The Esthetics Of Nasal Morphology Change In The Treatment Of Skeletal Class ? Malocclusion In Growing Patients

Orthodontic clinicians usually have 3 options for the treatment of skeletal class?malocclusion, including interceptive orthopedic treatment, camouflage treatment and surgery. According to the patient's age, status of growth, severity of malocclusion, profile and extent of crowding, an individualized treatment plan should be set to specifically resolve patient's problem. What makes a growing patient different is the fact that besides the typical symptoms of anterior crossbite, mesial molar relationship, concave profile, and anterior teeth compensation and so on, they also demonstrate unpredictable amount and direction of growth of the jaws. This makes the decision-making a huge challenge. Nowadays, most clinicians hold the opinion that orthopedic treatment is still the optimum choice for the patients who have growth potential. This is especially true for those with maxillary retrognathism. Maxillary protraction is an effective therapy for this kind of patients and has been used successfully for more than 50 years.In contemporary philosophy of treatment, orthodontics has been transformed from an occlusion-oriented one to a profile-oriented one. Besides the stable, functional occlusion, we should provide our patients the maximum esthetic elevation of overall esthetics. The traditional appraisal of lateral cephalograms is moving toward a more comprehensive 3 dimensional assessment, which includes more structural and esthetic information. Nose, which is located in the middle of face, plays a pivotal role in the appearance of people. Moreover, its morphology keeps changing in the process of orthopedic treatment. However, because of its irregular shape and complicated anatomic structure, nose didn't draw enough attention of orthodontists and seldom appeared in various soft tissue appraisal systems.In this paper, we firstly combine the nasal morphology and orthopedic treatment of skeletal class?malocclusion, focusing on the questions that what the nasal changes will be after the orthopedic treatment and what an impact these changes will have on the esthetics of patients both laterally and 3-dimensionally. The research are as follows:1. A study on the relationship between maxillary protraction treatment and changes of nasal profile of children with anterior crossbiteAIM:To study the relationship between maxillary protraction treatment and changes of nasal profile of children with crossbite, as so to provide some theoretical reference for treating the patients clinically with maxillary deficiency. METHODS:Twenty-four patients (male 12, female 12, aged 10~12 years) with maxillary deficiencies were selected. All of them had class?malocclusion. They were divided into 2 groups randomly:Experimental and control groups. The experimental group was given a maxillary protraction treatment with a face mask for 4-8 months, and no treatment was taken on the control group. By measuring the lateral cephalometric radiograph before and after the treatment, differences between the 2 groups were evaluated in a paired t-test. RESULTS:Compared with the control group, significant differences were found in the M-VL, PrN-VL, nasofrontal angle and columella-tip angle in the 2 groups(P<0.05), except the N'-VL and nasolabial angle. CONCLUSION:Besides the effect of correcting the Angle?malocclusion with maxillary retrognathism, the maxillary protraction also plays a great role in the recontouring of good nose.2. A study of the influence of nasal and lower facial soft tissue change after maxillary protraction treatment on profileAIM:To study the soft tissue change after maxillary protraction treatment of nasal and lower facial profile, as so to provide some theoretical reference for treating the patients clinically with maxillary deficiency. METHODS :Twenty-four patients (male 12, female 12, aged 10~12 years) with maxillary deficiencies were selected. All of them had class?malocclusion. They were assigned into 2 groups randomly : Experimental and control groups. The experimental group was given a maxillary protraction treatment with face mask for 4-8 months, and no treatment was taken on the control group. By measuring the lateral cephalometric radiograph before and after the treatment, differences between the 2 groups were evaluated in a paired t-test. RESULTS:Compared with the control group,significant differences were found in the PrN-VL, Ss-VL and Ls-VL, Ss-E line and Ls-E line in the 2 groups(P<0.05), except the Li-VL. CONCLUSION:Both the nasal and lower facial profile are dramatically improved after maxillary protraction treatment. The combining effect of these two changes results in a more harmony profile. 3. An appraisal system for the 3-dimensional nasal structureAIM: to construct an appraisal system for the 3-dimensional nasal morphology. METHODS:We select 9 landmarks and 7 measurements to build this system. The patients were told to keep the supine position, and a vernier caliper was used directly on the subjects to get the values of the measurements. CONCLUSION : This appraisal is easy to manipulate and has good reproducibility. It is eligible to assess the nasal morphology 3-dimensionally.4. Nasal morphology change after maxillary protraction treatment in skeletal class malocclusionAIM:To quantify the nasal change after maxillary protraction to correct skeletal class?malocclusion and to investigate whether this change will cause nose alar flare. METHODS: 24 growing subjects with skeletal class?malocclusion were recruited (male 12, female 12, with an average age of 11.5). The values of measurements from the nasal morphology appraisal system were obtained before and after maxillary protraction. A paired t-test was utilized to draw the statistic conclusion. The according changes of esthetics were analyzed, especially the alar width change. RESULTS:The nasal alar width and alar base width had increased significantly after the maxillary protraction. The nostril morphology also became wider. But the nasal bridge length remained unchanged. Both gender showed almost same tendency. CONCLUSION : Maxillary protraction can trigger a nasal alar flare, which is a adverse effect for the overall esthetics of our Asians. This should be taken into account when making the treatment plan.