Simultaneous maxillomandibular distraction osteogenesis in hemifacial microsomia: Report of 7 cases

Lefort 1 Osteotomy Study of Maxillary Bone in Caprine Skull Model: Comparison of Different Osteotomy Techniques (Piezo Versus Lindemann Bur Versus Manual Chisel)

OBJECTIVE

In this study, we aimed to compare the efficiency of different osteotomy techniques for Lefort 1 osteotomy in an experimental caprine skull model.

METHODS

Twelve caprine skulls were used for the study. Skulls were divided into 3 groups: (1) manual chisel group, (2) Lindemann bur group, and (3) piezo osteotomy group. Bilateral osteotomies were performed on each skull. Results were evaluated with three-dimensional computerized tomography scans and macroscopic observations of the mucosal tears and soft tissue.

RESULTS

The mean length of the bone gap in the manual, Lindemann, and piezo groups was 4.8 (±0.7), 3.38 (±1.49), and 1.39 (±0.3) mm, respectively ( P < 0.05). The mean number of comminuted fractures in the manual, Lindemann, and piezo groups was 5.5 (±1.4), 1.6 (±0.3), and 0.6 (±0.5), respectively ( P < 0.05). Mucosal tearing and soft tissue damage based on subjective inspection observations were negligible in the piezo technique. Soft tissue and mucosal damage were observed significantly more in the manual chisel osteotomy method compared with the other 2 techniques.

CONCLUSION

We anticipate that piezo, which has started to be used in new application areas besides rhinoplasty, will continue to be used more widely, especially in reconstructive orthognathic surgery, due to the minimal damage it causes to tissues. With the long-term results, much healthier interpretations can be made.

Treatment of severe micrognathia in an adult with distraction osteogenesis: A case report

Key Clinical Message

Distraction osteogenesis (DO) of the mandible is often performed at a young age, and there are few reports after age 30, as in this case. The Hybrid MMF used in this case was useful in that it allowed correction of fine directionality.

Abstract

DO is often performed in young patients with a high capability of osteogenesis. We performed distraction surgery for a 35-year-old man who had severe micrognathia with serious sleep apnea syndrome. Four years postoperatively, suitable occlusion and improvement of apnea were observed.

Efficacy and Versatility of Intraoral Monoplanar Distractors in the Correction of Extreme Mandibular Deformities and Severe Facial Asymmetries - A Retrospective Study

Introduction:

Distraction osteogenesis, has emerged as a revolutionary concept and an effective means to treat extensive craniomaxillofacial defects and malformations. In cases of mandibular distraction for patients with extreme acquired mandibular deformities, there is so far, no recorded literature on precise quantification and scientific estimation of the percentage of the efficacy of intraoral monoplanar distractors, for an objective evaluation of their effectiveness. The objective was to study the efficacy of intraoral mandibular monoplanar distractors in the correction of severe acquired mandibular deformities and gross facial asymmetries. To objectively evaluate their effectiveness by calculating the percentage of distraction achieved as against that aimed for, and to evaluate early and late complications encountered with their use.

Materials and Methods:

Five patients in the age group of 10–22 years, with extreme mandibular deformity and gross facial asymmetry secondary to longstanding temporomandibular joint (TMJ) ankylosis, were treated. Four patients had unilateral and one patient had bilateral TMJ ankylosis, with varying degrees of acquired mandibular hypoplasia, retrogenia, retrognathia, and asymmetry. They were managed by unilateral (3 patients) and bilateral (2 patients) mandibular distraction.

Results:

Maximum horizontal corpus and vertical Ramal distraction achieved was 19 mm and 17.6 mm, respectively. The percentage of the efficacy of the intraoral monoplanar distractors used in this study ranged from 65.38% to 109.09%. Severe mandibular deformities and facial asymmetries were successfully corrected in all five patients, with no major early or late complications encountered in any of them. Results achieved were stable with nil incidence of relapse.

Discussion:

Estimation of percentage of the efficacy of distraction achieved, helped in objectively evaluating the effectiveness of the intraoral mandibular distractors. A low complication rate and good esthetic and functional outcomes achieved in all the patients demonstrated the reliability of this treatment modality in the management of extreme mandibular deformities and severe facial asymmetries.

Dynamic orthognathic surgical procedure (DOSP) in asymmetric maxillomandibular dysmorphism secondary to unilateral micrognathia: Outcomes of 12 consecutive cases

This study aimed to evaluate the outcomes following a dynamic orthognathic surgical procedure performed at the end of growth to treat asymmetric maxillomandibular deformities linked to unilateral micrognathia when conventional orthognathic surgery was not feasible. The dynamic orthognathic surgical procedure (DOSP) combined concomitant mandibular distraction osteogenesis with contralateral poorly stabilized sagittal split osteotomy and Le Fort I osteotomy. Cephalometric studies were retrospectively conducted on pre- and postoperative lateral and frontal cephalographs, and maxillomandibular movements were calculated. Outcome scores were computed by both experts and laypersons based on photographic analyses. There was a significant postoperative increase in height of the micrognathic ramus in all patients (n = 12; p = 0.002). The angle between the occlusal cant and horizontal reference plane decreased significantly in all of the patients, as did the angle between the midline sagittal plane and mandibular tilt (p < 0.001). Postoperative outcome scores showed significant improvements in all cases, according to both expert and layperson groups. This procedure allows correction of maxillomandibular asymmetries linked to micrognathia. However, it cannot resolve all the factors participating in facial asymmetry, such as those originating in the oculo-auriculo-ventricular spectrum or complex tumor sequelae, and second-step procedures may be required.

A Qualitative Assessment of Bone Mineral Density in Individuals With Hemifacial Microsomia: A Cone-Beam Computed Tomography Study

OBJECTIVE

The purpose of this study is to utilize cone-beam computed tomography (CBCT) to compare the bone mineral density (BMD) on the affected versus nonaffected side, among individuals with hemifacial microsomia (HFM).

METHODS

This retrospective study included 9 patients with HFM. Pretreatment CBCT volumes were imported into Invivo5 software, which was used to measure BMD through Hounsfield units (HU) in 3 regions of the mandible; inferior to the lower lateral incisors, inferior to the first molar and at the ramus inferior to the sigmoid notch. Each region was measured at the buccal cortical bone, lingual cortical bone, and cancellous bone. The densities on the right and left sides were compared by Wilcoxon signed-rank test.

RESULTS

Overall, the BMD on the affected side tended to show slightly lower values when compared with the nonaffected side. Differences ranged from 14 HU at the lingual cortical plate of the first molar region to 234 HU at the buccal cortical plate of the ramus region. Differences were only statistically significant at the ramus region for the buccal (P = .002) and lingual (P < .001) cortical plates and at the lower incisor region at the buccal cortical plate (P = .016) and cancellous bone (P = .044). The differences, however, did not seem to be clinically significant.

CONCLUSIONS

The current study shows that the quality of bone on the affected side may be slightly reduced but did not seem to be clinically significant. This should be accounted for during surgical and orthodontic planning for patients with HFM.