth patterns using implants in upper and lower jaw bones that stable structures, which are not influenced by the growth do exist and so these must be the reference landmarks in the process of superimposition. In spite of such facts, for the last 40 years since the discovery of stable structures, most orthodontists have preferred best fit superimposition method to structural method. Cases such as Angle's Class II division 2 malocclusion that show characteristic forward and upward growth or one under long period of post-treatment observation demonstrate that distinct differences exist between the two methods of superimposition. Today, ethical concerns prohibit further growth studies that use implants, md so there is no choice but to use stable structural superimposition method based on $Bj\ddot{o}rk's$ data. Thus, to encourage clinical use of stable structural superimposition method, logic for the use of stable structural superimposition method will be demonstrated, and its technical methods of application will be introduced step by step.

• The korean journal of orthodontics
• /
• v.30 no.5 s.82
• /
• pp.579-589
• /
• 2000

The purpose of this study was to evaluate the position of tongue and hyoid bone in relation to vortical facial patterns in the adult and child. Lateral cephalograms taken in adults(63 cases, 11.7 years in average age) and children(69 cases, 22.6 years in average age) were traced and measured about position and posture of tongue and hyoid bone using the horizontal and vertical reference lines. The angle of mandibular plane to SN Plane was employed to classify the samples into groups of hypodivergent and hyperdivergent. The comparison of the tongue/hyoid bone measurements between hypodivergent group and hyperdivergent group in the adult and child were statistically executed with Student's f-test. The results were as follows, 1. The tongue height was lower in the hyperdivergent group than in hypodivergent group, and higher in children than in adults. 2. The vertical height of hyoid bone was higher in hypodivergent group than in hyperdivergent group and also higher in children than in adults. 3. The anteroposterior position was of no significant difference in relation to age or vortical facial pattern. 4. The inclination of hyoid bone in relation to cranial base was steeper in children than in adults.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.2
• /
• pp.129-137
• /
• 2017

The aim of this study was to enhancing the panoramic radiograph's clinical use for assessing mandibular measurements and formulating a function of those measurements from panoramic radiographs and lateral cephalograms in children. The panoramic radiographs and lateral cephalograms of 99 former orthodontic patients with skeletal class III malocclusion were selected. In each radiograph, gonial angles, ramus heights, and distance between lower incisors and symphysis were measured. The values of the studied parameters were compared by paired t-test, Pearson's correlation test and regression analysis. The mean value of the gonial angle in panoramic radiographs was $125.49^{\circ}$, and the value in lateral cephalograms was $127.50^{\circ}$. The Pearson's correlation coefficient (${\rho}$) between mean values of gonial angle in each radiograph was 0.945 (p < 0.001). The relationship between the gonial angle measurements obtained from each radiographs was represented as 'Gonial angle (Lateral cephalograms) = 0.920 ${\times}$ Average gonial angle (Panoramic radiographs) + 12.072' in the linear function. The coefficients of ramus heights, and distance between lower incisors and symphysis portrayed weaker correlations than gonial angles. A panoramic radiograph could be used to determine the gonial angle as accurately as a lateral cephalogram, and each gonial angle showed a strong positive relation. A panoramic radiograph is a useful tool for examining vertical growth pattern of patients, as well as a lateral cephalogram.

• The korean journal of orthodontics
• /
• v.25 no.1 s.48
• /
• pp.1-12
• /
• 1995

The purpose of this study was to predict the respose to the chincap therapy from the initial cephalometric measurements and to obtain the indication of chincap therapy. 40 patients selected for this study were classified into two groups by the occlusal stability after completion of permanent dentition and the improvement of facial profile, after chincap therapy. One was good response group which consisted of 25 children and the other was poor response group with 15 patients. Various measurements of the craniofacial structure in the initial lateral cephalogram were calculated and analyzed by t-test and discriminant analysis. The results were as follows: 1. Good response group had more horizontal growth pattern in initial stage of treatment, and the contributing measurements were $Bj\ddot{o}rk$ sum anterior-posterior facial height ratio, genial angle, lower genial angle and occlusal plane to AB plane angle. 2. The critical points and predictive values of the influential skeletal measurements were calculated. 3. The discriminant function was obtained from three major influential measurements; $Bj\ddot{o}rk$ sum, genial angle and occlusal plane to hn plane angle, and this function could discreminate correctly in $85\%$ of this samples.