A 14-year-old boy having excessive overjet and traumatic bite

Dr. Salma Aktar (MS Resident): A 14-year-old male came to the outpatient Department with the complaints of proclination of the tooth and inability to close his lips. The patient was psychologically depressed for his facial appearance. Extraoral clinical examination showed a mesocephalic symmetrical face with convex facial profile as well as his lower lip was trapped The nasolabial angle was acute (Figure 1). His mandibular movement was normal and there was no temporomandibular joint dysfunction. Intraoral clinical examination also revealed class II molar and canine relationship. Furthermore, the maxillay incisors were found excessively proclaimed and the overjet was 13 mm. The palatal impingement of the lower incisions was also found (Figure 2). A soft tissue lesion observed on the lower lip due to chronic irritation by sharp tip upper right canine. Moreover, underlying sagittal jaw discrepancy was severe. As the patient did not allow any orthognathic surgery, the selective extraction of two maxillary first premolar teeth was decided.


Pre-treatment Analysis
Dr. Aktar: The results of lateral cephalometric analysis (in degree) show that the Sella Nasion point A angel was 89. The Sella Nasion point B angel was 81. Point A Nasion point B angel, Frankfort mandibular plane angel and Frankfort mandibular incisor angel were 8, 16 and 61 respectively ( Figure 3).

Treatment Procedure
Dr. Aktar: Following extraction of the maxillary first premolars, the treatment was performed as follows: Stage 1: Anchorage preparation by transpalatal arch. Correction of deep overbite by the reverse curve of Spee in the lower arch. Stage 2: Leveling and alignment to correct intra-arch tooth positions by multiloop arch wire technique for tooth movement and achieve good arch form. The initial leveling was done in two stages (I and 2) by 0.014 and 0.016 inch stainless steel round wire. The arch wire was ligated loosely so it does not exert any strong force on the teeth and causes any distortion. Stage 3: Leveling in high degree, using 0.016 inch stainless steel round wire. Stage 4: Maxillary canine retraction by elastic power chain, and using 0.016 inch stainless steel wire. Stage 5: After leveling, canine retraction was performed with 0.016 inch stainless steel wire and then rectangular NiTi (0.017 x 0.025 inch) wire was inserted for the correction of tipped and rotated canine. Stage 6: Arch contraction or anterior retraction of the maxillary incisors and correction of anterior and posterior relationship by using 0.017 x 0.025 stainless steel rectangular wire with vertical loop and torque to close the space. Vertical loop was activated 1 mm per visit. Stage 7: Establishment of occlusion and ideal arch form by using 0.017 x 0.025 stainless steel wire and 0.016 inch stainless steel round wire was used to allow tooth settling to facilitate masticatory function. Stage 8: Fixed retainer was given by flexible spiral wire and then the brackets and bands were removed.

Post-treatment lateral cephalometric analysis (in degree)
The Sella Nasion point A angel was 84. The Sella Nasion point B angel, Point A Nasion point B angel, Frankfort mandibular plane angel and Frankfort mandibular incisor angel were 77.5, 6.5, 17 and 46 respectively ( Figure 3).

Provisional Diagnosis
Angel's class II malocclusion

Dr. Sultana Razia Khanam (MS Resident):
Bimaxillary protrusion is a state where maxilla and mandible are in balanced position in respect to cranial base. But the teeth especially the anterior teeth are forwardly placed leading to an appearance of prominence of soft tissues (lip). 1, 2 In this case the molar canine and incisor relation are class I. Furthermore, in bimaxillary prognathism, the jaw bones (basal) remain forward in relation to to the cranial bone. The facial profile is convex and lips are usually everted. 3, 4

Class II division 2 malocclusion
Dr. Aktar: In these cases, the molar relation is class II. The maxillary central incisors are retroclined, the lateral incisors are usually proclined and rotated or overlap the upper central incisors. 5, 6 There is natural dentoalveolar compensation for a class II skeletal pattern in order to decrease the overjet and increase the overbite. 7, 8 The arch is squarish in appearance and the facial profile is straight. 9, 10 The mandibular path of closure is backward and the lips are competent. 11 . 12, 13

Dr. Mohammad Rafiqul Islam (MS Resident):
Class III malocclusion is characterized by mandibular prognathism, anterior crossbite, negative overjet and underbite. 14, 15 Furthermore, the mesiobuccal cusp of upper molars occludes not only in the mesiobuccal groove but distal to it. 16,17 It is more complicated when the lower anterior teeth are more prominent than that of the upper anterior teeth. Moreover, the patient very often represents with a ratrognathic maxillary bone and prognathic mandible. 18, 19

Discussion on treatment methods
Dr. Aktar: During ttreatment of class II malocclusion, it is necessary to perform proper diagnosis, treatment plan, anchorage planning to establish natural esthetic, occlusal and functional requirements of the patient. So, the treatment of this malocclusion is always challenging. In this case, non -surgical treatment was performed according to some previous studies. 20, 21 Treatment was performed by using a combination of compensation mechanics and fixed orthodontic appliance. The treatment approach for the patient was camouflaged by the correction of the incisor relationship. Overall, facial, dental and the occlusal changes ware achieved. Patient's aesthetic and functional efficiency was improved. The soft tissue lesion resolved automatically when the fixed orthodontic treatment was carried out. The overall results without any surgical intervention make the patient very much confident and happy.

Comparison with other methods
Dr. Mahmood Sajedeen (Associate Professor: There are some patients having skeletal class II malocclusion who are in the border line regarding treatment option. This patient's active growth was almost completed and therefore the treatment option by orthopedic or functional appliance was excluded. Other treatment options include the orthognathic surgery and dental camouflage. 22, 23 Most of the patients want to avoid the surgical approach and accept dental camouflage. A previous study has indicated that the level of satisfaction of patients in camouflage treatment versus surgical orthodontic approach is almost similar. 24

Comparison with previous studies and relapse
Dr. Aktar: It is considered that the age of the patient also affect the success of the treatment. A study by    25 reported that if the treatment of class II malocclusion can be started before pubertal growth spurt, there is a significant improvements of dentoalveolar changes, overjet and molar relationships. Treatment at puberty produces significant long-term improvement of sagittal skeletal relationships, which is due to the mandibular changes. The result is similar to the present study. A study by Danz et al. (2018) 26 indicated that 10% of the patients showed relapse and their amount of overbite increase was low. It can be considered that cases with deep bite, gingival contact and palatal impingement were more prevalent for the relapse. In this case, the relapse was not found within the 6 months.

Follow-up
The patient was followed-up at an interval of every 6 months. Clinically, the improvement of the presenting complains like difficulties in bite were resolved. After completion of the treatment, it was noted that that the abnormal occlusion was changed to normal.