Case Report 3
These intraoral photographs show an extremely deep overbite malocclusion in the fifty-year-old man. The occlusion is a Class II, division 1 with procumbent upper incisors and 10mm of overbite (Fig. 3A, B). Because the patient had an extremely restricted ability to open his mouth, he consulted an orthodontist who recommended physical therapy for the mandible. The patient received physical therapy for 10 months, but to no avail. At his first appointment with me, he could open his mouth to only about 13mm of incisor clearance; my index finger barely could fit between the upper and the lower incisors. His bruxism was so long-term and severe that the crowns of the lower incisors were only one-half of the normal length. He reported that he previously had received orthodontic treatment during his early teens.
His cephalometric analysis revealed an ODI reading of 91 degrees and APDI of 89 degrees, indicating a Class III type of deep overbite pattern (Fig. 3C). In other words, the occlusion should not have been a Class II, but it was, probably due to an extremely deep overbite that caused the upper dentition to flare with the lower dentition was driven backward. Despite the fact that he had been bruxing severely, the alveolar bone level appeared to be reasonably good (Fig. 3D). Initially, it was a very difficult task to obtain a study model impression because of the patient’s limited mouth opening. Only after about 10 minutes of gradually but firmly opening his mouth was I able to take the impressions.
Treatment started with removal of the left third molars, followed by introduction of a bite block on the lower arch to clear the bite, and bonding of brackets on the upper teeth (Fig. 3E, F). All the spaces were closed except the ones between the lateral incisors and the canines. Subsequently, a space-closing mechanism was utilized, and the incisors were retracted (Fig 3G, H). Because the upper lateral incisors were undersized, some interdental spaces were left for future crowns. Finally, a maxillary bite plate was inserted, and the brackets were bonded on the lower teeth (Fig. 3I, J). At this point, the patient was able to open his mouth normally. He was ever so thankful.
After the alignment of the arches, the upper and the lower MEAW’s were inserted (Fig. 3K, L). Note that in the lower MEAW, the loops are pointing distally, in contrast with normal MEAW construction. These loops were bent purposely to provide the closing-loop effect, in order to extrude the molars and to intrude the incisors by stepping up the wire level for each tooth from the canine to the second molar. To correct the midline deviation, short Class III 3/16 inch elastics in double on the right and short Class II 3/16 inch elastics in double on the left were used.
Twenty-six months after the onset of treatment, a good occlusion was restored; at that time, the upper lateral incisors were enlarged with veneer crowns to fill in the interdental spaces (Fig. 3M,N). The post-treatment radiographs and superimposition of tracings showed intrusion of the upper and the lower incisors and some extrusion of the upper molars (Fig. 3O-R). Surprisingly, the lower molars showed no extrusion, although about 100 of uprighting was observed.
Two and 1/2 years later, the occlusion showed very little change (Fig. 3S,T) An upper wraparound retainer with a bite plate was used for one year on a full-time basis, followed by night-time wearing to manage the patient’s bruxism.