The predictability of dentoskeletal factors for soft-tissue chin strain during lip closure / 대한치과교정학회지

OBJECTIVE: To investigate the dentoskeletal factors which may predict soft-tissue chin strain during lip closure. METHODS: The pretreatment frontal and lateral facial photographs and lateral cephalograms of 209 women (aged 18-30 years) with Angle's Class I or II malocclusion were examined. The subjects were categorized by three examiners into the no-strain and strain groups according to the soft-tissue chin tension or deformation during lip closure. Relationships of the cephalometric measurements with the group classification were analyzed by logistic regression analysis, and a classification and regression tree (CART) model was used to define the predictive variables for the group classification. RESULTS: The lower the value of the overbite depth indicator (ODI) and the higher the values of upper incisor to Nasion-Pogonion (U1-NPog, mm), overjet, and upper incisor to upper lip (U1-upper lip, mm), the more likely was the subject to be classified into the strain group. The CART showed that U1-NPog was the most prominent predictor of soft-tissue chin strain (cut-off value of 14.2 mm), followed by overjet. CONCLUSIONS: To minimize strain of the soft-tissue chin, orthodontic treatment should be oriented toward increasing the ODI value while decreasing the U1-NPog, overjet, and U1 upper lip values.

Treatment for mentalis scars with expanded skin flaps / 中华医学美学美容杂志

Objective To investigate the cosmetic outcome of treatments for mentalis scars with expanded skin flaps.Methods From the experiences of past 26 cases in our department,we summarised the technique for treating the mentalis scars with expanded skin flaps.For simple mentalis scars or localized inferior facial scars,the mentalis,bottom jaw or facial skin were expanded and the expander kept superior to the neck-jaw angle.Otherwise the expander would only fill the angle and the expanding efficiency was reduced.For severe mentalis,neck or facial scars without extra normal treating skin,expanded deltopectoral flaps were chosen to cover the wound after cicatrectomy with pedicles which were cut 3 weeks later.Results All the local ordistant expanded flaps survived successfully in the 26 cases with optimistic outcomes.Conclusions Application of local or distant expanded flaps is a useful technique for mentalis scars treatment.

Oral myofunctional and electromyographic evaluation of the orbicularis oris and mentalis muscles in patients with class II/1 malocclusion submitted to first premolar extraction

Objective: The aim of this study was to assess the presence of oral myofunctional alterations before and after first premolar extraction in Class II/1 malocclusion patients that could endanger the long-term dental arch stability. Material and Methods: The study was performed by means of morphological, functional and electromyographic analyses in 17 Class II/1 malocclusion patients (group T) and 17 Class I malocclusion patients (group C -control), both groups with 12-30-year age range (mean age: 20.93 ± 4.94 years). Results: Data analyzed statistically by Student’s t-test showed a significant decrease (p<0.05) in the maxillary and mandibular dental arch perimeters after orthodontic treatment, but lip posture at rest did not present statistically significant differences after treatment (p>0.05). The Kruskal-Wallis test analyzed data from lip posture (orbicularis oris muscle) at rest and during swallowing, as well as the mentalis muscle behavior during the above-mentioned function, not showing statistically significant differences (p>0.05) after treatment (groups T1 and T2). However, group T differed significantly from group C (p<0.05). Lip posture during swallowing showed statistically significant differences (p<0.05) for subjects submitted to orthodontic therapy when compared to data acquired before the treatment. The electromyographic analysis confirmed these data. Conclusions: Found myofunctional alterations observed after the orthodontic treatment in Class II/1 malocclusion seemed to jeopardize the long-term orthodontic stability, making recurrence possible.

Intramuscular Hemangioma of the Mentalis Muscle: A Case Report

Intramuscular hemangiomas are uncommon tumors of the head and neck, consistituting of 0.8% of all hemangioma, but often occur in the trunk and extremities. In the head and neck area, the masseter and trapezius muscle occur frequently, in which diagnosis is often difficult even with accurate preoperative imaging. The definitive diagnosis is made by histological study of the surgical biopsy specimen. Treatment of choice is complete surgical excision. This is, to our knowledge, the first case of intramuscular hemangioma of the mentalis muscle to be reported in korea.