Progressive hemifacial atrophy (PHA) is a self-limited atrophy of subcutaneous tissues (and less frequently of hard tissues) on one side of the face. It is a sporadic, slowly progressing disease whose pathogenesis is still unknown. As a rule the asymmetry caused by PHA (usually of soft tissue) is treated by volume augmentation that involves free tissue grafting or a pedicled flap transfer.We describe a rare case of hard tissue PHA. The atrophic changes occurred in the left molar tooth, maxilla and mandible and were associated with moderate soft tissue atrophy. The left side of the patient's mouth was higher on the right side, and the occlusal plane was severely inclined in spite of normal occlusion. After no alteration and no progression of the atrophy were established, the patient was treated with orthodontic surgery. To correct the inclined occlusal plane and asymmetry profile, we performed a Le Fort I and intraoral vertical ramus osteotomy. In the 3-year follow-up, there were good occlusal balance and improved symmetrical profile without relapse or recurrence of the atrophy. Thus, orthodontic surgery was effective as a first procedure to treat hard tissue atrophy that appeared with moderate soft tissue atrophy.

Background: Craniofacial disharmony in cases of jaw deformity associated with abnormal lateral deviation of the jaw mostly involves both the maxilla and mandible. However, it has been still difficult to capture the jaw deviation aspect in a 3-dimensional and quantitative techniques. In this study, we focused on 3-dimensional mandibular morphology and position of the condylar head in relation to the base of the skull in patients with mandibular prognathism, one of the most common jaw deformities. We used cluster analysis to quantify and classify deviation and clarified its characteristics. We also investigated the degree of correlation between those findings and menton (Me) deviation measured on frontal cephalograms, which is a conventional indicator of jaw deformity. Results: Findings obtained from 100 patients (35 men, 65 women) were classified into the following three groups based on mandibular morphology and condylar position relative to the skull base. Then, reclassification using these parameters enabled classification of cluster analysis findings into seven groups based on abnormal jaw deviation characteristics. Comparison among these seven groups showed that the classification criteria were ramus height, mandibular body length, distance from the gonion to the apex of the coronoid process, and the lateral and vertical positions of the mandible. Weak correlation was also found between Me deviation on frontal cephalograms and each of the above parameters measured on 3D images. Conclusions Focusing on mandibular morphology and condylar position relative to the skull base in patients with mandibular prognathism, we used cluster analysis to quantify and classify jaw deviation. The present results showed that the 3D characteristics of the mandible based on mandibular morphology and condylar position relative to the skull base can be classified into seven groups. Further, we clarified that Me deviation on frontal cephalograms, which has been used to date, is inadequate for capturing jaw deviation characteristics.