Fine mapping and genetic heterogeneity in the pure form of autosomal dominant familial spastic paraplegia

We evaluated seven families segregating pure, autosomal dominant familial spastic paraplegia (SPG) for linkage to four recently identified SPG loci on chromosomes 2q (1), 8q (2), 12q (3), and 19q (4). These families were previously shown to be unlinked to SPG loci on chromosomes 2p, 14q, and 15q. Two families demonstrated linkage to the new loci. One family (family 3) showed significant evidence for linkage to chromosome 12q, peaking at D12S1691 (maximum lod = 3.22). Haplotype analysis of family 3 did not identify any recombinants among affected individuals in the 12q candidate region. Family 5 yielded a peak lod score of 2.02 at marker D19S868 and excluded linkage to other known SPG loci. Haplotype analysis of family 5 revealed several cross-overs in affected individuals, thereby potentially narrowing the SPG12 candidate region to a 5-cM region between markers D19S868 and D19S220. Three of the families definitively excluded all four loci examined, providing evidence for further genetic heterogeneity of pure, autosomal dominant SPG. In conclusion, these data confirm the presence of SPG10 (chromosome 12), potentially reduce the minimum candidate region for SPG12 (chromosome 19q), and suggest there is at least one additional autosomal dominant SPG locus.

Locus heterogeneity, anticipation and reduction of the chromosome 2p minimal candidate region in autosomal dominant familial spastic paraplegia

We examined 11 Caucasian pedigrees with autosomal dominant 'uncomplicated' familial spastic paraplegia (SPG) for linkage to the previously identified loci on chromosomes 2p, 14q and 15q. Chromosome 15q was excluded for all families. Five families showed evidence for linkage to chromosome 2p, one to chromosome 14q, and five families remained indeterminate. Homogeneity analysis of combined chromosome 2p and 14q data gave no evidence for a fourth as yet unidentified SPG locus. Recombination events reduced the chromosome 2p minimum candidate region (MCR) to a 3 cM interval between D2S352 and D2S367 and supported the previously reported 7 cM MCR for chromosome 14q. Age of onset (AO) was highly variable, indicating that subtypes of SPG are more appropriately defined on a genetic basis than by AO. Comparison of AO in parent-child pairs was suggestive of anticipation, with a median difference of 9.0 years (p<0.0001).

Implant of articular eminence for recurrent dislocation of the temporomandibular joint

Hypermobility of the temporomandibular joint is often caused by trauma, by opening the mouth too wide, by having a mouth forced open during general anesthesia procedures, or by dental procedures. The capsule may be stretched to an extent that dislocation occurs more easily thereafter. An implant of Vitallium mesh attached to the zygoma to restrict anterior movement of the condyle is used to prevent recurrent dislocation of the temporomandibular joint.

Evaluation of the surgical stability of 20 cases of inverted-L and C osteotomies

Twenty cases of inverted-L and C osteotomies were analyzed retrospectively to evaluate the stability of the surgical results. The incidence and degree of relapse are reported for each procedure. Possible compensatory mechanisms, which may be active in counteracting the skeletal relapse observed, are discussed. Several methods of compensating for the anticipated relapse are described. Since tabulation of the original data, 12 of the 20 patients have been followed up for an additional 6 to 12 months. Seven patients had been treated with the inverted-L osteotomy. In these patients, there was an additional 4% loss of the amount of correction in anterior facial height and 8% loss in posterior facial height. Five patients were in the C osteotomy group. An additional 3% of the initial advancement was lost in this interval. Significant occlusal changes were not observed in any of the cases and the skeletal results were still acceptable.

One-stage interpositional bone grafting and vestibuloplasty of the atrophic maxilla

A technique of one-stage autogenous bone grafting and submucous vestibuloplasty for reconstruction of the atrophic maxillary alveolar ridge has been presented. The advantages are described. Use of this procedure has currently been limited; however, initial success indicates this may be a valuable technique for use in the atrophic maxilla.